Electrospun poly(l-lactide)/zein nanofiber mats loaded with Rana chensinensis skin peptides for wound dressing

Recent advances in coaxial electrospun nanofibers for wound healing

The skin is the body's primary immune barrier, defending it against pathogenic invasion. Skin injuries impose a significant physiological burden on patients, making effective wound management essential. Dressings are commonly employed in wound care, and electrospun nanofiber dressings are a research hotspot owing to their ease of fabrication, cost-effectiveness, and structural similarity to the extracellular matrix. Coaxial electrospinning offers considerable advantages in drug delivery, fiber structure transformation, and enhanced interaction with the host. These attributes make coaxial electrospun materials promising candidates for precision and personalized wound dressings in medical treatments. This review provides a comprehensive overview of wound healing and its influencing factors. It also outlines coaxial electrospinning's production principles and benefits in wound dressings. Guided by the factors affecting wound healing, coaxial electrospun nanofiber dressings have different application modalities. Furthermore, we discuss the current limitations and future directions for enhancing the current coaxial electrospun dressing technologies.

The Promoting Effect of Animal Bioactive Proteins and Peptide Components on Wound Healing: A Review

The skin is the first line of defense to protect the host from external environmental damage. When the skin is damaged, the wound provides convenience for the invasion of external substances. The prolonged nonhealing of wounds can also lead to numerous subsequent complications, seriously affecting the quality of life of patients. To solve this problem, proteins and peptide components that promote wound healing have been discovered in animals, which can act on key pathways involved in wound healing, such as the PI3K/AKT, TGF-β, NF-κ B, and JAK/STAT pathways. So far, some formulations for topical drug delivery have been developed, including hydrogels, microneedles, and electrospinning nanofibers. In addition, some high-performance dressings have been utilized, which also have great potential in wound healing. Here, research progress on the promotion of wound healing by animal-derived proteins and peptide components is summarized, and future research directions are discussed.

An in vitro and in vivo study of electrospun polyvinyl alcohol/chitosan/sildenafil citrate mat on 3D-printed polycaprolactone membrane as a double layer wound dressing

Double-layer dermal substitutes (DS) generally provide more effective therapeutic outcomes than single-layer substitutes. The architectural design of DS incorporates an outer layer to protect against bacterial invasions and maintain wound hydration, thereby reducing the risk of infection and the frequency of dressing changes. Moreover, the outer layer is a mechanical support for the wound, preventing undue tension in the affected area. A 3D-printed polycaprolactone (PCL) membrane was utilized as the outer layer to fabricate DS wound dressing. Simultaneously, a polyvinyl alcohol/chitosan/sildenafil citrate (PVA/CS/SC) scaffold was electrospun onto the PCL membrane to facilitate cellular adhesion and proliferation. Scanning electron microscopy (SEM) analysis of the PCL filaments revealed a consistent cross-sectional surface and structure, with an average diameter of 562.72 ± 29.15 μm. SEM results also demonstrated uniform morphology and beadless structure for the PVA/CS/SC scaffold, with an average fiber diameter of 366.77 ± 1.81 nm for PVA/CS. The addition of SC led to an increase in fiber diameter while resulting in a reduction in tensile strength. However, drug release analysis indicated that the SC release from the sample can last up to 72 h. Animal experimentation confirmed that DS wound dressing positively accelerated wound closure and collagen deposition in the Wistar rat skin wound model.

Amphibian-derived wound healing peptides: chemical molecular treasure trove for skin wound treatment

Amphibian-derived wound healing peptides thus offer new intervention measures and strategies for skin wound tissue regeneration. As novel drug lead molecules, wound healing peptides can help analyze new mechanisms and discover new drug targets. Previous studies have identified various novel wound healing peptides and analyzed novel mechanisms in wound healing, especially competing endogenous RNAs (ceRNAs) (e.g., inhibition of miR-663a promotes skin repair). In this paper, we review amphibian-derived wound healing peptides, including the acquisition, identification, and activity of peptides, a combination of peptides with other materials, and the analysis of underlying mechanisms, to better understand the characteristics of wound healing peptides and to provide a molecular template for the development of new wound repair drugs.

Facile construction of calcium titanate-loaded silk fibroin scaffolds hybrid frameworks for accelerating neuronal cell growth in peripheral nerve regeneration

Different concentrations of calcium titanate (CaTiO3) nanoparticles were loaded into the Silk fibroin (SF) solution to construct porous SF@CaTiO3 hybrid scaffolds, which were shown to have enhanced properties for stimulating peripheral nerve regeneration. Surface charges, crystallization intensity, wettability, porosity, and morphology were measured and analyzed. We analyzed the hybrid porous SF@CaTiO₃ scaffolds that affected the expansion of Schwann cells. The results demonstrated a concentration-dependent influence on the dispersion of nanoparticles in the CaTiO₃ hybridized SF scaffolds. Incorporating CaTiO₃-NPs into the porous SF@CaTiO₃ hybrid scaffolds can boost hydrophobicity while decreasing surface charge density and porosity. The hybridized scaffolds mostly had an orthorhombic calcium titanate crystal structure with amorphous Silk fibroin mixed. Schwann cell cultures revealed that SF@CaTiO₃ hybrid scaffolds containing an optimal CaTiO₃-NPs concentration could stimulate the proliferation, attachment, and protection of Schwann cell biological functions, suggesting the scaffolds' potential for use in peripheral nerve regeneration.

Production and characterization of biodegradable bi-layer films from poly(lactic) acid and zein

Recently, packaging industry has turned to biodegradable packaging, and poly(lactic acid) has become the most remarkable polymer. However, the high oxygen permeability of PLA films significantly limits their use. Therefore, this study, it was aimed to improve the oxygen barrier properties of PLA films without adversely affecting the mechanical and water vapor barrier properties. Biodegradable PLA-Zein bi-layer films were produced by changing PLA and zein thickness. Transparent and UV barrier bi-layer films were obtained. Mechanical properties of PLA films were improved by the production of bi-layer films. Water vapor permeability of bi-layer films increased whereas the permeance decreased with zein coating of PLA. Multi-criteria decision hierarchy was used to select the best bi-layer films based on mechanical, permeance, and opacity results. Oxygen barrier properties of PLA film significantly improved by zein coating, and hydrophobicity of PLA film was not affected by zein coating. The crystallization and melting temperatures of films decreased when compared to PLA films, supporting the mechanical results. Homogeneous, non-porous, and smooth film surface was obtained and zein layer was in good compatibility with PLA layer. These results suggest that zein coatings could be used to decrease oxygen permeability of PLA films without negatively affecting other properties.

Zein as a versatile biopolymer: different shapes for different biomedical applications

In recent years, the interest regarding the use of proteins as renewable resources has deeply intensified. The strongest impact of these biomaterials is clear in the field of smart medicines and biomedical engineering. Zein, a vegetal protein extracted from corn, is a suitable biomaterial for all the above-mentioned purposes due to its biodegradability and biocompatibility. The controlled drug delivery of small molecules, fabrication of bioactive membranes, and 3D assembly of scaffold for tissue regeneration are just some of the topics now being extensively investigated and reported in the literature. Herein, we review the recent literature on zein as a biopolymer and its applications in the biomedical world, focusing on the different shapes and sizes through which it can be manipulated.

Zein a versatile biomaterial in the biomedical field. Easy to chemically functionalize with good emulsification properties, can be employed in drug delivery, fabrication of bioactive membranes and 3D scaffolds for tissue regeneration.

Nanofiber-Based Face Masks and Respirators as COVID-19 Protection: A Review

Wearing face masks, use of respirators, social distancing, and practicing personal hygiene are all measures to prevent the spread of the coronavirus disease (COVID-19). This pandemic has revealed the deficiency of face masks and respirators across the world. Therefore, significant efforts are needed to develop air filtration and purification technologies, as well as innovative, alternative antibacterial and antiviral treatment methods. It has become urgent-in order for humankind to have a sustainable future-to provide a feasible solution to air pollution, particularly to capture fine inhalable particulate matter in the air. In this review, we present, concisely, the air pollutants and adverse health effects correlated with long- and short-term exposure to humans; we provide information about certified face masks and respirators, their compositions, filtration mechanisms, and the variations between surgical masks and N95 respirators, in order to alleviate confusion and misinformation. Then, we summarize the electrospun nanofiber-based filters and their unique properties to improve the filtration efficiency of face masks and respirators.

Preparation of stretchable composite film and its application in skin burn repair

The poor elasticity of wound dressings often leads to wound healing failure due to rupture and fall off. In this study, the composite films of zein and hydrogel poly (acrylic acid) were developed in order to obtain stretchable wound dressing for skin burn repair. The mechanical test revealed that the maximum elongation of break of composite films could reach 349.76% when the mass ratio of zein to poly (acrylic acid) was 1.5. SEM and FTIR analysis demonstrated the good elasticity of composite films might be due to the formation of a dense structure and the strong interaction between zein and poly (acrylic acid). Interestingly, the composite films exhibited great adhesiveness to human finger skin and stretchable ability under strenuous joint exercise. CCK-8 assay and fluorescence staining showed that the composite films and their extract had good cytocompatibility on human foreskin fibroblasts (L929) cells. The in vivo experiment on rat's skin burning model indicated that the composite films could promote wound healing and collagen synthesis by comparison with commercial gauze. It could be concluded that the stretchable composite films of zein and hydrogel poly (acrylic acid) had the potential as the wound dressing.

Large-Scale Fabrication of Robust Artificial Skins from a Biodegradable Sealant-Loaded Nanofiber Scaffold to Skin Tissue via Microfluidic Blow-Spinning

Given that many people suffer from large-area skin damage, skin regeneration is a matter of high concern. Here, an available method is developed for the formation of large-area robust skins through three stages: fabrication of a biodegradable sealant-loaded nanofiber scaffold (SNS), skin tissue reconstruction, and skin regeneration. First, a microfluidic blow-spinning strategy is proposed to fabricate a large-scale nanofiber scaffold with an area of 140 cm × 40 cm, composed of fibrinogen-loaded polycaprolactone/silk fibroin (PCL/SF) ultrafine core-shell nanofibers with mean diameter of 65 nm. Then, the SNS forms, where the gelling reaction of fibrin sealant occurs in situ between thrombin and fibrinogen on PCL/SF nanofiber surface, to promote the migration and proliferation of fibroblasts, accelerating skin regeneration. Through an in vivo study, it is shown that the SNS can rapidly repair acute tissue damage such as vascular bleeding and hepatic hemorrhage, and also promote angiogenesis, large-area abdominal wall defect repair, and wound tissue regeneration for medical problems in the world. Besides, it avoids the risk of immune rejection and secondary surgery in clinical applications. This strategy offers a facile route to regenerate large-scale robust skin, which shows great potential in abdominal wall defect repair.

Aloe vera-loaded nanofibrous scaffold based on Zein/Polycaprolactone/Collagen for wound healing

Recently, the use of nanofibers (NFs) for tissue engineering has been more developed. For this purpose, we fabricated the NFs (Zein/Polycaprolactone/Collagen) (Zein/PCL/Collagen) incorporated by zinc oxide NPs (ZnO NPs) and Aloe-vera (NFs/ZnO/Alv) using the electrospinning method. Prepared NFs were studied for their morphological, mechanical, thermal stability, and hydrophilic properties. Among the developed NFs, those loaded by ZnO (1 wt%) and Alv (8 wt%) and with Zein/PCL (70:30) displayed the suitable thermal stability and mechanical properties. The water contact angle of NFs improved by decreasing the Zein/PCL blending ratio. Cell culture results showed that the NFs had good cytocompatibility. The cell adhesion potential of this mats were certified with studying by fibroblast cells for various time intervals (24 h and 72 h). The NFs/ZnO/Alv sample revealed inhibition activity against S. aureus (19.23 ± 1.35 mm) and E. coli (15.38 ± 1.12 mm) bacteria. Thus, these results offered that the prepared NFs can be promised as an active scaffold for wound healing uses.

Reinforced ZnONPs/ rosemary essential oil-incorporated zein electrospun nanofibers by κ-carrageenan

In this study, the reinforced ZnONPs/ rosemary essential oil-incorporated zein nanofibers with κ-carrageenan (Z/KC/ZnONPs/RE) were fabricated using the electrospinning technique for application in food packaging. The SEM images of Z/KC/ZnONPs/RE nanofiber displayed bead-free homogeneous morphology that its average fiber diameter was 672 ± 240 nm. The formation of new hydrogen bonds by addition of κ-carrageenan and active agents was approved by FT-IR and DSC structural conformations. The Z/KC/ZnONPs/RE nanofiber exhibited satisfactory thermal and mechanical properties, as well as high surface hydrophobicity. In addition, the Z/KC/ZnONPs/RE sample showed inhibition activity against S. aureus (18.5 ± 1.9 mm) and E. coli (14.7 ± 1.5 mm) bacteria. The DPPH scavenging activity of Z/KC/ZnONPs/RE nanofiber was 54.5 ± 3.6 %. Additionally, the fabricated nanofibers showed no cell cytotoxicity, indicating their good biocompatibility. Thus, we believe that the fabricated Z/KC/ZnONPs/RE electrospun nanofiber is a potential candidate for using as an active layer in food packaging system.

OA-GL21, a novel bioactive peptide from Odorrana andersonii, accelerated the healing of skin wounds

Nowadays, the number of chronic trauma cases caused by a variety of factors such as the world's population-ageing and chronic diseases is increasing steadily, and thus effective treatment for chronic wounds has become a severe clinical challenge, which also burdens the patient both physically and financially. Therefore, it is urgent to develop new drugs to accelerate the healing of wounds. Bioactive peptides, which are relatively low cost, easy to produce, store and transport, have become an excellent choice. In this research, we identified a novel peptide OA-GL21, with an amino acid sequence of 'GLLSGHYGRVVSTQSGHYGRG', from the skin secretions of Odorrana andersonii Our results showed that OA-GL21 exerted the ability to promote wound healing of human keratinocytes (HaCaT) and human fibroblasts in a dose- and time-denpendent manner. However, OA-GL21 had no significant effect on the proliferation of these two cells. Significantly, OA-GL21 showed obvious ability to promote wound healing in the full-thickness skin wound model in dose- and scar-free manners. Further studies showed that OA-GL21 had no direct antibacterial, hemolytic, and acute toxic activity; it had weak antioxidant activities but high stability. In conclusion, this research proved the promoting effects of OA-GL21 on cellular and animal wounds, and thus provided a new peptide template for the development of wound-repairing drugs.

Cellulose acetate/poly(vinyl alcohol) hybrid fibrous mat containing tetracycline hydrochloride and phenytoin sodium: Morphology, drug release, antibacterial, and cell culture studies

The objective of this study was to introduce an electrospun hybrid fibrous mat (a dual-fiber drug delivery system) based on cellulose acetate and poly(vinyl alcohol) containing tetracycline hydrochloride and phenytoin sodium, respectively. Characterization of samples was carried by morphology, drug release, cell cytotoxicity, adhesion, antibacterial property, and wettability investigations. The results showed a uniform shape and a narrow diameter distribution of fibers (between 160 ± 20 nm) for fabricated cellulose acetate/poly(vinyl alcohol) hybrid fibrous mat. The tetracycline hydrochloride release from cellulose acetate significantly decreased due to gel formation of poly(vinyl alcohol) in aqueous media. The best fit for drug release kinetic of hybrid sample was Higuchi model. Sample with tetracycline hydrochloride and phenytoin sodium drugs showed improved cell growth, viability, and antibacterial activity against Escherichia coli (~89%) and Staphylococcus aureus (~98%) in comparison with sample without drugs. The hydrophilic property of cellulose acetate/poly(vinyl alcohol) fibrous sample containing the drugs was also remarkable (~45°). To consider the obtained results, the presented hybrid fibrous mat shows a high potent for biomedical applications.

Synthesis of a thin-layer gelatin nanofiber mat for cultivating retinal cell

Thin-layer gelatin nanofiber mats were fabricated as a biodegradable scaffold for proliferating human retinal pigment epithelium. Together with MTT assay, the glucose consumption rate, lactate formation, and lactate dehydrogenase activity of the human retinal pigment epithelium cells—on the gelatin nanofibers—were analyzed as indicators for cell growth and viability. The results showed that gelatin nanofiber did not make any toxic effect on the cells and the growth rate was comparable to the tissue culture plates. Using the fabricated thin-layer nanofibers let the by-product to leave which in turn cause less adverse effect on the cells. The biodegradability and stability of the gelatin nanofibers were optimized as a function of reaction time.

Encapsulation of Bioactive Compound in Electrospun Fibers and Its Potential Application

Electrospinning is a simple and versatile encapsulation technology. Since electrospinning does not involve severe conditions of temperature or pressure or the use of harsh chemicals, it has great potential for effectively entrapping and delivering bioactive compounds. Recently, electrospinning has been used in the food industry to encapsulate bioactive compounds into different biopolymers (carbohydrates and proteins), protecting them from adverse environmental conditions, maintaining the health-promoting properties, and achieving their controlled release. Electrospinning opens a new horizon in food technology with possible commercialization in the near future. This review summarizes the principles and the types of electrospinning processes. The electrospinning of biopolymers and their application in encapsulating of bioactive compounds are highlighted. The existing scope, limitations, and future prospects of electrospinning bioactive compounds are also presented.