Continuous Chitosan/Poly (Vinyl Alcohol) Nanofiber in Collagen Hydrogel to Prepare Mechanically Robust Fibrous...

Collagen (Col) hydrogel scaffolds require mechanical properties comparable to those of implanted tissues; however, their significant shrinkage, opacity, and rapid degradation hinder their application in tissue engineering and therapeutic contexts. Furthermore, polymer-reinforced Col hydrogels often lose their fibrous morphology, leading to a reduction in cell binding sites. In this study, we aim to enhance the mechanical properties and biodegradation resistance of Col hydrogels while preserving their fibrous microstructure. We achieve this by blending Col hydrogel with a continuous chitosan/poly(vinyl alcohol) nanofiber suspension (CS/PVA@NF), utilizing a wet electrospinning process coupled with a falling film collector. Morphological assessment of CS/PVA@NF reveals a well-defined nanofibrous microstructure, in contrast to the non-fibrous morphology observed in conventional polymer-blended hydrogels. The mechanical properties of the composite hydrogel improve up to 24-fold (Young's modulus: 120 kPa). The incorporation of CS/PVA@NF enhances cell attachment and proliferation potential. Subcutaneous implantation of the hydrogels in a murine model shows no notable inflammation. This research presents an effective method for improving Col hydrogels while maintaining their nanofibrous structure.