Non-woven mats of poly(vinyl alcohol)/chitosan blends containing silver nanoparticles: Fabrication and characterization

Exploring the potential of a polyvinyl alcohol/chitosan-based nanofibrous matrix for erythromycin delivery: fabrication, in vitro and in vivo evaluation

This study aimed to investigate the potential of polyvinyl alcohol/chitosan nanofibers as a drug delivery system for erythromycin. Polyvinyl alcohol/chitosan nanofibers were fabricated using the electrospinning method and characterized using SEM, XRD, AFM, DSC, FTIR, swelling assessment and viscosity analysis. The in vitro drug release kinetics, biocompatibility, and cellular attachments of the nanofibers have been evaluated using in vitro release studies and cell culture assays. The results showed that the polyvinyl alcohol/chitosan nanofibers displayed improved in vitro drug release and biocompatibility compared to the free drug. The study provides important insights into the potential of polyvinyl alcohol/chitosan nanofibers as a drug delivery system for erythromycin and highlights the need for further investigation into the development of nanofibrous drug delivery systems based on polyvinyl alcohol/chitosan for improved therapeutic efficacy and reduced toxicity. The nanofibers prepared in this approach use less antibiotics, which may be beneficial to the environment. The resulting nanofibrous matrix can be used for external drug delivery applications, such as wound healing or topical antibiotic therapy.

Perspectives of nanofibrous wound dressings based on glucans and galactans - A review

Wound healing is a complex and dynamic process that needs an appropriate environment to overcome infection and inflammation to progress well. Wounds lead to morbidity, mortality, and a significant economic burden, often due to the non-availability of suitable treatments. Hence, this field has lured the attention of researchers and pharmaceutical industries for decades. As a result, the global wound care market is expected to be 27.8 billion USD by 2026 from 19.3 billion USD in 2021, at a compound annual growth rate (CAGR) of 7.6 %. Wound dressings have emerged as an effective treatment to maintain moisture, protect from pathogens, and impede wound healing. However, synthetic polymer-based dressings fail to comprehensively address optimal and quick regeneration requirements. Natural polymers like glucan and galactan-based carbohydrate dressings have received much attention due to their inherent biocompatibility, biodegradability, inexpensiveness, and natural abundance. Also, nanofibrous mesh supports better proliferation and migration of fibroblasts because of their large surface area and similarity to the extracellular matrix (ECM). Thus, nanostructured dressings derived from glucans and galactans (i.e., chitosan, agar/agarose, pullulan, curdlan, carrageenan, etc.) can overcome the limitations associated with traditional wound dressings. However, they require further development pertaining to the wireless determination of wound bed status and its clinical assessment. The present review intends to provide insight into such carbohydrate-based nanofibrous dressings and their prospects, along with some clinical case studies.

Chitosan/PVA Nanofibers as Potential Material for the Development of Soft Actuators

Chitosan/PVA nanofibrous electroresponsive soft actuators were successfully obtained using an electrospinning process, which showed fast speed displacement under an acidic environment. Chitosan/PVA nanofibers were prepared and characterized, and their electroactive response was tested. Chitosan/PVA nanofibers were electrospun from a chitosan/PVA solution at different chitosan contents (2.5, 3, 3.5, and 4 wt.%). Nanofibers samples were characterized using Fourier transform infrared analyses, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), optical microscopy, and tensile test. The electroactive behavior of the nanofiber hydrogels was tested under different HCl pH (2-6) under a constant voltage (10 V). The electroactive response test showed a dependence between the nanofiber's chitosan content and pH with the bending speed displacement, reaching a maximum speed displacement of 1.86 mm^-1 in a pH 3 sample with a chitosan content of 4 wt.%. The results of the electroactive response were further supported by the determination of the proportion of free amine groups, though deconvoluting the FTIR spectra in the range of 3000-3700 cm^-1. Deconvolution results showed that the proportion of free amine increased as the chitosan content was higher, being 3.6% and 4.59% for nanofibers with chitosan content of 2.5 and 4 wt.%, respectively.

Cyanine-Doped Nanofiber Mats for Laser Tissue Bonding

In spite of an extensive body of academic initiatives and innovative products, the toolkit of wound dressing has always revolved around a few common concepts such as adhesive patches and stitches and their variants. Our work aims at an alternative solution for an immediate restitutio ad integrum of the mechanical functionality in cutaneous repairs. We describe the fabrication and the application of electrospun mats of bioactive nanofibers all made of biocompatible components such as a natural polysaccharide and a cyanine dye for use as laser-activatable plasters, resembling the ultrastructure of human dermis. In particular, we investigate their morphological features and mechanical moduli under conditions of physiological relevance, and we test their use to bind a frequent benchmark of connective tissue as rabbit tendon and a significant case of clinical relevance as human dermis. Altogether, our results point to the feasibility of a new material for wound dressing combining translational potential, strength close to human dermis, extensibility exceeding 15% and state-of-art adhesive properties.

A review on removal strategies of microorganisms from water environment using nanomaterials and their behavioural characteristics

Significant findings for microbial removal have led to expertise on several kinds of nanomaterials that made new paths for removing various biological contaminants in a variety of water resources in recent years. Furthermore, advancements in multifunctional nanocomposites synthesis pave the enhanced possibility for their use in water treatment system design. The adsorption towards microbial elimination has been reviewed and compared in this review article using four common kinds of nanomaterials: carbon materials, metal oxides, metal/metal oxides, polymeric metal oxide nanocomposites and their most important mechanistic behavior also discussed. We also describe and analyze recent findings on the effects of engineered nanomaterials on microbial communities in natural and artificial environments. Understanding the removal mechanistic strategy is crucial to improving the nanoparticles (NPs) efficiency and increasing their applicability against a variety of bacteria in various environmental conditions. Also, our study focused on their behavioral effects on microbial structure and functionality towards the removal. Future research opportunities connected to the use of nanomaterials in microbial control and inactivation with societal and health implications are also discussed. We also highlight a number of interesting research subjects that might be of futuristic interest to the scientific community.

Poly (vinyl alcohol)/chitosan/polyethylene glycol-assembled graphene oxide bio-nanocomposites as a prosperous candidate for biomedical applications and drug/food packaging industry

The graphene oxide (GO) nanoplates and polyethylene glycol-decorated GO (GO-PEG nano-hybrid) were synthesized and characterized by FTIR, Raman, XRD, AFM, FE-SEM-EDAX and MTT assay. Obtained results confirmed the graphite oxidation and also assembly of PEG upon GO plates. The MTT assay indicated that GO-PEG nanohybrid enhanced biocompatibility to cells compared to the GO. The GO-PEG nanohybrid was introduced to the polyvinyl alcohol/chitosan carbohydrate (PVA/CS) blends. The bio-nanocomposite were prepared by simple casting method. The GO-PEG nanohybrids demonstrated a significant role in improving thermal, mechanical and antibacterial properties. Accordingly, bio-nanocomposites containing modified GO (PVA/CS/GO-PEG) exhibited higher glass transition temperature (Tg), Young's modulus, tensile strength, elongation at break and antibacterial properties than nanocomposites containing pure GO (PVA/CS/GO). The biodegradation outcomes indicated that the highest weight loss and degradability is related to the bio-nanocomposite containing modified GO (PVA/CS/GO-PEG), which was also confirmed by FE-SEM micrographs. Therefore, PVA/CS/GO-PEG bio-nanocomposites can be a suitable candidate for biomedical applications (tissue engineering, wound dressing) and food-drug packaging industry.

Fabrication of Antimicrobial Multilayered Nanofibrous Scaffolds-Loaded Drug via Electrospinning for Biomedical Application

Nanofibers prepared by biobased materials are widely used in the field of biomedicine, owing to outstanding biocompatibility, biodegradable characters, and excellent mechanical behavior. Herein, we fabricated multilayered nanofibrous scaffolds in order to improve the performance of drug delivery. The composite layer-by-layer scaffolds were incorporated by hydrophobic poly(l-lactic acid) (PLA): polycaprolactone (PCL) and hydrophilic poly(vinyl alcohol) (PVA) nanofibers via multilayer electrospinning. Morphological and structural characteristics of the developed scaffolds measured by scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirmed smooth and uniform fibers ranging in nanometer scale. The differences in contact angles and Fourier transform infrared spectrum (FTIR) between single-layered PVA nanofibers and multilayered scaffolds verified the existence of PLA: PCL surface. In vitro biodegradable and drug release analysis depicted multilayered scaffolds had good biodegradability and potential for medical application. Due to the model drug incorporation, scaffolds exhibited good antibacterial activity against Escherichia coli and Staphylococcus aureus by the zone of inhibition test. These results revealed that the multilayered scaffolds were proved to be desirable antibacterial materials for biomedical application.

Activity of Clove Oil and Chitosan Nanoparticles Incorporated PVA Nanocomposite Against Pythium aphanidermatum

The loss of fresh produces owing to the microbial infestation is a major challenge to the global food industry. The drastic food loss caused mainly by the fungal attack demands the need for development of active packaging materials with antimicrobial properties. Many studies have already been reported on the applications of polymers like polyvinyl alcohol (PVA) engineered with antimicrobial components as active antifungal packaging materials. In the current study, material properties of PVA alone, PVA incorporated with chitosan nanoparticles (PCS), clove oil (PCO), and their combination (PCSCO) have been studied for its microbial barrier and antifungal properties. All the developed films were characterised by the XRD and FTIR analysis, which confirmed the molecular interactions among the individual components of the nanocomposite. At the same time, the bionanocomposite PCSCO was found to have low moisture content and film solubility indicating its suitability for the modified atmosphere packaging applications. In addition, the presence of chitosan nanoparticles and clove oil was found to provide the microbial barrier properties to the PCS, PCO, and PCSCO films. The PCSCO film was further demonstrated to have superior antifungal activity against the selected Pythium aphanidermatum. The results of the study indicate the potential application of developed nanocomposite film as a promising antifungal packaging material.

Antimicrobial electrospun nanofiber mats of NaOH-hydrolyzed chitosan (HCS)/PVP/PVA incorporated with in-situ synthesized AgNPs: Fabrication, characterization, and antibacterial activity

This work aims to improve the electrospinability and antibacterial activity of chitosan (CS) - based nanofibers. Three approaches consisting of reducing molecular weight of CS by NaOH hydrolysis (HCS), blending with two carrying polymers (polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA)) and incorporating with in-situ synthesized silver nanoparticles (AgNPs) were integrated simultaneously for the first time to fabricate the HCS-AgNPs/PVP/PVA multicomponent nanofibers. The electrospinning parameters were optimized to obtain the smooth and uniform nanofibers without beads of both HCS/PVP/PVA and HCS-AgNPs/PVP/PVA systems. The presence of in-situ AgNPs in the multicomponent blends gives the better electrospinning performance and the lowest fiber diameter of 139 nm. In addition, the thermal properties, thermal stability and crystallinity index of both nanofibers also increased with increasing HCS or HCS-AgNPs fractions. Finally, the best antibacterial activity of HCS/PVP/PVA and HCS-AgNPs/PVP/PVA nanofibers against E. coli was found to be 74.4% and 99.9%, respectively. The significant enhancement in bactericidal activity of HCS-AgNPs/PVP/PVA nanofibers against E. coli is due to the synergistic properties of HCS/PVP/PVA blends and AgNPs. Both nanofiber mats displayed the excellent structural stability in moisture environment for at least 7 days. Therefore, the HCS-AgNPs/PVP/PVA nanofibers could be a potential material for applying in the medical purpose.

Preparation and characterization of antibacterial bacterial cellulose/chitosan hydrogels impregnated with silver sulfadiazine

Hydrogels with pH sensitivity and stable mechanical and antibacterial properties have many desirable qualities and broad applications. A hydrogel based on bacterial cellulose and chitosan, impregnated with silver sulfadiazine (<1% w/w), was prepared using glutaraldehyde as the crosslinking agent. The presence of SSd was confirmed by Fourier transform infrared spectroscopy. Micropore size, swelling ratio, pH- sensitivity, and gram positive and negative antibacterial properties were studied by disk diffusion and colony forming unit. X-ray diffraction confirmed the presence of amorphous and crystalline regions in the hydrogel matrix following addition of SSd. The elemental composition, morphology, and mechanical properties of the hydrogels were characterized. Incorporation of SSd into bacterial cellulose-chitosan hydrogels significantly improved their mechanical and antibacterial properties. The antibacterial activity against E. coli and S. aureus was evaluated and SSd-BC/Ch hydrogels are more toxic to S. aureus than to E. coli. We use FESEM to observe bacterial morphology before and after exposure to SSd-BC/Ch hydrogels. The BacLight LIVE/DEAD membrane permeability kit is used to evaluate the membrane permeability of bacteria. These antibacterial hydrogels have many promising applications in food packaging, tissue engineering, drug delivery, clinical, biotechnological, and biomedical fields.

Efficient drug delivery vehicles of environmentally benign nano-fibers comprising bioactive glass/chitosan/polyvinyl alcohol composites

Nano-fiber composites have shown promising potential in biomedical and biotechnological applications. Herein, novel nano-fiber composites constituting a blend of polyvinyl alcohol (PVA) and chitosan (CS) along with different weight ratios of nano-bioactive glass (BG) were prepared by electrospinning. Nano-fibers incorporating 10% (by wt.) of BG were uniform, dense and defect-free with a diameter of 20-125 nm. The model osteoporotic drug (Risedronate sodium) was blended with the electrospinning forming solution and the in-vitro drug release was further studied. About 30% of the drug was released after only 30 min and the release pattern was sustained over 96 h. Drug release took place through a two-stage intra-particle diffusion mechanism. BG-incorporated nano-fibers markedly retarded the drug release profile relative to their BG-free counterparts. They also enhanced the drug release efficiency by releasing 93 ± 4% of the drug. The developed nano-fiber composites can be potentially used as drug-delivery vehicles due to their efficiency and sustained drug release capacity.

Dual loading of Nigella sativa oil-atorvastatin in chitosan-carboxymethyl cellulose nanogel as a transdermal delivery system

Both Nigella sativa oil and atorvastatin possess anti-inflammatory, immunomodulatory, antioxidant, and antibacterial properties that benefit wound healing. In this work, chitosan-carboxymethyl cellulose was loaded on N. sativa oil to synthesize oil nanogel (ONG) which was later used to load with atorvastatin to obtain atorvastatin-oil nanogel (ATONG). Evaluation of the particle size of ONG and ATONG proved the average of 172 and 193 nm, and their surface charges were found to be 32.2 and 34.7 mV, respectively. Transmission electron microscopy of the sample showed that the particles had homogeneous size distributions with spherical structures. Moreover, drug loading efficiency, drug release, and stability of ATONG were investigated, and their results confirmed the appropriate loading and release of atorvastatin. Cytotoxicity evaluation demonstrated that ATONG can safely release atorvastatin intracellularly in fibroblasts. Results from in vitro skin permeation of ONG and ATONG also revealed that the nanogels (NGs) has proper flux through the skin layers. The in vitro wound closure assay for ATONG verified the proliferation and migration capabilities of fibroblasts, confirming the positive effect on wound-healing applications. In scratch model of fibroblasts, the treatment with ATONG resulted in an increase in the expression of the FGF2, TGF-β1, and VEGF genes involved in fibroblast proliferation and migration aimed at wound healing (p < .001). ATONG, also demonstrated bactericidal effects against Staphylococcus, S. aureus, and S. epidermidis species. Based on the results, ONG and ATONG exhibited great potential to be used as a transdermal drug carrier and skin wound healing NG, respectively.

Electrospun antibacterial poly(vinyl alcohol)/Ag nanoparticles membrane grafted with 3,3',4,4'-benzophenone tetracarboxylic acid for efficient air filtration

In this study, poly(vinyl alcohol) (PVA) membranes containing Ag nanoparticles (AgNPs) were prepared by electrospinning and grafted copolymerization with 3,3',4,4'-benzophenone tetracarboxylic acid (BPTA) to provide better mechanical properties, lower water vapor transmittance, and higher antibacterial activity (against Staphylococcus aureus and Escherichia coli) than the PVA/AgNPs membrane. The PVA/AgNPs/BPTA membrane showed higher antibacterial activity than the other membranes, and it produced inhibition zones with diameters of 18.12 ± 0.08 and 16.41 ± 0.05 mm against S. aureus and E. coli, respectively. The PVA/AgNPs/BPTA membrane was found to be capable of promoting reactive oxygen species (ROS) formation under both light and dark conditions. Cycling experiments performed following ROS quenching showed that the best-performing composite membrane retained >70% of its original OH⋅ radical and H₂O₂ charging capacity after seven cycles. In the filtration test, the electrospun nanofibrous membranes showed high filtration efficiencies of 99.98% for sodium chloride (NaCl). In addition, these membranes maintained a relatively low pressure drop of 168 Pa with a basis weight of 2.1 g m^-2. Thus, the PVA/AgNPs/BPTA membrane was concluded to be a promising medical protective material offering the benefits of structural stability and reusability.

Optically activated and interrogated plasmonic hydrogels for applications in wound healing

We disclose the use of hybrid materials featuring Au/Ag core/shell nanorods in porous chitosan/polyvinyl alcohol scaffolds for applications in tissue engineering and wound healing. The combination of Au and Ag in a single construct provides synergistic opportunities for optical activation of functions as near infrared laser tissue bonding, and remote interrogation to return parameters of prognostic relevance in wound healing monitoring. In particular, the bimetallic component ensures optical tunability, enhanced shelf life and photothermal stability, serves as a reservoir of germicidal silver cations, and changes in near-infrared and visible color according to the environmental level of oxidative stress. At the same time, the polymeric blend is ideal to bind connective tissue upon photothermal activation, and to support fabrication processes that provide high porosity, such as electrospinning, thus putting all the premises for cellular repopulation and antimicrobial protection.

Nonwoven fabric supported, chitosan membrane anchored with curcumin/TiO2 complex: Scaffolds for MRSA infected wound skin reconstruction

Use of biomaterial scaffolds as drug carriers for infected wounds treatment is of wide scope. A series of curcumin/TiO₂ complex loaded chitosan scaffolds are fabricated for the same. Synthesized wound dressing material is screened for their morphology, water absorption capacity; in vitro drug release patterns, in vitro antibacterial studies against gram +ve and a gram -ve bacteria, cell viability for 3T3-L1 cell lines as well as in vivo MRSA infected wound healing capability. Formation of curcumin/TiO₂ complex was confirmed by X-ray diffraction studies, the anchoring pattern of them on the chitosan scaffold was analyzed by FESEM and EDS mapping. All membranes showed a better performance towards in vitro antibacterial and in vivo wound healing properties than the control ones in 14 days. The bacterial count on wound for a regular time period was measured and the scaffold with higher amount of curcumin in its complex is found to give the better performance, along with skin regeneration due to synergistic effect of curcumin and TiO₂.

Effect of Sonication Duration in the Performance of Polyvinyl Alcohol/Chitosan Bilayer Films and Their Effect on Strawberry Preservation

In this study, we fabricated polyvinyl alcohol (PVA)/chitosan (CS) bilayer films by casting and investigated the effects of preparation conditions and CS content (2, 2.5, or 3 wt.%) on the ability of these films to preserve packaged strawberries. The best performance was achieved at a CS loading of 2.5 wt.% (ultrasound time, 25 min); the strain and stress values were 143.15 ± 6.43% and 70.67 ± 0.85 MPa, respectively, oxygen permeability was 0.16 ± 0.08 cm²·m²·day^-1·MPa^-1, water vapor permeability was 14.93 ± 4.09 g·cm^-1·s^-1·Pa^-1, and the shelf life of fresh strawberries packaged in the PVA/CS 2.5 wt.% bilayer film was determined to be 21 days at 5 ± 2 °C and a relative humidity of 60 ± 5%. Treatment with PVA/CS bilayer films prevented the decrease in the firmness of strawberries during storage (21 days). The evaluated physicochemical parameters (weight loss, decay, firmness, titratable acidity, soluble solid content, ascorbic acid content, and color) indicated that treatment with PVA/CS bilayer films led to better maintenance of the fruit quality. We believe that our study makes a significant contribution to literature because it paves the way to the fabrication of smart packaging materials and facilitates the commercialization of fresh strawberries as an important health food.

Silver sulfadiazine loaded zein nanofiber mats as a novel wound dressing

In this report a novel antibacterial wound dressing was prepared and then characterized for required testing. We loaded silver sulfadiazine (AgSD) for the first time by electrospinning. AgSD was added in zein (0.3%, 0.4%, 0.5%, and 0.6% by weight) and was electrospun to fabricate nanofiber mats for wound dressings. Nanofiber mats were characterized by Fourier transform infrared spectroscopy (FTIR) to check if there was any chemical reaction between AgSD and zein. Morphological properties were analyzed by Scanning Electron Microscopy (SEM), which showed uniform nanofibers without any bead formation. The diameter of the nanofibers gradually decreased with an increase in the amount of AgSD, which can be associated with strong physical bonding between zein and AgSD. Thermal properties of nanofiber mats were analyzed by Thermogravimetric Analysis (TGA). X-Ray Diffraction (XRD) further demonstrated the crystalline structure of the nanofiber mats, and X-ray Photoelectron spectroscopy (XPS) was performed to confirm Ag and S contents in the prepared wound dressings. In order to investigate antibacterial properties, a disc diffusion method was employed. Bacillus and E. coli bacteria strains were used as Gram-positive and Gram-negative strains respectively. The antibacterial effectiveness of AgSD released from zein nanofibers was determined from the zone inhibition of the bacteria. The antibacterial activity of zein nanofibers loaded with drug was observed with both strains of bacteria in comparison to a control. Excellent antibacterial efficacy was attributed to the sample with 0.6% AgSD. Excellent release properties were also associated with the sample with 0.6% AgSD in zein nanofibers. Keeping in mind the abovementioned characteristics, prepared nanofiber mats would be effective for application in wound dressings.

In this report a novel antibacterial wound dressing was prepared and then characterized for required testing. We loaded silver sulfadiazine (AgSD) for the first time by electrospinning.

Electrospun Polymer Nanofibers Decorated with Noble Metal Nanoparticles for Chemical Sensing

The integration of different noble metal nanostructures, which exhibit desirable plasmonic and/or electrocatalytic properties, with electrospun polymer nanofibers, which display unique mechanical and thermodynamic properties, yields novel hybrid nanoscale systems of synergistic properties and functions. This review summarizes recent advances on how to incorporate noble metal nanoparticles into electrospun polymer nanofibers and illustrates how such integration paves the way towards chemical sensing applications with improved sensitivity, stability, flexibility, compatibility, and selectivity. It is expected that further development of this field will eventually make a wide impact on many areas of research.

Antibacterial Electrospun Poly(vinyl alcohol)/Enzymatic Synthesized Poly(catechol) Nanofibrous Midlayer Membrane for Ultrafiltration

Two different nanofibrous antibacterial membranes containing enzymatically synthesized poly(catechol) (PC) or silver nitrate (AgNO₃, positive control) blended with poly(vinyl alcohol) (PVA) and electrospun onto a poly(vinylidene fluoride) (PVDF) basal disc to generate thin-film composite midlayers were produced for water ultrafiltration applications. The developed membranes were thoroughly characterized in terms of morphology, chemical composition, and general mechanical and thermal features, antimicrobial activity, and ultrafiltration capabilities. The electrospun blends were recognized as homogeneous. Data revealed relevant conformational changes in the PVA side groups, attributed to hydrogen bonding, high thermal stability, and residual mass. PVDF+PVA/AgNO₃ membrane displayed 100% growth inhibition of both Gram-positive and Gram-negative bacteria strains, despite the wide range of fiber diameters generated, from 24 to 125 nm, formation of numerous beads, and irregular morphology. The PVDF+PVA/PC membrane showed a good growth inhibition of Staphylococcus aureus (92%) and revealed a smooth morphology with no relevant bead formations and diameters ranging from 68 to 131 nm. The ultrafiltration abilities of the membrane containing PVA/PC were tested in a dead-end high-pressure cell (4 bar) using a reactive dye in distilled water and seawater. After 5 cycles, a maximum rejection of ≈85% with an average flux rate of 70 L m^-2 h^-1 for distilled water and ≈64% with an average flux rate of 62 L m^-2 h^-1 for seawater were determined with an overall salt rejection of ≈5%.

Recent advances on biomedical applications of scaffolds in wound healing and dermal tissue engineering

The tissue engineering field has developed in response to the shortcomings related to the replacement of the tissues lost to disease or trauma: donor tissue rejection, chronic inflammation and donor tissue shortages. The driving force behind the tissue engineering is to avoid the mentioned issues by creating the biological substitutes capable of replacing the damaged tissue. This is done by combining the scaffolds, cells and signals in order to create the living, physiological, three-dimensional tissues. A wide variety of skin substitutes are used in the treatment of full-thickness injuries. Substitutes made from skin can harbour the latent viruses, and artificial skin grafts can heal with the extensive scarring, failing to regenerate structures such as glands, nerves and hair follicles. New and practical skin scaffold materials remain to be developed. The current article describes the important information about wound healing scaffolds. The scaffold types which were used in these fields were classified according to the accepted guideline of the biological medicine. Moreover, the present article gave the brief overview on the fundamentals of the tissue engineering, biodegradable polymer properties and their application in skin wound healing. Also, the present review discusses the type of the tissue engineered skin substitutes and modern wound dressings which promote the wound healing.

Electrospun nanofibers for wound healing

Electrospinning has been widely used as a nanofiber fabrication technique. Its simple process, cost effectiveness and versatility have appealed to materials scientists globally. Pristine polymeric nanofibers or composite nanofibers with dissimilar morphologies and multidimensional assemblies ranging from one dimension (1D) to three dimensions (3D) can be obtained from electrospinning. Critically, these as-prepared nanofibers possessing high surface area to volume ratio, tunable porosity and facile surface functionalization present numerous possibilities for applications, particularly in biomedical field. This review gives us an overview of some recent advances of electrospinning-based nanomaterials in biomedical applications such as antibacterial mats, patches for rapid hemostasis, wound dressings, drug delivery systems, as well as tissue engineering. We further highlight the current challenges and future perspectives of electrospinning-based nanomaterials in the field of biomedicine.

Chitosan Combined with ZnO, TiO₂ and Ag Nanoparticles for Antimicrobial Wound Healing Applications: A Mini Review of the Research Trends

Chitosan is a natural polymer that has been widely utilized for many purposes in the food, textile, agriculture, water treatment, cosmetic and pharmaceutical industries. Based on its characteristics, including biodegradability, non-toxicity and antimicrobial properties, it has been employed effectively in wound healing applications. Importantly, however, it is necessary to improve chitosan's capacities by combination with zinc oxide (ZnO), titanium dioxide (TiO₂) and silver (Ag) nanoparticles (NPs). In this review of many of the latest research papers, we take a closer look at the antibacterial effectiveness of chitosan combined with ZnO, TiO₂ and Ag NPs and also evaluate the specific wound healing application potentials.