Effect of PVA/Col/HNT hydrogel on physiochemical properties of PVDF/PVA electrospun using casting and freeze-thawing method for nerve tissue regeneration application

Nerve tissue engineering requires biomaterials that provide mechanical strength, biocompatibility, and an optimal microenvironment for cell attachment and proliferation. Electrospun polymeric scaffolds have gained attention due to their structural similarity to the extracellular matrix. However, their inherent brittleness and limited bioactivity necessitate further enhancement. This study investigates the effects of incorporating a polyvinyl alcohol/collagen/halloysite nanotube (PVA/Col/HNT) hydrogel on the physicochemical properties of polyvinylidene fluoride/polyvinyl alcohol (PVDF/PVA) electrospun mats to improve their suitability for nerve regeneration applications. The hydrogel was integrated onto the electrospun matrices using casting and freeze-thawing techniques. The resultant composites were characterized for their morphological, mechanical, and biological properties. Field emission scanning electron microscopy revealed a uniform distribution and interconnectivity between the electrospun mat and hydrogel layer, supported by Fourier transform infrared spectroscopy spectra indicating strong hydrogen bonding interactions. Atomic force microscopy demonstrated reduced surface roughness (Ra: 5.3 nm electrospun surface, 41.9 nm hydrogel surface) compared to single-layer electrospun mats (Ra: 192.5 nm), promoting better cell attachment and proliferation. Mechanical testing showed a significant increase in tensile strength (1.762 MPa) and Young's modulus (39.612 MPa) while maintaining high elongation at break (316.253%), ensuring flexibility and durability. The scaffold's piezoelectric properties further enhanced its potential for nerve regeneration. In vitro biocompatibility assays using human fibroblast cells confirmed increased cell adhesion and proliferation, highlighting the suitability of the PVA/Col/HNT hydrogel-infused PVDF/PVA mats for soft tissue engineering. This study underscores the composite's potential in advancing nerve regeneration therapies.