Search Results (82)

Dendrons, also named dendritic wedges, are a kind of molecular tree, having a branched structure linked to a functional core. The functional core can be used in particular for the functionalization of materials. Different types of dendrons are known, synthesized either by a convergent process, from the external part to the core, or by a divergent process from the core to the external part. Polyphosphorhydrazone (PPH) dendrons are always synthesized by a divergent process, which enables a fine-tuning of both the core function and the external functions. They have been used for the functionalization of diverse materials such as silica, titanium dioxide, gold, graphene oxide, or different types of nanoparticles. Nanocomposites based on materials functionalized with PPH dendrons have been used in diverse fields such as catalysts, chemical sensors, for trapping pollutants, to support cell cultures, and against cancers, as will be emphasized in this review. Full article

Mechanical forces are increasingly recognised as fundamental regulators of cellular function, complementing classical biochemical cues to direct development, tissue homeostasis, and disease progression. Cells detect external and internal forces via mechanosensor proteins and adapt their cytoskeletal architecture, leading to changes in cell behaviour. Biomaterials and biodevices come to the aid of tailoring biomaterials’ properties in terms of chemical/physical properties and, by emulating dynamical forces, e.g., shear stress and cell swelling, they may enlighten mechanobiological processes. Additionally, emerging technologies expand the experimental toolkit for probing mechanobiological phenomena in complex, customisable settings. Central to these processes are mechanotransducer proteins and membrane–organelle networks that convert mechanical deformation into biochemical signals, orchestrating downstream transcriptional and post-translational modifications. This review highlights how through bridging material engineering and cellular mechanics, mechanobiology provides a unified framework to understand how physical forces shape tissues and drive pathologies. The continued integration of advanced biomaterials, dynamic biodevices, and multiscale analytical methods promises to uncover new mechanistic insights and inform the development of mechanotherapeutic strategies. Full article

Biomaterials and biomedical devices interact with the human body at different levels. At one end of the spectrum, medical devices in contact with tissue pose risks depending on whether they are deployed on the skin or implanted. On the other hand, food packaging and associated material technologies must also be biocompatible to prevent the transfer of harmful molecules and contamination of food, which could impact human health. These seemingly unlinked domains converge into a shared need for the elaboration of new laboratory evaluation protocols that consider recent advances in biomaterials and biodevices, coupled with increasing legal restrictions on the use of animal models. Here, we aim to select and prescribe physiologically relevant microenvironment conditions for biocompatibility testing of novel biomaterials and biodevices. Our discussion spans (1) the development of testing protocols according to material classes, (2) current legislation and standards, and (3) the preparation of biomimetic setups that replicate the microenvironment, with a focus on the multidisciplinary dimension of such studies. Testing spans several characterization domains, beginning with chemical properties, followed by mechanical integrity and, finally, biological response. Biomimetic testing conditions typically include temperature fluctuations, humidity, mechanical stress and loading, exposure to body fluids, and interaction with multifaceted biological systems. Full article

The constructs of lipid molecules follow self-assembly, driven by intermolecular interactions, forming stacking of lipid bilayer films. Achieving designed geometry at nano- to micro-levels with packing deviating from the near-equilibrium structure is difficult to achieve due to the strong tendency of lipid molecules to self-assemble. Using ultrasmall (<fL) droplets containing designed molecules, our prior work has demonstrated that molecular assembly, in principle, is governed mainly by transient inter-molecular interactions under their dynamic spatial confinement, i.e., tri-phase boundaries during drying. As a result, the assemblies can deviate, sometimes significantly, from the near-equilibrium structures of self-assembly. The present work applies the approach and concept to lipid molecules using 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Taking advantage of the high spatial precision and the minute size of the delivery probe in our combined atomic force microscopy and microfluidic delivery, the transient shape of each liquid droplet is regulated. In doing so, the final geometry of the POPC assemblies has been regulated to the designed geometry with nanometer precision. The results extend the concept of controlled assembly of molecules to amphiphilic systems. The outcomes exhibit high potential in lipid-based biomaterial science and biodevice engineering. Full article

Significant research accomplishments have been made so far for the development and application of ZnO nanomaterials in enhanced optical biodetection. The unparalleled optical properties of ZnO nanomaterials and their reduced dimensionality have been successfully exploited to push the limits of conventional optical biosensors and optical biodetection platforms for a wide range of bioanalytes. ZnO nanomaterial-enabled advancements in optical biosensors have been demonstrated to improve key sensor performance characteristics such as the limit of detection and dynamic range. In addition, all nanomaterial forms of ZnO, ranging from 0-dimensional (0D) and 1D to 2D nanostructures, have been proven to be useful, ensuring their versatile fabrication into functional biosensors. The employment of ZnO as an essential biosensing element has been assessed not only for ensembles but also for individual nanomaterials, which is advantageous for the realization of high miniaturization and minimal invasiveness in biosensors and biodevices. Moreover, the nanomaterials’ incorporations into biosensors have been shown to be useful and functional for a variety of optical detection modes, such as absorption, colorimetry, fluorescence, near-band-edge emission, deep-level emission, chemiluminescence, surface evanescent wave, whispering gallery mode, lossy-mode resonance, surface plasmon resonance, and surface-enhanced Raman scattering. The detection capabilities of these ZnO nanomaterial-based optical biosensors demonstrated so far are highly encouraging and, in some cases, permit quantitative analyses of ultra-trace level bioanalytes that cannot be measured by other means. Hence, steady research endeavors are expected in this burgeoning field, whose scientific and technological impacts will grow immensely in the future. This review provides a timely and much needed review of the research efforts made in the field of ZnO nanomaterial-based optical biosensors in a comprehensive and systematic manner. The topical discussions in this review are organized by the different modes of optical detection listed above and further grouped by the dimensionality of the ZnO nanostructures used in biosensors. Following an overview of a given optical detection mode, the unique properties of ZnO nanomaterials critical to enhanced biodetection are presented in detail. Subsequently, specific biosensing applications of ZnO nanomaterials are discussed for ~40 different bioanalytes, and the important roles that the ZnO nanomaterials play in bioanalyte detection are also identified. Full article

Breast cancers can appear and progress rapidly, necessitating more frequent monitoring outside of hospital settings to significantly reduce mortality rates. Recently, there has been considerable interest in developing techniques for portable, user-friendly, and low-cost breast tumor monitoring applications, enabling frequent and cost-efficient examinations. Microwave technique-based breast cancer detection, which is based on differential dielectric properties of malignant and healthy tissues, is regarded as a promising solution for cost-effective breast tumor monitoring. This paper presents the development process of the first proof-of-concept of a breast tumor monitoring vest which is based on the microwave technique. Two unique vests are designed and evaluated on realistic 3D human tissue phantoms having different breast density types. Additionally, the measured results are verified using simulations carried out on anatomically realistic voxel models of the electromagnetic simulations. The radio channel characteristics are evaluated and analyzed between the antennas embedded in the vest in tumor cases and reference cases. Both measurements and simulation results show that the proposed vest can detect tumors even if only 1 cm in diameter. Additionally, simulation results show detectability with 0.5 cm tumors. It is observed that the detectability of breast tumors depends on the frequency, antenna selection, size of the tumors, and breast types, causing differences of 0.5–30 dB in channel responses between the tumorous and reference cases. Due to simplicity and cost-efficiency, the proposed channel analysis-based breast monitoring vests can be used for breast health checks in smaller healthcare centers and for user-friendly home monitoring which can prove beneficial in rural areas and developing countries. Full article

Traditional methods for measuring blood oxygen use multiple wavelengths, which produce an intrinsic error due to ratiometric measurements. These methods assume that the absorption changes with the wavelength, but in fact the scattering changes as well and cannot be neglected. We found that if one measures in a specific angle around a cylindrical tissue, called the iso-pathlength (IPL) point, the reemitted light intensity is unaffected by the tissue’s scattering. Therefore, the absorption can be isolated from the scattering, which allows the extraction of the subject’s oxygen saturation. In this work, we designed an optical biosensor for reading the light intensity reemitted from the tissue, using a single light source and multiple photodetectors (PDs), with one of them in the IPL point’s location. Using this bio-device, we developed a methodology to extract the arterial oxygen saturation using a single wavelength light source. We proved this method is not dependent on the light source and is applicable to different measurement locations on the body, with an error of 0.5%. Moreover, we tested thirty-eight males and females with the biosensor under normal conditions. Finally, we show the results of measuring subjects in a hypoxic chamber that simulates extreme conditions with low oxygen. Full article

In the struggle against diseases, the development of nano-therapy has certainly been a tremendous progression owing to the various superiority, and chitosan is no doubt a kind of prominent biopolymer material with versatility for applications in disease treatments. For the rational construction of chitosan-related nano-biodevices, it is necessary to pay full attention to the material itself, where it is the material properties that guide the design criteria. Additionally, the well-matched preparation methods between material carriers and therapeutic agents draw much attention to the final construction since they seem to be more realistic. In detail, we present a comprehensive overview of recent advances in rational construction of chitosan-related nano-therapies with respect to material-property-oriented design criteria and preparation methods in the current review article, based on the foundation of continuous investigations. Based on this review, a portion of the various uses of chitosan-related nano-biodevices for biomedical applications are specifically discussed. Here, the strategies demonstrate the versatility of chitosan well, and the concept of being simple yet effective is well illustrated and vividly communicated. Altogether, a fresh concept concerning multi-functional chitosan and its derivative-related drug delivery systems for nano-therapy is proposed in this review, and this could be applied to other materials, which seems to be a novel angle. Full article

Currently, cities are the most vulnerable places on the planet to the effects of global change, both anthropogenic and climate-related, and this is not compatible with harmony and well-being regarding the economy, nature, and future generations. Young people have a unique potential to catalyze the transformative sustainable change that the planet needs now, as they are the first generation to grow up with tangible impacts of climate change. We tested a new strategy to empower young people to foster carbon neutrality in cities by engaging them in ecosystem services quantification and technological innovation to increase CO₂ sequestration in two Portuguese cities. The species with best performance for carbon sequestration were M. exelsa in Porto and O. europea in Loulé, and for air pollutant removal and hydrological regulation were P. hispanica in Porto and P. pinea in Loulé. Through the innovative advanced summer program SLI, a nature-based learning experience, young people developed two new concepts of technological solutions to accelerate city decarbonization by designing a hedge for air pollution hotspots and a biodevice to be placed at bus stops using autochthonous shrubs and mosses. Initiatives like SLI contribute to a greater awareness among young people about the drivers that brought us to the current climate emergency, motivating them towards more balanced lifestyles and creating innovative nature-based solutions towards a smart and sustainable city. Full article

Neurotransmitters are an important category of substances used inside the nervous system, whose detection with biosensors has been seriously addressed in the last decades. Dopamine, a neurotransmitter from the catecholamine family, was recently discovered to have implications for cardiac arrest or muscle contractions. In addition to having many other neuro-psychiatric implications, dopamine can be detected in blood, urine, and sweat. This review highlights the importance of biosensors as influential tools for dopamine recognition. The first part of this article is related to an introduction to biosensors for neurotransmitters, with a focus on dopamine. The regular methods in their detection are expensive and require high expertise personnel. A major direction of evolution of these biosensors has expanded with the integration of active biological materials suitable for molecular recognition near electronic devices. Secondly, for dopamine in particular, the miniaturized biosensors offer excellent sensitivity and specificity and offer cheaper detection than conventional spectrometry, while their linear detection ranges from the last years fall exactly on the clinical intervals. Thirdly, the applications of novel nanomaterials and biomaterials to these biosensors are discussed. Older generations, metabolism-based or enzymatic biosensors, could not detect concentrations below the micro-molar range. But new generations of biosensors combine aptamer receptors and organic electrochemical transistors, OECTs, as transducers. They have pushed the detection limit to the pico-molar and even femto-molar ranges, which fully correspond to the usual ranges of clinical detection of human dopamine in body humors that cover 0.1 ÷ 10 nM. In addition, if ten years ago the use of natural dopamine receptors on cell membranes seemed impossible for biosensors, the actual technology allows co-integrate transistors and vesicles with natural receptors of dopamine, like G protein-coupled receptors. The technology is still complicated, but the uni-molecular detection selectivity is promising. Full article

Although the effect of the conductive polymers PEDOT:PSS on the electroluminescence performance of doped-type organic light-emitting diodes (OLEDs) has been studied, the process of PEDOT:PSS regulation of exciton recombination region and concentration within the deoxyribonucleic acid (DNA)-based doped-type BioLEDs is still obscure. In this study, we fabricated Bio-devices with and without PEDOT:PSS using varying spin-coating speeds of PEDOT:PSS. The Alq₃:Rubrene-based BioLEDs achieve higher luminance (44,010 cd/m²) and higher luminance efficiency (8.1 cd/A), which are increased by 186% and 478%, respectively, compared to the reference BioLEDs without PEDOT:PSS. Similarly, the maximum luminance and efficiency of blue TCTA:TPBi exciplex-type BioLEDs are increased by 224% and 464%. In particular, our findings reveal that with an increasing thickness of PEDOT:PSS, the region of exciton recombination shifts towards the interface between the emitting layer (EML) and the hole transport layer (HTL). Meanwhile, the concentration of singlet exciton (S_1,Rub) and triplet exciton (T_1,Rub) increases, and the triplet-triplet annihilation (TTA) process is enhanced, resulting in the enhanced luminescence and efficiency of the devices. Accordingly, we provide a possible idea for achieving high performance doped-type BioLEDs by adding conductive polymers PEDOT:PSS, and revealing the effect of exciton recombination and conversion in BioLEDs given different PEDOT:PSS thicknesses. Full article

A monolayer of boron known as borophene has emerged as a novel and fascinating two-dimensional (2D) material with exceptional features, such as anisotropic metallic behavior and supple mechanical and optical capabilities. The engineering of smart functionalized opto-electric 2D materials is essential to obtain biosensors or biodevices of desired performance. Borophene is one of the most emerging 2D materials, and owing to its excellent electroactive surface area, high electron transport, anisotropic behavior, controllable optical and electrochemical properties, ability to be deposited on thin films, and potential to create surface functionalities, it has recently become one of the sophisticated platforms. Despite the difficulty of production, borophene may be immobilized utilizing chemistries, be functionalized on a flexible substrate, and be controlled over electro-optical properties to create a highly sensitive biosensor system that could be used for point-of-care diagnostics. Its electrochemical properties can be tailored by using appropriate nanomaterials, redox mediators, conducting polymers, etc., which will be quite useful for the detection of biomolecules at even trace levels with a high sensitivity and less detection time. This will be quite helpful in developing biosensing devices with a very high sensitivity and with less response time. So, this review will be a crucial foundation as we have discussed the basic properties, synthesis, and potential applications of borophene in nanobiosensing, as well as therapeutic applications. Full article

Plant fibers possess high strength, high fracture toughness and elasticity, and have proven useful because of their diversity, versatility, renewability, and sustainability. For biomedical applications, these natural fibers have been used as reinforcement for biocomposites to infer these hybrid biomaterials mechanical characteristics, such as stiffness, strength, and durability. The reinforced hybrid composites have been tested in structural and semi-structural biodevices for potential applications in orthopedics, prosthesis, tissue engineering, and wound dressings. This review introduces plant fibers, their properties and factors impacting them, in addition to their applications. Then, it discusses different methodologies used to prepare hybrid composites based on these widespread, renewable fibers and the unique properties that the obtained biomaterials possess. It also examines several examples of hybrid composites and their biomedical applications. Finally, the findings are summed up and some thoughts for future developments are provided. Overall, the focus of the present review lies in analyzing the design, requirements, and performance, and future developments of hybrid composites based on plant fibers. Full article

Injuries and diseases of the skin require accurate treatment using nontoxic and noninvasive biomaterials, which aim to mimic the natural structures of the body. There is a strong need to develop biodevices capable of accommodating nutrients and bioactive molecules and generating the process of vascularization. Electrospinning is a robust technique, as it can form fibrous structures for tissue engineering and wound dressings. The best way of forming such meshes for wound healing is to choose two polymers that complement each other regarding their properties. On the one hand, PVA is a water-soluble synthetic polymer widely used for the preparation of hydrogels in the field of biomedicine owing to its biocompatibility, water solubility, nontoxicity, and considerable mechanical properties. PVA is easy to subject to electrospinning and can offer strong mechanical stability of the mesh, but it is necessary to improve its biological properties. On the other hand, CS has good biological properties, including biodegradability, nontoxicity, biocompatibility, and antimicrobial properties. Still, it is harder to electrospin and does not possess as good mechanical properties as PVA. As these structures also allow the incorporation of bioactive agents due to their high surface-area-to-volume ratio, the interesting point was to incorporate usnic acid into the structure as it is a natural and suitable alternative agent for burn wounds treatment which avoids an improper or overuse of antibiotics and other invasive biomolecules. Thus, we report the fabrication of an electrospun nanofibrous mesh based on PVA, chitosan, and usnic acid with applications in wound healing. The obtained nanofibers mesh was physicochemically characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). In vitro biological assays were performed to evaluate the antimicrobial properties of the samples using the MIC (minimum inhibitory concentration) assay and evaluating the influence of fabricated meshes on the Staphylococcus aureus biofilm development, as well as their biocompatibility (demonstrated by fluorescence microscopy results, an XTT assay, and a glutathione (GSH) assay). Full article