Simple Agarose−Chitosan Gel Composite System for Enhanced Neuronal Growth in Three Dimensions

A simplified approach to increase neuronal attachment on an agarose hydrogel was proposed by blending agarose with another biocompatible polysaccharide, chitosan. The stiffness of the agarose gel was maintained despite the inclusion of chitosan, as determined by rheological tests. The structure of the blended hydrogels was characterized using light microscopy and scanning electron microscopy. An in vitro cell study revealed that the blends promoted neuron adhesion. The concentration of chitosan in the hydrogel had great influence on the morphology of neurons. An optimum range of chitosan concentration in agarose gel, to enhance neural cell attachment and differentiation, was identified based on the results (0.66-1.5 wt %). A "steric hindrance" effect of chitosan was proposed, which explains the origin of the morphological differences of neurons in the blended gels as well as the influence of the physical environment on neuron adhesion and outgrowth.