Potential Wound Dressings Research Articles

Release Kinetics of Dexamethasone Phosphate from Porous Chitosan: Comparison of Aerogels and Cryogels.

Porous chitosan materials as potential wound dressings were prepared via dissolution of chitosan, nonsolvent-induced phase separation in NaOH-water, formation of a hydrogel, and either freeze-drying or supercritical CO2 drying, leading to "cryogels" and "aerogels", respectively. The hydrophilic drug dexamethasone sodium phosphate was loaded by impregnation of chitosan hydrogel, and the release from cryogel or aerogel was monitored at two pH values relevant for wound healing. The goal was to compare the drug-loading efficiency and release behavior from aerogels and cryogels as a function of the drying method, the materials' physicochemical properties (density, morphology), and the pH of the release medium. Cryogels exhibited a higher loading efficiency and a faster release in comparison with aerogels. A higher sample density and lower pH value of the release medium resulted in a more sustained release in the case of aerogels. In contrast, for cryogels, the density and pH of the release medium did not noticeably influence release kinetics. The Korsmeyer-Peppas model showed the best fit to describe the release from the porous chitosan materials into the different media.

Electrospun Polycaprolactone/Chitosan Nanofibers Containing Cordia myxa Fruit Extract as Potential Biocompatible Antibacterial Wound Dressings.

The goal of the current work was to create an antibacterial agent by using polycaprolactone/chitosan (PCL/CH) nanofibers loaded with Cordia myxa fruit extract (CMFE) as an antimicrobial agent for wound dressing. Several characteristics, including morphological, physicomechanical, and mechanical characteristics, surface wettability, antibacterial activity, cell viability, and in vitro drug release, were investigated. The inclusion of CMFE in PCL/CH led to increased swelling capability and maximum weight loss. The SEM images of the PCL/CH/CMFE mat showed a uniform topology free of beads and an average fiber diameter of 195.378 nm. Excellent antimicrobial activity was shown towards Escherichia coli (31.34 ± 0.42 mm), Salmonella enterica (30.27 ± 0.57 mm), Staphylococcus aureus (21.31 ± 0.17 mm), Bacillus subtilis (27.53 ± 1.53 mm), and Pseudomonas aeruginosa (22.17 ± 0.12 mm) based on the inhibition zone assay. The sample containing 5 wt% CMFE had a lower water contact angle (47 ± 3.7°), high porosity, and high swelling compared to the neat mat. The release of the 5% CMFE-loaded mat was proven to be based on anomalous non-Fickian diffusion using the Korsmeyer-Peppas model. Compared to the pure PCL membrane, the PCL-CH/CMFE membrane exhibited suitable cytocompatibility on L929 cells. In conclusion, the fabricated antimicrobial nanofibrous films demonstrated high bioavailability, with suitable properties that can be used in wound dressings.

A paintable composite hydrogel patch for potential wound dressings

Hydrogel has incomparable advantages in promoting chronic wound healing due to its high-water content, softness and excellent physiological activity. However, as a treatment platform, most hydrogel dressings are fixed at the wound site in block form, which is difficult to fully contact and fit with the tissue, limiting their efficacy. Here, a composite hydrogel that can be conveniently painted to material surface and closely adhered is developed. The hydrogel is obtained through a double network strategy and multiple non-covalent interactions between N-(3,4-dihydroxyphenylethyl) acrylamide (NA)-acrylic acid-acrylamide terpolymer, nano Fe3O4 and chitosan. NA monomer with catechol-like structure can significantly improve the adhesion strength of the hydrogel to 25.06 kPa, which is superior to the commercially available fibrin glue (∼11.5 kPa). Notably, the high-efficiency paintability of the hydrogel can be achieved just by the initiation of ultra-trace potassium persulfate. The hydrogel patch also exhibits satisfactory mechanical properties and cytocompatibility. Hence, this multifunctional hydrogel will be conveniently painted to the wound bed as a patch without adverse liquid leakage, providing an optimistic material for chronic wound treatment.

Carboxymethyl cellulose/poloxamer Gels Enriched With Essential Oil and Ag Nanoparticles: Promising Wound Dressings

Aim: Essential oils are promising antibacterial and wound-healing agents that should be explored for the design of wound dressings. Materials & methods: Topical gels prepared from a combination of carboxymethyl celluloseand poloxamer were incorporated with tea tree and lavender oil together with Ag nanoparticles. In vitro release, cytotoxicity, antibacterial, and wound healing studies were performed. Results: The gels displayed good spreadability with viscosity in the range of 210-1200cP. The gels displayed promising antibacterial activity against selected Gram-positive and Gram-negative bacteria used in the study. The % cell viability of the gels was more than 90.83%. Conclusion: The topical gels displayed excellent wound closure in vitro revealing that they are potential wound dressings for bacteria-infected wounds.

Novel Nanocomposite Hydrogels Based on Crosslinked Microbial Polysaccharide as Potential Bioactive Wound Dressings.

A multitude of dressings have been developed to promote wound repair, such as membranes, foams, hydrocolloids and hydrogels. In this study, a crosslinked polysaccharide hydrogel was mixed with a bioactive ingredient to synthesize a novel nanocomposite material to be used in wound healing. Variation of the ratio between hydrogel components was followed and its effect was analyzed in regard to swelling, degradation rate and thermo-mechanical behavior. The resulting crosslinked structures were characterized by FTIR and microscopy analyses. The antimicrobial activity of the crosslinked hydrogels loaded with bioactive agent was evaluated using two bacterial strains (Gram-positive Staphylococcus aureus and Gram-negative bacteria Escherichia Coli). All the results showed that the new synthesized biopolymer nanocomposites have adequate properties to be used as antibacterial wound dressings.

Novel Collagen-Polyphenols-Loaded Silica Composites for Topical Application.

Lesions can affect skin functions and cause a simple issue, such as dehydration, or more challenging complications, such as bacterial infections. The purpose of this study was to design composites for topical application that can prevent and/or assist in bacterial infections and support cell regeneration using natural components. A polyphenolic extract obtained from Salvia officinalis was embedded in functionalized mesoporous silica nanoparticles for better stability, followed by their distribution into a collagen porous scaffold. The resulting polyphenols-loaded MSN exhibited enhanced antibacterial activity and good cytocompatibility. Improved thermal stability of the collagen porous scaffold was obtained due to the presence of the functionalized MSN. For the first time, collagen-polyphenols-loaded silica composites were reported in the literature as potential wound dressings. The newly developed composites showed excellent sterility.

Natural Carrier-Free Binary Small Molecule Self-Assembled Hydrogel Synergize Antibacterial Effects and Promote Wound Healing by Inhibiting Virulence Factors and Alleviating the Inflammatory Response.

Methicillin-resistant Staphylococcus aureus (MRSA)-infected skin wounds have caused a variety of diseases and seriously endanger global public health. Therefore, multidimensional strategies are urgently to find antibacterial dressings to combat bacterial infections. Antibacterial hydrogels are considered potential wound dressing, while their clinical translation is limited due to the unpredictable risks and high costs of carrier excipients. it is found that the natural star antibacterial and anti-inflammatory phytochemicals baicalin (BA) and sanguinarine (SAN) can directly self-assemble through non-covalent bonds such as electrostatic attraction, π-π stacking, and hydrogen bonding to form carrier-free binary small molecule hydrogel. In addition, BA-SAN gel exhibited a synergistic inhibitory effect on MRSA. And its plasticity and injectability allowed it to be applied as a wound dressing. Due to the matched physicochemical properties and synergistic therapeutic effects, BA-SAN gel can inhibit bacterial virulence factors, alleviate wound inflammation, promote wound healing, and has good biocompatibility. The current study not only provided an antibacterial hydrogel with clinical value but also opened up new prospects that carrier-free hydrogels can be designed and originated from clinically used small-molecule phytochemicals.

Investigation of wound healing efficiency of multifunctional eudragit/soy protein isolate electrospun nanofiber incorporated with ZnO loaded halloysite nanotubes and allantoin

One significant aspect of the current therapeutic agents employed in wound healing involves the engineering of nano polymeric scaffolds to mimic the properties of extracellular matrix (ECM). The present work aimed to prepare and evaluate Eudragit® L100 (EU) nanofibers in combination with soy protein isolate (SPI). Allantoin (Ala) with a 2 wt% was encapsulated as a model drug renowned for its anti-inflammatory and antioxidant agents. Moreover, the synthesized ZnO-halloysite nanotubes (ZHNTs) with different concentrations of 1, 3, and 5 wt% were incorporated into the EU/SPI/Ala nanofiber as a reinforcing filler and a remarkable antibacterial agent. The scanning electron microscope (SEM) analysis showed that by increasing the weight percentage of SPI from 1 % to 2.5 %, the average diameter of nanofibers decreased from 132.3 ± 51.3 nm to 126.7 ± 47.2 nm. It was 223.5 ± 95.6 nm for nanofibers containing 5 wt% ZHNTs (the optimal sample). The evaluation of in vitro release kinetics of Ala for 24 h, showed a burst release during the first 2 h and a sustained release during the subsequent times. Moreover, the structure, crystallinity, and thermal stability of synthesized nanofibers were characterized by Fourier Transform Infrared Spectrometry (FTIR), X-ray diffraction (XRD), and Thermo gravimetric analysis (TGA), respectively. In vitro degradation and mechanical characteristics of these nanofibers were studied. Furthermore, the capability of the nanofibers for cell proliferation was revealed through the MTT test and field emission scanning electron microscopy (FESEM) images of cell attachment. The antimicrobial activity of EU/SPI/Ala/ZHNTs showed that this sample with high ZHNTs content (5 w%t) had the most remarkable antibacterial activity against S. aureus. The results revealed that EU/SPI/Ala/ZHNTs mats could be promising potential wound dressings.

Development of Polyphenol-Functionalized Gelatin-Poly(vinylpyrrolidone) IPN for Potential Biomedical Applications.

Owing to their suitable physical and chemical properties, hydrogels have been considered a convenient choice for wound dressings because of the advantages that they offer, such as maintaining the moist environment required for wound healing. In this research, interpenetrating hydrogels of polyphenol-functionalized gelatin (GE), a water-soluble protein derived from natural polymer collagen with excellent biocompatibility, no immunogenicity, and hydrophilicity, and polyvinylpyrrolidone (PVP), a hydrophilic, non-toxic, biodegradable, biocompatible polymer that is soluble in many solvents, widely used in biomedical applications, particularly as a basic material for the manufacturing of hydrogel wound dressings, were synthesized. Gallic acid (GA) was selected in this work to study whether the interpenetrating polymer networks (IPNs) synthesized can provide antioxidant properties given that this material is intended to be used as a potential wound dressing. The obtained IPN hydrogels showed improved mechanical properties in comparison with pristine gelatin network (net-GE), a porous structure, and good thermal stability for biological applications. The antioxidant capacity of the IPNs functionalized with GA was compared to Trolox standards, obtaining a radical scavenging activity (RSA%) equivalent to a Trolox concentration of 400 µM.

Optimization and characterization of a novel tea tree oil-integrated poly (ε-caprolactone)/soy protein isolate electrospun mat as a wound care system

A set of poly (ε-caprolactone)/soy protein isolate (PCL/SPI) mats with different ratios of PCL to SPI was fabricated using the electrospinning method. The mat with PCL to SPI ratio of 95:5 (PS 95:5) had the narrowest nanofibers, the highest percentage of porosity, the lowest swelling ratio, the least vapor transmission, and the slowest degradation rate among the prepared mats. The hemolysis assay indicated that all mats can be considered biocompatible biomaterials. In continue, three different weight ratios of tea tree oil (TTO) were loaded into the PS 95:5 mat. The release profiles illustrated that higher amounts of TTO could be released in an acidic environment. The antioxidant activity of the mats increased by the increase in their TTO content. The cell viability test, cell adhesion images, and live/dead assay of TTO-loaded mats affirmed that all fabricated mats were biocompatible. The scratch wound assay expressed that TTO accelerates the rate of wound closure. The TTO-loaded mats illustrated antibacterial activity against both Escherichia coli and Staphylococcus aureus bacteria. The obtained outcomes revealed that TTO-loaded PCL/SPI mats can be considered promising potential wound dressings.

Simultaneous loading of clarithromycin and zinc oxide into the chitosan/gelatin/polyurethane core–shell nanofibers for wound dressing

Clarithromycin as a macrolide antibiotic and zinc oxide (ZnO) nanoparticles with antibacterial and anti-inflammatory properties was incorporated into the chitosan/gelatin/polyurethane (PU) core–shell nanofibers prepared by the coaxial electrospinning method. The morphology and structure of nanofibers were characterized using SEM, FTIR, water contact angle, degradation rate, and swelling tests. The mean fiber diameters of the chitosan/gelatin/PU (CGP), CGP containing 1000 μM clarithromycin, CGP containing 2000 μM clarithromycin, CGP containing 0.5% ZnO, CGP containing 1 wt% ZnO, CGP containing 1000 μM clarithromycin, and 0.5 wt% ZnO and CGP containing 2000 μM clarithromycin, and 1 wt% ZnO were 210 ± 110 nm, 235 ± 100 nm, 250 ± 120 nm, 300 ± 120 nm, 360 ± 130 nm, 410 ± 130 nm, and 460 ± 140 nm, respectively. The gradual faster release of ZnO nanoparticles from core–shell nanofibers was obtained within 24 h; whereas, the sustained release of clarithromycin was achieved during 120 h. Loading of clarithromycin and ZnO nanoparticles into the nanofibers resulted in 100% bactericidal activity of core–shell nanofibers against both Escherichia coli and Staphylococcus aureus. The cell viability results indicated that loading of 0.5 wt% ZnO nanoparticles and 2000 μM clarithromycin was suitable for the development of the synthesized core–shell nanofibers as a potential wound dressing.

Exploring Hyaluronic Acid as a Potential Standard Dressing for Burn Wound

A massive loss of dermis layer such as in deep burn wounds brings several important consequences and complications which contribute to major problems, personally and economically, for the burn patients and their families. Ideal burn wound treatment should not focus merely on removing devitalized tissue, controlling bacterial growth, and promoting healing, but also on accelerating the healing process and preventing scar-related complications. The evolution of biomaterial science for burn wounds has provided physicians with novel dressing materials based on natural and also synthetic polymers, and the latest development introduces the use of hyaluronic acid (HA) as a potential burn wound dressing. HA has been studied to have involvement in many phases of the wound healing process, such as inflammation, granulation, and re-epithelialization. Dealing with the unfavorable physical properties of the native polymer such as solubility and rapid degradation, modification and improvement are designed to produce insoluble molecules to facilitate hyaluronic acid-based (HA-based) wound dressing products as a valuable option for the treatment of deep burns. Our literature review shares the development and the outcome of the use of these products in burns. The currently available clinical experience suggests that these HA-based wound dressing products provide a safe therapeutic method useful for the treatment of acute burns and minimize scar-related complications, although further improvements are still required to make an ideal HA-based wound dressing product for standard burn wound treatment.

Heparinized Collagen Scaffolds Based on Schiff Base Bonds for Wound Dressings Accelerate Wound Healing without Scar.

Skin wound healing is a complex process with multiple growth factors and cytokines participating and regulating each other. It is essential to develop novel wound dressings to accelerate the wound healing process. In this study, we developed the heparinized collagen scaffold materials (OL-pA), and the cross-linking reaction was based on the Schiff base reaction between pig acellular dermal matrix (pADM) and dialdehyde low molecular weight heparin (LMWH). Compared with pADM, the OL-pA modified by cross-linking still retained the triple helix structure of native collagen. When the dosage of the OL cross-linking agent was 12 wt %, the cross-linking density of OL-pA was 49.67%, the shrinkage temperature was 75.6 °C, the tensile strength was 14.62 MPa, the elongation at break was 53.14%, and the water contact angle was 25.1°, all of which were significantly improved compared with pADM. The cytocompatibility test showed that L929 cells adhered better on the surface of OL-pA scaffolds, and the proliferation ability of primary fibroblasts was enhanced. In vivo experiments showed that the OL-pA scaffolds could better accelerate wound healing, more effectively promote the positive expression of bFGF, PDGF, and VEGF growth factors, accelerate capillary angiogenesis, and promote wound scarless healing. In summary, the OL-pA scaffolds have more excellent hygrothermal stability, mechanical properties, hydrophilicity, and cytocompatibility. Especially the scaffolds have significant pro-healing properties for the full-thickness skin wound of rats and are expected to be a potential pro-healing collagen-based wound dressing.

Oxidized Bletilla rhizome polysaccharide-based aerogel with synergistic antibiosis and hemostasis for wound healing

Uncontrolled bleeding and infection following trauma remain a clinical challenge. Here, we developed a synergistic hemostatic and antibacterial aerogel dressing based on oxidized Bletilla rhizome polysaccharide Schiff Base (ORBPS) and polyvinyl alcohol (PVA) by using a combined freeze-drying/cross-linking process. Bletilla rhizome polysaccharide (RBP) was extracted by water extraction and alcohol precipitation. RBP contained mannose and glucose in the molar ratio of 2:1 and its molecular weight was 8.2 × 105 g/mol. ORBPS was prepared via Schiff base reaction between silver sulfadiazine and oxidized RBP (ORBP), and verified by FTIR and NMR spectra. The resultant ORBPS/PVA aerogel exhibited excellent antibacterial and hemostatic capabilities. The aerogel also showed good liquid absorption capacity and biocompatibility. Full-thickness skin defect experiments indicated the aerogel enhanced wound healing by reducing inflammation, promoting angiogenesis, and accelerating epithelialization. Therefore, ORBPS/PVA aerogel may be a potential hemostasis and anti-infection wound dressing.

Dissolvable wound dressing loaded with silver nanoparticles together with ampicillin and ciprofloxacin.

Aim: The current study is focused on the development of water-soluble wound dressings, which are potential dressings for the treatment of burn wounds. Materials & methods: Sodium alginate-based dissolvable wound dressings were prepared and loaded with silver nanoparticles and various antibiotics (ampicillin and ciprofloxacin) followed by characterization and in vitro antibacterial studies. Results & conclusions: The prepared sodium alginate-based dissolvable wound dressing exhibited good porosity, water uptakeand moisture content, promising antibacterial activity, high absorption capacity of simulated wound exudates, excellent water vapor transmission ratein the range of 2000 to 5000g/m2 day-1, sustained drug-release profilesand watersolubility. The wound dressings were active against Proteus mirabilis, Staphylococcus aureus, Proteus vulgaris, Escherichia coliand Klebsiella aeruginosa strains of bacteria. The results obtained revealed the wound dressing as potential wound dressings for burn wounds and sensitive skin.

Carboxymethyl chitosan-based electrospun nanofibers with high citral-loading for potential anti-infection wound dressings

As a natural antibacterial agent with pleasant fragrance, citral possesses low aqueous solubility. To improve citral loading in hydrophilic nanofiber, Pickering emulsion electrospinning strategy was proposed for anti-infection dressing development. The in-situ aggerated β-cyclodextrin-citral inclusion complex particles (βCPs) were used as emulsion stabilizers, while citral and carboxymethyl chitosan (CMCS)/polyvinyl alcohol (PVA) mixed solutions were used as the inner “dispersed oil phase” and outer “continuous water phase”, respectively. The results of electronic microscope investigation shown βCPs possessed regular cube appearances with a size of 5.5 ± 2.2 μm, which might improve the emulsion storage stability based on visual investigation. Moreover, randomly oriented and bead-on-string nanofibers with βCPs uniformly distributed could be obtained under optimized compositions and electrospinning parameters. Despite volatilization during electrospinning, nanofibers with high citral loading possessed good antibacterial performance against Staphylococcus aureus and Escherichia coli. In vitro hemolysis test indicated that nanofibers were hemocompatible. In addition, both fiber matrix and citral could promote the proliferation of mouse fibroblast cells. And the permeability of the fibers was adjustable. Thus, CMCS/PVA/βCPs/citral nanofibers could potentially protect wound from infection. In summary, CMCS/PVA/βCPs/citral nanofibers seemed to be promising alternatives to conventional wound dressings.

Antibacterial composite hydrogels of graphene quantum dots and bacterial cellulose accelerate wound healing.

The increased antibiotic resistance of pathogenic bacteria requires intense research of new wound healing agents. Novel wound dressings should be designed to provide wound disinfection, good moisture, and fast epithelization. In this study, bacterial cellulose (BC) was impregnated with graphene quantum dots (GQDs) for potential use in wound healing treatment. The BC was successfully loaded with approximately 11.7wt% of GQDs. The actual release of GQDs from new designed composite hydrogels were 13%. Novel GQDs-BC hydrogel composites are biocompatible and showed significant inhibition towards Staphylococcus aureus and Streptococcus agalactiae and bactericidal effect towards Methicillin-resistant Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The in vitro healing analysis showed significant migration of human fibroblasts after the GQDs-BC hydrogels application. Furthermore, after 72 h exposure to GQDs-BC, endothelial nitric oxide synthase, vascular endothelial growth factor A, matrix metallopeptidase 9, and Vimentin gene expression in fibroblast were significantly upregulated promoting angiogenesis. GQDs-BC hydrogel composites showed very good wound fluid absorption and water retention, which satisfies good dressing properties. All obtained results propose new designed GQDs-BC hydrogels as potential wound dressings.

Bioactive Carboxymethyl Cellulose/ Silk Sericin Scaffolds Containing Medicinal Turmeric with Excellent Antibacterial and Anti-Inflammatory Activity as Potential Wound Dressings

Bioactive Carboxymethyl Cellulose/ Silk Sericin Scaffolds Containing Medicinal Turmeric with Excellent Antibacterial and Anti-Inflammatory Activity as Potential Wound Dressings

A Review of The X-ray Powder Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) Characterization for Essential Oil

The samples that were analysed using FTIR and XRD are reviewed in this study. Genuine commercial essential oils as well as essential oils mixed with nanoparticles were employed. According to FTIR studies, commercial essential oils only comprise 20% true essential oil and are mixed with impurities. Aside from that, each essential oil contains molecules such as C=C, C=O, and –OH. The creation of an inclusion complex between thymus essential oil (TEO) and nanoparticles (NS) components was revealed by XRD analysis. GEO composite sheets including PVA/GA/CS were found to be potential wound dressing and food packaging solutions.

Cellulose-Based Nanofibril Composite Materials as a New Approach to Fight Bacterial Infections.

Antibiotic resistant microorganisms have become an enormous global challenge, and are predicted to cause hundreds of millions of deaths. Therefore, the search for novel/alternative antimicrobial agents is a grand global challenge. Cellulose is an abundant biopolymer with the advantages of low cost, biodegradability, and biocompatibility. With the recent growth of nanotechnology and nanomedicine, numerous researchers have investigated nanofibril cellulose to try to develop an anti-bacterial biomaterial. However, nanofibril cellulose has no inherent antibacterial activity, and therefore cannot be used on its own. To empower cellulose with anti-bacterial properties, new efficient nanomaterials have been designed based on cellulose-based nanofibrils as potential wound dressings, food packaging, and for other antibacterial applications. In this review we summarize reports concerning the therapeutic potential of cellulose-based nanofibrils against various bacterial infections