In vitro and in vivo assessment of gallic acid-chitosan/polycaprolactone conjugate electrospun nanofibers for wound healing

Abstract

The development of innovative multifunctional wound healing materials based on natural bioactives has attracted a great deal of attention in recent years due to their ability to potentiate the healing process and minimize the challenges linked with conventional wound dressings. The current study demonstrates the development and evaluation of a novel nanofibrous wound healing mat made of Gallic acid-chitosan conjugate (GAC) incorporated within a polycaprolactone (PCL) matrix using an electrospinning technique. The GAC conjugate was synthesized by green synthesis using a free radical polymerization reaction to improve the chitosan's free radical scavenging properties. FTIR, DSC, XRD, and UV spectral analysis characterized the formation of GAC conjugate. The red shift observed in the UV spectrum suggested alterations in electronic transitions resulting from the creation of covalent bonds between Chitosan (CA) and Gallic acid (GA). The appearance of broader and weaker peaks in DSC and the reduced crystallinity in XRD spectrum, signify structural modifications, thereby providing valuable insights into the interaction and structural changes occurring in the GAC conjugates.The SEM image revealed a porous flake-like structural network of GAC conjugate due to the reduced intermolecular hydrogen bonding between them. The functional layer of the nanofibrous mat was produced by electrospinning GAC conjugate with polycaprolactone (PCL) to provide mechanical integrity to the nanofibrous mat. The electrospun nanofibers were characterized using FTIR, DSC, and SEM and evaluated for cell cytotoxicity, angiogenesis, and in vivo wound healing potential in female Wistar rats. The FTIR spectra confirmed the presence of GAC conjugate in the nanofibers, validating the conjugation process. The results demonstrated the successful incorporation of GAC conjugate within the PCL nanofibrous mat, thereby confirming the improvement in the biological properties of the mats. The nanofibrous mat showed angiogenesis activity in the yolk sac membrane assay confirming the property of nanofibers to facilitate cellular adhesion, migration and promotion of angiogenesis with no cytotoxic effect on the viability of mouse stromal cells. On the sixteenth day of therapy, wounds dressed with GAC/PCL nanofibrous mat exhibited a significant improvement in the percent wound closure (94.43%) as compared to the control group (p < 0.05). These results supported the application of GAC/PCL as a novel biomaterial for wound dressing to accelerate the process of wound healing.