Journal of Functional Biomaterials

15 pages, 1784 KiB

Open AccessEditor’s ChoiceArticle

Functional Properties of Low-Modulus PMMA Bone Cements Containing Linoleic Acid

by Céline Robo, David Wenner, S. J. Kumari A. Ubhayasekera, Jöns Hilborn, Caroline Öhman-Mägi and Cecilia Persson

J. Funct. Biomater. 2021, 12(1), 5; https://doi.org/10.3390/jfb12010005 - 17 Jan 2021

Cited by 11 | Viewed by 3998

Abstract

Acrylic bone cements modified with linoleic acid are a promising low-modulus alternative to traditional high-modulus bone cements. However, several key properties remain unexplored, including the effect of autoclave sterilization and the potential use of low-modulus cements in other applications than vertebral augmentation. In [...] Read more.

Acrylic bone cements modified with linoleic acid are a promising low-modulus alternative to traditional high-modulus bone cements. However, several key properties remain unexplored, including the effect of autoclave sterilization and the potential use of low-modulus cements in other applications than vertebral augmentation. In this work, we evaluate the effect of sterilization on the structure and stability of linoleic acid, as well as in the handling properties, glass transition temperature, mechanical properties, and screw augmentation potential of low-modulus cement containing the fatty acid. Neither ¹H NMR nor SFC-MS/MS analysis showed any detectable differences in autoclaved linoleic acid compared to fresh one. The peak polymerization temperature of the low-modulus cement was much lower (28–30 °C) than that of the high-modulus cement (67 °C), whereas the setting time remained comparable (20–25 min). The T_g of the low-modulus cement was lower (75–78 °C) than that of the high-stiffness cement (103 °C). It was shown that sterilization of linoleic acid by autoclaving did not significantly affect the functional properties of low-modulus PMMA bone cement, making the component suitable for sterile production. Ultimately, the low-modulus cement exhibited handling and mechanical properties that more closely match those of osteoporotic vertebral bone with a screw holding capacity of under 2000 N, making it a promising alternative for use in combination with orthopedic hardware in applications where high-stiffness augmentation materials can result in undesired effects. Full article

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11 pages, 3417 KiB

Open AccessEditor’s ChoiceArticle

Mechanical Consequences of Dynamically Loaded NiTi Wires under Typical Actuator Conditions in Rehabilitation and Neuroscience

by Umut D. Çakmak, Zoltán Major and Michael Fischlschweiger

J. Funct. Biomater. 2021, 12(1), 4; https://doi.org/10.3390/jfb12010004 - 8 Jan 2021

Cited by 3 | Viewed by 2754

Abstract

In the field of rehabilitation and neuroscience, shape memory alloys play a crucial role as lightweight actuators. Devices are exploiting the shape memory effect by transforming heat into mechanical work. In rehabilitation applications, dynamic loading of the respective device occurs, which in turn [...] Read more.

In the field of rehabilitation and neuroscience, shape memory alloys play a crucial role as lightweight actuators. Devices are exploiting the shape memory effect by transforming heat into mechanical work. In rehabilitation applications, dynamic loading of the respective device occurs, which in turn influences the mechanical consequences of the phase transforming alloy. Hence in this work, dynamic thermomechanical material behavior of temperature-triggered phase transforming NiTi shape memory alloy (SMA) wires with different chemical compositions and geometries was experimentally investigated. Storage modulus and mechanical loss factor of NiTi alloys at different temperatures and loading frequencies were analyzed under force-controlled conditions. Counterintuitive storage modulus- and loss factor-dependent trends regarding the loading frequency dependency of the mechanical properties on the materials’ composition and geometry were, hence, obtained. It was revealed that loss factors showed a pronounced loading frequency dependency, whereas the storage modulus was not affected. It was shown that force-controlled conditions led to a lower storage modulus than expected. Furthermore, it turned out that a simple empirical relation could capture the characteristic temperature dependency of the storage modulus, which is an important input relation for modeling the rehabilitation device behavior under different dynamic and temperature loading conditions, taking directly into account the material behavior of the shape memory alloy. Full article

(This article belongs to the Special Issue Experimentation, Numerical and Analytical Methods in Functional Biomaterials)

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26 pages, 1069 KiB

Open AccessEditor’s ChoiceReview

Silver Nanoparticles: Mechanism of Action and Probable Bio-Application

by Ekaterina O. Mikhailova

J. Funct. Biomater. 2020, 11(4), 84; https://doi.org/10.3390/jfb11040084 - 26 Nov 2020

Cited by 425 | Viewed by 18061

Abstract

This review is devoted to the medical application of silver nanoparticles produced as a result of “green” synthesis using various living organisms (bacteria, fungi, plants). The proposed mechanisms of AgNPs synthesis and the action mechanisms on target cells are highlighted. Full article

(This article belongs to the Special Issue Bioactive Properties of Advanced Nanomaterials)

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11 pages, 1233 KiB

Open AccessFeature PaperEditor’s ChoiceReview

The Role of Scaffolds in Tendon Tissue Engineering

by Angelo V. Vasiliadis and Konstantinos Katakalos

J. Funct. Biomater. 2020, 11(4), 78; https://doi.org/10.3390/jfb11040078 - 1 Nov 2020

Cited by 46 | Viewed by 7228

Abstract

Tendons are unique forms of connective tissue aiming to transmit the mechanical force of muscle contraction to the bones. Tendon injury may be due to direct trauma or might be secondary to overuse injury and age-related degeneration, leading to inflammation, weakening and subsequent [...] Read more.

Tendons are unique forms of connective tissue aiming to transmit the mechanical force of muscle contraction to the bones. Tendon injury may be due to direct trauma or might be secondary to overuse injury and age-related degeneration, leading to inflammation, weakening and subsequent rupture. Current traditional treatment strategies focus on pain relief, reduction of the inflammation and functional restoration. Tendon repair surgery can be performed in people with tendon injuries to restore the tendon’s function, with re-rupture being the main potential complication. Novel therapeutic approaches that address the underlying pathology of the disease is warranted. Scaffolds represent a promising solution to the challenges associated with tendon tissue engineering. The ideal scaffold for tendon tissue engineering needs to exhibit physiologically relevant mechanical properties and to facilitate functional graft integration by promoting the regeneration of the native tissue. Full article

(This article belongs to the Special Issue Experimentation, Numerical and Analytical Methods in Functional Biomaterials)

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29 pages, 1146 KiB

Open AccessEditor’s ChoiceReview

Recent Advances of Conducting Polymers and Their Composites for Electrochemical Biosensing Applications

by John H. T. Luong, Tarun Narayan, Shipra Solanki and Bansi D. Malhotra

J. Funct. Biomater. 2020, 11(4), 71; https://doi.org/10.3390/jfb11040071 - 25 Sep 2020

Cited by 48 | Viewed by 6633

Abstract

Conducting polymers (CPs) have been at the center of research owing to their metal-like electrochemical properties and polymer-like dispersion nature. CPs and their composites serve as ideal functional materials for diversified biomedical applications like drug delivery, tissue engineering, and diagnostics. There have also [...] Read more.

Conducting polymers (CPs) have been at the center of research owing to their metal-like electrochemical properties and polymer-like dispersion nature. CPs and their composites serve as ideal functional materials for diversified biomedical applications like drug delivery, tissue engineering, and diagnostics. There have also been numerous biosensing platforms based on polyaniline (PANI), polypyrrole (PPY), polythiophene (PTP), and their composites. Based on their unique properties and extensive use in biosensing matrices, updated information on novel CPs and their role is appealing. This review focuses on the properties and performance of biosensing matrices based on CPs reported in the last three years. The salient features of CPs like PANI, PPY, PTP, and their composites with nanoparticles, carbon materials, etc. are outlined along with respective examples. A description of mediator conjugated biosensor designs and enzymeless CPs based glucose sensing has also been included. The future research trends with required improvements to improve the analytical performance of CP-biosensing devices have also been addressed. Full article

(This article belongs to the Special Issue Salient Features of Functional Polymers and Their Composites with Nanomaterials in Chemosensors and Biosensors)

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36 pages, 9300 KiB

Open AccessEditor’s ChoiceReview

Bio-Based Electrospun Fibers for Wound Healing

by Bahareh Azimi, Homa Maleki, Lorenzo Zavagna, Jose Gustavo De la Ossa, Stefano Linari, Andrea Lazzeri and Serena Danti

J. Funct. Biomater. 2020, 11(3), 67; https://doi.org/10.3390/jfb11030067 - 22 Sep 2020

Cited by 188 | Viewed by 14364

Abstract

Being designated to protect other tissues, skin is the first and largest human body organ to be injured and for this reason, it is accredited with a high capacity for self-repairing. However, in the case of profound lesions or large surface loss, the [...] Read more.

Being designated to protect other tissues, skin is the first and largest human body organ to be injured and for this reason, it is accredited with a high capacity for self-repairing. However, in the case of profound lesions or large surface loss, the natural wound healing process may be ineffective or insufficient, leading to detrimental and painful conditions that require repair adjuvants and tissue substitutes. In addition to the conventional wound care options, biodegradable polymers, both synthetic and biologic origin, are gaining increased importance for their high biocompatibility, biodegradation, and bioactive properties, such as antimicrobial, immunomodulatory, cell proliferative, and angiogenic. To create a microenvironment suitable for the healing process, a key property is the ability of a polymer to be spun into submicrometric fibers (e.g., via electrospinning), since they mimic the fibrous extracellular matrix and can support neo- tissue growth. A number of biodegradable polymers used in the biomedical sector comply with the definition of bio-based polymers (known also as biopolymers), which are recently being used in other industrial sectors for reducing the material and energy impact on the environment, as they are derived from renewable biological resources. In this review, after a description of the fundamental concepts of wound healing, with emphasis on advanced wound dressings, the recent developments of bio-based natural and synthetic electrospun structures for efficient wound healing applications are highlighted and discussed. This review aims to improve awareness on the use of bio-based polymers in medical devices. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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17 pages, 11862 KiB

Open AccessEditor’s ChoiceArticle

Electrosprayed Chitin Nanofibril/Electrospun Polyhydroxyalkanoate Fiber Mesh as Functional Nonwoven for Skin Application

by Bahareh Azimi, Lily Thomas, Alessandra Fusco, Ozlem Ipek Kalaoglu-Altan, Pooja Basnett, Patrizia Cinelli, Karen De Clerck, Ipsita Roy, Giovanna Donnarumma, Maria-Beatrice Coltelli, Serena Danti and Andrea Lazzeri

J. Funct. Biomater. 2020, 11(3), 62; https://doi.org/10.3390/jfb11030062 - 3 Sep 2020

Cited by 53 | Viewed by 6664

Abstract

Polyhydroxyalkanoates (PHAs) are a family of bio-based polyesters that have found different biomedical applications. Chitin and lignin, byproducts of fishery and plant biomass, show antimicrobial and anti-inflammatory activity on the nanoscale. Due to their polarities, chitin nanofibril (CN) and nanolignin (NL) can be [...] Read more.

Polyhydroxyalkanoates (PHAs) are a family of bio-based polyesters that have found different biomedical applications. Chitin and lignin, byproducts of fishery and plant biomass, show antimicrobial and anti-inflammatory activity on the nanoscale. Due to their polarities, chitin nanofibril (CN) and nanolignin (NL) can be assembled into micro-complexes, which can be loaded with bioactive factors, such as the glycyrrhetinic acid (GA) and CN-NL/GA (CLA) complexes, and can be used to decorate polymer surfaces. This study aims to develop completely bio-based and bioactive meshes intended for wound healing. Poly(3-hydroxybutyrate)/Poly(3-hydroxyoctanoate-co-3-hydroxydecanoate), P(3HB)/P(3HO-co-3HD) was used to produce films and fiber meshes, to be surface-modified via electrospraying of CN or CLA to reach a uniform distribution. P(3HB)/P(3HO-co-3HD) fibers with desirable size and morphology were successfully prepared and functionalized with CN and CLA using electrospinning and tested in vitro with human keratinocytes. The presence of CN and CLA improved the indirect antimicrobial and anti-inflammatory activity of the electrospun fiber meshes by downregulating the expression of the most important pro-inflammatory cytokines and upregulating human defensin 2 expression. This natural and eco-sustainable mesh is promising in wound healing applications. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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20 pages, 3361 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Biodegradable Polymeric Micro/Nano-Structures with Intrinsic Antifouling/Antimicrobial Properties: Relevance in Damaged Skin and Other Biomedical Applications

by Mario Milazzo, Giuseppe Gallone, Elena Marcello, Maria Donatella Mariniello, Luca Bruschini, Ipsita Roy and Serena Danti

J. Funct. Biomater. 2020, 11(3), 60; https://doi.org/10.3390/jfb11030060 - 19 Aug 2020

Cited by 34 | Viewed by 7699

Abstract

Bacterial colonization of implanted biomedical devices is the main cause of healthcare-associated infections, estimated to be 8.8 million per year in Europe. Many infections originate from damaged skin, which lets microorganisms exploit injuries and surgical accesses as passageways to reach the implant site [...] Read more.

Bacterial colonization of implanted biomedical devices is the main cause of healthcare-associated infections, estimated to be 8.8 million per year in Europe. Many infections originate from damaged skin, which lets microorganisms exploit injuries and surgical accesses as passageways to reach the implant site and inner organs. Therefore, an effective treatment of skin damage is highly desirable for the success of many biomaterial-related surgical procedures. Due to gained resistance to antibiotics, new antibacterial treatments are becoming vital to control nosocomial infections arising as surgical and post-surgical complications. Surface coatings can avoid biofouling and bacterial colonization thanks to biomaterial inherent properties (e.g., super hydrophobicity), specifically without using drugs, which may cause bacterial resistance. The focus of this review is to highlight the emerging role of degradable polymeric micro- and nano-structures that show intrinsic antifouling and antimicrobial properties, with a special outlook towards biomedical applications dealing with skin and skin damage. The intrinsic properties owned by the biomaterials encompass three main categories: (1) physical–mechanical, (2) chemical, and (3) electrostatic. Clinical relevance in ear prostheses and breast implants is reported. Collecting and discussing the updated outcomes in this field would help the development of better performing biomaterial-based antimicrobial strategies, which are useful to prevent infections. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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17 pages, 4203 KiB

Open AccessEditor’s ChoiceArticle

Electrospun Scaffolds Containing Silver-Doped Hydroxyapatite with Antimicrobial Properties for Applications in Orthopedic and Dental Bone Surgery

by Thomas E. Paterson, Rui Shi, Jingjing Tian, Caroline J. Harrison, Mailys De Sousa Mendes, Paul V. Hatton, Zhou Li and Ilida Ortega

J. Funct. Biomater. 2020, 11(3), 58; https://doi.org/10.3390/jfb11030058 - 14 Aug 2020

Cited by 32 | Viewed by 5089

Abstract

Preventing the development of osteomyelitis while enhancing bone regeneration is challenging, with relatively little progress to date in translating promising technologies to the clinic. Nanoscale hydroxyapatite (nHA) has been employed as a bone graft substitute, and recent work has shown that it may [...] Read more.

Preventing the development of osteomyelitis while enhancing bone regeneration is challenging, with relatively little progress to date in translating promising technologies to the clinic. Nanoscale hydroxyapatite (nHA) has been employed as a bone graft substitute, and recent work has shown that it may be modified with silver to introduce antimicrobial activity against known pathogens. The aim of this study was to incorporate silver-doped nHA into electrospun scaffolds for applications in bone repair. Silver-doped nHA was produced using a modified, rapid mixing, wet precipitation method at 2, 5, 10 mol.% silver. The silver-doped nHA was added at 20 wt.% to a polycaprolactone solution for electrospinning. Bacteria studies demonstrated reduced bacterial presence, with Escherichia coli and Staphylococcus aureus undetectable after 96 h of exposure. Mesenchymal stem cells (MSCs) were used to study both toxicity and osteogenicity of the scaffolds using PrestoBlue^® and alkaline phosphatase (ALP) assays. Innovative silver nHA scaffolds significantly reduced E. coli and S. aureus bacterial populations while maintaining cytocompatibility with mammalian cells and enhancing the differentiation of MSCs into osteoblasts. It was concluded that silver-doped nHA containing scaffolds have the potential to act as an antimicrobial device while supporting bone tissue healing for applications in orthopedic and dental bone surgery. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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24 pages, 8934 KiB

Open AccessEditor’s ChoiceReview

Natural Architectures for Tissue Engineering and Regenerative Medicine

by Floris Honig, Steven Vermeulen, Amir A. Zadpoor, Jan de Boer and Lidy E. Fratila-Apachitei

J. Funct. Biomater. 2020, 11(3), 47; https://doi.org/10.3390/jfb11030047 - 7 Jul 2020

Cited by 13 | Viewed by 6261

Abstract

The ability to control the interactions between functional biomaterials and biological systems is of great importance for tissue engineering and regenerative medicine. However, the underlying mechanisms defining the interplay between biomaterial properties and the human body are complex. Therefore, a key challenge is [...] Read more.

The ability to control the interactions between functional biomaterials and biological systems is of great importance for tissue engineering and regenerative medicine. However, the underlying mechanisms defining the interplay between biomaterial properties and the human body are complex. Therefore, a key challenge is to design biomaterials that mimic the in vivo microenvironment. Over millions of years, nature has produced a wide variety of biological materials optimised for distinct functions, ranging from the extracellular matrix (ECM) for structural and biochemical support of cells to the holy lotus with special wettability for self-cleaning effects. Many of these systems found in biology possess unique surface properties recognised to regulate cell behaviour. Integration of such natural surface properties in biomaterials can bring about novel cell responses in vitro and provide greater insights into the processes occurring at the cell-biomaterial interface. Using natural surfaces as templates for bioinspired design can stimulate progress in the field of regenerative medicine, tissue engineering and biomaterials science. This literature review aims to combine the state-of-the-art knowledge in natural and nature-inspired surfaces, with an emphasis on material properties known to affect cell behaviour. Full article

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11 pages, 3497 KiB

Open AccessEditor’s ChoiceArticle

Time-Transient Effects of Silver and Copper in the Porous Titanium Dioxide Layer on Antibacterial Properties

by Masaya Shimabukuro, Akari Hiji, Tomoyo Manaka, Kosuke Nozaki, Peng Chen, Maki Ashida, Yusuke Tsutsumi, Akiko Nagai and Takao Hanawa

J. Funct. Biomater. 2020, 11(2), 44; https://doi.org/10.3390/jfb11020044 - 22 Jun 2020

Cited by 25 | Viewed by 4501

Abstract

Recently, silver (Ag) and copper (Cu) have been incorporated into a titanium (Ti) surface to realize their antibacterial property. This study investigated both the durability of the antibacterial effect and the surface change of the Ag- and Cu-incorporated porous titanium dioxide (TiO₂ [...] Read more.

Recently, silver (Ag) and copper (Cu) have been incorporated into a titanium (Ti) surface to realize their antibacterial property. This study investigated both the durability of the antibacterial effect and the surface change of the Ag- and Cu-incorporated porous titanium dioxide (TiO₂) layer. Ag- and Cu-incorporated TiO₂ layers were formed by micro-arc oxidation (MAO) treatment using the electrolyte with Ag and Cu ions. Ag- and Cu-incorporated specimens were incubated in saline during a period of 0–28 days. The changes in both the concentrations and chemical states of the Ag and Cu were characterized using X-ray photoelectron spectroscopy (XPS). The durability of the antibacterial effects against Escherichia coli (E. coli) were evaluated by the international organization for standardization (ISO) method. As a result, the Ag- and Cu-incorporated porous TiO₂ layers were formed on a Ti surface by MAO. The chemical state of Ag changed from Ag₂O to metallic Ag, whilst that of Cu did not change by incubation in saline for up to 28 days. Cu existed as a stable Cu₂O compound in the TiO₂ layer during the 28 days of incubation in saline. The concentrations of Ag and Cu were dramatically decreased by incubation for up to 7 days, and remained a slight amount until 28 days. The antibacterial effect of Ag-incorporated specimens diminished, and that of Cu was maintained even after incubation in saline. Our study suggests the importance of the time-transient effects of Ag and Cu on develop their antibacterial effects. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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9 pages, 1966 KiB

Open AccessEditor’s ChoiceArticle

Novel Coatings to Minimize Bacterial Adhesion and Promote Osteoblast Activity for Titanium Implants

by Samira E. A. Camargo, Tanaya Roy, Patrick H. Carey IV, Chaker Fares, Fan Ren, Arthur E. Clark and Josephine F. Esquivel-Upshaw

J. Funct. Biomater. 2020, 11(2), 42; https://doi.org/10.3390/jfb11020042 - 16 Jun 2020

Cited by 22 | Viewed by 4910

Abstract

Titanium nitride (TiN) and silicon carbide (SiC) adhesion properties to biofilm and the proliferation of human osteoblasts were studied. Quaternized titanium nitride (QTiN) was produced by converting the surface nitrogen on TiN to a positive charge through a quaternization process to further improve [...] Read more.

Titanium nitride (TiN) and silicon carbide (SiC) adhesion properties to biofilm and the proliferation of human osteoblasts were studied. Quaternized titanium nitride (QTiN) was produced by converting the surface nitrogen on TiN to a positive charge through a quaternization process to further improve the antibacterial efficiency. The SiC required a nitridation within the plasma chamber of the surface layer before quaternization could be carried out to produce quaternized SiC (QSiC). The antimicrobial activity was evaluated on the reference strains of Porphyromonas gingivalis for 4 h by fluorescence microscopy using a live/dead viability kit. All the coatings exhibited a lower biofilm coverage compared to the uncoated samples (Ti—85.2%; TiN—24.22%; QTiN—11.4%; SiC—9.1%; QSiC—9.74%). Scanning Electron Microscope (SEM) images confirmed the reduction in P. gingivalis bacteria on the SiC and TiN-coated groups. After 24 h of osteoblast cultivation on the samples, the cell adhesion was observed on all the coated and uncoated groups. Fluorescence images demonstrated that the osteoblast cells adhered and proliferated on the surfaces. TiN and SiC coatings can inhibit the attachment of Porphyromonas gingivalis and promote osteoblast adhesion on the titanium used for implants. These coatings may possess the ability to prevent the development of peri-implantitis and stimulate osteointegration. Full article

(This article belongs to the Special Issue Advanced Functional Biomaterials for Dental Implants)

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20 pages, 14494 KiB

Open AccessEditor’s ChoiceArticle

Skin-Compatible Biobased Beauty Masks Prepared by Extrusion

by Maria-Beatrice Coltelli, Luca Panariello, Pierfrancesco Morganti, Serena Danti, Adone Baroni, Andrea Lazzeri, Alessandra Fusco and Giovanna Donnarumma

J. Funct. Biomater. 2020, 11(2), 23; https://doi.org/10.3390/jfb11020023 - 6 Apr 2020

Cited by 30 | Viewed by 7179

Abstract

In the cosmetic sector, natural and sustainable products with a high compatibility with skin, thus conjugating wellness with a green-oriented consumerism, are required by the market. Poly(hydroxyalkanoate) (PHA)/starch blends represent a promising alternative to prepare flexible films as support for innovative beauty masks, [...] Read more.

In the cosmetic sector, natural and sustainable products with a high compatibility with skin, thus conjugating wellness with a green-oriented consumerism, are required by the market. Poly(hydroxyalkanoate) (PHA)/starch blends represent a promising alternative to prepare flexible films as support for innovative beauty masks, wearable after wetting and releasing starch and other selected molecules. Nevertheless, preparing these films by extrusion is difficult due to the high viscosity of the polymer melt at the temperature suitable for processing starch. The preparation of blends including poly(butylene succinate-co-adipate) (PBSA) or poly(butylene adipate-co-terephthalate) (PBAT) was investigated as a strategy to better modulate melt viscosity in view of a possible industrial production of beauty mask films. The release properties of films in water, connected to their morphology, was also investigated by extraction trials, infrared spectroscopy and stereo and electron microscopy. Then, the biocompatibility with cells was assessed by considering both mesenchymal stromal cells and keratinocytes. All the results were discussed considering the morphology of the films. This study evidenced the possibility of modulating thanks to the selection of composition and the materials processing of the properties necessary for producing films with tailored properties and processability for beauty masks. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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23 pages, 2742 KiB

Open AccessEditor’s ChoiceArticle

Properties and Skin Compatibility of Films Based on Poly(Lactic Acid) (PLA) Bionanocomposites Incorporating Chitin Nanofibrils (CN)

by Maria-Beatrice Coltelli, Laura Aliotta, Alessandro Vannozzi, Pierfrancesco Morganti, Luca Panariello, Serena Danti, Simona Neri, Cristina Fernandez-Avila, Alessandra Fusco, Giovanna Donnarumma and Andrea Lazzeri

J. Funct. Biomater. 2020, 11(2), 21; https://doi.org/10.3390/jfb11020021 - 1 Apr 2020

Cited by 40 | Viewed by 7109

Abstract

Nanobiocomposites suitable for preparing skin compatible films by flat die extrusion were prepared by using plasticized poly(lactic acid) (PLA), poly(butylene succinate-co-adipate) (PBSA), and Chitin nanofibrils as functional filler. Chitin nanofibrils (CNs) were dispersed in the blends thanks to the preparation of pre-nanocomposites containing [...] Read more.

Nanobiocomposites suitable for preparing skin compatible films by flat die extrusion were prepared by using plasticized poly(lactic acid) (PLA), poly(butylene succinate-co-adipate) (PBSA), and Chitin nanofibrils as functional filler. Chitin nanofibrils (CNs) were dispersed in the blends thanks to the preparation of pre-nanocomposites containing poly(ethylene glycol). Thanks to the use of a melt strength enhancer (Plastistrength) and calcium carbonate, the processability and thermal properties of bionanocomposites films containing CNs could be tuned in a wide range. Moreover, the resultant films were flexible and highly resistant. The addition of CNs in the presence of starch proved not advantageous because of an extensive chain scission resulting in low values of melt viscosity. The films containing CNs or CNs and calcium carbonate resulted biocompatible and enabled the production of cells defensins, acting as indirect anti-microbial. Nevertheless, tests made with Staphylococcus aureus and Enterobacter spp. (Gram positive and negative respectively) by the qualitative agar diffusion test did not show any direct anti-microbial activity of the films. The results are explained considering the morphology of the film and the different mechanisms of direct and indirect anti-microbial action generated by the nanobiocomposite based films. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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17 pages, 1861 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Pullulan for Advanced Sustainable Body- and Skin-Contact Applications

by Maria-Beatrice Coltelli, Serena Danti, Karen De Clerck, Andrea Lazzeri and Pierfrancesco Morganti

J. Funct. Biomater. 2020, 11(1), 20; https://doi.org/10.3390/jfb11010020 - 18 Mar 2020

Cited by 77 | Viewed by 12666

Abstract

The present review had the aim of describing the methodologies of synthesis and properties of biobased pullulan, a microbial polysaccharide investigated in the last decade because of its interesting potentialities in several applications. After describing the implications of pullulan in nano-technology, biodegradation, compatibility [...] Read more.

The present review had the aim of describing the methodologies of synthesis and properties of biobased pullulan, a microbial polysaccharide investigated in the last decade because of its interesting potentialities in several applications. After describing the implications of pullulan in nano-technology, biodegradation, compatibility with body and skin, and sustainability, the current applications of pullulan are described, with the aim of assessing the potentialities of this biopolymer in the biomedical, personal care, and cosmetic sector, especially in applications in contact with skin. Full article

(This article belongs to the Special Issue High Performance Functional Bio-based Polymers for Skin-contact Products)

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26 pages, 3387 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Fabrication of Polymeric Microparticles by Electrospray: The Impact of Experimental Parameters

by Alan Í. S. Morais, Ewerton G. Vieira, Samson Afewerki, Ricardo B. Sousa, Luzia M. C. Honorio, Anallyne N. C. O. Cambrussi, Jailson A. Santos, Roosevelt D. S. Bezerra, Josy A. O. Furtini, Edson C. Silva-Filho, Thomas J. Webster and Anderson O. Lobo

J. Funct. Biomater. 2020, 11(1), 4; https://doi.org/10.3390/jfb11010004 - 15 Jan 2020

Cited by 97 | Viewed by 10877

Abstract

Microparticles (MPs) with controlled morphologies and sizes have been investigated by several researchers due to their importance in pharmaceutical, ceramic, cosmetic, and food industries to just name a few. In particular, the electrospray (ES) technique has been shown to be a viable alternative [...] Read more.

Microparticles (MPs) with controlled morphologies and sizes have been investigated by several researchers due to their importance in pharmaceutical, ceramic, cosmetic, and food industries to just name a few. In particular, the electrospray (ES) technique has been shown to be a viable alternative for the development of single particles with different dimensions, multiple layers, and varied morphologies. In order to adjust these properties, it is necessary to optimize different experimental parameters, such as polymer solvent, voltage, flow rate (FR), type of collectors, and distance between the collector and needle tip, which will all be highlighted in this review. Moreover, the influence and contributions of each of these parameters on the design and fabrication of polymeric MPs are described. In addition, the most common configurations of ES systems for this purpose are discussed, for instance, the main configuration of an ES system with monoaxial, coaxial, triaxial, and multi-capillary delivery. Finally, the main types of collectors employed, types of synthesized MPs and their applications specifically in the pharmaceutical and biomedical fields will be emphasized. To date, ES is a promising and versatile technology with numerous excellent applications in the pharmaceutical and biomaterials field and such MPs generated should be employed for the improved treatment of cancer, healing of bone, and other persistent medical problems. Full article

(This article belongs to the Section Biomaterials for Tissue Engineering and Regenerative Medicine)

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35 pages, 1622 KiB

Open AccessEditor’s ChoiceArticle

An Insight into Advanced Approaches for Photosensitizer Optimization in Endodontics—A Critical Review

by Patrícia Diogo, M. Amparo F. Faustino, M. Graça P. M. S. Neves, Paulo J. Palma, Isabel P. Baptista, Teresa Gonçalves and João Miguel Santos

J. Funct. Biomater. 2019, 10(4), 44; https://doi.org/10.3390/jfb10040044 - 30 Sep 2019

Cited by 38 | Viewed by 10021

Abstract

Apical periodontitis is a biofilm-mediated disease; therefore, an antimicrobial approach is essential to cure or prevent its development. In the quest for efficient strategies to achieve this objective, antimicrobial photodynamic therapy (aPDT) has emerged as an alternative to classical endodontic irrigation solutions and [...] Read more.

Apical periodontitis is a biofilm-mediated disease; therefore, an antimicrobial approach is essential to cure or prevent its development. In the quest for efficient strategies to achieve this objective, antimicrobial photodynamic therapy (aPDT) has emerged as an alternative to classical endodontic irrigation solutions and antibiotics. The aim of the present critical review is to summarize the available evidence on photosensitizers (PSs) which has been confirmed in numerous studies from diverse areas combined with several antimicrobial strategies, as well as emerging options in order to optimize their properties and effects that might be translational and useful in the near future in basic endodontic research. Published data notably support the need for continuing the search for an ideal endodontic photosensitizer, that is, one which acts as an excellent antimicrobial agent without causing toxicity to the human host cells or presenting the risk of tooth discoloration. The current literature on experimental studies mainly relies on assessment of mixed disinfection protocols, combining approaches which are already available with aPDT as an adjunct therapy. In this review, several approaches concerning aPDT efficiency are appraised, such as the use of bacteriophages, biopolymers, drug and light delivery systems, efflux pump inhibitors, negative pressure systems, and peptides. The authors also analyzed their combination with other approaches for aPDT improvement, such as sonodynamic therapy. All of the aforementioned techniques have already been tested, and we highlight the biological challenges of each formulation, predicting that the collected information may encourage the development of other effective photoactive materials, in addition to being useful in endodontic basic research. Moreover, special attention is dedicated to studies on detailed conditions, aPDT features with a focus on PS enhancer strategies, and the respective final antimicrobial outcomes. From all the mentioned approaches, the two which are most widely discussed and which show the most promising outcomes for endodontic purposes are drug delivery systems (with strong development in nanoparticles) and PS solubilizers. Full article

(This article belongs to the Special Issue Endodontic Biomaterials)

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20 pages, 1901 KiB

Open AccessEditor’s ChoiceReview

Stimuli-Responsive Drug Release from Smart Polymers

by Carlos M. Wells, Michael Harris, Landon Choi, Vishnu Priya Murali, Fernanda Delbuque Guerra and J. Amber Jennings

J. Funct. Biomater. 2019, 10(3), 34; https://doi.org/10.3390/jfb10030034 - 31 Jul 2019

Cited by 239 | Viewed by 14496

Abstract

Over the past 10 years, stimuli-responsive polymeric biomaterials have emerged as effective systems for the delivery of therapeutics. Persistent with ongoing efforts to minimize adverse effects, stimuli-responsive biomaterials are designed to release in response to either chemical, physical, or biological triggers. The stimuli-responsiveness [...] Read more.

Over the past 10 years, stimuli-responsive polymeric biomaterials have emerged as effective systems for the delivery of therapeutics. Persistent with ongoing efforts to minimize adverse effects, stimuli-responsive biomaterials are designed to release in response to either chemical, physical, or biological triggers. The stimuli-responsiveness of smart biomaterials may improve spatiotemporal specificity of release. The material design may be used to tailor smart polymers to release a drug when particular stimuli are present. Smart biomaterials may use internal or external stimuli as triggering mechanisms. Internal stimuli-responsive smart biomaterials include those that respond to specific enzymes or changes in microenvironment pH; external stimuli can consist of electromagnetic, light, or acoustic energy; with some smart biomaterials responding to multiple stimuli. This review looks at current and evolving stimuli-responsive polymeric biomaterials in their proposed applications. Full article

(This article belongs to the Special Issue Smart Biomaterials)

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15 pages, 849 KiB

Open AccessEditor’s ChoiceReview

The Role of In Vitro Immune Response Assessment for Biomaterials

by Alistair Lock, Jillian Cornish and David S. Musson

J. Funct. Biomater. 2019, 10(3), 31; https://doi.org/10.3390/jfb10030031 - 12 Jul 2019

Cited by 56 | Viewed by 8478

Abstract

Grafts are required to restore tissue integrity and function. However, current gold standard autografting techniques yield limited harvest, with high rates of complication. In the search for viable substitutes, the number of biomaterials being developed and studied has increased rapidly. To date, low [...] Read more.

Grafts are required to restore tissue integrity and function. However, current gold standard autografting techniques yield limited harvest, with high rates of complication. In the search for viable substitutes, the number of biomaterials being developed and studied has increased rapidly. To date, low clinical uptake has accompanied inherently high failure rates, with immune rejection a specific and common end result. The objective of this review article was to evaluate published immune assays evaluating biomaterials, and to stress the value that incorporating immune assessment into evaluations carries. Immunogenicity assays have had three areas of focus: cell viability, maturation and activation, with the latter being the focus in the majority of the literature due to its relevance to functional outcomes. With recent studies suggesting poor correlation between current in vitro and in vivo testing of biomaterials, in vitro immune response assays may be more relevant and enhance ability in predicting acceptance prior to in vivo application. Uptake of in vitro immune response assessment will allow for substantial reductions in experimental time and resources, including unnecessary and unethical animal use, with a simultaneous decrease in inappropriate biomaterials reaching clinic. This improvement in bench to bedside safety is paramount to reduce patient harm. Full article

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13 pages, 3952 KiB

Open AccessEditor’s ChoiceArticle

Development of Highly pH-Sensitive Hybrid Membranes by Simultaneous Electrospinning of Amphiphilic Nanofibers Reinforced with Graphene Oxide

by Mohsen Gorji, Ali Sadeghianmaryan, Hossein Rajabinejad, Saman Nasherolahkam and Xiongbiao Chen

J. Funct. Biomater. 2019, 10(2), 23; https://doi.org/10.3390/jfb10020023 - 21 May 2019

Cited by 26 | Viewed by 7507

Abstract

Nanofibrous-based pH sensors have shown promise in a wide range of industrial and medical applications due to their fast response time and good mechanical properties. In the present study, we fabricated pH-sensitive sensors of nanofibrous membranes by electrospinning polyurethane (PU)/poly 2-acrylamido-2-methylpropanesulfonic acid (PAMPS)/graphene [...] Read more.

Nanofibrous-based pH sensors have shown promise in a wide range of industrial and medical applications due to their fast response time and good mechanical properties. In the present study, we fabricated pH-sensitive sensors of nanofibrous membranes by electrospinning polyurethane (PU)/poly 2-acrylamido-2-methylpropanesulfonic acid (PAMPS)/graphene oxide (GO) with indicator dyes. The morphology of the electrospun nanofibers was examined using scanning electron microscopy (SEM). The effect of hydrophilic polymer ratio and concentration of GO on the sensing response time was investigated. The sensitivity of the membranes was studied over a wide pH range (1–8) in solution tests, with color change measured by calculating total color difference using UV-vis spectroscopy. The membranes were also subjected to vapor tests at three different pH values (1, 4, 8). SEM results show the successful fabrication of bimodal fiber diameter distributions of PU (mean fiber diameter 519 nm) and PAMPS (mean fiber diameter 78 nm). Sensing response time decreased dramatically with increasing concentrations of PAMPS and GO. The hybrid hydrophobic/hydrophilic/GO nanofibrous membranes are capable of instantly responding to changes in solution pH as well as detecting pH changes in chemical vapor solution in as little as 7 s. Full article

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14 pages, 3366 KiB

Open AccessEditor’s ChoiceArticle

Fabrication of Porous Bone Scaffolds Using Alginate and Bioactive Glass

by Jonathan Hatton, Graham Roy Davis, Abdel-Hamid I. Mourad, Nizamudeen Cherupurakal, Robert G. Hill and Sahar Mohsin

J. Funct. Biomater. 2019, 10(1), 15; https://doi.org/10.3390/jfb10010015 - 4 Mar 2019

Cited by 40 | Viewed by 9093

Abstract

Porous composite scaffold using an alginate and bioactive glass ICIE16M was synthesized by a simple freeze-drying technique. The scaffold was characterized using compression testing, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), X-ray microtomography (XMT) and scanning electron microscopy (SEM). [...] Read more.

Porous composite scaffold using an alginate and bioactive glass ICIE16M was synthesized by a simple freeze-drying technique. The scaffold was characterized using compression testing, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), X-ray microtomography (XMT) and scanning electron microscopy (SEM). The bioactivity of the scaffold was evaluated by its ability to form apatite on its surface in simulated body fluid (SBF). The data collected showed evidence that the novel material produced had an appropriate pore size for osteoconduction, with an average pore size of 110 µm and maximum pore size of 309 µm. Statistical analysis confirmed that the glass filler significantly (P < 0.05) increased the collapse yield of the scaffolds compared with pure alginate scaffolds. The ICIE16M glass had an amorphous structure, favorable for bioactivity. Full article

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21 pages, 3108 KiB

Open AccessEditor’s ChoiceArticle

Towards the Development of Artificial Bone Grafts: Combining Synthetic Biomineralisation with 3D Printing

by Mima Kurian, Ross Stevens and Kathryn M McGrath

J. Funct. Biomater. 2019, 10(1), 12; https://doi.org/10.3390/jfb10010012 - 20 Feb 2019

Cited by 19 | Viewed by 8373

Abstract

A synthetic technique inspired by the biomineralisation process in nacre has been previously reported to be effective in replicating the nanostructural elements of nacre in 2D chitosan hydrogel films. Here we evaluate the applicability of this synthetic biomineralisation technique, herein called the McGrath [...] Read more.

A synthetic technique inspired by the biomineralisation process in nacre has been previously reported to be effective in replicating the nanostructural elements of nacre in 2D chitosan hydrogel films. Here we evaluate the applicability of this synthetic biomineralisation technique, herein called the McGrath method, in replicating the flat tabular morphology of calcium carbonate and other nanostructural elements obtained when 2D chitosan hydrogel films were used, on a 3D porous chitosan hydrogel-based scaffold, hence developing 3D chitosan-calcium carbonate composites. Nozzle extrusion-based 3D printing technology was used to develop 3D porous scaffolds using chitosan hydrogel as the printing ink in a custom-designed 3D printer. The rheology of the printing ink and print parameters were optimised in order to fabricate 3D cylindrical structures with a cubic lattice-based internal structure. The effects of various dehydration techniques, including air-drying, critical point-drying and freeze-drying, on the structural integrity of the as-printed scaffolds from the nano to macroscale, were evaluated. The final 3D composite materials were characterised using scanning electron microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy. The study has shown that McGrath method can be used to develop chitosan-calcium carbonate composites wherein the mineral and matrix are in intimate association with each other at the nanoscale. This process can be successfully integrated with 3D printing technology to develop 3D compartmentalised polymer-mineral composites. Full article

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7 pages, 228 KiB

Open AccessFeature PaperEditor’s ChoiceReview

4D Printing: The Shape-Morphing in Additive Manufacturing

by Ana P. Piedade

J. Funct. Biomater. 2019, 10(1), 9; https://doi.org/10.3390/jfb10010009 - 22 Jan 2019

Cited by 55 | Viewed by 10258

Abstract

3D printing of polymers can now be considered as a common processing technology for the development of biomaterials. These can be constituted out of polymeric abiotic material alone or can be co-printed with living cells. However, the adaptive and shape-morphing characteristics cannot be [...] Read more.

3D printing of polymers can now be considered as a common processing technology for the development of biomaterials. These can be constituted out of polymeric abiotic material alone or can be co-printed with living cells. However, the adaptive and shape-morphing characteristics cannot be developed with the rigid, pre-determined structures obtained by 3D printing. In order to produce functional engineered biomaterials, the dynamic properties/characteristics of the living cells must be attained. 4D printing can be envisaged as a route to achieve these goals. This paper intends to give a brief review of the pioneer 4D printing research that has been developed and to present an insight into future research in this field. Full article

(This article belongs to the Special Issue Four-dimensional Biofabrication: Stimuli-responsive Mechanisms for Tissue Engineering)

15 pages, 714 KiB

Open AccessEditor’s ChoiceReview

Biocompatible Polymer Nanoparticles for Drug Delivery Applications in Cancer and Neurodegenerative Disorder Therapies

by Eleonora Calzoni, Alessio Cesaretti, Alice Polchi, Alessandro Di Michele, Brunella Tancini and Carla Emiliani

J. Funct. Biomater. 2019, 10(1), 4; https://doi.org/10.3390/jfb10010004 - 8 Jan 2019

Cited by 373 | Viewed by 17318

Abstract

Polymer nanoparticles (NPs) represent one of the most innovative non-invasive approaches for drug delivery applications. NPs main objective is to convey the therapeutic molecule be they drugs, proteins, or nucleic acids directly into the target organ or tissue. Many polymers are used for [...] Read more.

Polymer nanoparticles (NPs) represent one of the most innovative non-invasive approaches for drug delivery applications. NPs main objective is to convey the therapeutic molecule be they drugs, proteins, or nucleic acids directly into the target organ or tissue. Many polymers are used for the synthesis of NPs and among the currently most employed materials several biocompatible synthetic polymers, namely polylactic acid (PLA), poly lactic-co-glycolic acid (PLGA), and polyethylene glycol (PEG), can be cited. These molecules are made of simple monomers which are naturally present in the body and therefore easily excreted without being toxic. The present review addresses the different approaches that are most commonly adopted to synthetize biocompatible NPs to date, as well as the experimental strategies designed to load them with therapeutic agents. In fact, drugs may be internalized in the NPs or physically dispersed therein. In this paper the various types of biodegradable polymer NPs will be discussed with emphasis on their applications in drug delivery. Close attention will be devoted to the treatment of cancer, where both active and passive targeting is used to enhance efficacy and reduce systemic toxicity, and to diseases affecting the central nervous system, inasmuch as NPs can be modified to target specific cells or cross membrane barriers. Full article

(This article belongs to the Special Issue Advanced Functional Nanobiomaterials)

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36 pages, 4388 KiB

Open AccessEditor’s ChoiceReview

Biomaterials, Current Strategies, and Novel Nano-Technological Approaches for Periodontal Regeneration

by Giorgio Iviglia, Saeid Kargozar and Francesco Baino

J. Funct. Biomater. 2019, 10(1), 3; https://doi.org/10.3390/jfb10010003 - 2 Jan 2019

Cited by 151 | Viewed by 15410

Abstract

Periodontal diseases involve injuries to the supporting structures of the tooth and, if left untreated, can lead to the loss of the tooth. Regenerative periodontal therapies aim, ideally, at healing all the damaged periodontal tissues and represent a significant clinical and societal challenge [...] Read more.

Periodontal diseases involve injuries to the supporting structures of the tooth and, if left untreated, can lead to the loss of the tooth. Regenerative periodontal therapies aim, ideally, at healing all the damaged periodontal tissues and represent a significant clinical and societal challenge for the current ageing population. This review provides a picture of the currently-used biomaterials for periodontal regeneration, including natural and synthetic polymers, bioceramics (e.g., calcium phosphates and bioactive glasses), and composites. Bioactive materials aim at promoting the regeneration of new healthy tissue. Polymers are often used as barrier materials in guided tissue regeneration strategies and are suitable both to exclude epithelial down-growth and to allow periodontal ligament and alveolar bone cells to repopulate the defect. The problems related to the barrier postoperative collapse can be solved by using a combination of polymeric membranes and grafting materials. Advantages and drawbacks associated with the incorporation of growth factors and nanomaterials in periodontal scaffolds are also discussed, along with the development of multifunctional and multilayer implants. Tissue-engineering strategies based on functionally-graded scaffolds are expected to play an ever-increasing role in the management of periodontal defects. Full article

(This article belongs to the Special Issue Advanced Functional Nanobiomaterials)

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