Editor’s Choice Articles

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

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Review

15 pages, 1299 KiB  
Review
Upconversion Nanomaterials in Bioimaging and Biosensor Applications and Their Biological Response
by Zayakhuu Gerelkhuu, Yong-Ill Lee and Tae Hyun Yoon
Nanomaterials 2022, 12(19), 3470; https://doi.org/10.3390/nano12193470 - 4 Oct 2022
Cited by 4 | Viewed by 2245
Abstract
In recent decades, upconversion nanomaterials (UCNMs) have attracted considerable research interest because of their unique optical properties, such as large anti-Stokes shifts, sharp emissions, non-photobleaching, and long lifetime. These unique properties make them ideal candidates for unified applications in biomedical fields, including drug [...] Read more.
In recent decades, upconversion nanomaterials (UCNMs) have attracted considerable research interest because of their unique optical properties, such as large anti-Stokes shifts, sharp emissions, non-photobleaching, and long lifetime. These unique properties make them ideal candidates for unified applications in biomedical fields, including drug delivery, bioimaging, biosensing, and photodynamic therapy for specific cancers. This review describes the general mechanisms of upconversion, synthesis methods, and potential applications in biology and their biological responses. Additionally, the biological toxicity of UCNMs is explained and summarized with the associated intracellular association mechanisms. Finally, the prospects and future challenges of UCNMs at the clinical level in biological applications are described, along with a summary of opportunity for biological as well as clinical applications of UCNMs. Full article
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16 pages, 5601 KiB  
Review
Recent Advances of Transition Metal Chalcogenides as Cathode Materials for Aqueous Zinc-Ion Batteries
by Ying Liu and Xiang Wu
Nanomaterials 2022, 12(19), 3298; https://doi.org/10.3390/nano12193298 - 22 Sep 2022
Cited by 7 | Viewed by 2799
Abstract
In recent years, advances in lithium-ion batteries (LIBs) have pushed the research of other metal-ion batteries to the forefront. Aqueous zinc ion batteries (AZIBs) have attracted much attention owing to their low cost, high capacity and non-toxic characteristics. Among various cathodes, transition metal [...] Read more.
In recent years, advances in lithium-ion batteries (LIBs) have pushed the research of other metal-ion batteries to the forefront. Aqueous zinc ion batteries (AZIBs) have attracted much attention owing to their low cost, high capacity and non-toxic characteristics. Among various cathodes, transition metal chalcogenides (TMCs) with a layered structure are considered as suitable electrode materials. The large layer spacing facilitates the intercalation/de-intercalation of Zn2+ between the layers. In this mini-review, we summarize a variety of design strategies for the modification of TMCs. Then, we specifically emphasize the zinc storage capacity of the optimized electrodes. Finally, we propose the challenges and future prospects of cathode materials for high-energy AZIBs. Full article
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32 pages, 3047 KiB  
Review
Adverse Outcome Pathways Associated with the Ingestion of Titanium Dioxide Nanoparticles—A Systematic Review
by Dora Rolo, Ricardo Assunção, Célia Ventura, Paula Alvito, Lídia Gonçalves, Carla Martins, Ana Bettencourt, Peter Jordan, Nádia Vital, Joana Pereira, Fátima Pinto, Paulo Matos, Maria João Silva and Henriqueta Louro
Nanomaterials 2022, 12(19), 3275; https://doi.org/10.3390/nano12193275 - 21 Sep 2022
Cited by 9 | Viewed by 3578
Abstract
Titanium dioxide nanoparticles (TiO2-NPs) are widely used, and humans are exposed through food (E171), cosmetics (e.g., toothpaste), and pharmaceuticals. The oral and gastrointestinal (GIT) tract are the first contact sites, but it may be systemically distributed. However, a robust adverse outcome [...] Read more.
Titanium dioxide nanoparticles (TiO2-NPs) are widely used, and humans are exposed through food (E171), cosmetics (e.g., toothpaste), and pharmaceuticals. The oral and gastrointestinal (GIT) tract are the first contact sites, but it may be systemically distributed. However, a robust adverse outcome pathway (AOP) has not been developed upon GIT exposure to TiO2-NPs. The aim of this review was to provide an integrative analysis of the published data on cellular and molecular mechanisms triggered after the ingestion of TiO2-NPs, proposing plausible AOPs that may drive policy decisions. A systematic review according to Prisma Methodology was performed in three databases of peer-reviewed literature: Pubmed, Scopus, and Web of Science. A total of 787 records were identified, screened in title/abstract, being 185 used for data extraction. The main endpoints identified were oxidative stress, cytotoxicity/apoptosis/cell death, inflammation, cellular and systemic uptake, genotoxicity, and carcinogenicity. From the results, AOPs were proposed where colorectal cancer, liver injury, reproductive toxicity, cardiac and kidney damage, as well as hematological effects stand out as possible adverse outcomes. The recent transgenerational studies also point to concerns with regard to population effects. Overall, the findings further support a limitation of the use of TiO2-NPs in food, announced by the European Food Safety Authority (EFSA). Full article
(This article belongs to the Special Issue New Insights in Toxicity and Cytotoxicity of Nanomaterials)
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23 pages, 2534 KiB  
Review
Metal-Polymer Nanoconjugates Application in Cancer Imaging and Therapy
by André Q. Figueiredo, Carolina F. Rodrigues, Natanael Fernandes, Duarte de Melo-Diogo, Ilídio J. Correia and André F. Moreira
Nanomaterials 2022, 12(18), 3166; https://doi.org/10.3390/nano12183166 - 13 Sep 2022
Cited by 5 | Viewed by 2586
Abstract
Metallic-based nanoparticles present a unique set of physicochemical properties that support their application in different fields, such as electronics, medical diagnostics, and therapeutics. Particularly, in cancer therapy, the plasmonic resonance, magnetic behavior, X-ray attenuation, and radical oxygen species generation capacity displayed by metallic [...] Read more.
Metallic-based nanoparticles present a unique set of physicochemical properties that support their application in different fields, such as electronics, medical diagnostics, and therapeutics. Particularly, in cancer therapy, the plasmonic resonance, magnetic behavior, X-ray attenuation, and radical oxygen species generation capacity displayed by metallic nanoparticles make them highly promising theragnostic solutions. Nevertheless, metallic-based nanoparticles are often associated with some toxicological issues, lack of colloidal stability, and establishment of off-target interactions. Therefore, researchers have been exploiting the combination of metallic nanoparticles with other materials, inorganic (e.g., silica) and/or organic (e.g., polymers). In terms of biological performance, metal-polymer conjugation can be advantageous for improving biocompatibility, colloidal stability, and tumor specificity. In this review, the application of metallic-polymer nanoconjugates/nanohybrids as a multifunctional all-in-one solution for cancer therapy will be summarized, focusing on the physicochemical properties that make metallic nanomaterials capable of acting as imaging and/or therapeutic agents. Then, an overview of the main advantages of metal-polymer conjugation as well as the most common structural arrangements will be provided. Moreover, the application of metallic-polymer nanoconjugates/nanohybrids made of gold, iron, copper, and other metals in cancer therapy will be discussed, in addition to an outlook of the current solution in clinical trials. Full article
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29 pages, 4714 KiB  
Review
Roles of Inorganic Oxide Based HTMs towards Highly Efficient and Long-Term Stable PSC—A Review
by M. Shahinuzzaman, Sanjida Afroz, Hamidreza Mohafez, M. S. Jamal, Mayeen Uddin Khandaker, Abdelmoneim Sulieman, Nissren Tamam and Mohammad Aminul Islam
Nanomaterials 2022, 12(17), 3003; https://doi.org/10.3390/nano12173003 - 30 Aug 2022
Cited by 7 | Viewed by 2466
Abstract
In just a few years, the efficiency of perovskite-based solar cells (PSCs) has risen to 25.8%, making them competitive with current commercial technology. Due to the inherent advantage of perovskite thin films that can be fabricated using simple solution techniques at low temperatures, [...] Read more.
In just a few years, the efficiency of perovskite-based solar cells (PSCs) has risen to 25.8%, making them competitive with current commercial technology. Due to the inherent advantage of perovskite thin films that can be fabricated using simple solution techniques at low temperatures, PSCs are regarded as one of the most important low-cost and mass-production prospects. The lack of stability, on the other hand, is one of the major barriers to PSC commercialization. The goal of this review is to highlight the most important aspects of recent improvements in PSCs, such as structural modification and fabrication procedures, which have resulted in increased device stability. The role of different types of hole transport layers (HTL) and the evolution of inorganic HTL including their fabrication techniques have been reviewed in detail in this review. We eloquently emphasized the variables that are critical for the successful commercialization of perovskite devices in the final section. To enhance perovskite solar cell commercialization, we also aimed to obtain insight into the operational stability of PSCs, as well as practical information on how to increase their stability through rational materials and device fabrication. Full article
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25 pages, 7100 KiB  
Review
Composition and Structure Progress of the Catalytic Interface Layer for Bipolar Membrane
by Di Zhao, Jinyun Xu, Yu Sun, Minjing Li, Guoqiang Zhong, Xudong Hu, Jiefang Sun, Xiaoyun Li, Han Su, Ming Li, Ziqi Zhang, Yu Zhang, Liping Zhao, Chunming Zheng and Xiaohong Sun
Nanomaterials 2022, 12(16), 2874; https://doi.org/10.3390/nano12162874 - 21 Aug 2022
Cited by 3 | Viewed by 2445
Abstract
Bipolar membranes, a new type of composite ion exchange membrane, contain an anion exchange layer, a cation exchange layer and an interface layer. The interface layer or junction is the connection between the anion and cation exchange layers. Water is dissociated into protons [...] Read more.
Bipolar membranes, a new type of composite ion exchange membrane, contain an anion exchange layer, a cation exchange layer and an interface layer. The interface layer or junction is the connection between the anion and cation exchange layers. Water is dissociated into protons and hydroxide ions at the junction, which provides solutions to many challenges in the chemical, environmental and energy fields. By combining bipolar membranes with electrodialysis technology, acids and bases could be produced with low cost and high efficiency. The interface layer or junction of bipolar membranes (BPMs) is the connection between the anion and cation exchange layers, which the membrane and interface layer modification are vital for improving the performance of BPMs. This paper reviews the effect of modification of a bipolar membrane interface layer on water dissociation efficiency and voltage across the membrane, which divides into three aspects: organic materials, inorganic materials and newly designed materials with multiple components. The structure of the interface layer is also introduced on the performance of bipolar membranes. In addition, the remainder of this review discusses the challenges and opportunities for the development of more efficient, sustainable and practical bipolar membranes. Full article
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19 pages, 2270 KiB  
Review
Current Challenges in Image-Guided Magnetic Hyperthermia Therapy for Liver Cancer
by Anirudh Sharma, Erik Cressman, Anilchandra Attaluri, Dara L. Kraitchman and Robert Ivkov
Nanomaterials 2022, 12(16), 2768; https://doi.org/10.3390/nano12162768 - 12 Aug 2022
Cited by 8 | Viewed by 2779
Abstract
For patients diagnosed with advanced and unresectable hepatocellular carcinoma (HCC), liver transplantation remains the best option to extend life. Challenges with organ supply often preclude liver transplantation, making palliative non-surgical options the default front-line treatments for many patients. Even with imaging guidance, success [...] Read more.
For patients diagnosed with advanced and unresectable hepatocellular carcinoma (HCC), liver transplantation remains the best option to extend life. Challenges with organ supply often preclude liver transplantation, making palliative non-surgical options the default front-line treatments for many patients. Even with imaging guidance, success following treatment remains inconsistent and below expectations, so new approaches are needed. Imaging-guided thermal therapy interventions have emerged as attractive procedures that offer individualized tumor targeting with the potential for the selective targeting of tumor nodules without impairing liver function. Furthermore, imaging-guided thermal therapy with added standard-of-care chemotherapies targeted to the liver tumor can directly reduce the overall dose and limit toxicities commonly seen with systemic administration. Effectiveness of non-ablative thermal therapy (hyperthermia) depends on the achieved thermal dose, defined as time-at-temperature, and leads to molecular dysfunction, cellular disruption, and eventual tissue destruction with vascular collapse. Hyperthermia therapy requires controlled heat transfer to the target either by in situ generation of the energy or its on-target conversion from an external radiative source. Magnetic hyperthermia (MHT) is a nanotechnology-based thermal therapy that exploits energy dissipation (heat) from the forced magnetic hysteresis of a magnetic colloid. MHT with magnetic nanoparticles (MNPs) and alternating magnetic fields (AMFs) requires the targeted deposition of MNPs into the tumor, followed by exposure of the region to an AMF. Emerging modalities such as magnetic particle imaging (MPI) offer additional prospects to develop fully integrated (theranostic) systems that are capable of providing diagnostic imaging, treatment planning, therapy execution, and post-treatment follow-up on a single platform. In this review, we focus on recent advances in image-guided MHT applications specific to liver cancer Full article
(This article belongs to the Special Issue Nanomaterials in Biological Systems: Opportunities and Challenges)
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14 pages, 1713 KiB  
Review
Nanosized Calcium Phosphates as Novel Macronutrient Nano-Fertilizers
by Francisco J. Carmona, Antonietta Guagliardi and Norberto Masciocchi
Nanomaterials 2022, 12(15), 2709; https://doi.org/10.3390/nano12152709 - 6 Aug 2022
Cited by 27 | Viewed by 3606
Abstract
The need for qualitatively and quantitatively enhanced food production, necessary for feeding a progressively increasing World population, requires the adoption of new and sustainable agricultural protocols. Among them, limiting the waste of fertilizers in the environment has become a global target. Nanotechnology can [...] Read more.
The need for qualitatively and quantitatively enhanced food production, necessary for feeding a progressively increasing World population, requires the adoption of new and sustainable agricultural protocols. Among them, limiting the waste of fertilizers in the environment has become a global target. Nanotechnology can offer the possibility of designing and preparing novel materials alternative to conventional fertilizers, which are more readily absorbed by plant roots and, therefore, enhance nutrient use efficiency. In this context, during the last decade, great attention has been paid to calcium phosphate nanoparticles (CaP), particularly nanocrystalline apatite and amorphous calcium phosphate, as potential macronutrient nano-fertilizers with superior nutrient-use efficiency to their conventional counterparts. Their inherent content in macronutrients, like phosphorus, and gradual solubility in water have been exploited for their use as slow P-nano-fertilizers. Likewise, their large (specific) surfaces, due to their nanometric size, have been functionalized with additional macronutrient-containing species, like urea or nitrate, to generate N-nano-fertilizers with more advantageous nitrogen-releasing profiles. In this regard, several studies report encouraging results on the superior nutrient use efficiency showed by CaP nano-fertilizers in several crops than their conventional counterparts. Based on this, the advances of this topic are reviewed here and critically discussed, with special emphasis on the preparation and characterization approaches employed to synthesize/functionalize the engineered nanoparticles, as well as on their fertilization properties in different crops and in different (soil, foliar, fertigation and hydroponic) conditions. In addition, the remaining challenges in progress toward the real application of CaP as nano-fertilizers, involving several fields (i.e., agronomic or material science sectors), are identified and discussed. Full article
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35 pages, 4514 KiB  
Review
Semiconductor Quantum Dots as Target Analytes: Properties, Surface Chemistry and Detection
by Jesús Sanmartín-Matalobos, Pilar Bermejo-Barrera, Manuel Aboal-Somoza, Matilde Fondo, Ana M. García-Deibe, Julio Corredoira-Vázquez and Yeneva Alves-Iglesias
Nanomaterials 2022, 12(14), 2501; https://doi.org/10.3390/nano12142501 - 21 Jul 2022
Cited by 12 | Viewed by 3746
Abstract
Since the discovery of Quantum Dots (QDs) by Alexey I. Ekimov in 1981, the interest of researchers in that particular type of nanomaterials (NMs) with unique optical and electrical properties has been increasing year by year. Thus, since 2009, the number of scientific [...] Read more.
Since the discovery of Quantum Dots (QDs) by Alexey I. Ekimov in 1981, the interest of researchers in that particular type of nanomaterials (NMs) with unique optical and electrical properties has been increasing year by year. Thus, since 2009, the number of scientific articles published on this topic has not been less than a thousand a year. The increasing use of QDs due to their biomedical, pharmaceutical, biological, photovoltaics or computing applications, as well as many other high-tech uses such as for displays and solid-state lighting (SSL), has given rise to a considerable number of studies about its potential toxicity. However, there are a really low number of reported studies on the detection and quantification of QDs, and these include ICP–MS and electrochemical analysis, which are the most common quantification techniques employed for this purpose. The knowledge of chemical phenomena occurring on the surface of QDs is crucial for understanding the interactions of QDs with species dissolved in the dispersion medium, while it paves the way for a widespread use of chemosensors to facilitate its detection. Keeping in mind both human health and environmental risks of QDs as well as the scarcity of analytical techniques and methodological approaches for their detection, the adaptation of existing techniques and methods used with other NMs appears necessary. In order to provide a multidisciplinary perspective on QD detection, this review focused on three interrelated key aspects of QDs: properties, surface chemistry and detection. Full article
(This article belongs to the Special Issue Nanoparticle Analysis, Toxicity and Environmental Impact)
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22 pages, 2152 KiB  
Review
Localized Nanopore Fabrication via Controlled Breakdown
by Cuifeng Ying, Tianji Ma, Lei Xu and Mohsen Rahmani
Nanomaterials 2022, 12(14), 2384; https://doi.org/10.3390/nano12142384 - 12 Jul 2022
Cited by 2 | Viewed by 2724
Abstract
Nanopore sensors provide a unique platform to detect individual nucleic acids, proteins, and other biomolecules without the need for fluorescent labeling or chemical modifications. Solid-state nanopores offer the potential to integrate nanopore sensing with other technologies such as field-effect transistors (FETs), optics, plasmonics, [...] Read more.
Nanopore sensors provide a unique platform to detect individual nucleic acids, proteins, and other biomolecules without the need for fluorescent labeling or chemical modifications. Solid-state nanopores offer the potential to integrate nanopore sensing with other technologies such as field-effect transistors (FETs), optics, plasmonics, and microfluidics, thereby attracting attention to the development of commercial instruments for diagnostics and healthcare applications. Stable nanopores with ideal dimensions are particularly critical for nanopore sensors to be integrated into other sensing devices and provide a high signal-to-noise ratio. Nanopore fabrication, although having benefited largely from the development of sophisticated nanofabrication techniques, remains a challenge in terms of cost, time consumption and accessibility. One of the latest developed methods—controlled breakdown (CBD)—has made the nanopore technique broadly accessible, boosting the use of nanopore sensing in both fundamental research and biomedical applications. Many works have been developed to improve the efficiency and robustness of pore formation by CBD. However, nanopores formed by traditional CBD are randomly positioned in the membrane. To expand nanopore sensing to a wider biomedical application, controlling the localization of nanopores formed by CBD is essential. This article reviews the recent strategies to control the location of nanopores formed by CBD. We discuss the fundamental mechanism and the efforts of different approaches to confine the region of nanopore formation. Full article
(This article belongs to the Special Issue Nanomaterials for Optical Bio/Chemical Sensing)
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21 pages, 13232 KiB  
Review
Selective Overview of 3D Heterogeneity in CMOS
by Cheng Li, Zijin Pan, Xunyu Li, Weiquan Hao, Runyu Miao and Albert Wang
Nanomaterials 2022, 12(14), 2340; https://doi.org/10.3390/nano12142340 - 8 Jul 2022
Cited by 4 | Viewed by 1828
Abstract
As the demands for improved performance of integrated circuit (IC) chips continue to increase, while technology scaling driven by Moore’s law is becoming extremely challenging, if not impractical or impossible, heterogeneous integration (HI) emerges as an attractive pathway to further enhance performance of [...] Read more.
As the demands for improved performance of integrated circuit (IC) chips continue to increase, while technology scaling driven by Moore’s law is becoming extremely challenging, if not impractical or impossible, heterogeneous integration (HI) emerges as an attractive pathway to further enhance performance of Si-based complementary metal-oxide-semiconductor (CMOS) chips. The underlying basis for using HI technologies and structures is that IC performance goes well beyond classic logic functions; rather, functionalities and complexity of smart chips span across the full information chain, including signal sensing, conditioning, processing, storage, computing, communication, control, and actuation, which are required to facilitate comprehensive human–world interactions. Therefore, HI technologies can bring in more function diversifications to make system chips smarter within acceptable design constraints, including costs. Over the past two decades or so, a large number of HI technologies have been explored to increase heterogeneities in materials, technologies, devices, circuits, and system architectures, making it practically impossible to provide one single comprehensive review of everything in the field in one paper. This article chooses to offer a topical overview of selected HI structures that have been validated in CMOS platforms, including a stacked-via vertical magnetic-cored inductor structure in CMOSs, a metal wall structure in the back end of line (BEOL) of CMOSs to suppress global flying noises, an above-IC graphene nano-electromechanical system (NEMS) switch and nano-crossbar array electrostatic discharge (ESD) protection structure, and graphene ESD interconnects. Full article
(This article belongs to the Special Issue Abridging the CMOS Technology)
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35 pages, 12546 KiB  
Review
A Decade of Progress on MAO-Treated Tantalum Surfaces: Advances and Contributions for Biomedical Applications
by Luísa Fialho, Cristiana F. Almeida Alves and Sandra Carvalho
Nanomaterials 2022, 12(14), 2319; https://doi.org/10.3390/nano12142319 - 6 Jul 2022
Cited by 10 | Viewed by 1959
Abstract
Micro-structured coatings with functional properties have been investigated due to a wide range of applications. It is known that micro-structures can play an important role in surface interactions determining the materials’ performance. Amongst the other materials, there has been an increasing interest in [...] Read more.
Micro-structured coatings with functional properties have been investigated due to a wide range of applications. It is known that micro-structures can play an important role in surface interactions determining the materials’ performance. Amongst the other materials, there has been an increasing interest in tantalum oxide (Ta2O5). This attention is mainly due to its variety of properties: biocompatibility and bioactivity; high dielectric constant; good thermal and chemical stability; excellent corrosion and mechanical resistance. Moreover, there is a wide range of applications in which the properties can be fitted. Furthermore, according to the final application, these properties can be enhanced or tailored through surface micro-structures manipulation. Due to this purpose, over the past decade, Ta surface modification by micro-arc oxidation (MAO) has been investigated mostly for biomedical applications. Therefore, this review focuses on Ta surface functionalization using the MAO technique. A clear understanding of the micro-discharge phenomena and the formation mechanism of a Ta2O5 anodic coating by MAO is supplied. The Ta2O5 coating morphology, topography, chemistry, and structure are explored, establishing their correlation with the MAO parameters. Additionally, an understanding of Ta2O5’s biological, mechanical, and electrochemical properties is provided and reviewed. Full article
(This article belongs to the Special Issue Current Review in Synthesis, Interfaces, and Nanostructures)
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24 pages, 3088 KiB  
Review
Reactive Oxygen Species Formed by Metal and Metal Oxide Nanoparticles in Physiological Media—A Review of Reactions of Importance to Nanotoxicity and Proposal for Categorization
by Amanda Kessler, Jonas Hedberg, Eva Blomberg and Inger Odnevall
Nanomaterials 2022, 12(11), 1922; https://doi.org/10.3390/nano12111922 - 4 Jun 2022
Cited by 58 | Viewed by 4422
Abstract
Diffusely dispersed metal and metal oxide nanoparticles (NPs) can adversely affect living organisms through various mechanisms and exposure routes. One mechanism behind their toxic potency is their ability to generate reactive oxygen species (ROS) directly or indirectly to an extent that depends on [...] Read more.
Diffusely dispersed metal and metal oxide nanoparticles (NPs) can adversely affect living organisms through various mechanisms and exposure routes. One mechanism behind their toxic potency is their ability to generate reactive oxygen species (ROS) directly or indirectly to an extent that depends on the dose, metal speciation, and exposure route. This review provides an overview of the mechanisms of ROS formation associated with metal and metal oxide NPs and proposes a possible way forward for their future categorization. Metal and metal oxide NPs can form ROS via processes related to corrosion, photochemistry, and surface defects, as well as via Fenton, Fenton-like, and Haber–Weiss reactions. Regular ligands such as biomolecules can interact with metallic NP surfaces and influence their properties and thus their capabilities of generating ROS by changing characteristics such as surface charge, surface composition, dissolution behavior, and colloidal stability. Interactions between metallic NPs and cells and their organelles can indirectly induce ROS formation via different biological responses. H2O2 can also be generated by a cell due to inflammation, induced by interactions with metallic NPs or released metal species that can initiate Fenton(-like) and Haber–Weiss reactions forming various radicals. This review discusses these different pathways and, in addition, nano-specific aspects such as shifts in the band gaps of metal oxides and how these shifts at biologically relevant energies (similar to activation energies of biological reactions) can be linked to ROS production and indicate which radical species forms. The influences of kinetic aspects, interactions with biomolecules, solution chemistry (e.g., Cl and pH), and NP characteristics (e.g., size and surface defects) on ROS mechanisms and formation are discussed. Categorization via four tiers is suggested as a way forward to group metal and metal oxide NPs based on the ROS reaction pathways that they may undergo, an approach that does not include kinetics or environmental variations. The criteria for the four tiers are based on the ability of the metallic NPs to induce Fenton(-like) and Haber–Weiss reactions, corrode, and interact with biomolecules and their surface catalytic properties. The importance of considering kinetic data to improve the proposed categorization is highlighted. Full article
(This article belongs to the Special Issue Advances in Nano-Bio Interactions: Nanosafety and Nanotoxicology)
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37 pages, 3379 KiB  
Review
Nanosafety: An Evolving Concept to Bring the Safest Possible Nanomaterials to Society and Environment
by Filipa Lebre, Nivedita Chatterjee, Samantha Costa, Eli Fernández-de-Gortari, Carla Lopes, João Meneses, Luís Ortiz, Ana R. Ribeiro, Vânia Vilas-Boas and Ernesto Alfaro-Moreno
Nanomaterials 2022, 12(11), 1810; https://doi.org/10.3390/nano12111810 - 25 May 2022
Cited by 16 | Viewed by 4476
Abstract
The use of nanomaterials has been increasing in recent times, and they are widely used in industries such as cosmetics, drugs, food, water treatment, and agriculture. The rapid development of new nanomaterials demands a set of approaches to evaluate the potential toxicity and [...] Read more.
The use of nanomaterials has been increasing in recent times, and they are widely used in industries such as cosmetics, drugs, food, water treatment, and agriculture. The rapid development of new nanomaterials demands a set of approaches to evaluate the potential toxicity and risks related to them. In this regard, nanosafety has been using and adapting already existing methods (toxicological approach), but the unique characteristics of nanomaterials demand new approaches (nanotoxicology) to fully understand the potential toxicity, immunotoxicity, and (epi)genotoxicity. In addition, new technologies, such as organs-on-chips and sophisticated sensors, are under development and/or adaptation. All the information generated is used to develop new in silico approaches trying to predict the potential effects of newly developed materials. The overall evaluation of nanomaterials from their production to their final disposal chain is completed using the life cycle assessment (LCA), which is becoming an important element of nanosafety considering sustainability and environmental impact. In this review, we give an overview of all these elements of nanosafety. Full article
(This article belongs to the Special Issue Health, Environment and Nanosafety)
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26 pages, 8054 KiB  
Review
Dynamics of Spin Crossover Molecular Complexes
by Thilini K. Ekanayaka, Krishna Prasad Maity, Bernard Doudin and Peter A. Dowben
Nanomaterials 2022, 12(10), 1742; https://doi.org/10.3390/nano12101742 - 19 May 2022
Cited by 10 | Viewed by 3037
Abstract
We review the current understanding of the time scale and mechanisms associated with the change in spin state in transition metal-based spin crossover (SCO) molecular complexes. Most time resolved experiments, performed by optical techniques, rely on the intrinsic light-induced switching properties of this [...] Read more.
We review the current understanding of the time scale and mechanisms associated with the change in spin state in transition metal-based spin crossover (SCO) molecular complexes. Most time resolved experiments, performed by optical techniques, rely on the intrinsic light-induced switching properties of this class of materials. The optically driven spin state transition can be mediated by a rich interplay of complexities including intermediate states in the spin state transition process, as well as intermolecular interactions, temperature, and strain. We emphasize here that the size reduction down to the nanoscale is essential for designing SCO systems that switch quickly as well as possibly retaining the memory of the light-driven state. We argue that SCO nano-sized systems are the key to device applications where the “write” speed is an important criterion. Full article
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40 pages, 5745 KiB  
Review
Carbon-Based Nanocatalysts (CnCs) for Biomass Valorization and Hazardous Organics Remediation
by Dimitrios A. Giannakoudakis, Foteini F. Zormpa, Antigoni G. Margellou, Abdul Qayyum, Ramón Fernando Colmenares-Quintero, Christophe Len, Juan Carlos Colmenares and Konstantinos S. Triantafyllidis
Nanomaterials 2022, 12(10), 1679; https://doi.org/10.3390/nano12101679 - 14 May 2022
Cited by 16 | Viewed by 3877
Abstract
The continuous increase of the demand in merchandise and fuels augments the need of modern approaches for the mass-production of renewable chemicals derived from abundant feedstocks, like biomass, as well as for the water and soil remediation pollution resulting from the anthropogenic discharge [...] Read more.
The continuous increase of the demand in merchandise and fuels augments the need of modern approaches for the mass-production of renewable chemicals derived from abundant feedstocks, like biomass, as well as for the water and soil remediation pollution resulting from the anthropogenic discharge of organic compounds. Towards these directions and within the concept of circular (bio)economy, the development of efficient and sustainable catalytic processes is of paramount importance. Within this context, the design of novel catalysts play a key role, with carbon-based nanocatalysts (CnCs) representing one of the most promising class of materials. In this review, a wide range of CnCs utilized for biomass valorization towards valuable chemicals production, and for environmental remediation applications are summarized and discussed. Emphasis is given in particular on the catalytic production of 5-hydroxymethylfurfural (5-HMF) from cellulose or starch-rich food waste, the hydrogenolysis of lignin towards high bio-oil yields enriched predominately in alkyl and oxygenated phenolic monomers, the photocatalytic, sonocatalytic or sonophotocatalytic selective partial oxidation of 5-HMF to 2,5-diformylfuran (DFF) and the decomposition of organic pollutants in aqueous matrixes. The carbonaceous materials were utilized as stand-alone catalysts or as supports of (nano)metals are various types of activated micro/mesoporous carbons, graphene/graphite and the chemically modified counterparts like graphite oxide and reduced graphite oxide, carbon nanotubes, carbon quantum dots, graphitic carbon nitride, and fullerenes. Full article
(This article belongs to the Special Issue Nanoscale Materials for Water Purification and Catalysis)
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16 pages, 3682 KiB  
Review
When Super-Resolution Localization Microscopy Meets Carbon Nanotubes
by Somen Nandi, Karen Caicedo and Laurent Cognet
Nanomaterials 2022, 12(9), 1433; https://doi.org/10.3390/nano12091433 - 22 Apr 2022
Cited by 9 | Viewed by 2654
Abstract
We recently assisted in a revolution in the realm of fluorescence microscopy triggered by the advent of super-resolution techniques that surpass the classic diffraction limit barrier. By providing optical images with nanometer resolution in the far field, super-resolution microscopy (SRM) is currently accelerating [...] Read more.
We recently assisted in a revolution in the realm of fluorescence microscopy triggered by the advent of super-resolution techniques that surpass the classic diffraction limit barrier. By providing optical images with nanometer resolution in the far field, super-resolution microscopy (SRM) is currently accelerating our understanding of the molecular organization of bio-specimens, bridging the gap between cellular observations and molecular structural knowledge, which was previously only accessible using electron microscopy. SRM mainly finds its roots in progress made in the control and manipulation of the optical properties of (single) fluorescent molecules. The flourishing development of novel fluorescent nanostructures has recently opened the possibility of associating super-resolution imaging strategies with nanomaterials’ design and applications. In this review article, we discuss some of the recent developments in the field of super-resolution imaging explicitly based on the use of nanomaterials. As an archetypal class of fluorescent nanomaterial, we mainly focus on single-walled carbon nanotubes (SWCNTs), which are photoluminescent emitters at near-infrared (NIR) wavelengths bearing great interest for biological imaging and for information optical transmission. Whether for fundamental applications in nanomaterial science or in biology, we show how super-resolution techniques can be applied to create nanoscale images “in”, “of” and “with” SWCNTs. Full article
(This article belongs to the Special Issue Super-resolution Microscopy and Nanoscience)
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26 pages, 1561 KiB  
Review
Nanocarriers for Drug Delivery: An Overview with Emphasis on Vitamin D and K Transportation
by Andreea Crintea, Alina Gabriela Dutu, Alina Sovrea, Anne-Marie Constantin, Gabriel Samasca, Aurelian Lucian Masalar, Brigitta Ifju, Eugen Linga, Lidia Neamti, Rares Andrei Tranca, Zsolt Fekete, Ciprian Nicolae Silaghi and Alexandra Marioara Craciun
Nanomaterials 2022, 12(8), 1376; https://doi.org/10.3390/nano12081376 - 17 Apr 2022
Cited by 9 | Viewed by 4536
Abstract
Mounting evidence shows that supplementation with vitamin D and K or their analogs induces beneficial effects in various diseases, e.g., osteoarticular, cardiovascular, or carcinogenesis. The use of drugs delivery systems via organic and inorganic nanocarriers increases the bioavailability of vitamins and analogs, enhancing [...] Read more.
Mounting evidence shows that supplementation with vitamin D and K or their analogs induces beneficial effects in various diseases, e.g., osteoarticular, cardiovascular, or carcinogenesis. The use of drugs delivery systems via organic and inorganic nanocarriers increases the bioavailability of vitamins and analogs, enhancing their cellular delivery and effects. The nanotechnology-based dietary supplements and drugs produced by the food and pharmaceutical industries overcome the issues associated with vitamin administration, such as stability, absorption or low bioavailability. Consequently, there is a continuous interest in optimizing the carriers’ systems in order to make them more efficient and specific for the targeted tissue. In this pioneer review, we try to circumscribe the most relevant aspects related to nanocarriers for drug delivery, compare different types of nanoparticles for vitamin D and K transportation, and critically address their benefits and disadvantages. Full article
(This article belongs to the Special Issue Nanoparticles Drug Delivery)
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26 pages, 2245 KiB  
Review
Experimental and Computational Nanotoxicology—Complementary Approaches for Nanomaterial Hazard Assessment
by Valérie Forest
Nanomaterials 2022, 12(8), 1346; https://doi.org/10.3390/nano12081346 - 14 Apr 2022
Cited by 21 | Viewed by 3116
Abstract
The growing development and applications of nanomaterials lead to an increasing release of these materials in the environment. The adverse effects they may elicit on ecosystems or human health are not always fully characterized. Such potential toxicity must be carefully assessed with the [...] Read more.
The growing development and applications of nanomaterials lead to an increasing release of these materials in the environment. The adverse effects they may elicit on ecosystems or human health are not always fully characterized. Such potential toxicity must be carefully assessed with the underlying mechanisms elucidated. To that purpose, different approaches can be used. First, experimental toxicology consisting of conducting in vitro or in vivo experiments (including clinical studies) can be used to evaluate the nanomaterial hazard. It can rely on variable models (more or less complex), allowing the investigation of different biological endpoints. The respective advantages and limitations of in vitro and in vivo models are discussed as well as some issues associated with experimental nanotoxicology. Perspectives of future developments in the field are also proposed. Second, computational nanotoxicology, i.e., in silico approaches, can be used to predict nanomaterial toxicity. In this context, we describe the general principles, advantages, and limitations especially of quantitative structure–activity relationship (QSAR) models and grouping/read-across approaches. The aim of this review is to provide an overview of these different approaches based on examples and highlight their complementarity. Full article
(This article belongs to the Special Issue Toxicity Evaluation of Nanoparticles)
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34 pages, 1113 KiB  
Review
A New Look at the Effects of Engineered ZnO and TiO2 Nanoparticles: Evidence from Transcriptomics Studies
by Shuyuan Wang, Harri Alenius, Hani El-Nezami and Piia Karisola
Nanomaterials 2022, 12(8), 1247; https://doi.org/10.3390/nano12081247 - 7 Apr 2022
Cited by 13 | Viewed by 3155
Abstract
Titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles (NPs) have attracted a great deal of attention due to their excellent electrical, optical, whitening, UV-adsorbing and bactericidal properties. The extensive production and utilization of these NPs increases their chances of being released [...] Read more.
Titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles (NPs) have attracted a great deal of attention due to their excellent electrical, optical, whitening, UV-adsorbing and bactericidal properties. The extensive production and utilization of these NPs increases their chances of being released into the environment and conferring unintended biological effects upon exposure. With the increasingly prevalent use of the omics technique, new data are burgeoning which provide a global view on the overall changes induced by exposures to NPs. In this review, we provide an account of the biological effects of ZnO and TiO2 NPs arising from transcriptomics in in vivo and in vitro studies. In addition to studies on humans and mice, we also describe findings on ecotoxicology-related species, such as Danio rerio (zebrafish), Caenorhabditis elegans (nematode) or Arabidopsis thaliana (thale cress). Based on evidence from transcriptomics studies, we discuss particle-induced biological effects, including cytotoxicity, developmental alterations and immune responses, that are dependent on both material-intrinsic and acquired/transformed properties. This review seeks to provide a holistic insight into the global changes induced by ZnO and TiO2 NPs pertinent to human and ecotoxicology. Full article
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28 pages, 443 KiB  
Review
Applications and Prospects of Nanotechnology in Food and Cosmetics Preservation
by Paraskevi Angelopoulou, Efstathios Giaouris and Konstantinos Gardikis
Nanomaterials 2022, 12(7), 1196; https://doi.org/10.3390/nano12071196 - 3 Apr 2022
Cited by 22 | Viewed by 4333
Abstract
Cosmetic and food products containing water are prone to contamination during the production, storage, and transit process, leading to product spoilage and degraded organoleptic characteristics. The efficient preservation of food and cosmetics is one of the most important issues the industry is facing [...] Read more.
Cosmetic and food products containing water are prone to contamination during the production, storage, and transit process, leading to product spoilage and degraded organoleptic characteristics. The efficient preservation of food and cosmetics is one of the most important issues the industry is facing today. The use of nanotechnology in food and cosmetics for preservation purposes offers the possibility to boost the activity of antimicrobial agents and/or promote their safer distribution into the end product upon incorporation into packaging or film constructions. In this review, current preservation strategies are discussed and the most recent studies in nanostructures used for preservation purposes are categorized and analyzed in a way that hopefully provides the most promising strategies for both the improvement of product safety and shelf-life extension. Packaging materials are also included since the container plays a major role in the preservation of such products. It is conclusively revealed that most of the applications refer to the nanocomposites as part of the packaging, mainly due to the various possibilities that nanoscience offers to this field. Apart from that, the route of exposure being either skin or the gastrointestinal system involves safety concerns, and since migration of nanoparticles (NPs) from their container can be measured, concerns can be minimized. Conclusion: Nanomaterial science has already made a significant contribution to food and cosmetics preservation, and rapid developments in the last years reinforce the belief that in the future much of the preservation strategies to be pursued by the two industries will be based on NPs and their nanocomposites. Full article
19 pages, 2098 KiB  
Review
Current Methods in the Study of Nanomaterials for Bone Regeneration
by Manabu Tanaka, Makoto Izumiya, Hisao Haniu, Katsuya Ueda, Chuang Ma, Koki Ueshiba, Hirokazu Ideta, Atsushi Sobajima, Shigeharu Uchiyama, Jun Takahashi and Naoto Saito
Nanomaterials 2022, 12(7), 1195; https://doi.org/10.3390/nano12071195 - 2 Apr 2022
Cited by 7 | Viewed by 2481
Abstract
Nanomaterials show great promise as bone regeneration materials. They can be used as fillers to strengthen bone regeneration scaffolds, or employed in their natural form as carriers for drug delivery systems. A variety of experiments have been conducted to evaluate the osteogenic potential [...] Read more.
Nanomaterials show great promise as bone regeneration materials. They can be used as fillers to strengthen bone regeneration scaffolds, or employed in their natural form as carriers for drug delivery systems. A variety of experiments have been conducted to evaluate the osteogenic potential of bone regeneration materials. In vivo, such materials are commonly tested in animal bone defect models to assess their bone regeneration potential. From an ethical standpoint, however, animal experiments should be minimized. A standardized in vitro strategy for this purpose is desirable, but at present, the results of studies conducted under a wide variety of conditions have all been evaluated equally. This review will first briefly introduce several bone regeneration reports on nanomaterials and the nanosize-derived caveats of evaluations in such studies. Then, experimental techniques (in vivo and in vitro), types of cells, culture media, fetal bovine serum, and additives will be described, with specific examples of the risks of various culture conditions leading to erroneous conclusions in biomaterial analysis. We hope that this review will create a better understanding of the evaluation of biomaterials, including nanomaterials for bone regeneration, and lead to the development of versatile assessment methods that can be widely used in biomaterial development. Full article
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24 pages, 10863 KiB  
Review
Modified Breath Figure Methods for the Pore-Selective Functionalization of Honeycomb-Patterned Porous Polymer Films
by Shahkar Falak, Bokyoung Shin and Dosung Huh
Nanomaterials 2022, 12(7), 1055; https://doi.org/10.3390/nano12071055 - 24 Mar 2022
Cited by 7 | Viewed by 2955
Abstract
Recent developments in the field of the breath figure (BF) method have led to renewed interest from researchers in the pore-selective functionalization of honeycomb-patterned (HCP) films. The pore-selective functionalization of the HCP film gives unique properties to the film which can be used [...] Read more.
Recent developments in the field of the breath figure (BF) method have led to renewed interest from researchers in the pore-selective functionalization of honeycomb-patterned (HCP) films. The pore-selective functionalization of the HCP film gives unique properties to the film which can be used for specific applications such as protein recognition, catalysis, selective cell culturing, and drug delivery. There are several comprehensive reviews available for the pore-selective functionalization by the self-assembly process. However, considerable progress in preparation technologies and incorporation of new materials inside the pore surface for exact applications have emerged, thus warranting a review. In this review, we have focused on the pore-selective functionalization of the HCP films by the modified BF method, in which the self-assembly process is accompanied by an interfacial reaction. We review the importance of pore-selective functionalization, its applications, present limitations, and future perspectives. Full article
(This article belongs to the Special Issue Fabrication of Nanoporous Polymer Films and Applications)
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25 pages, 3119 KiB  
Review
Recent Advances in Theoretical Development of Thermal Atomic Layer Deposition: A Review
by Mina Shahmohammadi, Rajib Mukherjee, Cortino Sukotjo, Urmila M. Diwekar and Christos G. Takoudis
Nanomaterials 2022, 12(5), 831; https://doi.org/10.3390/nano12050831 - 1 Mar 2022
Cited by 22 | Viewed by 6064
Abstract
Atomic layer deposition (ALD) is a vapor-phase deposition technique that has attracted increasing attention from both experimentalists and theoreticians in the last few decades. ALD is well-known to produce conformal, uniform, and pinhole-free thin films across the surface of substrates. Due to these [...] Read more.
Atomic layer deposition (ALD) is a vapor-phase deposition technique that has attracted increasing attention from both experimentalists and theoreticians in the last few decades. ALD is well-known to produce conformal, uniform, and pinhole-free thin films across the surface of substrates. Due to these advantages, ALD has found many engineering and biomedical applications. However, drawbacks of ALD should be considered. For example, the reaction mechanisms cannot be thoroughly understood through experiments. Moreover, ALD conditions such as materials, pulse and purge durations, and temperature should be optimized for every experiment. It is practically impossible to perform many experiments to find materials and deposition conditions that achieve a thin film with desired applications. Additionally, only existing materials can be tested experimentally, which are often expensive and hazardous, and their use should be minimized. To overcome ALD limitations, theoretical methods are beneficial and essential complements to experimental data. Recently, theoretical approaches have been reported to model, predict, and optimize different ALD aspects, such as materials, mechanisms, and deposition characteristics. Those methods can be validated using a different theoretical approach or a few knowledge-based experiments. This review focuses on recent computational advances in thermal ALD and discusses how theoretical methods can make experiments more efficient. Full article
(This article belongs to the Section Theory and Simulation of Nanostructures)
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23 pages, 5175 KiB  
Review
Strain Engineering: A Pathway for Tunable Functionalities of Perovskite Metal Oxide Films
by Samyak Dhole, Aiping Chen, Wanyi Nie, Baeho Park and Quanxi Jia
Nanomaterials 2022, 12(5), 835; https://doi.org/10.3390/nano12050835 - 1 Mar 2022
Cited by 15 | Viewed by 4388
Abstract
Perovskite offers a framework that boasts various functionalities and physical properties of interest such as ferroelectricity, magnetic orderings, multiferroicity, superconductivity, semiconductor, and optoelectronic properties owing to their rich compositional diversity. These properties are also uniquely tied to their crystal distortion which is directly [...] Read more.
Perovskite offers a framework that boasts various functionalities and physical properties of interest such as ferroelectricity, magnetic orderings, multiferroicity, superconductivity, semiconductor, and optoelectronic properties owing to their rich compositional diversity. These properties are also uniquely tied to their crystal distortion which is directly affected by lattice strain. Therefore, many important properties of perovskite can be further tuned through strain engineering which can be accomplished by chemical doping or simply element substitution, interface engineering in epitaxial thin films, and special architectures such as nanocomposites. In this review, we focus on and highlight the structure–property relationships of perovskite metal oxide films and elucidate the principles to manipulate the functionalities through different modalities of strain engineering approaches. Full article
(This article belongs to the Special Issue Structure, Properties and Applications of Nanocrystalline Thin Films)
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25 pages, 1824 KiB  
Review
Magnetic Nanoparticles in Bone Tissue Engineering
by Akshith Dasari, Jingyi Xue and Sanjukta Deb
Nanomaterials 2022, 12(5), 757; https://doi.org/10.3390/nano12050757 - 24 Feb 2022
Cited by 30 | Viewed by 6870
Abstract
Large bone defects with limited intrinsic regenerative potential represent a major surgical challenge and are associated with a high socio-economic burden and severe reduction in the quality of life. Tissue engineering approaches offer the possibility to induce new functional bone regeneration, with the [...] Read more.
Large bone defects with limited intrinsic regenerative potential represent a major surgical challenge and are associated with a high socio-economic burden and severe reduction in the quality of life. Tissue engineering approaches offer the possibility to induce new functional bone regeneration, with the biomimetic scaffold serving as a bridge to create a microenvironment that enables a regenerative niche at the site of damage. Magnetic nanoparticles have emerged as a potential tool in bone tissue engineering that leverages the inherent magnetism of magnetic nano particles in cellular microenvironments providing direction in enhancing the osteoinductive, osteoconductive and angiogenic properties in the design of scaffolds. There are conflicting opinions and reports on the role of MNPs on these scaffolds, such as the true role of magnetism, the application of external magnetic fields in combination with MNPs, remote delivery of biomechanical stimuli in-vivo and magnetically controlled cell retention or bioactive agent delivery in promoting osteogenesis and angiogenesis. In this review, we focus on the role of magnetic nanoparticles for bone-tissue-engineering applications in both disease modelling and treatment of injuries and disease. We highlight the materials-design pathway from implementation strategy through the selection of materials and fabrication methods to evaluation. We discuss the advances in this field and unmet needs, current challenges in the development of ideal materials for bone-tissue regeneration and emerging strategies in the field. Full article
(This article belongs to the Special Issue Nanomaterials in Dentistry)
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27 pages, 7692 KiB  
Review
Light-Driven Charge Transport and Optical Sensing in Molecular Junctions
by Chaolong Tang, Mehrdad Shiri, Haixin Zhang, Ridwan Tobi Ayinla and Kun Wang
Nanomaterials 2022, 12(4), 698; https://doi.org/10.3390/nano12040698 - 19 Feb 2022
Cited by 10 | Viewed by 4664
Abstract
Probing charge and energy transport in molecular junctions (MJs) has not only enabled a fundamental understanding of quantum transport at the atomic and molecular scale, but it also holds significant promise for the development of molecular-scale electronic devices. Recent years have witnessed a [...] Read more.
Probing charge and energy transport in molecular junctions (MJs) has not only enabled a fundamental understanding of quantum transport at the atomic and molecular scale, but it also holds significant promise for the development of molecular-scale electronic devices. Recent years have witnessed a rapidly growing interest in understanding light-matter interactions in illuminated MJs. These studies have profoundly deepened our knowledge of the structure–property relations of various molecular materials and paved critical pathways towards utilizing single molecules in future optoelectronics applications. In this article, we survey recent progress in investigating light-driven charge transport in MJs, including junctions composed of a single molecule and self-assembled monolayers (SAMs) of molecules, and new opportunities in optical sensing at the single-molecule level. We focus our attention on describing the experimental design, key phenomena, and the underlying mechanisms. Specifically, topics presented include light-assisted charge transport, photoswitch, and photoemission in MJs. Emerging Raman sensing in MJs is also discussed. Finally, outstanding challenges are explored, and future perspectives in the field are provided. Full article
(This article belongs to the Special Issue Molecular Electronics: Challenges and Opportunities)
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25 pages, 5125 KiB  
Review
Instantaneous Property Prediction and Inverse Design of Plasmonic Nanostructures Using Machine Learning: Current Applications and Future Directions
by Xinkai Xu, Dipesh Aggarwal and Karthik Shankar
Nanomaterials 2022, 12(4), 633; https://doi.org/10.3390/nano12040633 - 14 Feb 2022
Cited by 11 | Viewed by 3291
Abstract
Advances in plasmonic materials and devices have given rise to a variety of applications in photocatalysis, microscopy, nanophotonics, and metastructures. With the advent of computing power and artificial neural networks, the characterization and design process of plasmonic nanostructures can be significantly accelerated using [...] Read more.
Advances in plasmonic materials and devices have given rise to a variety of applications in photocatalysis, microscopy, nanophotonics, and metastructures. With the advent of computing power and artificial neural networks, the characterization and design process of plasmonic nanostructures can be significantly accelerated using machine learning as opposed to conventional FDTD simulations. The machine learning (ML) based methods can not only perform with high accuracy and return optical spectra and optimal design parameters, but also maintain a stable high computing efficiency without being affected by the structural complexity. This work reviews the prominent ML methods involved in forward simulation and inverse design of plasmonic nanomaterials, such as Convolutional Neural Networks, Generative Adversarial Networks, Genetic Algorithms and Encoder–Decoder Networks. Moreover, we acknowledge the current limitations of ML methods in the context of plasmonics and provide perspectives on future research directions. Full article
(This article belongs to the Special Issue Optical Resonators: Advanced Platform for Sensing Applications)
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17 pages, 1123 KiB  
Review
Nanodelivery Strategies for Skin Diseases with Barrier Impairment: Focusing on Ceramides and Glucocorticoids
by Cíntia Almeida, Patrícia Filipe, Catarina Rosado and Catarina Pereira-Leite
Nanomaterials 2022, 12(2), 275; https://doi.org/10.3390/nano12020275 - 15 Jan 2022
Cited by 10 | Viewed by 3246
Abstract
The human epidermis has a characteristic lipidic composition in the stratum corneum, where ceramides play a crucial role in the skin barrier homeostasis and in water-holding capacity. Several skin diseases, such as atopic dermatitis and psoriasis, exhibit a dysfunction in the lipid barrier [...] Read more.
The human epidermis has a characteristic lipidic composition in the stratum corneum, where ceramides play a crucial role in the skin barrier homeostasis and in water-holding capacity. Several skin diseases, such as atopic dermatitis and psoriasis, exhibit a dysfunction in the lipid barrier with altered ceramide levels and increased loss of transepidermal water. Glucocorticoids are normally employed in the therapeutical management of these pathologies. However, they have shown a poor safety profile and reduced treatment efficiency. The main objective of this review is to, within the framework of the limitations of the currently available therapeutical approaches, establish the relevance of nanocarriers as a safe and efficient delivery strategy for glucocorticoids and ceramides in the topical treatment of skin disorders with barrier impairment. Full article
(This article belongs to the Special Issue Delivery Systems Based on Innovative Nanomaterials)
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24 pages, 2103 KiB  
Review
The Impact of the Surface Modification on Tin-Doped Indium Oxide Nanocomposite Properties
by Arash Fattahi, Peyman Koohsari, Muhammad Shadman Lakmehsari and Khashayar Ghandi
Nanomaterials 2022, 12(1), 155; https://doi.org/10.3390/nano12010155 - 3 Jan 2022
Cited by 2 | Viewed by 2985
Abstract
This review provides an analysis of the theoretical methods to study the effects of surface modification on structural properties of nanostructured indium tin oxide (ITO), mainly by organic compounds. The computational data are compared with experimental data such as X-ray diffraction (XRD), atomic [...] Read more.
This review provides an analysis of the theoretical methods to study the effects of surface modification on structural properties of nanostructured indium tin oxide (ITO), mainly by organic compounds. The computational data are compared with experimental data such as X-ray diffraction (XRD), atomic force microscopy (AFM) and energy-dispersive X-ray spectroscopy (EDS) data with the focus on optoelectronic and electrocatalytic properties of the surface to investigate potential relations of these properties and applications of ITO in fields such as biosensing and electronic device fabrication. Our analysis shows that the change in optoelectronic properties of the surface is mainly due to functionalizing the surface with organic molecules and that the electrocatalytic properties vary as a function of size. Full article
(This article belongs to the Special Issue Advances in Nanostructured Semiconductors and Heterojunctions)
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28 pages, 13003 KiB  
Review
Efficient and Stable Perovskite Solar Cells Based on Inorganic Hole Transport Materials
by Helen Hejin Park
Nanomaterials 2022, 12(1), 112; https://doi.org/10.3390/nano12010112 - 30 Dec 2021
Cited by 23 | Viewed by 4806
Abstract
Although power conversion efficiencies of organic-inorganic lead halide perovskite solar cells (PSCs) are approaching those of single-crystal silicon solar cells, the working device stability due to internal and external factors, such as light, temperature, and moisture, is still a key issue to address. [...] Read more.
Although power conversion efficiencies of organic-inorganic lead halide perovskite solar cells (PSCs) are approaching those of single-crystal silicon solar cells, the working device stability due to internal and external factors, such as light, temperature, and moisture, is still a key issue to address. The current world-record efficiency of PSCs is based on organic hole transport materials, which are usually susceptible to degradation from heat and diffusion of dopants. A simple solution would be to replace the generally used organic hole transport layers (HTLs) with a more stable inorganic material. This review article summarizes recent contributions of inorganic hole transport materials to PSC development, focusing on aspects of device performance and long-term stability. Future research directions of inorganic HTLs in the progress of PSC research and challenges still remaining will also be discussed. Full article
(This article belongs to the Special Issue Applications of Metal Halide Perovskites in Optoelectronic Devices)
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13 pages, 628 KiB  
Review
Metal and Metal Oxide Nanoparticles in Caries Prevention: A Review
by Mohammed Zahedul Islam Nizami, Veena W. Xu, Iris X. Yin, Ollie Y. Yu and Chun-Hung Chu
Nanomaterials 2021, 11(12), 3446; https://doi.org/10.3390/nano11123446 - 20 Dec 2021
Cited by 34 | Viewed by 5110
Abstract
Nanoparticles based on metal and metallic oxide have become a novel trend for dental use as they interfere with bacterial metabolism and prevent biofilm formation. Metal and metal oxide nanoparticles demonstrate significant antimicrobial activity by metal ion release, oxidative stress induction and non-oxidative [...] Read more.
Nanoparticles based on metal and metallic oxide have become a novel trend for dental use as they interfere with bacterial metabolism and prevent biofilm formation. Metal and metal oxide nanoparticles demonstrate significant antimicrobial activity by metal ion release, oxidative stress induction and non-oxidative mechanisms. Silver, zinc, titanium, copper, and magnesium ions have been used to develop metal and metal oxide nanoparticles. In addition, fluoride has been used to functionalise the metal and metal oxide nanoparticles. The fluoride-functionalised nanoparticles show fluoride-releasing properties that enhance apatite formation, promote remineralisation, and inhibit demineralisation of enamel and dentine. The particles’ nanoscopic size increases their surface-to-volume ratio and bioavailability. The increased surface area facilitates their mechanical bond with tooth tissue. Therefore, metal and metal oxide nanoparticles have been incorporated in dental materials to strengthen the mechanical properties of the materials and to prevent caries development. Another advantage of metal and metal oxide nanoparticles is their easily scalable production. The aim of this study is to provide an overview of the use of metal and metal oxide nanoparticles in caries prevention. The study reviews their effects on dental materials regarding antibacterial, remineralising, aesthetic, and mechanical properties. Full article
(This article belongs to the Special Issue Metallic and Metal Oxide Nanoparticles and Their Applications)
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30 pages, 1839 KiB  
Review
Microfluidics Technology for the Design and Formulation of Nanomedicines
by Eman Jaradat, Edward Weaver, Adam Meziane and Dimitrios A. Lamprou
Nanomaterials 2021, 11(12), 3440; https://doi.org/10.3390/nano11123440 - 18 Dec 2021
Cited by 24 | Viewed by 5495
Abstract
In conventional drug administration, drug molecules cross multiple biological barriers, distribute randomly in the tissues, and can release insufficient concentrations at the desired pathological site. Controlling the delivery of the molecules can increase the concentration of the drug in the desired location, leading [...] Read more.
In conventional drug administration, drug molecules cross multiple biological barriers, distribute randomly in the tissues, and can release insufficient concentrations at the desired pathological site. Controlling the delivery of the molecules can increase the concentration of the drug in the desired location, leading to improved efficacy, and reducing the unwanted effects of the molecules under investigation. Nanoparticles (NPs), have shown a distinctive potential in targeting drugs due to their unique properties, such as large surface area and quantum properties. A variety of NPs have been used over the years for the encapsulation of different drugs and biologics, acting as drug carriers, including lipid-based and polymeric NPs. Applying NP platforms in medicines significantly improves the disease diagnosis and therapy. Several conventional methods have been used for the manufacturing of drug loaded NPs, with conventional manufacturing methods having several limitations, leading to multiple drawbacks, including NPs with large particle size and broad size distribution (high polydispersity index), besides the unreproducible formulation and high batch-to-batch variability. Therefore, new methods such as microfluidics (MFs) need to be investigated more thoroughly. MFs, is a novel manufacturing method that uses microchannels to produce a size-controlled and monodispersed NP formulation. In this review, different formulation methods of polymeric and lipid-based NPs will be discussed, emphasizing the different manufacturing methods and their advantages and limitations and how microfluidics has the capacity to overcome these limitations and improve the role of NPs as an effective drug delivery system. Full article
(This article belongs to the Special Issue Nanomaterials for Applied Nanotechnology and Nanoscience)
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38 pages, 8844 KiB  
Review
On-Demand Drug Delivery Systems Using Nanofibers
by Baljinder Singh, Kibeom Kim and Myoung-Hwan Park
Nanomaterials 2021, 11(12), 3411; https://doi.org/10.3390/nano11123411 - 16 Dec 2021
Cited by 37 | Viewed by 4688
Abstract
On-demand drug-delivery systems using nanofibers are extensively applicable for customized drug release based on target location and timing to achieve the desired therapeutic effects. A nanofiber formulation is typically created for a certain medication and changing the drug may have a significant impact [...] Read more.
On-demand drug-delivery systems using nanofibers are extensively applicable for customized drug release based on target location and timing to achieve the desired therapeutic effects. A nanofiber formulation is typically created for a certain medication and changing the drug may have a significant impact on the release kinetics from the same delivery system. Nanofibers have several distinguishing features and properties, including the ease with which they may be manufactured, the variety of materials appropriate for processing into fibers, a large surface area, and a complex pore structure. Nanofibers with effective drug-loading capabilities, controllable release, and high stability have gained the interest of researchers owing to their potential applications in on-demand drug delivery systems. Based on their composition and drug-release characteristics, we review the numerous types of nanofibers from the most recent accessible studies. Nanofibers are classified based on their mechanism of drug release, as well as their structure and content. To achieve controlled drug release, a suitable polymer, large surface-to-volume ratio, and high porosity of the nanofiber mesh are necessary. The properties of nanofibers for modified drug release are categorized here as protracted, stimulus-activated, and biphasic. Swellable or degradable polymers are commonly utilized to alter drug release. In addition to the polymer used, the process and ambient conditions can have considerable impacts on the release characteristics of the nanofibers. The formulation of nanofibers is highly complicated and depends on many variables; nevertheless, numerous options are available to accomplish the desired nanofiber drug-release characteristics. Full article
(This article belongs to the Special Issue Current Review in Synthesis, Interfaces, and Nanostructures)
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28 pages, 7223 KiB  
Review
Magnetic Nanomaterials for Arterial Embolization and Hyperthermia of Parenchymal Organs Tumors: A Review
by Natalia E. Kazantseva, Ilona S. Smolkova, Vladimir Babayan, Jarmila Vilčáková, Petr Smolka and Petr Saha
Nanomaterials 2021, 11(12), 3402; https://doi.org/10.3390/nano11123402 - 15 Dec 2021
Cited by 11 | Viewed by 2951
Abstract
Magnetic hyperthermia (MH), proposed by R. K. Gilchrist in the middle of the last century as local hyperthermia, has nowadays become a recognized method for minimally invasive treatment of oncological diseases in combination with chemotherapy (ChT) and radiotherapy (RT). One type of MH [...] Read more.
Magnetic hyperthermia (MH), proposed by R. K. Gilchrist in the middle of the last century as local hyperthermia, has nowadays become a recognized method for minimally invasive treatment of oncological diseases in combination with chemotherapy (ChT) and radiotherapy (RT). One type of MH is arterial embolization hyperthermia (AEH), intended for the presurgical treatment of primary inoperable and metastasized solid tumors of parenchymal organs. This method is based on hyperthermia after transcatheter arterial embolization of the tumor’s vascular system with a mixture of magnetic particles and embolic agents. An important advantage of AEH lies in the double effect of embolotherapy, which blocks blood flow in the tumor, and MH, which eradicates cancer cells. Consequently, only the tumor undergoes thermal destruction. This review introduces the progress in the development of polymeric magnetic materials for application in AEH. Full article
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37 pages, 3518 KiB  
Review
Nanoparticle Systems for Cancer Phototherapy: An Overview
by Thais P. Pivetta, Caroline E. A. Botteon, Paulo A. Ribeiro, Priscyla D. Marcato and Maria Raposo
Nanomaterials 2021, 11(11), 3132; https://doi.org/10.3390/nano11113132 - 20 Nov 2021
Cited by 39 | Viewed by 4590
Abstract
Photodynamic therapy (PDT) and photothermal therapy (PTT) are photo-mediated treatments with different mechanisms of action that can be addressed for cancer treatment. Both phototherapies are highly successful and barely or non-invasive types of treatment that have gained attention in the past few years. [...] Read more.
Photodynamic therapy (PDT) and photothermal therapy (PTT) are photo-mediated treatments with different mechanisms of action that can be addressed for cancer treatment. Both phototherapies are highly successful and barely or non-invasive types of treatment that have gained attention in the past few years. The death of cancer cells because of the application of these therapies is caused by the formation of reactive oxygen species, that leads to oxidative stress for the case of photodynamic therapy and the generation of heat for the case of photothermal therapies. The advancement of nanotechnology allowed significant benefit to these therapies using nanoparticles, allowing both tuning of the process and an increase of effectiveness. The encapsulation of drugs, development of the most different organic and inorganic nanoparticles as well as the possibility of surfaces’ functionalization are some strategies used to combine phototherapy and nanotechnology, with the aim of an effective treatment with minimal side effects. This article presents an overview on the use of nanostructures in association with phototherapy, in the view of cancer treatment. Full article
(This article belongs to the Special Issue Application of Nanomaterials in Biomedical Imaging and Cancer Therapy)
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35 pages, 11125 KiB  
Review
Physically Switchable Antimicrobial Surfaces and Coatings: General Concept and Recent Achievements
by Roman Elashnikov, Pavel Ulbrich, Barbora Vokatá, Vladimíra Svobodová Pavlíčková, Václav Švorčík, Oleksiy Lyutakov and Silvie Rimpelová
Nanomaterials 2021, 11(11), 3083; https://doi.org/10.3390/nano11113083 - 16 Nov 2021
Cited by 17 | Viewed by 2986
Abstract
Bacterial environmental colonization and subsequent biofilm formation on surfaces represents a significant and alarming problem in various fields, ranging from contamination of medical devices up to safe food packaging. Therefore, the development of surfaces resistant to bacterial colonization is a challenging and actively [...] Read more.
Bacterial environmental colonization and subsequent biofilm formation on surfaces represents a significant and alarming problem in various fields, ranging from contamination of medical devices up to safe food packaging. Therefore, the development of surfaces resistant to bacterial colonization is a challenging and actively solved task. In this field, the current promising direction is the design and creation of nanostructured smart surfaces with on-demand activated amicrobial protection. Various surface activation methods have been described recently. In this review article, we focused on the “physical” activation of nanostructured surfaces. In the first part of the review, we briefly describe the basic principles and common approaches of external stimulus application and surface activation, including the temperature-, light-, electric- or magnetic-field-based surface triggering, as well as mechanically induced surface antimicrobial protection. In the latter part, the recent achievements in the field of smart antimicrobial surfaces with physical activation are discussed, with special attention on multiresponsive or multifunctional physically activated coatings. In particular, we mainly discussed the multistimuli surface triggering, which ensures a better degree of surface properties control, as well as simultaneous utilization of several strategies for surface protection, based on a principally different mechanism of antimicrobial action. We also mentioned several recent trends, including the development of the to-detect and to-kill hybrid approach, which ensures the surface activation in a right place at a right time. Full article
(This article belongs to the Special Issue Biocompatibility of Nanomaterials in Medical Applications)
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29 pages, 4883 KiB  
Review
Modal Properties of Photonic Crystal Cavities and Applications to Lasers
by Marco Saldutti, Meng Xiong, Evangelos Dimopoulos, Yi Yu, Mariangela Gioannini and Jesper Mørk
Nanomaterials 2021, 11(11), 3030; https://doi.org/10.3390/nano11113030 - 12 Nov 2021
Cited by 22 | Viewed by 4268
Abstract
Photonic crystal cavities enable strong light–matter interactions, with numerous applications, such as ultra-small and energy-efficient semiconductor lasers, enhanced nonlinearities and single-photon sources. This paper reviews the properties of the modes of photonic crystal cavities, with a special focus on line-defect cavities. In particular, [...] Read more.
Photonic crystal cavities enable strong light–matter interactions, with numerous applications, such as ultra-small and energy-efficient semiconductor lasers, enhanced nonlinearities and single-photon sources. This paper reviews the properties of the modes of photonic crystal cavities, with a special focus on line-defect cavities. In particular, it is shown how the fundamental resonant mode in line-defect cavities gradually turns from Fabry–Perot-like to distributed-feedback-like with increasing cavity size. This peculiar behavior is directly traced back to the properties of the guided Bloch modes. Photonic crystal cavities based on Fano interference are also covered. This type of cavity is realized through coupling of a line-defect waveguide with an adjacent nanocavity, with applications to Fano lasers and optical switches. Finally, emerging cavities for extreme dielectric confinement are covered. These cavities promise extremely strong light–matter interactions by realizing deep sub-wavelength mode size while keeping a high quality factor. Full article
(This article belongs to the Special Issue Semiconductor and Nanophotonic Devices)
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15 pages, 1670 KiB  
Review
Carbon Nanomaterials Modified Biomimetic Dental Implants for Diabetic Patients
by Renjini Vijay, Jayanti Mendhi, Karthika Prasad, Yin Xiao, Jennifer MacLeod, Kostya (Ken) Ostrikov and Yinghong Zhou
Nanomaterials 2021, 11(11), 2977; https://doi.org/10.3390/nano11112977 - 5 Nov 2021
Cited by 9 | Viewed by 3574
Abstract
Dental implants are used broadly in dental clinics as the most natural-looking restoration option for replacing missing or highly diseased teeth. However, dental implant failure is a crucial issue for diabetic patients in need of dentition restoration, particularly when a lack of osseointegration [...] Read more.
Dental implants are used broadly in dental clinics as the most natural-looking restoration option for replacing missing or highly diseased teeth. However, dental implant failure is a crucial issue for diabetic patients in need of dentition restoration, particularly when a lack of osseointegration and immunoregulatory incompetency occur during the healing phase, resulting in infection and fibrous encapsulation. Bio-inspired or biomimetic materials, which can mimic the characteristics of natural elements, are being investigated for use in the implant industry. This review discusses different biomimetic dental implants in terms of structural changes that enable antibacterial properties, drug delivery, immunomodulation, and osseointegration. We subsequently summarize the modification of dental implants for diabetes patients utilizing carbon nanomaterials, which have been recently found to improve the characteristics of biomimetic dental implants, including through antibacterial and anti-inflammatory capabilities, and by offering drug delivery properties that are essential for the success of dental implants. Full article
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16 pages, 1380 KiB  
Review
Direct and Indirect Genotoxicity of Graphene Family Nanomaterials on DNA—A Review
by Kangying Wu, Qixing Zhou and Shaohu Ouyang
Nanomaterials 2021, 11(11), 2889; https://doi.org/10.3390/nano11112889 - 28 Oct 2021
Cited by 30 | Viewed by 3226
Abstract
Graphene family nanomaterials (GFNs), including graphene, graphene oxide (GO), reduced graphene oxide (rGO), and graphene quantum dots (GQDs), have manifold potential applications, leading to the possibility of their release into environments and the exposure to humans and other organisms. However, the genotoxicity of [...] Read more.
Graphene family nanomaterials (GFNs), including graphene, graphene oxide (GO), reduced graphene oxide (rGO), and graphene quantum dots (GQDs), have manifold potential applications, leading to the possibility of their release into environments and the exposure to humans and other organisms. However, the genotoxicity of GFNs on DNA remains largely unknown. In this review, we highlight the interactions between DNA and GFNs and summarize the mechanisms of genotoxicity induced by GFNs. Generally, the genotoxicity can be sub-classified into direct genotoxicity and indirect genotoxicity. The direct genotoxicity (e.g., direct physical nucleus and DNA damage) and indirect genotoxicity mechanisms (e.g., physical destruction, oxidative stress, epigenetic toxicity, and DNA replication) of GFNs were summarized in the manuscript, respectively. Moreover, the influences factors, such as physicochemical properties, exposure dose, and time, on the genotoxicity of GFNs are also briefly discussed. Given the important role of genotoxicity in GFNs exposure risk assessment, future research should be conducted on the following: (1) developing reliable testing methods; (2) elucidating the response mechanisms associated with genotoxicity in depth; and (3) enriching the evaluation database regarding the type of GFNs, applied dosages, and exposure times. Full article
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25 pages, 61242 KiB  
Review
Graphene Transfer: A Physical Perspective
by Xavier Langston and Keith E. Whitener, Jr.
Nanomaterials 2021, 11(11), 2837; https://doi.org/10.3390/nano11112837 - 25 Oct 2021
Cited by 10 | Viewed by 5517
Abstract
Graphene, synthesized either epitaxially on silicon carbide or via chemical vapor deposition (CVD) on a transition metal, is gathering an increasing amount of interest from industrial and commercial ventures due to its remarkable electronic, mechanical, and thermal properties, as well as the ease [...] Read more.
Graphene, synthesized either epitaxially on silicon carbide or via chemical vapor deposition (CVD) on a transition metal, is gathering an increasing amount of interest from industrial and commercial ventures due to its remarkable electronic, mechanical, and thermal properties, as well as the ease with which it can be incorporated into devices. To exploit these superlative properties, it is generally necessary to transfer graphene from its conductive growth substrate to a more appropriate target substrate. In this review, we analyze the literature describing graphene transfer methods developed over the last decade. We present a simple physical model of the adhesion of graphene to its substrate, and we use this model to organize the various graphene transfer techniques by how they tackle the problem of modulating the adhesion energy between graphene and its substrate. We consider the challenges inherent in both delamination of graphene from its original substrate as well as relamination of graphene onto its target substrate, and we show how our simple model can rationalize various transfer strategies to mitigate these challenges and overcome the introduction of impurities and defects into the graphene. Our analysis of graphene transfer strategies concludes with a suggestion of possible future directions for the field. Full article
(This article belongs to the Special Issue Two Dimensional Nanomaterials: Energy Conversion and Storage)
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35 pages, 5713 KiB  
Review
Spherical Cellulose Micro and Nanoparticles: A Review of Recent Developments and Applications
by João P. F. Carvalho, Ana C. Q. Silva, Armando J. D. Silvestre, Carmen S. R. Freire and Carla Vilela
Nanomaterials 2021, 11(10), 2744; https://doi.org/10.3390/nano11102744 - 17 Oct 2021
Cited by 41 | Viewed by 7489
Abstract
Cellulose, the most abundant natural polymer, is a versatile polysaccharide that is being exploited to manufacture innovative blends, composites, and hybrid materials in the form of membranes, films, coatings, hydrogels, and foams, as well as particles at the micro and nano scales. The [...] Read more.
Cellulose, the most abundant natural polymer, is a versatile polysaccharide that is being exploited to manufacture innovative blends, composites, and hybrid materials in the form of membranes, films, coatings, hydrogels, and foams, as well as particles at the micro and nano scales. The application fields of cellulose micro and nanoparticles run the gamut from medicine, biology, and environment to electronics and energy. In fact, the number of studies dealing with sphere-shaped micro and nanoparticles based exclusively on cellulose (or its derivatives) or cellulose in combination with other molecules and macromolecules has been steadily increasing in the last five years. Hence, there is a clear need for an up-to-date narrative that gathers the latest advances on this research topic. So, the aim of this review is to portray some of the most recent and relevant developments on the use of cellulose to produce spherical micro- and nano-sized particles. An attempt was made to illustrate the present state of affairs in terms of the go-to strategies (e.g., emulsification processes, nanoprecipitation, microfluidics, and other assembly approaches) for the generation of sphere-shaped particles of cellulose and derivatives thereof. A concise description of the application fields of these cellulose-based spherical micro and nanoparticles is also presented. Full article
(This article belongs to the Special Issue Nanoparticles from Natural Polymers: Synthesis and Applications)
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26 pages, 727 KiB  
Review
Nanotechnology Innovations to Enhance the Therapeutic Efficacy of Quercetin
by Rúben G. R. Pinheiro, Marina Pinheiro and Ana Rute Neves
Nanomaterials 2021, 11(10), 2658; https://doi.org/10.3390/nano11102658 - 9 Oct 2021
Cited by 29 | Viewed by 4292
Abstract
Quercetin is a flavonol present in many vegetables and fruits. Generally, quercetin can be found in aglycone and glycoside forms, mainly in leaves. The absorption of this compound occurs in the large and small intestine, where it suffers glucuronidation, sulfidation, and methylation to [...] Read more.
Quercetin is a flavonol present in many vegetables and fruits. Generally, quercetin can be found in aglycone and glycoside forms, mainly in leaves. The absorption of this compound occurs in the large and small intestine, where it suffers glucuronidation, sulfidation, and methylation to improve hydrophilicity. After metabolization, which occurs mainly in the gut, it is distributed throughout the whole organism and is excreted by feces, urine, and exhalation of carbon dioxide. Despite its in vitro cytotoxicity effects, in vivo studies with animal models ensure its safety. This compound can protect against cancer, cardiovascular diseases, chronic inflammation, oxidative stress, and neurodegenerative diseases due to its radical scavenging and anti-inflammatory properties. However, its poor bioavailability dampens the potential beneficial effects of this flavonoid. In that sense, many types of nanocarriers have been developed to improve quercetin solubility, as well as to design tissue-specific delivery systems. All these studies manage to improve the bioavailability of quercetin, allowing it to increase its concentration in the desired places. Collectively, quercetin can become a promising compound if nanotechnology is employed as a tool to enhance its therapeutic efficacy. Full article
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17 pages, 6354 KiB  
Review
Recent Advances in Layered-Double-Hydroxides Based Noble Metal Nanoparticles Efficient Electrocatalysts
by Zexuan Zhang, Peilong Li, Xin Zhang, Cun Hu, Yuwen Li, Bin Yu, Ning Zeng, Chao Lv, Jiangfeng Song and Mingcan Li
Nanomaterials 2021, 11(10), 2644; https://doi.org/10.3390/nano11102644 - 8 Oct 2021
Cited by 19 | Viewed by 3532
Abstract
With the energy crisis and environmental pollution becoming more and more serious, it is urgent to develop renewable and clean energy. Hydrogen production from electrolyzed water is of great significance to solve the energy crisis and environmental problems in the future. Recently, layered [...] Read more.
With the energy crisis and environmental pollution becoming more and more serious, it is urgent to develop renewable and clean energy. Hydrogen production from electrolyzed water is of great significance to solve the energy crisis and environmental problems in the future. Recently, layered double hydroxides (LDHs) materials have been widely studied in the electrocatalysis field, due to their unique layered structure, tunable metal species and highly dispersed active sites. Moreover, the LDHs supporting noble metal catalysts obtained through the topotactic transformation of LDHs precursors significantly reduce the energy barrier of electrolyzing water, showing remarkable catalytic activity, good conductivity and excellent durability. In this review, we give an overview of recent advances on LDHs supporting noble metal catalysts, from a brief introduction, to their preparation and modification methods, to an overview of their application in the electrocatalysis field, as well as the challenges and outlooks in this promising field on the basis of current development. Full article
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47 pages, 3065 KiB  
Review
Advances in Non-Animal Testing Approaches towards Accelerated Clinical Translation of Novel Nanotheranostic Therapeutics for Central Nervous System Disorders
by Mark J. Lynch and Oliviero L. Gobbo
Nanomaterials 2021, 11(10), 2632; https://doi.org/10.3390/nano11102632 - 7 Oct 2021
Cited by 5 | Viewed by 3632
Abstract
Nanotheranostics constitute a novel drug delivery system approach to improving systemic, brain-targeted delivery of diagnostic imaging agents and pharmacological moieties in one rational carrier platform. While there have been notable successes in this field, currently, the clinical translation of such delivery systems for [...] Read more.
Nanotheranostics constitute a novel drug delivery system approach to improving systemic, brain-targeted delivery of diagnostic imaging agents and pharmacological moieties in one rational carrier platform. While there have been notable successes in this field, currently, the clinical translation of such delivery systems for the treatment of neurological disorders has been limited by the inadequacy of correlating in vitro and in vivo data on blood–brain barrier (BBB) permeation and biocompatibility of nanomaterials. This review aims to identify the most contemporary non-invasive approaches for BBB crossing using nanotheranostics as a novel drug delivery strategy and current non-animal-based models for assessing the safety and efficiency of such formulations. This review will also address current and future directions of select in vitro models for reducing the cumbersome and laborious mandate for testing exclusively in animals. It is hoped these non-animal-based modelling approaches will facilitate researchers in optimising promising multifunctional nanocarriers with a view to accelerating clinical testing and authorisation applications. By rational design and appropriate selection of characterised and validated models, ranging from monolayer cell cultures to organ-on-chip microfluidics, promising nanotheranostic particles with modular and rational design can be screened in high-throughput models with robust predictive power. Thus, this article serves to highlight abbreviated research and development possibilities with clinical translational relevance for developing novel nanomaterial-based neuropharmaceuticals for therapy in CNS disorders. By generating predictive data for prospective nanomedicines using validated in vitro models for supporting clinical applications in lieu of requiring extensive use of in vivo animal models that have notable limitations, it is hoped that there will be a burgeoning in the nanotherapy of CNS disorders by virtue of accelerated lead identification through screening, optimisation through rational design for brain-targeted delivery across the BBB and clinical testing and approval using fewer animals. Additionally, by using models with tissue of human origin, reproducible therapeutically relevant nanomedicine delivery and individualised therapy can be realised. Full article
(This article belongs to the Special Issue Nanobiotechnology for Drug Delivery System)
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22 pages, 13774 KiB  
Review
Current Knowledge of Silver and Gold Nanoparticles in Laboratory Research—Application, Toxicity, Cellular Uptake
by Patrycja Talarska, Maciej Boruczkowski and Jakub Żurawski
Nanomaterials 2021, 11(9), 2454; https://doi.org/10.3390/nano11092454 - 21 Sep 2021
Cited by 49 | Viewed by 4385
Abstract
Silver and gold nanoparticles can be found in a range of household products related to almost every area of life, including patches, bandages, paints, sportswear, personal care products, food storage equipment, cosmetics, disinfectants, etc. Their confirmed ability to enter the organism through respiratory [...] Read more.
Silver and gold nanoparticles can be found in a range of household products related to almost every area of life, including patches, bandages, paints, sportswear, personal care products, food storage equipment, cosmetics, disinfectants, etc. Their confirmed ability to enter the organism through respiratory and digestive systems, skin, and crossing the blood–brain barrier raises questions of their potential effect on cell function. Therefore, this manuscript aimed to summarize recent reports concerning the influence of variables such as size, shape, concentration, type of coating, or incubation time, on effects of gold and silver nanoparticles on cultured cell lines. Due to the increasingly common use of AgNP and AuNP in multiple branches of the industry, further studies on the effects of nanoparticles on different types of cells and the general natural environment are needed to enable their long-term use. However, some environmentally friendly solutions to chemically synthesized nanoparticles are also investigated, such as plant-based synthesis methods. Full article
(This article belongs to the Special Issue Cytotoxicity and Genotoxicity of Nanoparticles)
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24 pages, 17456 KiB  
Review
3D-Printable Nanocellulose-Based Functional Materials: Fundamentals and Applications
by Abraham Samuel Finny, Oluwatosin Popoola and Silvana Andreescu
Nanomaterials 2021, 11(9), 2358; https://doi.org/10.3390/nano11092358 - 11 Sep 2021
Cited by 27 | Viewed by 5896
Abstract
Nanomaterials obtained from sustainable and natural sources have seen tremendous growth in recent times due to increasing interest in utilizing readily and widely available resources. Nanocellulose materials extracted from renewable biomasses hold great promise for increasing the sustainability of conventional materials in various [...] Read more.
Nanomaterials obtained from sustainable and natural sources have seen tremendous growth in recent times due to increasing interest in utilizing readily and widely available resources. Nanocellulose materials extracted from renewable biomasses hold great promise for increasing the sustainability of conventional materials in various applications owing to their biocompatibility, mechanical properties, ease of functionalization, and high abundance. Nanocellulose can be used to reinforce mechanical strength, impart antimicrobial activity, provide lighter, biodegradable, and more robust materials for packaging, and produce photochromic and electrochromic devices. While the fabrication and properties of nanocellulose are generally well established, their implementation in novel products and applications requires surface modification, assembly, and manufacturability to enable rapid tooling and scalable production. Additive manufacturing techniques such as 3D printing can improve functionality and enhance the ability to customize products while reducing fabrication time and wastage of materials. This review article provides an overview of nanocellulose as a sustainable material, covering the different properties, preparation methods, printability and strategies to functionalize nanocellulose into 3D-printed constructs. The applications of 3D-printed nanocellulose composites in food, environmental, and energy devices are outlined, and an overview of challenges and opportunities is provided. Full article
(This article belongs to the Special Issue Synthesis, Applications and Biological Impact of Nanocellulose)
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20 pages, 3950 KiB  
Review
Influence of Titanium Dioxide Nanoparticles on Human Health and the Environment
by Mohammad Mamunur Rashid, Petra Forte Tavčer and Brigita Tomšič
Nanomaterials 2021, 11(9), 2354; https://doi.org/10.3390/nano11092354 - 10 Sep 2021
Cited by 70 | Viewed by 5673
Abstract
Nanotechnology has enabled tremendous breakthroughs in the development of materials and, nowadays, is well established in various economic fields. Among the various nanomaterials, TiO2 nanoparticles (NPs) occupy a special position, as they are distinguished by their high availability, high photocatalytic activity, and [...] Read more.
Nanotechnology has enabled tremendous breakthroughs in the development of materials and, nowadays, is well established in various economic fields. Among the various nanomaterials, TiO2 nanoparticles (NPs) occupy a special position, as they are distinguished by their high availability, high photocatalytic activity, and favorable price, which make them useful in the production of paints, plastics, paper, cosmetics, food, furniture, etc. In textiles, TiO2 NPs are widely used in chemical finishing processes to impart various protective functional properties to the fibers for the production of high-tech textile products with high added value. Such applications contribute to the overall consumption of TiO2 NPs, which gives rise to reasonable considerations about the impact of TiO2 NPs on human health and the environment, and debates regarding whether the extent of the benefits gained from the use of TiO2 NPs justifies the potential risks. In this study, different TiO2 NPs exposure modes are discussed, and their toxicity mechanisms—evaluated in various in vitro and in vivo studies—are briefly described, considering the molecular interactions with human health and the environment. In addition, in the conclusion of this study, the toxicity and biocompatibility of TiO2 NPs are discussed, along with relevant risk management strategies. Full article
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72 pages, 3944 KiB  
Review
Iron Oxide Nanoparticles in Regenerative Medicine and Tissue Engineering
by Ralf P. Friedrich, Iwona Cicha and Christoph Alexiou
Nanomaterials 2021, 11(9), 2337; https://doi.org/10.3390/nano11092337 - 8 Sep 2021
Cited by 58 | Viewed by 7653
Abstract
In recent years, many promising nanotechnological approaches to biomedical research have been developed in order to increase implementation of regenerative medicine and tissue engineering in clinical practice. In the meantime, the use of nanomaterials for the regeneration of diseased or injured tissues is [...] Read more.
In recent years, many promising nanotechnological approaches to biomedical research have been developed in order to increase implementation of regenerative medicine and tissue engineering in clinical practice. In the meantime, the use of nanomaterials for the regeneration of diseased or injured tissues is considered advantageous in most areas of medicine. In particular, for the treatment of cardiovascular, osteochondral and neurological defects, but also for the recovery of functions of other organs such as kidney, liver, pancreas, bladder, urethra and for wound healing, nanomaterials are increasingly being developed that serve as scaffolds, mimic the extracellular matrix and promote adhesion or differentiation of cells. This review focuses on the latest developments in regenerative medicine, in which iron oxide nanoparticles (IONPs) play a crucial role for tissue engineering and cell therapy. IONPs are not only enabling the use of non-invasive observation methods to monitor the therapy, but can also accelerate and enhance regeneration, either thanks to their inherent magnetic properties or by functionalization with bioactive or therapeutic compounds, such as drugs, enzymes and growth factors. In addition, the presence of magnetic fields can direct IONP-labeled cells specifically to the site of action or induce cell differentiation into a specific cell type through mechanotransduction. Full article
(This article belongs to the Special Issue Advanced Nanomaterials for Tissue Engineering Applications)
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17 pages, 3799 KiB  
Review
Anisotropic Silver Nanomaterials by Photochemical Reactions: Synthesis and Applications
by Vittorio Scardaci
Nanomaterials 2021, 11(9), 2226; https://doi.org/10.3390/nano11092226 - 29 Aug 2021
Cited by 7 | Viewed by 2390
Abstract
Silver-based nanoparticles have attracted a broad interest due to their outstanding optical and chemical properties and have been studied for applications in many fields. While different synthetic routes have been explored, photochemical synthesis has attracted a special interest for its limited use of [...] Read more.
Silver-based nanoparticles have attracted a broad interest due to their outstanding optical and chemical properties and have been studied for applications in many fields. While different synthetic routes have been explored, photochemical synthesis has attracted a special interest for its limited use of chemicals and ease of control over the shape and size of the nanoparticles. This paper reviews the main factors affecting the synthesis of anisotropic silver nanoparticles, such as irradiation wavelength, pH, etc., and the role of specific key molecules, such as citrate. The paper is structured into different sections depending on how the synthesis is initiated; thus, after the introduction, the photochemical conversion reaction starting from nanoparticles, or seeds, obtained chemically, is covered, followed by reactions from nanoparticles obtained by laser ablation by seedless reactions. After that, the applications proposed for anisotropic nanoparticles obtained by the methods discussed in the previous sections are briefly covered and, finally, the conclusions and the author’s perspectives are given. Full article
(This article belongs to the Special Issue Advanced Noble Metal Nanoparticles)
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