Regulation of Neural stem cell differentiation, proliferation and forming of neural networks by changing pore size of self-organized honeycomb films

Neural stem cells (NSCs) have self-renewal potency and can differentiate into glial cells and neurons. It is important for neural tissue engineering to regulate differentiation and proliferation of NSCs. Recently, it has been reported that nano/micro patterned materials on substrates regulate cell morphologies, proliferation, differentiation and function. We have succeeded in preparing porous biodegradable polymer films with highly regular pores (honeycomb film) by a simple casting method. In this report, we cultured NSCs on honeycomb films (pore size, 3, 5, 8, and 10 μm) and investigated influences of the pore size on differentiation and proliferation of NSCs. On honeycomb films with pore size of 10 μm, NSCs differentiated into neurons. The neurons extended neurites along the honeycomb patterns. On the other hands, NSCs proliferated and formed spheroids on the honeycomb films with pore size of 3 μm. This study demonstrated for the first time that the proliferation and differentiation of NSCs are controlled by the structural patternens on substrates in minimum essential condition without using cytokines. The honeycomb films are potential scaffolds for neural tissue engineering.