Morphology and topography of chitosan-Zn complex/PEO fiber mats influence cell viability and attachment

Electrospun fiber mats with therapeutic potential show great promise as wound healing biomaterials. This study aims to compare the biophysical properties and biocompatibility of four different biodegradable fiber mats; namely chitosan and chitosan‑zinc complex (ChiZn)/(polyethylene oxide) PEO fibers, each with either nanometer-sized (~200 nm) or micron-sized (~1000 nm) diameters. Zn was incorporated to impact antibacterial properties of the fibers, ChiZn was synthesized using the in-situ precipitation method, and the influence of zinc chelation on the material structure and morphology was assessed using XRD, FTIR, XPS, and EDX, documenting the complexation and homogeneous distribution of zinc. ChiZn was then blended with PEO for electrospinning in a benign solvent system and crosslinked with glutaraldehyde vapor. SEM was used to examine fiber morphology while AFM documented a correlation between the roughness and fiber diameter. The effects of topography and composition on the viability, adhesion, and proliferation of stromal cells and mouse fibroblasts were investigated, showing higher cell viability on mats composed of nanosized fibers, whereas complex fiber mats composed of micron-sized fibers exhibited reduced cell viability. SEM evaluations showed that cells spread only on the surface of the nanosized fibers, independently of the presence of Zn, while cell infiltration into the mats was observed for micron-sized fibers.