In vivo evaluation of the wound healing properties of bio-nanofiber chitosan/ polyvinyl alcohol incorporating honey and Nepeta dschuparensis

Accelerating healing of infected wounds with G. glabra extract and curcumin Co-loaded electrospun nanofibrous dressing

This study aimed to construct a nanofibrous wound dressing composed of polyvinyl alcohol (PVA) and chitosan (CS) containing curcumin and Glycyrrhiza glabra root extract to inhibit infection and accelerate wound healing. Loading 10 wt% of G. glabra extract-curcumin (50:50) by electrospinng technique resulted in the formation of nanofibers (NFs) with diameter distribution 303 ± 38 and had a uniform and defect-free morphology. FTIR analysis confirmed the loading of the components without adverse interactions. Also, the results showed extremely high porosity, extraordinary liquid absorption capacity, and complete wettability. In addition, G. glabra extract-curcumin showed significant antioxidant activity and their release profile from NFs was continuous and sustained. Also, the prepared NF could inhibit the growth of both Gram-positive Saureus and Gram-negative E. coli strains. Wound healing evaluation in the infected animal model showed that the NFs caused full wound closure and accelerated skin regeneration. The studies on inhibiting the bacteria growth at the wound site also revealed complete inhibitory effects. Moreover, histopathology studies confirmed the complete regeneration of skin layers, formation of collagen fibers, and angiogenesis. Finally, PVA/CS NFs containing G. glabra extract-curcumin as a multifunctional bioactive wound dressing presented a promising approach for promoting the healing of infected wounds.

Production and performance evaluation of chitosan/collagen/honey nanofibrous membranes for wound dressing applications

Persistent bacterial infections are the leading risk factor that complicates the healing of chronic wounds. In this work, we formulate mixtures of polyvinyl alcohol (P), chitosan (CH), collagen (C), and honey (H) to produce nanofibrous membranes with healing properties. The honey effect at concentrations of 0 % (PCH and PCHC), 5 % (PCHC-5H), 10 % (PCHC-10H), and 15 % (PCHC-15H) on the physicochemical, antibacterial, and biological properties of the developed nanofibers was investigated. Morphological analysis by SEM demonstrated that PCH and PCHC nanofibers had a uniform and homogeneous distribution on their surfaces. However, the increase in honey content increased the fiber diameter (118.11-420.10) and drastically reduced the porosity of the membranes (15.79-92.62 nm). The addition of honey reduces the water vapor transmission rate (WVTR) and the adsorption properties of the membranes. Mechanical tests revealed that nanofibers were more flexible and elastic when honey was added, specifically the PCHC-15H nanofibers with the lowest modulus of elasticity (15 MPa) and the highest elongation at break (220 %). Also, honey significantly improved the antibacterial efficiency of the nanofibers, mainly PCHC-15H nanofibers, which presented the best bacterial reduction rates against Staphylococcus aureus (59.84 %), Pseudomonas aeruginosa (47.27 %), Escherichia coli (65.07 %), and Listeria monocytogenes (49.58 %). In vitro tests with cell cultures suggest that nanofibers were not cytotoxic and exhibited excellent biocompatibility with human fibroblasts (HFb) and keratinocytes (HaCaT), since all treatments showed higher or similar cell viability as opposed to the cell control. Based on the findings, PVA-chitosan-collagen-honey nanofibrous membranes have promise as an antibacterial dressing substitute.

Preparation and characterization of PVA/chitosan nanofibers loaded with Dragon's blood or poly helixan as wound dressings

Nanofibers have been investigated in regenerative medicine. Dragon's blood (DB)- and poly helixan PF (PHPF) are natural materials used in cosmetics. Herein, we generated DB- and PHPF-loaded polyvinyl alcohol/chitosan (PVA/CS/DB and PVA/CS/PHPF, respectively) nanofibers. PVA/CS/DB and PVA/CS/PHPF nanofibers had an average diameter of 547.5 ± 17.13 and 521 ± 24.67 nm, respectively as assessed by SEM, and a degradation rate of 43.1 and 47.6 % after 14 days, respectively. PVA/CS/DB and PVA/CS/PHPF nanofibers had a hemolysis rate of 0.10 and 0.39 %, respectively, and a water vapor transmission rate of ∼2200 g.m-2.day-1. These nanofibers exhibited favorable antimicrobial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis in vitro. PVA/CS/DB and PVA/CS/PHPF nanofibers demonstrated a sustained release of 77.91 and 76.55 % over 72 h. PVA/CS/DB and PVA/CS/PHPF nanofibers had a high rate of cytocompatibility and significantly improved the viability of NIH/3T3 cells as compared with free drugs or unloaded nanofibers. Histological inspection via H&E and Verhoeff's staining demonstrated PVA/CS/DB and PVA/CS/PHPF nanofibers enhanced the wound healing and damaged tissue recovery of unsplinted wound models by promoting epithelial layer formation, collagen deposition, and enhancing the presence of fibroblasts. Conclusively, PVA/CS/DB and PVA/CS/PHPF can be introduced as potential wound dressing candidates with favorable properties.

Electrospun nanofibers synthesized from polymers incorporated with bioactive compounds for wound healing

The development of innovative wound dressing materials is crucial for effective wound care. It's an active area of research driven by a better understanding of chronic wound pathogenesis. Addressing wound care properly is a clinical challenge, but there is a growing demand for advancements in this field. The synergy of medicinal plants and nanotechnology offers a promising approach to expedite the healing process for both acute and chronic wounds by facilitating the appropriate progression through various healing phases. Metal nanoparticles play an increasingly pivotal role in promoting efficient wound healing and preventing secondary bacterial infections. Their small size and high surface area facilitate enhanced biological interaction and penetration at the wound site. Specifically designed for topical drug delivery, these nanoparticles enable the sustained release of therapeutic molecules, such as growth factors and antibiotics. This targeted approach ensures optimal cell-to-cell interactions, proliferation, and vascularization, fostering effective and controlled wound healing. Nanoscale scaffolds have significant attention due to their attractive properties, including delivery capacity, high porosity and high surface area. They mimic the Extracellular matrix (ECM) and hence biocompatible. In response to the alarming rise of antibiotic-resistant, biohybrid nanofibrous wound dressings are gradually replacing conventional antibiotic delivery systems. This emerging class of wound dressings comprises biopolymeric nanofibers with inherent antibacterial properties, nature-derived compounds, and biofunctional agents. Nanotechnology, diminutive nanomaterials, nanoscaffolds, nanofibers, and biomaterials are harnessed for targeted drug delivery aimed at wound healing. This review article discusses the effects of nanofibrous scaffolds loaded with nanoparticles on wound healing, including biological (in vivo and in vitro) and mechanical outcomes.

A novel approach to wound healing: Green synthetic nano-zinc oxide embedded with sodium alginate and polyvinyl alcohol hydrogels for dressings

Wound healing constitutes a formidable challenge within the healthcare system, attributable to infection risks and protracted recovery periods. The pressing need for innovative wound healing methods has spurred the urgency to develop novel approaches. This study sought to advance wound healing by introducing a novel approach employing a composite sponge dressing. The composite sponge dressing, derived from LFL-ZnO (synthesized through the green methodology utilizing Lactobacillus plantarum ZDY2013 fermentation liquid), polyvinyl alcohol (PVA), and sodium alginate (SA) via a freeze-thaw cycle and freeze-drying molding process, demonstrated notable properties. The findings elucidate the commendable swelling, moisturizing, and mechanical attributes of the SA/LFL-ZnO/PVA composite sponge dressing, characterized by a porous structure. Remarkably, the dressing incorporating LFL-ZnO exhibited substantial inhibition against both methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus (S. aureus). Hemolysis and cytotoxicity tests corroborated the excellent biocompatibility of the sponge dressing. In vivo evaluation of the therapeutic efficacy of the 1 mg/mL LFL-ZnO composite dressing on scald wounds and S. aureus-infected wounds revealed its capacity to accelerate wound healing and exert pronounced antibacterial effects. Consequently, the composite sponge dressings synthesized in this study hold significant potential for application in wound treatment.

Catecholamines polymerization crosslinking for alginate-based burn wound dressings developed with ciprofloxacin and zinc oxide interactions

There is an increasing demand for stable and durable wound dressings to treat burn injuries and infections. Bioactive electrospun nanofibrous mats with antibacterial properties are promising for wound dressing usage. Electrospinning of biopolymers for wound dressing applications needs post-spinning crosslinking to prevent mat dissolution in moist wound environments. Here, we prepared durable wound dressing by using the Dopamine (DA) polymerization crosslinking in Alginate (ALG)/Polyvinyl alcohol (PVA) nanofibrous mats, which are developed by Ciprofloxacin (CIP) and Zinc oxide (ZO). The nanofibrous mats were investigated by FESEM, FTIR, mechanical strength, water contact angle, degradation, degree of swelling, and WVTR tests. The analyses demonstrate the nanofibrous mats with uniform and unbranched fibers, with a hydrophilic nature, which was porous, durable, and stable. Also, it showed the CIP and ZO addition enhanced their durability by crosslinking reinforcement. In addition, the drug release and antibacterial assays demonstrated the pH-sensitive release with more drug release at higher pH (bacterial invasion) and impressive antibacterial activity (up to 99 %). In the burn wound model in rats, the ALG/PVA/DA/CIP/ZO nanofibrous mats displayed excellent wound healing ability in wound closure and tissue regeneration. Also, complete re-epithelization and remodeling and highest collagen synthesis in histological assessment.

Trends in the Incorporation of Antiseptics into Natural Polymer-Based Nanofibrous Mats

Nanofibrous materials represent a very promising form of advanced carrier systems that can be used industrially, especially in regenerative medicine as highly functional bandages, or advanced wound dressings. By incorporation of antimicrobial additives directly into the structure of the nanofiber carrier, the functionality of the layer is upgraded, depending on the final requirement-bactericidal, bacteriostatic, antiseptic, or a generally antimicrobial effect. Such highly functional nanofibrous layers can be prepared mostly by electrospinning technology from both synthetic and natural polymers. The presence of a natural polymer in the composition is very advantageous. Especially in medical applications where, due to the presence of the material close to the human body, the healing process is more efficient and without the occurrence of an unwanted inflammatory response. However, converting natural polymers into nanofibrous form, with a homogeneously distributed and stable additive, is a great challenge. Thus, a combination of natural and synthetic materials is often used. This review clearly summarizes the issue of the incorporation and effectiveness of different types of antimicrobial substances, such as nanoparticles, antibiotics, common antiseptics, or substances of natural origin, into electrospun nanofibrous layers made of mostly natural polymer materials. A section describing the problematic aspects of antimicrobial polymers is also included.

Versatile Bioactive Glass/Zeolitic Imidazolate Framework-8-Based Skin Scaffolds toward High-Performance Wound Healing

Designing a novel biomaterial for wound healing is based on biocompatibility and excellent mechanical strength. In this study, bioactive glass (BG) and zeolitic imidazolate framework-8 (ZIF-8) have been incorporated into poly(ε-caprolactone)/poly(vinyl alcohol) (PCL/PVA) composite skin scaffolds via microfluidic electrospinning. Interestingly, the addition of ZIF-8 further strengthens the BG stability and demonstrates better antibacterial effects. Utilizing the slow release of Zn, Ca, and Si ions, it also significantly promotes growth factor expression and skin regeneration. In addition, it is further demonstrated by in vitro and in vivo studies that the prepared composite skin scaffolds possess excellent biocompatibility, antibacterial capabilities, and mechanical properties. The prepared BG/ZIF-8-loaded scaffold possesses high tensile strength (26 MPa) and excellent antibacterial properties (achieves 89.64 and 78.8% inhibition of E. coli and S. aureus, respectively), and cell viability increased by 51.2%. More importantly, the wound shrinkage of the BG/ZIF-8-loaded scaffold is better than that of an unloaded scaffold, and the shrinkage rates of PCL/PVA@BG/ZIF-8(1 wt %) group is 95% with 2.2 mm granulation growth thickness within 12 days. Thus, the composite skin scaffold loaded with BG/ZIF-8 prepared by microfluidic electrospinning provides a new perspective for accelerating wound healing and is a potential novel therapeutic strategy for efficient wound healing.

In vitro and in vivo studies of Dragon's blood plant (D. cinnabari)-loaded electrospun chitosan/PCL nanofibers: Cytotoxicity, antibacterial, and wound healing activities

The D. cinnabari plant was loaded into the chitosan (Chn)/polycaprolactone (PCL) nanofibers in two forms: resin (D. cinnabari) and its ethyl acetate fraction. The Chn/PCL, Chn/PCL/D. cinnabari (CPD, 1, 3, and 5 %), and Chn/PCL/ethyl acetate extract D. cinnabari (CPED, 1, 3, and 5 %) showed no toxicity against human dermal fibroblast cells. The lactate dehydrogenase assay results indicated that the toxicity of pour, coated D. cinnabari, and CPED nanofibers were lower than 10 and 15 % after 1 and 3 days, respectively. The antibacterial results showed the inhibition zone for ethyl acetate extract D. cinnabari (ED-3 %), the Chn/PCL-2, and CPED3% nanofibers was 8.1, 7.4, 4.2, 5.1 mm, 12.8, 12.4, 21.7, 17.2 mm, and 24.7, 22.9, 37.1, 30.2 mm against S. aureus, B. subtilis, E. coli, and P. aeruginosa, respectively. The antibacterial activity results showed synergistic effect between the Chn/PCL and ethyl acetate extract D. cinnabari occurred. The diameter of wounds (1.50 × 1.50 cm diameter) made on the dorsal surface of rabbits reduced to 1.50 × 0.70, 0.50 × 0.30, 1.00 × 1.00, 0.60 × 0.50, 0.20 × 0.05, and 0.00 × 0.00 cm in the presence of ordinary gauze dressing, silver sulfadiazine, ED-3 %, Chn/PCL-2, CPD3%, and CPED3%nanofibers, respectively, after 14 days.

Electrospun Antimicrobial Drug Delivery Systems and Hydrogels Used for Wound Dressings

Wounds and chronic wounds can be caused by bacterial infections and lead to discomfort in patients. To solve this problem, scientists are working to create modern wound dressings with antibacterial additives, mainly because traditional materials cannot meet the general requirements for complex wounds and cannot promote wound healing. This demand is met by material engineering, through which we can create electrospun wound dressings. Electrospun wound dressings, as well as those based on hydrogels with incorporated antibacterial compounds, can meet these requirements. This manuscript reviews recent materials used as wound dressings, discussing their formation, application, and functionalization. The focus is on presenting dressings based on electrospun materials and hydrogels. In contrast, recent advancements in wound care have highlighted the potential of thermoresponsive hydrogels as dynamic and antibacterial wound dressings. These hydrogels contain adaptable polymers that offer targeted drug delivery and show promise in managing various wound types while addressing bacterial infections. In this way, the article is intended to serve as a compendium of knowledge for researchers, medical practitioners, and biomaterials engineers, providing up-to-date information on the state of the art, possibilities of innovative solutions, and potential challenges in the area of materials used in dressings.

Therapeutic effects of electrospun chitosan nanofibers on animal skin wounds: A systematic review and meta-analysis

Electrospun chitosan nanofibers (QSNFs) enhance the healing process by mimicking skin structure and function. The aim of this study was to analyze the therapeutic effects of QSNFs application on animal skin wounds to identify a potential direction for translational research in dermatology. The PRISMA methodology and the PICO scheme were used. A random effects model and mean difference analysis were applied for the meta-analysis. A meta-regression model was constructed, risk of bias was determined, and methodological quality assessment was performed. Of the 2370 articles collected, 54 studies were selected based on the inclusion and exclusion criteria. The wound healing area was used for building models on the 3rd, 7th, and 14th days of follow-up; the results were - 10.4% (95% CI, -18.2% to -2.6%, p = 0.001), -21.0% (95% CI, -27.3% to -14.7%, p = 0.001), and - 14.0% (95% CI, -19.1 to -8.8%, p = 0.001), respectively. Antioxidants and synthetic polymers combined with QSNFs further reduced skin wound areas (p < 0.05). The results show a more efficient reduction in wound area percentages in experimental groups than in control groups, so QSNFs could potentially be applied in translational human medicine research.

PEGylated curcumin-loaded poly(vinyl alcohol)/Zwitterionic poly(sulfobetaine vinylimidazole)-grafted chitosan nanofiber as a second-degree burn wound dressing

Burn injuries damage skin function and increased the risk of infection. Using natural-inspired antibiotic-free nanofibrous in wound healing has attracted increasing attention. Here, mPEG-Curcumin (mPEG-CUR) was synthesized through a novel, cheap, and high-efficiency method, and incorporated onto poly(vinyl alcohol) (PVA)/zwitterionic poly(sulfobetaine vinylimidazole)-grafted chitosan (CS-g-PNVIS) nanofiber. Due to the lack of electrospinning capability of CS-g-PNVIS and its brittleness, to obtain nanofibers with uniform and bead-free morphology, PVA was used as an electrospinning aid polymer, so that the prepared nanofibers have suitable mechanical properties with an average diameter between 115 ± 18-157 ± 39 nm. The heat-treated nanofibers have adequate swelling and dimensional stability. Time-killing assay proved the antibacterial activity of the mPEG-CUR-loaded nanofibers towards Gram-positive and Gram-negative bacterium. The MTT investigation illustrated the non-cytotoxicity and biocompatibility of the nanofibers. In vivo studies exhibited significant improvement in the mean wound area closure by applying mPEG-CUR nanofibers. The mPEG-CUR-loaded nanofibers showed the highest antioxidant (86 %) power after 40 min. Moreover, nanofibers possess a desirable WVT rate (3.4 ± 0.24-5.5 ± 0.3 kg/m2.d) and good breathability and had the potential to supply a suitable moist environment in the wounded area. This approach can be the beginning of a new path in designing a new generation of nanofiber mats for wound healing applications.

Hypericum perforatum Oil and Vitamin A Palmitate-Loaded Gelatin Nanofibers Cross-Linked by Tannic Acid as Wound Dressings

Recent studies in wound dressing applications offer new therapies to promote the wound healing process. The main strategy of this study is to combine the traditional perspective of using medicinal oils with polymeric scaffolds manufactured by an engineering approach to fabricate a potential tissue engineering product that provides both new tissue formation and wound healing. Thus, Hypericum perforatum oil (HPO) and vitamin A palmitate (VAP) incorporated gelatin (Gt) nanofibrous scaffolds were successfully prepared by the electrospinning method. Tannic acid (TA) was used as the cross-linking agent. The amounts of VAP and HPO loaded in the base Gt solution [15% w/v in 4:6 v/v acetic acid/deionized water] were 5 and 50 wt % (based on the weight of Gt), respectively. The obtained scaffolds were studied regarding their microstructure, chemical structure, thermal stability, antibacterial activity, in vitro release study, and cellular proliferation assay. In the light of these studies, it was determined that VAP and HPO were incorporated successfully in Gt nanofibers cross-linked with TA. Release kinetic tests confirmed that the patterns of TA and VAP release were consistent with the Higuchi model, whereas HPO release was consistent with the first-order kinetic model. In addition, this membrane was biocompatible with L929 fibroblast cells and had antibacterial activity and thermal stability. This preliminary study suggests potential applicability of the proposed dressing to treat skin wounds in clinics.

Asymmetric wettable polycaprolactone-chitosan/chitosan oligosaccharide nanofibrous membrane as antibacterial dressings

Wound infection and inflammation hinder the process of wound healing and bother human beings chronically. As a naturally degradable macromolecule, chitosan (CS) has been widely used in antibacterial wound dressings. However, the antibacterial property of chitosan is inhibited by its water insolubility. In this study, we prepared a bilayered asymmetric nanofibrous membrane with the hydrophilic CS/chitosan oligosaccharide (COS) nanofibrous membrane as the bottom layer and the hydrophobic polycaprolactone (PCL) nanofibrous membrane as the top layer. Results showed that incorporating COS improved the CS membrane's wettability, and adding 0.5 % COS increased the inhibition zone diameter of Escherichia coli and Staphylococcus aureus by 23 % and 26 %, respectively. Moreover, the PCL layer could prevent the adhesion of water and bacteria. The PCL-CS/COS_0.5% membrane showed relatively good mechanical properties, excellent water absorptivity (460 %), and appropriate cytocompatibility. This asymmetric wettable membrane has a massive potential to serve as a new antibacterial dressing for wound healing.

PDDA/Honey Antibacterial Nanofiber Composites for Diabetic Wound-Healing: Preparation, Characterization, and In Vivo Studies

In this paper, Poly (diallyldimethylammonium chloride) (PDDA)/honey nanofiber wound dressing composites were prepared and their effects on the diabetic wound-healing was evaluated using in vivo experiments. The release of effective compounds and the solubility of nanofibers were controlled through the crosslinking process by glutaraldehyde. The crosslinked nanofibers (crosslinking time was 3 h) showed an absorption capacity at a maximum value of 989.54%. Interestingly, the resultant composites were able to prevent 99.9% of Staphylococcus aureus and Escherichia coli bacteria. Furthermore, effective compounds were continuously released from nanofibers for up to 125 h. In vivo evaluation indicated that the use of PDDA/honey (40/60) significantly enhanced wound-healing. On the day 14th, the average healing rate for samples covered by conventional gauze bandage, PDDA, PDDA/honey (50/50), and PDDA/honey (40/60) were 46.8 ± 0.2, 59.4 ± 0.1, 81.7 ± 0.3, and 94.3 ± 0.2, respectively. The prepared nanofibers accelerated the wound-healing process and reduced the acute and chronic inflammation. Hence, our PDDA/honey wound dressing composites open up new future treatment options for diabetic wound diseases.

Wound healing promotion by flaxseed extract-loaded polyvinyl alcohol/chitosan nanofibrous scaffolds

Impaired wound healing is a severe complication of sufferers, related to prolonged wound closure, a high infection rate, and eventually disabilities of organs. To aid resolve this issue, we developed the electrospun polyvinyl alcohol and chitosan (PVA/CS) nanofibrous scaffold-loaded flaxseed extract. The scaffold containing 10 wt% of the extract indicated a three-dimensional cross-network with a nano-scale diameter (257 ± 37 nm) and smooth surface. Also, the relevant analyses confirmed high water absorption, porosity, and wettability of the scaffold. Fourier-transform infrared (FTIR), degradation, and mechanical studies revealed the intact presence and loading of the extract into the scaffold, the complete degradation over 48 h, and a high tensile elastic modulus. Besides, the advanced scaffold displayed remarkable anti-oxidant and could inhibit the growth of both Gram-positive and negative bacteria compared to the free PVA/CS scaffold. Desired fibroblast viability and blood compatibility of flaxseed-loaded scaffold endorsed the biocompatibility for wound zones. The in vitro studies showed that the flaxseed-loaded scaffold resulted in an accelerated wound healing process and 100 % closure of the scratched area within 48 h. The results obtained reveal that the flaxseed-loaded PVA/CS electrospun scaffold could be effectively applied for wound healing promotion.

Extraction and characterization of chitosan from Eupolyphaga sinensis Walker and its application in the preparation of electrospinning nanofiber membranes

Due to its capabilities for wound healing, antimicrobial defense, hemostasis, and biodegradation, chitosan has seen increased use in biomedical disciplines in recent years. In the meantime, efforts have been made to develop and use insect chitosan as a source to address the seasonal, irritating, and regional shortcomings of traditional shrimp and crab chitosan. In this study, a new type of insect chitosan (DCS) was first extracted from Eupolyphaga sinensis Walker by a low-temperature intermittent method and was compared with commercially available pharmaceutical chitosan (CS). Firstly, the degree of deacetylation and molecular weight of DCS were determined, and DCS was characterized by FT-IR, ¹H NMR, XRD, and TGA-DTG. On this basis, DCS was mixed with PVA and PEO to create a novel electrospun nanofiber membrane. The air permeability, antibacterial properties, and biocompatibility of the nanofiber membrane were evaluated, as well as the membrane's shape, structure, and mechanical characteristics. Finally, the activity of nanofiber membranes in promoting wound healing was verified with a rat full-thickness skin defect model, hoping to provide a reference for the development of new drug delivery carriers and wound dressings.

Chitosan-based electrospun nanofibers for diabetic foot ulcer management; recent advances

Diabetic foot ulcer (DFU) healing has long been a major medical challenge. The type of dressing is an essential factor in wound healing, prevention of local infection, and scar formation. Today, smart wound dressings or wound healing patches can precisely control drug delivery to the target tissue and prevent this significant complication. Nanofiber (NF) wound dressings are effective in reducing wound scarring and helping to speed up the healing process for DFU. The electrospun NFs have a suitable surface topography, density, and three-dimensional structure, which can be considered an efficient method to produce a substrate for tissue engineering and wound healing. Chitosan (CS) is one of the most well-known biopolymers in wound healing tissue engineering and drug delivery systems. The unique properties of CS make it suitable for biomedical applications. Based on new studies in the field of hemostatic and antimicrobial effects of CS in controlling bleeding and wound healing and application of NF wound dressings, the purpose of this study is a review relevant works on CS-based NFs to improve the DFU.

Nanomaterials Based on Honey and Propolis for Wound Healing-A Mini-Review

Wound healing is a public health concern worldwide, particularly in chronic wounds due to delayed healing and susceptibility to bacterial infection. Nanomaterials are widely used in wound healing treatments due to their unique properties associated with their size and very large surface-area-to-volume ratio compared to the same material in bulk. The properties of nanomaterials can be expanded and improved upon with the addition of honey and propolis, due to the presence of bioactive molecules such as polyphenols, flavonoids, peptides, and enzymes. These bionanomaterials can act at different stages of wound healing and through different mechanisms, including anti-inflammatory, antimicrobial, antioxidant, collagen synthesis stimulation, cell proliferation, and angiogenic effects. Biomaterials, at the nanoscale, show new alternatives for wound therapy, allowing for targeted and continuous delivery of beekeeping products at the injection site, thus avoiding possible systemic adverse effects. Here, we summarize the most recent therapies for wound healing based on bionanomaterials assisted by honey and propolis, with a focus on in vitro and in vivo studies. We highlight the type, composition (honey, propolis, and polymeric scaffolds), biological, physicochemical/mechanical properties, potential applications and patents related of the last eight years. Furthermore, we discuss the challenges, advantages, disadvantages and stability of different bionanomaterials related to their clinical translation and insight into the investigation and development of new treatments for wound healing.

Investigation on wound healing effect of Mediterranean medicinal plants and some related phenolic compounds: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The human skin constitutes a biological barrier against external stress and wounds can reduce the role of its physiological structure. In medical sciences, wounds are considered a major problem that requires urgent intervention. For centuries, medicinal plants have been used in the Mediterranean countries for many purposes and against wounds.

AIM OF THIS REVIEW

Provides an outlook on the Mediterranean medicinal plants used in wound healing. Furthermore, the wound healing effect of polyphenolic compounds and their chemical structures are also summarized. Moreover, we discussed the wound healing process, the structure of the skin, and the current therapies in wound healing.

MATERIALS AND METHODS

The search was performed in several databases such as ScienceDirect, PubMed, Google Scholar, Scopus, and Web of Science. The following Keywords were used individually and/or in combination: the Mediterranean, wound healing, medicinal plants, phenolic compounds, composition, flavonoid, tannin.

RESULTS

The wound healing process is distinguished by four phases, which are respectively, hemostasis, inflammation, proliferation, and remodeling. The Mediterranean medicinal plants are widely used in the treatment of wounds. The finding showed that eighty-nine species belonging to forty families were evaluated for their wound-healing effect in this area. The Asteraceae family was the most reported family with 12 species followed by Lamiaceae (11 species). Tunisia, Egypt, Morocco, and Algeria were the countries where these plants are frequently used in wound healing. In addition to medicinal plants, results showed that nineteen phenolic compounds from different classes are used in wound treatment. Tyrosol, hydroxytyrosol, curcumin, luteolin, chrysin, rutin, kaempferol, quercetin, icariin, morin, epigallocatechin gallate, taxifolin, silymarin, hesperidin, naringin, isoliquiritin, puerarin, genistein, and daidzein were the main compounds that showed wound-healing effect.

CONCLUSION

In conclusion, medicinal plants and polyphenolic compounds provide therapeutic evidence in wound healing and for the development of new drugs in this field.

Nigella/honey/garlic/olive oil co-loaded PVA electrospun nanofibers for potential biomedical applications

The current work focuses on the formation of nanofibrous mats without the use of toxic solvents and metallic nanoparticles utilizing polyvinyl alcohol (PVA) and a blend of nigella, honey, garlic, and olive oil. Using deionized water (DI) water as a solvent, nanofibrous mats composed of PVA/nigella/honey (PNH) and PVA/garlic/honey/olive oil (PGHO) were developed. Methanol extraction was utilized to extract the therapeutic components of nigella sativa. Antibacterial and moisture management tests (MMT) were employed to examine the antibacterial and absorbance characteristics of the PNH and PGHO nanofibrous. Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) tests were employed to analyze the morphological and chemical characteristics. PGHO showed thermal stability up to 245 °C, and PNH withstands until 225 °C. PNH and PGHO both exhibited antibacterial activity against Staphylococcus aureus (S. aureus), with inhibition zones of 36 mm and 35 mm, respectively. The synthesized materials exhibited excellent absorbance properties, thermal stability, cytotoxicity, and the production of thin nanofibers with an average diameter between 150 and 170 nm. The samples were characterized using FTIR spectra, which confirmed the presence of all components in the developed samples. To date, extensive research on electrospinning for biomedical applications has been undertaken using a variety of hazardous solvents and metallic nanoparticles. Briefly, our objective is to develop nanofibrous materials from plant extracts through a process called "green electrospinning" to observe the synergistic effect of multiple biocomponents incorporated nanofibers avoiding toxic solvents and metallic compounds for potential biomedical applications.

Co-electrospun poly(vinyl alcohol)/poly(ɛ-caprolactone) nanofiber scaffolds containing coffee and Calendula officinalis extracts for wound healing applications

Fabrication of a biocompatible nanofibrous dressing with the advantage of the inclusion of bioactive herbal extracts is a promising approach in skin tissue engineering and wound healing applications. Herbal extracts possess many properties to promote the wound healing process, such as antioxidant properties, anti-inflammation activities as well as enhancing fibroblasts proliferation and migration.

In this study, Calendula officinalis ( C. officinalis) and coffee extracts were loaded into poly(vinyl alcohol)/poly(ɛ-caprolactone) (PVA/PCL) nanofibrous mats. The obtained scaffolds were then characterized using scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared (ATR-FTIR), contact angle, and mechanical measurements. Also, the antioxidant activity, scratch assay, and cell viability of fibroblast cells were also evaluated. The results showed PVA/PCL scaffold loaded with 10 wt% C. officinalis and coffee extracts displayed smooth homogenous morphology with 317 ± 106 nm average diameter. Moreover, the relevant analyses confirmed that the extracts were incorporated into the nanofibers with suitable hydrophilicity and higher mechanical strength (4 ± 0.4 MPa). The antioxidant assay showed that IC50 values of coffee and C. officinalis extracts were 46 ± 1 ppm and 101 ± 4 ppm, successively, which presented a high antioxidant activity. The combination of both extracts showed a higher rate of migration than individual extracts with not detected cytotoxic effects on the human dermal fibroblast cells. In conclusion, our results confirmed that the coffee and C. officinalis extracts loaded PVA/PCL nanofibrous scaffolds could provide an appropriate construct for wound healing applications.

Polysaccharide Electrospun Nanofibers for Wound Healing Applications

As a type of biological macromolecule, natural polysaccharides have been widely used in wound healing due to their low toxicity, good biocompatibility, degradability and reproducibility. Electrospinning is a versatile and simple technique for producing continuous nanoscale fibers from a variety of natural and synthetic polymers. The application of electrospun nanofibers as wound dressings has made great progress and they are considered one of the most effective wound dressings. This paper reviews the preparation of polysaccharide nanofibers by electrospinning and their application prospects in the field of wound healing. A variety of polysaccharide nanofibers, including chitosan, starch, alginate, and hyaluronic acid are introduced. The preparation strategy of polysaccharide electrospun nanofibers and their functions in promoting wound healing are summarized. In addition, the future prospects and challenges for the preparation of polysaccharide nanofibers by electrospinning are also discussed.

Honey: An Advanced Antimicrobial and Wound Healing Biomaterial for Tissue Engineering Applications

Honey was used in traditional medicine to treat wounds until the advent of modern medicine. The rising global antibiotic resistance has forced the development of novel therapies as alternatives to combat infections. Consequently, honey is experiencing a resurgence in evaluation for antimicrobial and wound healing applications. A range of both Gram-positive and Gram-negative bacteria, including antibiotic-resistant strains and biofilms, are inhibited by honey. Furthermore, susceptibility to antibiotics can be restored when used synergistically with honey. Honey’s antimicrobial activity also includes antifungal and antiviral properties, and in most varieties of honey, its activity is attributed to the enzymatic generation of hydrogen peroxide, a reactive oxygen species. Non-peroxide factors include low water activity, acidity, phenolic content, defensin-1, and methylglyoxal (Leptospermum honeys). Honey has also been widely explored as a tissue-regenerative agent. It can contribute to all stages of wound healing, and thus has been used in direct application and in dressings. The difficulty of the sustained delivery of honey’s active ingredients to the wound site has driven the development of tissue engineering approaches (e.g., electrospinning and hydrogels). This review presents the most in-depth and up-to-date comprehensive overview of honey’s antimicrobial and wound healing properties, commercial and medical uses, and its growing experimental use in tissue-engineered scaffolds.

PVA-Based Electrospun Biomembranes with Hydrolyzed Collagen and Ethanolic Extract of Hypericum perforatum for Potential Use as Wound Dressing: Fabrication and Characterization

Biological, physicochemical, structural, and thermal properties of PVA-based electrospun wound dressings added with hydrolyzed collagen (HC) and different concentrations of Hypericum perforatum ethanolic extract (EEHP) were studied. Membrane characterization was carried out by X-ray diffraction, Fourier infrared spectroscopy, differential scanning calorimetry, barrier properties, scanning electron microscopy, image analysis (diameter and pore size), as well as antimicrobial and anti-inflammatory activities. Results showed that the PVA/HC/EEHP materials, fabricated under controlled conditions of temperature and humidity, generated fiber membranes with diameters between 140−390 nm, adequate porosity and pore size for cell growth (67−90% and 4−16 µm, respectively), and good barrier properties (0.005−0.032 g·m−2 s−1) to be used in the treatment of conditions on the skin, and was even better than some commercial products. Finally, they showed to have anti-inflammatory (>80%), and antimicrobial activity against S. aureus and S. epiderm. Furthermore, higher crystalline structure was observed according to the EEHP concentration. In addition, this is the first report in which PVA/HC/EEHP membranes are successfully fabricated and characterized.

Chitosan/PVA Hetero-Composite Hydrogel Containing Antimicrobials, Perfluorocarbon Nanoemulsions, and Growth Factor-Loaded Nanoparticles as a Multifunctional Dressing for Diabetic Wound Healing: Synthesis, Characterization, and In Vitro/In Vivo Evaluation

Diabetic foot ulcers remain one of the most difficult-to-treat complications of diabetes and may seriously threaten the life of patients since it frequently results in limb loss due to amputation, suggesting that an effective therapeutic strategy is still urgently needed. In this study, a chitosan-based heterogeneous composite hydrogel encapsulating perfluorocarbon emulsions, epidermal growth factor (EGF)-loaded chitosan nanoparticles, and polyhexamethylene biguanide (PHMB) named PEENPPCH was developed for diabetic wound healing. The PEENPPCH could sustainably release EGF and PHMB in an ion-rich environment to exert antibacterial effects and promote cell growth for wound repair. In addition, the PEENPPCH can provide anti-inflammatory effects functioned by its main constituent of chitosan. Moreover, the PEENPPCH can proactively offer oxygen delivery through the incorporation of perfluorocarbon and, therefore, is able to alleviate hypoxia conditions on diabetic wounds. These functionalities enabled a markedly enhanced wound healing efficacy on diabetic rats treated with the PEENPPCHs, including thorough re-epithelization, a reduced inflammatory response, faster collagen deposition, and advanced collagen maturation resulting in a 95% of wound closure degree after 15 days that was 12.6% (p < 0.05) higher than the value of the group treated with the commercial dressing HeraDerm. Given the aforementioned advantages, together with the known merits of hydrogels, the developed PEENPPCH is anticipated to be a feasible tool for clinical diabetic wound treatment.

Nanomaterials for application in wound Healing: current state-of-the-art and future perspectives

Nanoparticles are the gateway to the new era in drug delivery of biocompatible agents. Several products have emerged from nanomaterials in quest of developing practical wound healing dressings that are nonantigenic, antishear stress, and gas-exchange permeable. Numerous studies have isolated and characterised various wound healing nanomaterials and nanoproducts. The electrospinning of natural and synthetic materials produces fine products that can be mixed with other wound healing medications and herbs. Various produced nanomaterials are highly influential in wound healing experimental models and can be used commercially as well. This article reviewed the current state-of-the-art and briefly specified the future concerns regarding the different systems of nanomaterials in wound healing (i.e., inorganic nanomaterials, organic and hybrid nanomaterials, and nanofibers). This review may be a comprehensive guidance to help health care professionals identify the proper wound healing materials to avoid the usual wound complications.

Nanofiber Systems as Herbal Bioactive Compounds Carriers: Current Applications in Healthcare

Nanofibers have emerged as a potential novel platform due to their physicochemical properties for healthcare applications. Nanofibers’ advantages rely on their high specific surface-area-to-volume and highly porous mesh. Their peculiar assembly allows cell accommodation, nutrient infiltration, gas exchange, waste excretion, high drug release rate, and stable structure. This review provided comprehensive information on the design and development of natural-based polymer nanofibers with the incorporation of herbal medicines for the treatment of common diseases and their in vivo studies. Natural and synthetic polymers have been widely used for the fabrication of nanofibers capable of mimicking extracellular matrix structure. Among them, natural polymers are preferred because of their biocompatibility, biodegradability, and similarity with extracellular matrix proteins. Herbal bioactive compounds from natural extracts have raised special interest due to their prominent beneficial properties in healthcare. Nanofiber properties allow these systems to serve as bioactive compound carriers to generate functional matrices with antimicrobial, anti-inflammatory, antioxidant, antiseptic, anti-viral, and other properties which have been studied in vitro and in vivo, mostly to prove their wound healing capacity and anti-inflammation properties.

Fabrication of stable electrospun blended chitosan-poly(vinyl alcohol) nanofibers for designing naked-eye colorimetric glucose biosensor based on GOx/HRP

In this study, designing of a stable electrospun blended chitosan (CS)-poly(vinyl alcohol) (PVA) nanofibers for colorimetric glucose biosensing in an aqueous medium was investigated. CS and PVA solutions were blended to acquire an optimum content (CS/PVA:1/4) and electrospunned to obtain uniform and bead-free CS/PVA nanofiber structures following the optimization of the electrospinning parameters (33 kV, 20 cm, and 1.2 ml.h^-1). Crosslinking process applied subsequently provided mechanically and chemically stable nanofibers with an average diameter of 378 nm. The morphological homogeneity, high fluid absorption ability (>%50), thermal (<230 °C) and morphological stability, surface hydrophilicity and degrability properties of cross-linked CS/PVA nanofiber demonstrated their great potential to be developed as an eye-readable strip for biosensing applications. The glucose oxidase (GOx) and horseradish peroxidase (HRP) was immobilized by physical adsorption on the cross-linked CS/PVA nanofiber. The glucose assay analysis by ultraviolet-visible (UV-Vis) spectrophotometry using the same enzymatic system of the proposed glucose strips in form of absorbance versus concentration plot was found to be linear over a glucose concentration range of 2.7 to 13.8 mM. The prepared naked eye colorimetric glucose detection strips, with lower detection limit of 2.7 mM, demonstrated dramatic color change from white (0 mM) to brownish-orange (13.8 mM). The developed cross-linked CS/PVA nanofiber strips, prepared by electrospinnig procedure, could be easily adapted to a color map, as an alternative material for glucose sensing. Design of a practical, low-cost, and environmental-friendly bio-based CS/PVA testing strips for eye readable detection were presented and suggested as an applicable medium for a wide range of glucose concentrations.

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.

Recent advances in PVA-polysaccharide based hydrogels and electrospun nanofibers in biomedical applications: A review

Among several types of carbohydrate polymers blend PVA hydrogel membranes used for biomedical applications in particular wound dressings; electrospun nanofibrous membranes have gained increased interest because of their extraordinary features e.g. huge surface area to volume ratio, high porosity, adequate permeability, excellent wound-exudates absorption capacity, architecture similarity with skin ECM and sustained release-profile over long time. In this study, modern perspectives of synthesized/developed electrospun nanofibrous hydrogel membranes based popular carbohydrate polymers blend PVA which recently have been employed for versatile biomedical applications particularly wound dressings, were discussed intensively and compared in detail with traditional fabricated membranes based films, as well. Clinically relevant and advantages of electrospun nanofibrous membranes were discussed in terms of their biocompatibility and easily fabrication and functionalization in different biomedical applications.

Radioprotective effect of a novel and green bio-nanohybrid, chitosan/silver/cobalt complex, based on Ferulago angulate plant

A novel bio-nanocomposite was developed by incorporating the extracted nanochitosan from shrimp wastes with Schiff base cobalt complex (Chit-Co complex). The phytosynthesis of Chit-Co complex/Ag bio-nanocomposite was designed utilizing Chit-Co complex at the presence of Ferulago angulate extraction and characterized by AFM, SEM, EDAX, TEM, FT-IR, and elemental analysis. The radioprotective application of this bio-nanocomposite on human lymphocyte cells was evaluated using micronucleus (MN) assay. Total antioxidant activities of it were evaluated using FRAP and DPPH assays. Chit-Co complex/Ag bio-nanocomposite significantly decreased the frequency of micronuclei in human lymphocytes exposed to ionization irradiation (IR). The highest protection was observed at 200 μg/ml. Also, maximum antioxidant activities of bio-nanocomposite were provided at the same dose. These data exhibit the radioprotective effect of a bio-nanocomposite based on wastes of living organisms can be an excellent radioprotective agent, which can protect the normal cells of human against the genetic damage by IR.

Chitin and chitosan on the nanoscale

In a matter of decades, nanomaterials from biomass, exemplified by nanocellulose, have rapidly transitioned from once being a subject of curiosity to an area of fervent research and development, now reaching the stages of commercialization and industrial relevance. Nanoscale chitin and chitosan, on the other hand, have only recently begun to raise interest. Attractive features such as excellent biocompatibility, antibacterial activity, immunogenicity, as well as the tuneable handles of their acetylamide (chitin) or primary amino (chitosan) functionalities indeed display promise in areas such as biomedical devices, catalysis, therapeutics, and more. Herein, we review recent progress in the fabrication and development of these bio-nanomaterials, describe in detail their properties, and discuss the initial successes in their applications. Comparisons are made to the dominant nanocelluose to highlight some of the inherent advantages that nanochitin and nanochitosan may possess in similar application.

Fabrication of Hybrid Nanofibers from Biopolymers and Poly (Vinyl Alcohol)/Poly (ε-Caprolactone) for Wound Dressing Applications

The management of chronic wounds is challenging. The factors that impede wound healing include malnutrition, diseases (such as diabetes, cancer), and bacterial infection. Most of the presently utilized wound dressing materials suffer from severe limitations, including poor antibacterial and mechanical properties. Wound dressings formulated from the combination of biopolymers and synthetic polymers (i.e., poly (vinyl alcohol) or poly (ε-caprolactone) display interesting properties, including good biocompatibility, improved biodegradation, good mechanical properties and antimicrobial effects, promote tissue regeneration, etc. Formulation of these wound dressings via electrospinning technique is cost-effective, useful for uniform and continuous nanofibers with controllable pore structure, high porosity, excellent swelling capacity, good gaseous exchange, excellent cellular adhesion, and show a good capability to provide moisture and warmth environment for the accelerated wound healing process. Based on the above-mentioned outstanding properties of nanofibers and the unique properties of hybrid wound dressings prepared from poly (vinyl alcohol) and poly (ε-caprolactone), this review reports the in vitro and in vivo outcomes of the reported hybrid nanofibers.

Fabrication of a Polylactide-Glycolide/Poly-ε-Caprolactone/Dextran/Plastrum Testudinis Extract Composite Anti-Inflammation Nanofiber Membrane via Electrospinning for Annulus Fibrosus Regeneration

Tissue engineering is a promising approach for the treatment of chronic lower back pain (LBP) caused by intervertebral disc degeneration (IDD) resulting from degeneration and inflammation of annulus fibrosus (AF) tissue. However, scaffold with an anti-inflammatory effect on AF cells has not been reported. In this study, we fabricated a polylactide-glycolide (PLGA)/poly-ε-caprolactone (PCL)Zdextran (DEX) composite membrane loaded with plastrum testudinis extract (PTE), a Traditional Chinese Medicine herbal extract, via electrospinning. The membranes were characterized by mechanical measurements and scanning electron microscopy (SEM). Using an in vitro inflammation model induced by interleukin (IL)-1β, the cytocompatibility and anti-inflammatory effects of the composites were investigated by CCK-8 assay and flow cytometry. Potential regulatory mechanisms were examined by RT-qPCR and Western blotting. The results showed that the P10P8D2 (PLGA 10 g, PCL 8 g, DEX 2 g) composite nanofiber membrane exhibited the most uniform diameter distribution, best mechanical properties, a moderate degradation rate, and the best cytocompatibility characteristics. The optimal concentration of PTE was 120 µg/mL. Importantly, P10P8D2 combined with PTE exhibited anti-inflammatory and cell proliferation promotion effects. Moreover, the NF-κBB/NLRP3/IL-β signaling pathway was inactivated. Our findings suggested that the nanofiber membrane composed of P10P8D2 and PTE has anti-inflammatory and pro-proliferation effects on AF cells. It may provide an effective strategy for AF tissue regeneration.