Effective Wound Dressings Research Articles

Capparis sepiaria-Loaded Sodium Alginate Single- and Double-Layer Membrane Composites for Wound Healing.

Background: Effective wound dressing is the key solution to combating the increased death rate and prolonged hospital stay common to patients with wounds. Methods: Sodium alginate-based single- and double-layer membranes incorporated with Capparis sepiaria root extract were designed using the solvent-casting method from a combination of polyvinyl alcohol (PVA), Pluronic F127 (PF127), and gum acacia. Results: The successful preparation of the membranes and loading of the extract were confirmed using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The prepared membranes were biodegradable and non-toxic to human skin cells (HaCaT), with high biocompatibility of 92 to 112% cell viability and good hemocompatibility with absorbance ranging from 0.17 to 0.30. The membrane's highest water vapor transmission rate was 1654.7333 ± 0.736 g/m2/day and the highest % porosity was 76%. The membranes supported cellular adhesion and migration, with the highest closure being 68% after 4 days compared with the commercial wound dressings. This membrane exhibited enhanced antimicrobial activity against the pathogens responsible for wound infections. Conclusions: The distinct features of the membranes make them promising wound dressings for treating infected wounds.

Assessment of chitosan-PVA hydrogels infused with marine collagen peptides for potential wound healing applications

Ideal wound dressings should show enhanced moisture management at the wound site, antibacterial and physical barrier, and mechanical robustness. Additionally, it should be easy to apply to the wound and be biocompatible and non-toxic. In this study, a linker-free freeze-thaw procedure was used to create an array of chitosan/PVA hydrogels blended with commercially available marine collagen peptides. Marine collagen peptides (CP) are easily available as by-products of the marine food industry and are an inexpensive and novel source of biomaterial in this field. The different weight ratios of chitosan, PVA, and CP influenced the hydrogel properties such as swelling, gel content, evaporation, and mechanical properties. Furthermore, SEM and ATR-FTIR were used to characterize the hydrogels generated under ideal conditions. After 24 h, the optimum hydrogel (chitosan:PVA:CP ratio of 1:5:1) showed a water absorption capacity of up to 900 %, a gel content of 80 %, and a 40 % evaporation rate. The physical interactions between marine collagen peptide and gel-forming components were validated by ATR-FTIR spectra, and the hydrogel kept a sufficient porous structure for potential wound dressing application. To test the mechanical integrity of the hydrogels, compression testing was carried out showing a compressive modulus of up to ∼40 kPa. The addition of marine collagen peptide in the chitosan/PVA hydrogel increased its wettability, antimicrobial capabilities, and hemostatic properties. Furthermore, the hydrogel preparation procedure is simple and does not use toxic chemicals, serving as a model for developing safe and effective hydrogel wound dressing.

Zinc-induced photocrosslinked konjac glucomannan/glycyrrhizic acid hydrogel promotes skin wound healing in diabetic mice through immune regulation

Diabetic wound healing is a complex process. Owing to the lack of effective wound dressings, diabetic wound healing is often delayed. Here, injectable composite hydrogels with methacrylic anhydride (MA)-modified Konjac glucomannan and Zn2+-induced glycyrrhizic acid self-assembly were developed for skin wound healing in diabetic mice. Under induction with a photoinitiator and Zn2+, the hydrogel formed rapidly (<5 s) in vitro. The KGMMA/GA/Zn hydrogel demonstrated excellent mechanical properties (strain [40 %] >28 KPa) and physicochemical characteristics, which enabled the adaptation to various complex skin wound environments. Crucially, in vitro and in vivo experiments revealed that the hydrogel had good biocompatibility and low hemolytic properties (1.7 %) and promoted cell migration and tube formation. Hydrogels can modulate the innate properties of the immune system, regulate the polarization of macrophages in the M2 direction, and inhibit the production of ROS and inflammatory factors without the addition of cytokines or drugs in vivo and in vitro. In vivo animal experiments revealed that the hydrogel significantly accelerated the repair process of skin wounds, with a repair efficiency reaching 97.2 %. In summary, this novel hydrogel constitutes a highly effective wound healing dressing and may be a promising approach in tissue regeneration engineering.

Fabrication and development of biogenic selenium nanoparticles incorporated alginate hydrogel wound care material: a pre-clinical study

ABSTRACT In this study, we attempted to make a nanocomposite wound dressing that was both interactive and bioactive. In order to characterize the biogenic selenium nanoparticles, characterization techniques such as SEM, EDX, DLS, Zetasizer, FTIR, and XRD were utilized. The XRD results showed that the peaks located at around 2θ = 23.9°, 30.1°, 41.6°, 44.1°, and 52.9° that are corresponded to the (100), (101), (110), (102), and (201) reflections of the pure hexagonal phase of selenium crystals. The results of zeta potential measurement showed that the biosynthesized SeNPs have a zeta potential of around −27.5 mV. Studies conducted on animals using a full-thickness wound model of the rat’s skin showed that the wound dressing was able to speed up the natural process of wound healing. Based on the findings, it was determined that the wound dressing has the potential to serve as an effective wound dressing and healing material.

A low-cost, antimicrobial aloe-alginate hydrogel film containing Australian First Nations remedy ‘lemon myrtle oil’ (Backhousia citriodora) – Potential for incorporation into wound dressings

Chronic wounds pose a global public health challenge, particularly in remote settings where access to specialised wound care and dressings can be limited and cost-prohibitive. First Nations communities in Australia are at a significantly higher risk for developing chronic wounds and this risk further increases for people living in remote regions. There is an urgent need to develop inexpensive but effective wound dressings to improve wound outcomes. Over the past decade, sodium alginate (SA)-based hydrogel polymers have emerged as a cost-effective and biocompatible component in wound dressings, and many have been successfully commercialised. In this study, we have developed and evaluated various prototypes of SA-based hydrogels with the addition of another low-cost component, aloe vera (AV) to further tailor the physicochemical properties of the hydrogel. Since the presence of microbes is a major contributor to the pathophysiology of chronic wounds, we also evaluated the antimicrobial activity of lemon myrtle oil (LMO) (Backhousia citriodora) incorporated into the hydrogel, a remedy used traditionally by First Nations Australians. Novel formulations of AV-SA-LMO hydrogel prototypes in the absence and presence of lemon myrtle oil (at a concentration of 5 μg/mL) were assessed for their physicochemical and antimicrobial properties and compared to a commercially available hydrogel-based dressing. The addition of lemon myrtle oil imparted viscoelastic behaviour for improved processability of AV-SA-LMO hydrogel prototypes, while increasing protein adhesion, enhancing physical properties, and demonstrating antimicrobial activity against the common wound-infecting microbes Staphylococcus epidermidis and Candida albicans. Fourier transmission infrared (FTIR) spectra confirmed the molecular structures of the hydrogel prototypes as predicted. The prototypes also demonstrated biocompatibility with the HaCaT human keratinocyte cell line. This study has provided preliminary evidence that a 25:75 aloe vera:sodium alginate hydrogel with 5 μg/mL lemon myrtle oil has comparable physicochemical characteristics to a commercial hydrogel-based wound dressing and antimicrobial properties against S. epidermidis and C. albicans.

Fabrication of tetra‐n‐butylammonium hydrogen sulfate‐based poly(lactic acid)‐poly(ethylene glycol) composite electrospun wound dressing

AbstractIn this study, poly(lactic acid)‐poly(ethylene glycol)‐tetra‐n‐butylammonium hydrogen sulfate (PLA‐PEG‐HS) electrospun mats were fabricated by electrospinning as effective wound dressings against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), which are the most prevalent species of gram‐positive and gram‐negative bacteria, respectively. PLA is a polymer with high biocompatibility and biodegradability, but its structure is fragile. Therefore, we aimed to improve its structural properties using PEG as a plasticizer and to provide antibacterial properties with HS salt. The nanofibers characterized using differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA), and drying time tests. The addition of HS eliminated the beads in the PLA‐PEG nanofiber and improved the homogeneity of the fiber distribution. Concerning this result, when the liquid absorption capacity (LAC) test was evaluated, PLA‐PEG‐HS nanofiber production was achieved with the highest rate of 480.95%. The thermal properties of nanofibers increased with the addition of HS. Cytotoxicity test results of PLA‐PEG‐HS wound dressings showed high cell viability of 129.05% in L292 mouse fibroblast cells at the end of the 24th hour. PLA‐PEG‐HS nanofibers with 99.99% antibacterial activity against tow bacteria. Considering the modern wound dressing requirements, antibacterial wound dressing production has been successfully achieved.

Introducing PCL-Based Electrospun Nanocomposite Wound Dressings: Synergistic Effects of Curcumin and Reduced Graphene Oxide

ABSTRACT The development of effective wound dressings is critical for enhancing patient outcomes in both acute and chronic wound care scenarios. In this research, electrospun nanofibrous scaffolds were fabricated from poly(ε-caprolactone) (PCL), enhanced with curcumin and reduced graphene oxide (RGO) to optimize their biomedical applications, particularly in wound healing. The resulting scaffolds were rigorously characterized through scanning electron microscopy, contact angle measurements, water uptake capacity, and water vapor transmission rate assays. The biocompatibility of these novel nanofibers was affirmed through MTT assays. Antibacterial tests confirmed the scaffolds’ ability to inhibit both Gram-negative and Gram-positive bacteria, with inhibition zones measuring up to 9.9 mm for S. aureus and 9.2 mm for E. coli. Additionally, scaffolds containing curcumin exhibited significant antioxidant activity, achieving up to 40% radical scavenging efficiency. The study further revealed the scaffolds’ capability for sustained drug release, with an initial burst release within the first 12 hours followed by a gradual release over 168 hours. Overall, the PCL-curcumin-RGO electrospun mats demonstrated considerable potential for biomedical applications, notably in the field of wound dressings, due to their enhanced antibacterial, antioxidant, and biocompatible properties.

Evaluating mechanical and biological responses of bipolymeric drug-chitosan-hydroxyapatite scaffold for wounds: Fabrication, characterization, and finite element analysis

This study aims to explore the potential of a scaffold composed of drug-chitosan-hydroxyapatite (HA) in improving tissue treatment. The focus of the investigation lies in analyzing the physical and biological properties of the scaffold and evaluating its mechanical characteristics through finite-element analysis. To synthesize microcapsules containing dextran-diclofenac sodium, the electrospraying method was employed. The drug-chitosan-HA scaffold with varying volume fractions (VF) of the synthesized microcapsules (10, 15, and 20) was fabricated using the freeze-drying technique. Microscopic and scanning electron microscopy (SEM) images were utilized to evaluate the morphology, shape, and size of the microcapsules, as well as the porosity of the scaffolds for wound healing purposes. The mechanical properties of the synthesized microcapsules were determined via a nanoindentation test, while the mechanical behavior of the fabricated scaffolds was assessed through compression testing. Additionally, a multiscale finite-element model was developed to predict the mechanical properties of tissue scaffolds containing pharmaceutical microcapsules. The findings indicate that the incorporation of drug-chitosan-hydroxyapatite into the tissue significantly enhances both mechanical and biological responses. The mechanical evaluations demonstrate that the drug-chitosan-hydroxyapatite tissue exhibits excellent resistance to pressure, making it a suitable protective covering for skin wounds. Moreover, biological evaluations reveal that an increase in scaffold porosity leads to higher swelling behavior. The scaffold containing 20 % pharmaceutical microcapsules demonstrated the greatest swelling and desirable antibacterial properties, thereby indicating its potential as an effective wound dressing. Furthermore, a multiscale finite-element model was developed to predict the mechanical properties of tissue containing pharmaceutical microcapsules. The results indicated that the average size of the microcapsules was in the range of 170 to 180 µm, and the porosity of the prepared tissue was between 52 % and 61 %. The experimental compressive properties revealed that an increase in the volume fraction of the embedded microcapsules led to an increase in the maximum compressive stress and compressive modulus of the scaffolds by up to 54.95 % and 53.18 %, respectively, for the scaffold containing 20 % VF of pharmaceutical microcapsules compared to the specimen containing 10 % VF. In conclusion, the developed scaffold has the potential to serve as an effective wound dressing, with the ability to provide structural support, facilitate controlled drug release, and promote wound healing.

Design of Scaffolds Based on Zinc-Modified Marine Collagen and Bilberry Leaves Extract-Loaded Silica Nanoparticles as Wound Dressings.

In this study, wound dressings were designed using zinc-modified marine collagen porous scaffold as host for wild bilberry (WB) leaves extract immobilized in functionalized mesoporous silica nanoparticles (MSN). These new composites were developed as an alternative to conventional wound dressings. In addition to the antibacterial activity of classic antibiotics, a polyphenolic extract could act as an antioxidant and/or an anti-inflammatory agent as well. Wild bilberry leaves extract was prepared by ultrasound-assisted extraction in ethanol and its properties were evaluated by UV-Vis spectroscopy (radical scavenging activity, total amount of polyphenols, flavonoids, anthocyanins, and condensed tannins). The extract components were identified by HPLC, and the antidiabetic properties of the extract were evaluated via α-glucosidase inhibitory activity. Spherical MSN were modified with propionic acid or proline moieties by post-synthesis method and used as carriers for the WB leaves extract. The textural and structural features of functionalized MSN were assessed by nitrogen adsorption/desorption isotherms, small-angle XRD, SEM, TEM, and FTIR spectroscopy. The composite porous scaffolds were prepared by freeze drying of the zinc-modified collagen suspension containing WB extract loaded silica nanoparticles. The properties of the new composites demonstrated enhanced properties in terms of thermal stability of the zinc-collagen scaffold, without altering the protein conformation, and stimulation of NCTC fibroblasts mobility. The results of the scratch assay showed contributions of both zinc ions from collagen and the polyphenolic extract incorporated in functionalized silica in the wound healing process. The extract encapsulated in functionalized MSN proved enhanced biological activities compared to the extract alone: better inhibition of P. aeruginosa and S. aureus strains, higher biocompatibility on HaCaT keratinocytes, and anti-inflammatory potential demonstrated by reduced IL-1β and TNF-α levels. The experimental data shows that the novel composites can be used for the development of effective wound dressings.

Harnessing Bioprinting Technologies for Diabetic Wound Regeneration.

A chronic metabolic condition, diabetes mellitus (DM), is becoming more common all over the globe. Diabetic complications include diabetic foot ulcers (DFUs). Between fifteen and twenty-five percent of people with diabetes will experience DFU at some point in their lives. Prolonged hospital stays and amputations are common outcomes of DFUs due to the absence of targeted therapy and appropriate wound dressings. Specialized DFU wound care is expected to be in high demand due to the anticipated increase in the prevalence of DM. Therefore, there is a strong need to enhance and create more effective wound dressings and therapies that are unique to DFU. Bioengineered tissues, individualised prostheses, and implants are just a few examples of how 3D bioprinting has revolutionised healthcare in the past decade. This review delves into the difficulties of wound management and explores how 3D bioprinting could improve existing treatment approaches and biomanufacturing composite 3D human skin substitutes as an alternative to skin grafting. To alleviate the healthcare burden caused by the rising incidence of DM, it will be crucial to co-develop 3D bioprinting technologies with new therapeutic techniques to address the unique pathophysiological problems of DFU in the future.

Multifunctional double-network hydrogel with antibacterial and anti-inflammatory synergistic effects contributes to wound healing of bacterial infection

Wound infection not only hinders the time sequence of tissue repair, but also may lead to serious complications. Multifunctional wound dressings with biocompatibility, excellent mechanical properties and antibacterial properties can promote wound healing during skin infection and reduce the use of antibiotics. In this study, a multifunctional dual-network antibacterial hydrogel was constructed based on the electrostatic interaction of two polyelectrolytes, hydroxypropyl trimethyl ammonium chloride chitosan (HACC) and sodium alginate (SA). Attributing to the suitable physical crosslinking between HACC and SA, the hydrogel not only has good biocompatibility, mechanical property, but also has broad-spectrum antibacterial properties. In vivo results showed that the hydrogel could regulate M2 polarization, promote early vascular regeneration, and create a good microenvironment for wound healing. Therefore, this hydrogel is an effective multifunctional wound dressing. Consequently, we propose a novel hydrogel with combined elements to expedite the intricate repair of wound infection.

A multifunctional protein-based hydrogel with Au nanozyme-mediated self generation of H2S for diabetic wound healing

Diabetics usually suffer from chronic impaired wound healing due to facile infection, excessive inflammation, diabetic neuropathy, and peripheral vascular disease. Hence, the development of effective diabetic wound therapy remains a critical clinical challenge. Hydrogen sulfide (H2S) regulates inflammation, oxidative stress, and angiogenesis, suggesting a potential role in promoting diabetic wound healing. Herein, we propose a first example of fabricating an antibiotic-free antibacterial protein hydrogel with self-generation of H2S gas (H2S-Hydrogel) for diabetic wound healing by simply mixing bovine serum albumin‑gold nanoclusters (BSA-AuNCs) with Bis[tetrakis(hydroxymethyl)phosphonium] sulfate (THPS) at room temperature within a few minutes. In this process, the amino group in BAS and the aldehyde group in THPS are crossed together by Mannich reaction. At the same time, tris(hydroxymethyl) phosphorus (trivalent phosphorus) from THPS hydrolysis could reduce disulfide bonds in BSA to sulfhydryl groups, and then the sulfhydryl group generates H2S gas under the catalysis of BSA-AuNCs. THPS in H2S-Hydrogel can destroy bacterial biofilms, while H2S can inhibit oxidative stress, promote proliferation and migration of epidermal/endothelial cells, increase angiogenesis, and thus significantly increase wound closure. It would open a new perspective on the development of effective diabetic wound dressing.

Modulating the hAM/PCL Biocomposite for Expedited Wound Healing: A Chemical-Free Approach for Boosting Regenerative Potential.

There is an arising need for effective wound dressings that retain the bioactivity of a cellular treatment, but without the high costs and complexities associated with manufacturing, storing, and applying cell-based products. As skin wound recovery is a dynamic and complicated process, a significant obstacle to the healing of skin wounds is the lack of an appropriate wound dressing that can imitate the microenvironment of healthy skin and prevent bacterial infection. It requires the well-orchestrated integration of biological and molecular events. In this study, we have fabricated full-thickness skin graft biocomposite membranes to target full-thickness skin excision wounds. We reinforced human amniotic membrane (hAM) with electrospun polycaprolactone (PCL) to develop composite membranes, namely, PCL/hAM and PCL/hAM/PCL. Composite membranes were compared for physical, biological, and mechanical properties with the native counterpart. PCL/hAM and PCL/hAM/PCL displayed improved stability and delayed degradation, which further synergically improved the rapid wound healing property of hAM, driven primarily by wound closure analysis and histological assessment. Moreover, PCL/hAM displayed a comparable cellular interaction to hAM. On application as a wound dressing, histological analysis demonstrated that hAM and PCL/hAM promoted early epidermis and dermis formation. Studies on in vivo wound healing revealed that although hAM accelerates cell development, the overall wound healing process is similar in PCL/hAM. This finding is further supported by the immunohistochemical analysis of COL-1/COL-3, CD-31, and TGF-β. Overall, this conjugated PCL and hAM-based membrane has considerable potential to be applied in skin wound healing. The facile fabrication of the PCL/hAM composite membrane provided the self-regenerating wound dressing with the desired mechanical strength as an ideal regenerative property for skin tissue regeneration.

Silver-loaded poly(vinyl alcohol)/polycaprolactone polymer scaffold as a biocompatible antibacterial system

A chronic nonhealing wound poses a significant risk for infection and subsequent health complications, potentially endangering the patient‘s well-being. Therefore, effective wound dressings must meet several crucial criteria, including: (1) eliminating bacterial pathogen growth within the wound, (2) forming a barrier against airborne microbes, (3) promoting cell proliferation, (4) facilitating tissue repair. In this study, we synthesized 8 ± 3 nm Ag NP with maleic acid and incorporated them into an electrospun polycaprolactone (PCL) matrix with 1.6 and 3.4 µm fiber sizes. The Ag NPs were anchored to the matrix via electrospraying water-soluble poly(vinyl) alcohol (PVA), reducing the average sphere size from 750 to 610 nm in the presence of Ag NPs. Increasing the electrospraying time of Ag NP-treated PVA spheres demonstrated a more pronounced antibacterial effect. The resultant silver-based material exhibited 100% inhibition of gram-negative Escherichia coli and gram-positive Staphylococcus aureus growth within 6 h while showing non-cytotoxic effects on the Vero cell line. We mainly discuss the preparation method aspects of the membrane, its antibacterial properties, and cytotoxicity, suggesting that combining these processes holds promise for various medical applications.

In vitro analysis of electrospun nanofibrous polycaprolactone loaded with Rhamnus prinoides leaf extract as potential wound dressing

AbstractRhamnus prinoides, an indigenous Ethiopian traditional medicinal plant, has been used for treating various ailments including skin conditions in traditional formulations. In this study, plant leaf extract has been incorporated into polycaprolactone (PCL) nanofibers through electrospinning at concentrations of 1%, 3%, 5%, 7% wt/vol for the first time. The presence of extract in the nanofiber was analyzed using Fourier transform infrared. The in vitro antibacterial activity, release, contact angle, thermal, and mechanical properties of the nano mats were characterized. The scanning electron microscopy (SEM) analysis revealed that the produced mats are continuous, smooth, bead‐less, and inter connected. The examination of SEM images using ImageJ revealed that the fiber diameter ranged from 219 ± 47 nm to 284 ± 114 nm. The mats showed excellent anti‐bactericidal activity against both Staphylococcus aureus and Escherichia coli. During the 72‐h in vitro release investigation, an initial burst release was observed within the first 12 h, followed by sustained release of the extract over long period of time. The contact angle analysis showed, addition of leaf extract to the PCL nanofiber increased hydrophilicity. Furthermore, the nanofiber membranes had favorable mechanical properties. Overall, these findings suggested that R. prinoides leaf extract‐functionalized PCL nanofibers could be effective wound dressings with broad‐spectrum antimicrobial activity.

An Injectable, Self-Healing, Adhesive Multifunctional Hydrogel Promotes Bacteria-Infected Wound Healing.

Bacterial infections have a serious impact on public health. It is urgent to develop antibacterial hydrogels with good biocompatibility to reduce the use of antibiotics. In this study, poly(lipoic acid-co-sodium lipoate)-phytic acid (P(LA-SL)-PA) hydrogels are prepared by a simple mixture of the natural small molecules lipoic acid (LA) and phytic acid (PA) in a mild and green reaction environment. The crosslinking network is constructed through the connection of covalent disulfide bonds as well as the hydrogen bonds, which endow the injectable and self-healing properties. The P(LA-SL)-PA hydrogels exhibit an adjustable compression modulus and adhesion. The in vitro agar plates assay indicates that the antibacterial rate of hydrogels against Escherichia coli and Staphylococcus aureus is close to 95%. In the rat-infected wound model, the P(LA-SL)-PA hydrogels adhere closely to the tissue and promote epithelialization and collagen deposition with a significant effect on wound healing. These results prove that the P(LA-SL)-PA hydrogels could act as effective wound dressings for promoting the healing of infected wounds.

Biomedical Efficacy of Garlic‐Extract‐Loaded Core‐Sheath Plasters for Natural Antimicrobial Wound Care

AbstractThis work explores the application of Allium sativum (Garlic) extract, in the creation of novel polymeric core‐sheath fibers for wound therapy applications. The core‐sheath pressurized gyration (CS PG) technology is utilized to mass‐produce fibers with a polycaprolactone (PCL) core and a polyethylene oxide (PEO) sheath, loaded with garlic extract. The produced fibers maintain structural integrity, long‐term stability and provide a cell‐friendly surface with rapid antibacterial activity. The physical properties, morphology, therapeutic delivery, cytotoxicity, thermal and chemical stability of PCL, PEO, PEO/Garlic, Core‐Sheath (CS) PEO/PCL and PEO/Garlic/PCL fibers are analyzed. Findings show that the addition of garlic extract greatly increases the fibers’ thermal durability, while decreasing their diameter, thus improving cell adhesion and proliferation. In‐vitro release tests reveal a rapid release of garlic extract, which has significant antibacterial action against both Gram‐negative Escherichia coli (E. coli) and Gram‐positive Staphylococcus aureus (S. aureus) bacteria species. Cell viability experiments validate the fiber samples' biocompatibility and nontoxicity, making them appropriate for integrative medicine applications. These core‐sheath structures emphasize the potential of combining natural therapeutic agents with advanced material technologies to develop cost‐effective, sustainable and highly effective wound dressings, offering a promising solution to the growing concerns associated with conventional synthetic antibacterial agents.

Antibacterial and wound healing performance of a novel electrospun nanofibers based on polymethyl-methacrylate/gelatin impregnated with different content of propolis

Wound management and care mainly relies on the production of new and effective wound dressing materials. Chronic wounds require protection against pathogens and bacterial infection. Therefore, it is very important to design wound dressings with antibacterial and restorative capabilities. In this research, polymethyl-methacrylate (PMMA) and gelatin (Gel) nanofibers (NFs) were produced in different ratios by electrospinning method. Propolis (Pro) as a wound healing drug was added to the optimal PMMA70/Gel30 parent scaffold at different concentrations (10, 30 and 50 %w/v). Physical and chemical characterization, porosity, degradation, water vapor transmission rate (WVTR), swelling, mechanical properties and contact angle of the mats were analyzed. The NFs presented a homogeneous and defect-free morphology. The PMMA70/Gel30 mats showed the lowest average diameter (362.1 ± 132.3 nm) among the scaffolds. In addition, the highest wettability (∼70°) and WVTR (∼250 g/m2 × 24h) are related to PMMA70/Gel30. The addition of Pro extract (up to 50%) increased the mean diameter of NF (571.1 ± 171.8 nm). None of the scaffolds showed toxicity in the environment. The optimal PMMA/Gel/Pro50% NF showed more adhesion and higher cell viability than other samples. The antioxidant activity of PMMA/Gel/Pro50% is more about 10 times compared to PMMA70/Gel30. Pro extract showed significant antibacterial activity in the scaffolds, so that the release of Pro (∼70% in 24hrs) in the PMMA/Gel/Pro50% caused the inhibition of S. aureus (9 mm) and E. coli (11 mm) bacteria in Mueller's culture medium. All these findings confirm that the produced NF mats, especially those loaded with Pro, have a high potential to be used as an effective wound dressing.

Heparin-loaded hierarchical fiber/microsphere scaffolds for anti-inflammatory and promoting wound healing

Chronic non-healing wounds induced by oxidative stress and inflammation can activate inflammatory cells and produce large amounts of inflammatory mediators, which fail to maintain homeostasis in the skin and delay the wound-healing process. To tackle this issue, heparin-loaded hierarchical composite scaffolds comprised of electrospun fibers and electrosprayed microspheres were prepared to act as an effective anti-inflammatory wound dressing. Microspheres with different electrosprayed densities were deposited into the surface of the electrospun fibers for the improvement of surface topographical cues and cellular activities. The results indicated that the electrospun fibers followed by electrosprayed for 3 ​min to fabricate the composite fiber/microsphere scaffolds contributed to the best performance in terms of promoting cellular activities, with no obvious cytotoxicity, good adhesion morphology, and the fastest cell migration rate. In addition, a suitable amount of heparin was added to the composite scaffolds to alleviate inflammation. The significant adsorption efficiency of heparin-loaded composite scaffolds on inflammatory mediator MCP-1 indicates a favorable anti-inflammation effect in vitro. Furthermore, the heparin-loaded hierarchical scaffolds accelerated the pace of inflammatory wound healing in vivo when compared to commercial 3 ​M Tegaderm and non-heparin-loaded scaffolds. Our work provided a facile strategy for fabricating heparin-loaded hierarchical fiber/microsphere scaffolds to modulate cellular activities via topographical cues and accelerating the inflammatory wound healing process by electrostatic interactions between heparin and MCP-1. These findings suggested that the heparin-loaded hierarchical scaffold was expected to be a promising dressing for inflammatory wound healing.

Plant-Based Films and Hydrogels for Wound Healing.

Skin is constantly exposed to injury and infectious agents that can compromise its structural integrity and cause wounds. When this occurs, microorganisms from the skin microbiota and external bacteria and fungi can penetrate the wound and cause an infection, which complicates the healing process. Nowadays, there are several types of wound dressings available to treat wounds, some of which are incorporated with antimicrobial agents. However, the number of microorganisms resistant to these substances is rising. Therefore, the search for new, natural alternatives such as essential oils (EOs) and plant extracts (PEs) is on the rise. However, these substances present some limitations (poor bioavailability and poor target capacity), which limits their efficiency. Their incorporation in formulations in the form of films and hydrogels (HGs) can help to overcome these issues and may be a potential alternative to the current treatments. HGs and films incorporated with PEs and EOs have antimicrobial activity, promote the viability of skin cells and fibroblast migration, and are non-toxic and biocompatible. This review discusses the use of films and HGs for the topical delivery of EOs and PEs for wound treatment and their formulations as effective wound dressings, while debating some mechanisms and biological properties to elucidate their presumptive clinical relevance and possible applications.