Improving stability and mechanical strength of electrospun chitosan-polycaprolactone scaffolds using genipin cross-linking for biomedical applications

Abstract

Electrospun nanofiber scaffolds have become vital in biomedical applications due to their high surface area and tunable properties. Chitosan (CS) is widely used, but its rapid degradation limits its effectiveness. This study addresses this limitation by blending CS with polycaprolactone (PCL) and applying genipin cross-linking to enhance its stability and mechanical properties. Scanning electron microscopy indicated a uniform morphology of the electrospun fibers, and further, the crystallinity of the scaffolds before and after cross-linking is verified. Fourier-transform infrared spectroscopy is used to analyze the chemical structure, identifying the presence of trifluoroacetic acid residues in the as-spun fibers. These residues are successfully eliminated through neutralization and cross-linking, which are critical for enhancing stability and cell viability in in-vitro studies. Mechanical testing revealed that cross-linked CS+PCL scaffolds exhibit a 350% increase in tensile strength compared to pure CS, and zeta potential reaches the favorable for cell development -26.27 mV. The cytotoxicity assay results with murine NIH 3T3 fibroblast cells indicate the suitability of CS+PCL scaffolds for targeted tissue engineering and wound healing. This work establishes the potential for fine-tuning scaffold properties to create stable, functional, and biocompatible substrates for extended biomedical use.