Bilayer Electrospun Membrane Modification with Phytochemicals for Wound Healing / Scar Removal

Abstract

The main aim of this work was to synthesize bilayer polymeric membranes through electrospinning and then modify the surface of those membranes with phytochemicals by dip coating. These modified membranes are prospective candidates for wound healing and scar removal. Electrospinning is relatively a new technique to produce nano and micro fibrous membranes having nano and microporous morphology for various biomedical applications. Phytochemicals such as Licorice and Bearberry extracts have been used for centuries in Ayurveda and traditional medicine throughout the world, including Persia, China, India and the Pakistan. These extracts have been found effective in the treatment of wounds, hyperpigmentation, melanin reduction, skin aging, freckles and scars for hundreds of years. Many phytochemicals such as alkaloids, flavonoids, tannins, terpenes, arbutin, glyrrhizic acid, volatile oils and organic acids have been found in the chemical composition of the licorice and bearberry extracts. These compounds possess antibacterial, antioxidant, anti-inflammatory, antimicrobial, and in anticancer activities. These extracts were loaded on the electrospun membranes using chitosan to modify the surface by dip coating. The concentrations ranging from 2%, 4%, 8% of both extracts was used. The characterization of the modified electrospun scaffolds was done by FTIR and SEM analysis to evaluate the chemical and physical structure. In vitro release of the extracts was conducted to analyze the release profile of the coated membranes. The in vitro biocompatibility and wound healing properties of the extracts was studied using the mouse Fibroblast cell line NH3T3 (ATCC CRL 1658) by co-culturing the cells with coated membranes for 1, 3, and 7 days. The analysis of proliferation was conducted using Alamar blue assay and cell migration through scratch test analysis. It was found that the modified membranes showed presence of phytochemicals such as flavonoids, triterpenes, glyrrhizic acid, Gallic acid, ursolic acid, tannic acid, resin, arbutin and hydroquinone after the surface coating. The physical morphology showed microfibrous and nanofibrous structure with great pore size. Both features are highly desirable for the drug release and tissue engineering applications. Contact angle x

measurements suggest increase in the hydrophilicity of the membranes due to chitosan coating which may further influence the cell attachment needed for the controlled release of drug. The in vitro drug release from 8% BE was 53%, and 8% LE was 62% after 15 days which suggests a sustained release potential. The modified membranes were found to be highly biocompatible and with high cell proliferation on all time points (1, 3 and 7 days). The significantly higher cell proliferation was observed on day 1 and day 7 in all membranes compared to the control (cell on TCP Tissue culture plastic). The scratch test analysis of the cells co-cultured with loaded phytochemicals confirmed that extracts positively affect the migration of the cells in vitro which is an evaluation of wound healing. The results suggest that the electrospun membranes coated with extracts possess regenerative potential and activate the wound healing. Further molecular analysis and in vivo tests may prove their effectiveness as scar removing dressings.