Poly(L-lysine) modified zein nanofibrous membranes as efficient scaffold for adhesion, proliferation, and differentiation of neural stem cells

Excellent biocompatibility and bioactivity are necessary requirements for a scaffold for nerve repair and regeneration. Natural plant protein zein was chosen as the primary material and poly(L-lysine), which is composed of common amino acids in the human body, was used to modify it. Poly(L-lysine) modified zein (ZPLL) with different PLL contents of 1.46%, 3.57%, and 6.18% was synthesized and nanofibrous membranes were prepared by electrospinning. The hydrophilicity of the membranes improved with an increase of PLL content. The biodegradability of the membranes was proved by in vitro experiments. Compared with pure zein membranes, ZPLL membranes can efficiently improve cell viability, adhesion, proliferation, and differentiation of neural stem cells (NSCs) and the effect of PLL content was further investigated. The results show that when the PLL content was 3.57%, cell adhesion and proliferation proved to be the best and most differentiated toward mature neurons with extensive neurite formation and astrocytes rather than oligodendrocytes. The ZPLL was made into nerve conduits for future study and they may be a promising biomaterial for nerve repair and regeneration.