(459b) Influence of Micropatterned Polymer Substrates on Neural Stem Cell Growth and Differentiation

Control of neural stem cell differentiation is crucial in being able to use them in a regenerative framework. Rat adult hippocampal progenitor cells (AHPCs) were co-cultured with astrocytes on micropatterned polystyrene substrates with extracellular matrix proteins such as laminin selectively adsorbed in the microgrooves. One-half of the substrate was smooth with the adsorbed extracellular matrix proteins and pre-seeded astrocytes and was used as a control. Differentiation of AHPCs into neurons, oligodendrocytes or astrocytes was ascertained by immunocyotchemistry using markers such as TUJ1, RIP and GFAP respectively. The synergistic combination of physical, chemical and biological cues was found to promote selective differentiation of AHPCs into neurons on the micropatterned half of the substrates as opposed to smooth half of the substrates. This provides a unique method to spatially control the differentiation of neural stem cells on different regions of the same substrate. The effect of diffusional limitations of factors secreted by astrocytes was hypothesized to be the reason behind the difference in behavior on smooth and patterned substrates. This hypothesis is being tested by using two-dimensional protein patterning on substrates with co-cultures of astrocytes and AHPCs.