Materials For Wound Healing Applications Research Articles

Fabrication of pH-stimuli hydrogel as bioactive materials for wound healing applications

Hydrogels exhibit exceptional suitability as wound dressing due to their remarkable three-dimensional (3D) characteristics. Here, we have reported the fabrication of hydrogels from biopolymers carboxymethyl cellulose (CMC), polyvinyl alcohol (PVA), and gelatin via a simple blending method to mimic the natural extracellular matrix. Scanning electron microscopy (SEM), water contact meters (WCM), and Fourier-transform infrared spectroscopy (FTIR) were used to evaluate the chemical structural, morphological, and wettability behavior. The wetting and degradation behavior were also found to be different for different formulations (Min. (51.60o) and Max. (113.60o)) and (Min. (38.82 mg) and Max. (3.72 mg)), respectively. Swelling was investigated in different media, including phosphate buffer saline solution (PBS) and aqueous media. It was observed that the hydrogel displayed the highest degree of swelling in an aqueous medium (Min. (597.32–1121.49 %) and Max. (1089.51–2139.73 %)) compared to PBS media (Min. (567.01–1021.85 %) and Max. (899.13–1639.17 %)). The release of Neomycin was studied in a PBS medium via the Franz diffusion method at 37 °C. The maximal release in various media demonstrated pH-responsive behavior. The viability and proliferation of fibroblast (3T3) cell lines were examined in vitro to evaluate cytocompatibility. Human Embryonic Kidney (HEK) 293 cells were used to evaluate the hydrogels' ability to promote vascularization and angiogenesis. Therefore, the data demonstrate that hydrogels that have been manufactured have qualities that make them promising for use as wound dressings in wound healing applications.

Characterization of polyvinyl alcohol and vitex negundo blended bio nanofilm for wound healing scaffold

Polyvinyl alcohol blended nanofilms have shown great promise as a material for wound healing applications because of their biocompatibility, biodegradability, and antibacterial characteristics. This article has typically utilized electrospinning to create a scaffold for wound healing meanwhile investigating the characteristics of the polyvinyl alcohol (PVA) and vitex negundo (VN) blend nanofilm. The PVA concentrations were kept at 10% Weight/Volume (W/V), which was then mixed with VN solution at various volumetric ratios and electrospun into nanofilms. Field Emission Scanning Electron Microscopy (FESEM) was used to determine and analyze the nanofiber diameter. The plant extract concentration and the viscosity of the electrospinning solution influenced the fiber diameter to grow from 120.32 nanometers (nm) to 171.11 nanometers (nm). Fourier Transform Infrared Spectroscopy (FTIR) verifies the interaction between plant extract and PVA and records a new peak between 1731 and 1750 cm−1, which represents the production of the ester group. The swellability of the developed sample was studied which is negligibly reduced when the plant extract was added. In comparison to both Gram-positive and Gram-negative bacteria, the pure plant extract and composite nanofibrous web demonstrated greater antibacterial activity. PVA-blended nanofilms can promote cell migration, proliferation, and differentiation, hence promoting wound healing by creating a moist environment.

In situ fabricated ZnO nanostructures within carboxymethyl cellulose-based ternary hydrogels for wound healing applications

Zinc oxide nanostructures (ZnO NS) were fabricated in situ within a ternary hydrogel system composed of carboxymethyl cellulose-agarose-polyvinylpyrrolidone (CAP@ZnO TNCHs) by a one-pot method employing moist-heat solution casting. The percentages of CMC and ZnO NS were varied in the CAP hydrogel films and then they were investigated by different techniques, such as ATR/FTIR, TGA, XRD, XPS, and FE-SEM analysis. Furthermore, the mechanical properties, hydrophilicity, swelling, porosity, and antibacterial activity of the CAP@ZnO TNCHs were studied. In-vitro biocompatibility assays were performed with skin fibroblast (CCD-986sk) cells. In-vitro culture of CCD-986sk fibroblasts showed that the ZnO NS facilitated cell adhesion and proliferation. Furthermore, the application of CAP@ZnO TNCHs enhanced cellular interactions and physico-chemical, antibacterial bacterial, and biological performance relative to unmodified CAP hydrogels. Also, an in vivo wound healing study verified that the CAP@ZnO TNCHs promoted wound healing significantly within 18 days, an effect superior to that of unmodified CAP hydrogels. Hence, these newly developed cellulose-based ZnO TNCHs are promising materials for wound healing applications.

Natural Polymer‐Based Materials for Wound Healing Applications

Skin injuries pose significant health challenges, with conditions like burns and diabetic, venous, and pressure ulcers presenting complex wound management scenarios. Effective wound care strategies for these injuries encompass a range of interventions, from simple wound dressings to bioactive materials and surgical procedures involving skin substitutes and skin grafting. This review explores the potential of natural polymers, including silk, collagen, gelatin, elastin, cellulose, chitosan, alginate, and hyaluronic acid, in wound management. Natural polymers offer several advantages, including abundance, biodegradability, and compatibility with traditional and modern material fabrication techniques, and have demonstrated safety and efficacy in clinical applications, modulating various facets of the wound healing process. Highlighting preclinical and clinical studies, along with commercial products, this review showcases the versatility and utility of natural polymers in wound management and provides insights into emerging developments, such as 3D bioprinting and stimuli‐responsive materials, which hold promise for personalized wound treatments. Additionally, we discuss the importance of the material format and morphology in engineering the next generation of wound dressings and skin substitutes, offering a pathway to optimize natural polymers for enhanced wound healing outcomes.

PEDOT:PSS based electrospun nanofibres used as trigger for fibroblasts differentiation

Electrospun nanofibres based on poly(styrene sulfonate) doped poly(3,4-ethylenedioxythiophene) (PEDOT:PSS) were fabricated using a straightforward procedure which combines electrospinning, sputtering deposition and electrochemical synthesis. In general, electrospun fibre meshes based on conducting polymers are prepared by mixing the conducting polymer with a carrier polymer or chemically coverage of the fibres. In contrast, freestanding nylon 6/6 nanofibre webs were prepared through electrospinning and were coated by sputtering with gold in order to make them conductive. Further, a PEDOT:PSS layer was electrochemically deposited onto the metalized nanofibre meshes and the synthesis parameters were chosen in such a way to preserve the high active area of the fibres. The prepared material was morphologically characterized and the formation of PEDOT:PSS was also demonstrated. The PEDOT:PSS coated nanofibres revealed remarkable electrical properties (sheet resistance of about 3.5 Ω cm−2), similar to those of metalized nanofibres (sheet resistance around 3 Ω cm2). The in vitro studies using L929 fibroblast mouse cells showed that the bioactive material has no cytotoxic effect and allows proliferation. Moreover, after 72 h of incubation, the fibroblasts shrunk their nuclei and spread suggesting that a differentiation in myofibroblast occurs without application of any kind of external stimuli. These results will be helpful for developing efficient materials for wound healing applications that work without energy consumption.

In vitro and in vivo evaluation of alginate hydrogel-based wound dressing loaded with green chemistry cerium oxide nanoparticles.

Interactive wound dressings have displayed promising outcomes in enhancing the wound healing process. This study focuses on creating a nanocomposite wound dressing with interactive and bioactive properties, showcasing potent antioxidant effects. To achieve this, we developed cerium oxide nanoparticles utilizing curcumin as both the reducing and capping agent. Characterization techniques such as SEM, EDX, DLS, Zetasizer, FTIR, and XRD were utilized to analyze the cerium oxide nanoparticles synthesized through a green approach. The image analysis on the obtained TEM images showed that the curcumin-assisted biosynthesized CeO2NPs have a size of 18.8 ± 4.1nm. The peaks located at 28.1, 32.7, 47.1, 56.0, 58.7, 69.0, and 76.4 correspond to (111), (200), (220), (311), (222), (400), and (331) crystallographic planes. We applied the Debye-Scherrer equation and observed that the approximate crystallite size of the biosynthesized NPs is around 8.2nm based on the most intensive broad Bragg peak at 28.1°. The cerium oxide nanoparticles synthesized were integrated into an alginate hydrogel matrix, and the microstructure, porosity, and swelling behavior of the resulting wound dressing were assessed. The characterization analyses provided insights into the physical and chemical properties of the green-synthesized cerium oxide nanoparticles and the alginate hydrogel-based wound dressing. In vitro studies demonstrated that the wound dressing based on alginate hydrogel exhibited favorable antioxidant properties and displayed hemocompatibility and biocompatibility. Animal studies conducted on a rat full-thickness skin wound model showed that the alginate hydrogel-based wound dressing effectively accelerated the wound healing process. Overall, these findings suggest that the alginate hydrogel-based wound dressing holds promise as a highly effective material for wound healing applications.

Exploring the bioactivity of reduced graphene oxide and TiO2 nanocomposite for the regenerative medicinal applications

Millions of people globally suffer from issues related to chronic wounds due to infection, burn, obesity, and diabetes. Nanocomposite with antibacterial and anti-inflammatory properties is a promising material to promote wound healing. This investigation primarily aims to synthesize reduced graphene oxide and titanium dioxide (rGO@TiO2) nanocomposite for wound healing applications. The rGO@TiO2 nanocomposite was synthesized by the one-step hydrothermal technique, and the physicochemical characterization of synthesized nanocomposite was performed by X-ray diffraction, Fourier transforms infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy, and dynamic light scattering. Further, the nanocomposite antibacterial, cytotoxicity, and wound-healing properties were analyzed by disc diffusion method, MTT assay, and in vitro scratch assay, respectively. Based on the TEM images, the average particle size of TiO2 nanoparticles was around 9.26 ± 1.83 nm. The characteristics peak of Ti–O–Ti bonds was observed between 500 and 850 cm−1 in the Fourier transforms infrared spectrum. The Raman spectrum of graphene oxide (GO) was obtained for bands D and G at 1354 cm−1 and at 1593 cm−1, respectively. This GO peak intensity was reduced in rGO, revealing the oxygen functional group reduction. Moreover, the rGO@TiO2 nanocomposite exhibited dose-dependent antibacterial properties against the positive and negative bacterium. The cytotoxicity for 5–100 µg/mL of rGO@TiO2 nanocomposite was above the half-maximal inhibitory concentration value. The in vitro scratch assay for rGO@TiO2 indicates that the nanocomposite promotes cell proliferation and migration. The nanocomposite recovered the wound within 48 h. The rGO@TiO2 nanocomposite shows potential materials for wound healing applications.

Multifunctional Gold-Silver-Carbon Quantum Dots Nano-Hybrid Composite: Advancing Antibacterial Wound Healing and Cell Proliferation.

The urgent need for innovative materials that effectively eliminate bacteria while promoting cell growth to accelerate wound healing has led to the exploration of new options, as current antimicrobial nanoparticles often exhibit high cytotoxicity, which hinders wound closure. In this study, a nano-hybrid composite, named gold-silver-carbon quantum dots (AuAg-CDs), was prepared by embedding gold and silver nanoclusters into carbon dots. The AuAg-CDs nano-hybrid composite demonstrates remarkable biocompatibility, displays potent antibacterial activity, and possesses a unique capability to promote cell proliferation. By physically disrupting bacterial membranes and promoting mammalian cell proliferation, this composite emerges as a highly promising material for wound healing applications. The underlying mechanism of the multifunctional AuAg-CDs was investigated through comprehensive analyses encompassing cell morphology, bacterial membrane potential, levels of reactive oxygen species (ROS), and adenosine triphosphate (ATP) production in both bacterial and mammalian cells. Additionally, AuAg-CDs were incorporated into alginate to create a hydrogel wound dressing, which underwent evaluation using animal models. The results underscore the remarkable potential of the AuAg-CDs wound dressing in facilitating the proliferation of wound fibroblasts and combating bacterial infections. The significance of designing multifunctional nanomaterials to address the challenges associated with pathogenic bacterial infections and regenerative medicine is highlighted by this study, paving the way for future advancements in these fields.

Ascorbic acid-loaded gellan-g-poly(ethylene glycol) methacrylate matrix as a wound-healing material

Ascorbic acid (AA) is one of the important biomolecules involved in all phases of wound healing. The aim of this study was to develop a new hydrogel system that offers topical delivery of ascorbic acid to wounds during wound care management. In this work, we grafted poly (ethylene glycol) methacrylate onto a renewable biopolymer gellan, and the graft copolymer (GPMA) formed was crosslinked covalently and ionically, and used as a matrix for delivering AA to the wounds. By the processes of grafting and crosslinking, the mechanical properties of the gellan increased several fold compared to mechanically weak native gellan. In vitro cytotoxicity evaluation showed that GPMA was non-cytotoxic to fibroblast cells. GPMA hydrogel matrix allowed the sustained release of AA. When AA was incorporated in GPMA, a significant improvement in wound closure was observed in scratch wound assay performed with keratinocytes. Since AA acts as a cofactor in collagen synthesis, the controlled delivery of AA to the wound microenvironment favors the up-regulation of colα1 gene expression. This study revealed that ascorbic acid, at a concentration of 150 μM, has a favorable impact on wound healing when tested in vitro. Overall results indicate that the GPMA matrix could be a promising material for wound healing applications.

A REVIEW ON MECHANICAL PROPERTIES OF CHITOSAN-BASED FOR WOUND DRESSING MATERIALS

An effective wound dressing material should be flexible structure, biocompatible, maintain wound moisture and adsorb exudate. The rate of the wound healing process depends on the type of wound care dressing materials. The chitosan-based dressing has become attention for wound dressing application for decades. This study aims to review the mechanical characterization of chitosan-based material for wound healing applications. In this review, the process of searching research papers was performed according to the PRISMA-P protocol that begins by searching literature on the selected databases such as Science Direct, PubMed, and Google Scholar from the year of 2012 to 2022. The pre-determined keywords (chitosan-based material, physicochemical characterization, wound dressing, wound healing, wound treatment) were used in data searching protocol. The search retrieved 284 articles. Assessment of eligibility retrieved 19 articles based on the inclusion and exclusion criteria. This review provides the knowledge of physicochemical characterization studied on chitosan-based wound dressing material including the porosity, swelling behaviour, water vapour transmission rate and mechanical properties.

Antibacterial and antibiofilm activities of sodium ibuprofen- and paracetamol-loaded nanofibers

Nanofibers loaded with pharmaceutical agents for various medical purposes have become more important in recent years because of their advantages, such as control on release, gas permeability, high surface area, and lightweight matrices. In the present study, polylactic acid (PLA)-gelatin (Gel) nanofibers were successfully loaded with Ibuprofen-Na/Paracetamol (henceforth Ibu-Na and Par, respectively) by electrospinning. The nanofibers were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The Ibu-Na/Par content of the nanofibers was determined by using high-performance liquid chromatography (HPLC). Their antibacterial activities were tested against Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa PA01, opportunistic pathogenic bacteria which are frequently associated with infections. Moreover, their antibiofilm activities against P. aeruginosa and E. faecalis were also investigated. The Ibu-Na-containing nanofibers exhibited antibacterial activity against S. aureus, E. coli, and E. faecalis. The inhibition zone diameters of PLA-Gel-Ibu-Na 300 against E. faecalis, S. aureus, and E. coli were calculated to be 23.0 ± 2.1 mm, 18.0 ± 1.5 mm, and 12.0 ± 1.2 mm, respectively. It was found that PLA-Gel-Ibu-Na 300 and PLA-Gel-Par 300 nanofibers’ capacity to show biofilm formation inhibition originated remarkable effects on P. aeruginosa, which were found to be 48 % and 50.4 %, respectively. This study indicated that Ibu-Na/Par-loaded nanofibers are promising materials for wound healing applications.

Role of Graphene Oxide in Bacterial Cellulose-Gelatin Hydrogels for Wound Dressing Applications.

Biopolymer-based hydrogels have several advantages, including robust mechanical tunability, high biocompatibility, and excellent optical properties. These hydrogels can be ideal wound dressing materials and advantageous to repair and regenerate skin wounds. In this work, we prepared composite hydrogels by blending gelatin and graphene oxide-functionalized bacterial cellulose (GO-f-BC) with tetraethyl orthosilicate (TEOS). The hydrogels were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscope (AFM), and water contact angle analyses to explore functional groups and their interactions, surface morphology, and wetting behavior, respectively. The swelling, biodegradation, and water retention were tested to respond to the biofluid. Maximum swelling was exhibited by GBG-1 (0.01 mg GO amount) in all media (aqueous = 1902.83%, PBS = 1546.63%, and electrolyte = 1367.32%). All hydrogels were hemocompatible, as their hemolysis was less than 0.5%, and blood coagulation time decreased as the hydrogel concentration and GO amount increased under in vitro standard conditions. These hydrogels exhibited unusual antimicrobial activities against Gram-positive and Gram-negative bacterial strains. The cell viability and proliferation were increased with an increased GO amount, and maximum values were found for GBG-4 (0.04 mg GO amount) against fibroblast (3T3) cell lines. The mature and well-adhered cell morphology of 3T3 cells was found for all hydrogel samples. Based on all findings, these hydrogels would be a potential wound dressing skin material for wound healing applications.

Polyphenol Iongel Patches with Antimicrobial, Antioxidant and Anti-Inflammatory Properties.

There is an actual need for developing materials for wound healing applications with anti-inflammatory, antioxidant, or antibacterial properties in order to improve the healing performance. In this work, we report the preparation and characterization of soft and bioactive iongel materials for patches, based on polymeric poly(vinyl alcohol) (PVA) and four ionic liquids containing the cholinium cation and different phenolic acid anions, namely cholinium salicylate ([Ch][Sal]), cholinium gallate ([Ch][Ga]), cholinium vanillate ([Ch][Van]), and cholinium caffeate ([Ch][Caff]). Within the iongels, the phenolic motif in the ionic liquids plays a dual role, acting as a PVA crosslinker and a bioactive compound. The obtained iongels are flexible, elastic, ionic conducting, and thermoreversible materials. Moreover, the iongels demonstrated high biocompatibility, non-hemolytic activity, and non-agglutination in mice blood, which are key-sought material specifications in wound healing applications. All the iongels have shown antibacterial properties, being PVA-[Ch][Sal], the one with higher inhibition halo for Escherichia Coli. The iongels also revealed high values of antioxidant activity due to the presence of the polyphenol, with the PVA-[Ch][Van] iongel having the highest activity. Finally, the iongels show a decrease in NO production in LPS-stimulated macrophages, with the PVA-[Ch][Sal] iongel displaying the best anti-inflammatory activity (>63% at 200 µg/mL).

Biomass-derived ultrafast cross-linked hydrogels with double dynamic bonds for hemostasis and wound healing.

Developing novel hemostatic materials with accelerating wound healing functions has raised widespread attention recently. To adapt to irregular and incompressible wounds, we fabricated a series of biomass-derived ultrafast cross-linked adhesive hydrogels with adjustable gelation time and injectable properties through Schiff-base and ionic coordinate bonds among catechol-conjugated gelatin (GelDA), dialdehyde cellulose nanocrystals (DACNCs), calcium ions (Ca2+) and ferric iron (Fe3+). The fast-gelling hydrogels possess adjustable gelation time and mechanical properties by altering the contents of DACNCs and Fe3+. With double-dynamic-bond crosslinking, the hydrogels are endowed with the desired self-healing and injectable performance compared to gelatin-based hydrogels without DACNCs. Additionally, the hydrogels present enhanced adhesiveness, NIR responsiveness and antibacterial activity with the introduction of catechol groups and the formation of catechol-Fe complexes. Both in vitro and in vivo hemostatic assays and degradation experiments confirm that the hydrogels achieve rapid hemostasis and display fantastic biodegradability. As demonstrated by a rat full-thickness skin defect model, the hydrogels with multifunctionality remarkably accelerate the regeneration of wound tissues. Thus, the ultrafast cross-linked hydrogels are potentially valuable as hemostatic materials for wound healing applications in the biomedical field.

Zn-based Metal-Organic Frameworks (MOFs) Incorporated into Collagen-Polysaccharide-based Composite Hydrogels for Their Use in Wound Healing

Based on the physicochemical properties of metal-organic frameworks (MOFs), and the need of having an anti-inflammatory and antibacterial effect at the same time in a material for wound healing applications, a multicomponent polymer system was synthesized. Zn-based MOFs having different amino acids acting as ligands (L-tryptophan (Trp), L-phenylalanine (Phe), and L-histidine (His)) in their coordination sphere were successfully prepared and validated by FTIR and XRD. Each MOF was incorporate d into a semi-interpenetrated polymeric network (semi-IPN) based on collagen (C)-guar gum (GG)-polyurethane (PU), given composite hydrogels as end products. The physicochemical properties of these novel composite hydrogels, their in vitro biocompatibility, and their use as cell carriers were studied. The maximum swelling capacity was shown by CGG-Zn(Trp) while the crosslinking index was higher for CGG-Zn(Phe) and CGG-Zn(His), indicating that the chemical structure of the amino acid of the Zn-based MOF tailors these physicochemical properties. All composite hydrogels were resistant to a hydrolysis degradation process (at pH=5 and 7.4) being not entirely degraded after 14 days and having residual masses above 57%. The incorporation of Zn-based MOFs increased the biocompatibility in terms of metabolic activity and proliferation of porcine fibroblast in contact with the composite hydrogels. The low release capacity of fibroblast encapsula ted inside hydrogels evaluated for 10 days indicated the non-efficient capacity of these matrixes as cell carriers, regardless of the structure of the Zn-based MOF. The strong adhesion of porcine fibroblast to the composite hydrogels is related to improving metabolic activity al lowing its proliferation, making these multicomponent polymeric systems useful as efficient materials in biomedical applications such as wound dressing and tissue engineering.

Preparation and Investigation of Antibacterial Activities of Ciprofloxacin Imprinted p(HEMAH) Cryogels

Staphylococcus aureus, Enterococcus faecalis and Escherichia coli are the common causes of wound infections. For the treatment of these infections, ciprofloxacin can be recommended as a broad-spectrum antibiotic that acts on both Gram-negative and Gram-positive microorganisms. Besides, antimicrobial agents could be integrated into polymeric materials. Cryogels, one of these polymeric materials, are spongy polymers showing high macroporosity. In addition to their attractive usage as affinity support materials and scaffolds, they also appear as drug carrier materials in recent years. Molecular imprinting method is a recognition technique prepared by forming a polymeric network around the template. Although this method has been used in purification and separation processes for more than thirty years, it has gained great interest as a new approach that provides an advantage in drug release studies in terms of high drug loading capacity and long-term release.
 In this study, ciprofloxacin (CIP) imprinted 2-Hydroxyethyl methacrylate (HEMA) based N-methacryloyl-(L)-histidine methyl ester (MAH) containing [CIP-p(HEMAH)] cryogels was prepared and characterized. CIP releasing experiments were performed, and then, antimicrobial activities of CIP p(HEMAH) cryogels were examined against S. aureus, E. faecalis and E. coli. It can be concluded that CIP-p(HEMAH) cryogels could be proposed as promising polymeric materials for wound healing applications.

Haemostatic materials for wound healing applications.

Wounds are one of the most common health issues, and the cost of wound care and healing has continued to increase over the past decade. The first step in wound healing is haemostasis, and the development of haemostatic materials that aid wound healing has accelerated in the past 5 years. Numerous haemostatic materials have been fabricated, composed of different active components (including natural polymers, synthetic polymers, silicon-based materials and metal-containing materials) and in various forms (including sponges, hydrogels, nanofibres and particles). In this Review, we provide an overview of haemostatic materials in wound healing, focusing on their chemical design and operation. We describe the physiological process of haemostasis to elucidate the principles that underpin the design of haemostatic wound dressings. We also highlight the advantages and limitations of the different active components and forms of haemostatic materials. The main challenges and future directions in the development of haemostatic materials for wound healing are proposed.

Acrylate-endcapped urethane-based hydrogels: An in vivo study on wound healing potential

Improving wound healing by developing innovative dressing materials has been an important focus over the past few years in the biomedical field. In this regard, the current study focuses on developing new dressings based on acrylate-endcapped urethane-based polymers (AUPs). The materials have been processed into films and electrospun mats. Exudate uptake capacity, mechanical properties and fiber morphology were evaluated herein. The results showed superior uptake capacity of both films and mats when compared to Aquacel®Ag, Exufiber® and Help®. Addition of a high molar mass poly(ethylene glycol) to the AUP polymers benefits both the film and electrospun dressings in terms of flexibility and elongation. An in vivo study was conducted to assess the wound healing properties of these dressings on an acute wound model induced to rats. A macroscopic evaluation indicated that wound contraction and wound fraction percentages were improved significantly in case of the AUP-materials when compared to both the positive (Aquacel®Ag) and negative (Exufiber® and Help®) controls. A histopathological assay, to underline the changes noticed on a macroscopical level, was also performed. The data obtained proved that the developed dressings are beneficial towards tissue regeneration and accelerated wound healing. These findings offer a practical yet adequate strategy for the fabrication of acrylate-endcapped urethane-based materials for wound healing applications.

Chitosan/Graphene Oxide Composite Films and Their Biomedical and Drug Delivery Applications: A Review

The healing of wounds is still a challenging clinical problem for which an efficient and fast treatment is needed. Therefore, recent studies have created a new generation of wound dressings that can accelerate the wound healing process with minimal side effects. Chitosan, a natural biopolymer, is an attractive candidate for preparing biocompatible dressings. The biodegradability, non-toxicity, and antibacterial activities of chitosan have made it a promising biopolymer for treating wounds. Graphene oxide has also been considered by researchers as a non-toxic, inexpensive, and biocompatible material for wound healing applications. This review paper discusses the potential use of chitosan/graphene oxide composite films and their application in wound dressing and drug delivery systems.

Advanced Functional Materials Based on Nanocellulose for Pharmaceutical/Medical Applications.

Nanocelluloses (NCs), with their remarkable characteristics, have proven to be one of the most promising “green” materials of our times and have received special attention from researchers in nanomaterials. A diversity of new functional materials with a wide range of biomedical applications has been designed based on the most desirable properties of NCs, such as biocompatibility, biodegradability, and their special physicochemical properties. In this context and under the pressure of rapid development of this field, it is imperative to synthesize the successes and the new requirements in a comprehensive review. The first part of this work provides a brief review of the characteristics of the NCs (cellulose nanocrystals—CNC, cellulose nanofibrils—CNF, and bacterial nanocellulose—BNC), as well as of the main functional materials based on NCs (hydrogels, nanogels, and nanocomposites). The second part presents an extensive review of research over the past five years on promising pharmaceutical and medical applications of nanocellulose-based materials, which have been discussed in three important areas: drug-delivery systems, materials for wound-healing applications, as well as tissue engineering. Finally, an in-depth assessment of the in vitro and in vivo cytotoxicity of NCs-based materials, as well as the challenges related to their biodegradability, is performed.