Electrospun gelatin/PCL nanofibers incorporating curcumin loaded hydroxyapatite: a dual function antibacterial wound dressing for controlled drug release and accelerated skin repair

A comparative study on pre- and post-production plasma treatments of PCL films and nanofibers for improved cell-material interactions

In the current study, a novel wound dressing material for an effective wound healing was developed by loading Uridine (URD), an endogenous compound known for its regenerative properties, into polycaprolactone (PCL) nanofibers. Initially, PCL nanofibers without URD were fabricated from different PCL solutions (7, 8, 10 and 11% w/w) by electrospinning and optimum PCL concentration (10% w/w) for URD loading was determined. After loading URD at different concentrations (0.1, 0.5 and 1% w/w) into 10% PCL solution, PCL/URD nanofibers were electrospun. Structural characteristics, release kinetics as well as in vitro and in vivo effects of the PCL/URD nanofibers were studied and in vivo effects were compared with a conventional wound dressing material. Loading URD increased nanofiber diameters from 248 to 509 nm and decreased contact angles from 123.76° to 94.3° with increasing URD concentrations. URD showed a burst release in the first 60 min following a more gradual release up to the 5th day which best fitted with Korsmeyer–Peppas model. PCL/URD mats provided enhanced viability in vitro in MTT assay using mouse L929 fibroblast cell line. Furthermore, in vivo wound closure studies revealed an immediate and robust wound healing in rats treated with PCL/URD mats compared to PCL mats without URD as well as the conventional wound dressing material. These data suggest that URD-loaded PCL nanofiber mats are promising materials as wound dressing.Graphical abstract

The present work demonstrated an efficient cutaneous wound healing using Bixin-loaded polycaprolactone (PCL) nanofibers as a controlled delivery system. The influence of Bixin (Bix) content on PCL nanofiber, Bix-PCL1(2.5% w/w bix) and Bix-PCL2 (12.5% w/w bix) formation was investigated using electrical conductivity, attenuated total reflectance infrared spectroscopy, X-ray diffraction, thermal analysis, and scanning electronic microscopy. The results showed that a greater bixin concentration resulted in higher polymeric solution electrical conductivity. Moreover, higher polymeric solution electrical conductivity provides lower nanofibers in terms of average diameter than pure PCL nanofibers. In vitro release was largely governed by a diffusion-controlled mechanism. The initial Bixin release domain showed a burst release over the first 10 hours where approximately 30% and 40% of Bixin was released from Bix-PCL1 and Bix-PCL2 nanofibers, respectively. The second kinetic domain was comprised of a continuous and slow Bixin release that led to almost 100% of the Bixin being released within 14 days. The results on excisional wound model in induced diabetic mice indicated that the low concentration of Bixin released from loaded Bix-PCL nanofibers maintain the biological activity of Bixin and is efficient in accelerating the wound healing as well as in reducing the scar tissue area compared with pure PCL nanofibers. Therefore, soft material Bixin-loaded PCL nanofibers are a promising candidate for use in wound dressing. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1938-1949, 2017.

Development of thymol-loaded polymeric films designed as wound dressing materials: Physical, antioxidant, antibacterial, cytocompatibility, and wound healing properties

In this study, nanofibers were produced by the electrospinning method by adding 1%, 3%, 5%, and 7% silver nanoparticles (Ag NPs) into the polyvinyl alcohol/sodium caseinate (60/40, w/w) mixture. Electrospun materials were cross‐linked by immersion in a glutaraldehyde bath. Thus, antibacterial wound dressings that could be used on exuding wounds were developed. According to the scanning electron microscopy images of nanofibers, the cross‐linking process by immersion method did not cause negative effects such as breakage or adhesion on the surface of fibers. The cross‐linking of nanofibers was demonstrated by the presence of acetal linkages by Fourier‐transform infrared spectroscopy analysis. The cross‐linking process significantly improved the thermal properties of the nanofibers. The lowest crystallinity calculated in the differential scanning calorimeter was observed in the 3% Ag NP‐added nanofiber with a value of 1.83%. It exhibited the lowest total soluble matter content with a value of 11.98% owing to its high cross‐linking density. In addition, the 3% Ag NP‐added nanofiber, which had the highest toughness and ductility, displayed the highest tensile stress with 3.5 MPa and the highest tensile strain with 7.53%. Moreover, it showed 78.11% cell viability on the L929 fibroblast cell line at the end of the 24th hour. It was indicated that although the electrospun mats maintained 100% antibacterial effectiveness, they could not be used as a wound dressing for 48 h. It was reported that only 3% Ag NP‐added nanofiber could be used as a 100% effective antibacterial wound dressing for both Escherichia coli and Staphylococcus aureus provided that it was renewed every 24 h. Consequently, it was notified that cross‐linking by the immersion method can be used in biomedical applications. Highlights The antibacterial effects of Ag NP‐doped PVA/NaCAS electrospun mats were significant. The cross‐linking process did not induce toxic effects some of the nanofibers. High cross‐linking density was observed in the nanofibers. The swelling property of nanofibers is a good feature required in an ideal wound dressing.

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

The skin serves as a critical barrier against external pathogens, and its wound healing is a complex biological process that requires careful management to ensure optimal tissue regeneration. Hydrogels, a class of hydrophilic polymers, have emerged as promising materials for wound dressings due to their biocompatibility, biodegradability, and ability to create a moist wound environment conducive to cell proliferation and migration. In this research, a hydrogel dressing containing cefdinir (Cef) was made from a combination of carboxymethyl cellulose (CMC) and gelatin (Gel) by a physical crosslinking method, and their physicochemical, mechanical, and biological properties were investigated. Results show that the addition of Cef does not cause a significant change in the morphology or the tensile strength of the wound dressing. The swelling and degradation rate of the hydrogel slightly increased in the presence of Cef. The presence of Cef enhanced antibacterial effects up to 2.5-fold against P. aeruginosa (35 mm), S. aureus (36 mm), and S. pyogenes (35 mm). The results of the cytotoxicity test showed the absence of cytotoxicity in both drug-containing and drug-free wound dressings, as well as a survival rate of over 75% in cells after 48 h. The drug-containing wound dressing accelerates the formation of the epidermis layer and the production of fibroblast cells, and as a result, accelerates the wound healing process. The percentage of wound healing on the ninth day of treatment for an untreated wound was 30%, while this percentage was 40% with a wound dressing without medicine and 60% with a wound dressing containing medicine, and on the fifteenth day of treatment, the wound treated with both wound dressings had more than 85% healing. As a result, it is possible to use CMC/Gel hydrogel polymeric wound dressing containing Cef as a wound dressing for wound healing, according to the desired physicochemical properties and biocompatibility.

Rhamnus 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.

Evaluation of sericin/collagen membranes as prospective wound dressing biomaterial

Development of drug-loaded wound dressings is often performed without systematic consideration of the changing wound environment that can influence such materials' performance. Among the crucial changes are the wound pH and temperature, which have an immense effect on the drug release. Detailed release studies based on the consideration of these changing properties provide an important aspect of the in vitro performance testing of novel wound dressing materials. A sodium carboxymethyl cellulose-based wound dressing, with the incorporated non-steroidal anti-inflammatory drug diclofenac, was developed and characterised in regard to its physico-chemical, structural and morphological properties. Further, the influence of pH and temperature were studied on the drug release. Finally, the biocompatibility of the wound dressing towards human skin cells was tested. Incorporation of diclofenac did not alter important properties (water retention value, air permeability) of the host material. Changes in the pH and temperature were shown to influence the release performance and have to be accounted for in the evaluation of such dressings. Furthermore, the knowledge about the potential changes of these parameters in the wound bed could be used potentially to predict, and potentially even to control the drug release from the developed wound dressing. The prepared wound dressing was also proven biocompatible towards human skin cells, making it interesting for potential future use in the clinics.

Recently, with the progression in wound dressings, the importance of the biocompatible material with enhanced features for potential applications in the biomedical field has been more developed. Current strategies focus on the acceleration of the wound healing by systematically designed dressing materials. In this study, biocompatible hydrogel films with the combination of silk fibroin, hyaluronic acid and gelatin biopolymers were fabricated. To gain the enhanced wound healing behavior of wound dressings, boric acid (BA) was formulated in various ratios. The prepared hydrogel films were characterized in terms of FTIR, TGA, DSC, and SEM analysis. Following to the swelling and mechanical tests, in vitro biocompatibility and wound healing tests were performed against L929 fibroblast cell line. Results suggest that the presence of 1% (wt/vol) BA in the formulation of silk fibroin/gelatin/hyaluronic acid based hydrogel films is the key in providing such an enhanced mechanical and wound healing feature and may offer an alternative approach for wound healing treatment.

Surface modification of biomaterials is a way to tailor cell responses whilst retaining the bulk properties. In this work, chitosan membranes were prepared by solvent casting and treated with nitrogen or argon plasma at 20 W for 10-40 min. AFM indicated an increase in the surface roughness as a result of the ongoing etching process. XPS and contact angle measurements showed different surface elemental compositions and higher surface free energy. The MTS test and direct contact assays with an L929 fibroblast cell line indicated that the plasma treatment improved the cell adhesion and proliferation. Overall, the results demonstrated that such plasma treatments could significantly improve the biocompatibility of chitosan membranes and thus improve their potential in wound dressings and tissue engineering applications.

Tissue engineered implants derived from sustainable nanocellulose and polyethylene glycol (PEG) loaded with polyphenols: An in vivo study on albino rats for wound dressing.

Antimicrobial nanofibers of poly(ϵ‐caprolactone) (PCL) were prepared by electrospinning of a PCL solution with small amounts of silver‐loaded zirconium phosphate nanoparticles (nanoAgZ) for potential use in wound dressing applications. The electrospun nanoAgZ‐containing PCL nanofibers were characterized using field emission scanning electron microscopy, energy dispersive X‐ray spectrum (EDX), X‐ray diffraction analysis (XRD), antimicrobial tests, and biocompatibility tests. The SEM, EDX, and XRD investigations of the electrospun fibers confirmed that silver‐containing nanoparticles were incorporated and well dispersed in smooth and beadless PCL nanofibers. The results of the antimicrobial tests showed that these fibers have maintained the strong killing abilities of Ag+ existed in the nanoAgZ against the tested bacteria strains and discoloration has not been observed for the nanofibers. To test the biocompatibility of nanofibers as potential wound dressings, primary human dermal fibroblasts (HDFs) were cultured on the nanofibrous mats. The cultured cells were evaluated in terms of cell proliferation and morphology. The results indicated that the cells attached and proliferated as continuous layers on the nanoAgZ‐containing nanofibers and maintained the healthy morphology of HDFs. The earlier results suggested that nanoAgZ‐containing fibers may be expected to be a novel material for potential wound dressing applications because of the significant bacteriostatic activities and good biocompatibility. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

Nanocellulose as drug delivery system for honey as antimicrobial wound dressing