Poly (L-lactic acid) nanofibrous scaffolds support the proliferation and neural differentiation of mouse neural stem and progenitor cells.

Abstract

The distribution and growth of cells on nanofibrous scaffolds seem to be an indispensable precondition in cell tissue engineering. The potential use of biomaterial scaffolds in neural stem cell therapy is increasingly attracting attention. In this study, we produced porous nanofibrous scaffolds fabricated from random poly-L-lactic acid (PLLA) to support neurogenic differentiation of neural stem and progenitor cells (NSPCs), isolated from the subventricular zone (SVZ) of the adult mouse brain. The viability and proliferation of the NSPCs on the nanofibrous PLLA scaffold were also tested by nuclear staining with 4, 6-diamidino-2-phenylindole dihydrochloride (DAPI), 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay and scanning electron microscopy (SEM). To investigate the differentiation potential of NSPCs on the scaffolds, the cells were treated with a neurogenic differentiation medium, and immunostaining was done to detect neuronal and glial cells after 14 and 21days of cultivation. Furthermore, the morphology of differentiated cells on the scaffold was examined using SEM. The DAPI staining revealed the proliferation of NSPCs onto the surface of the nanofibrous PLLA scaffold. DAPI-positive cells were counted on days 2 and 5 after cultivation. The mean number of cells in each microscopic field was significantly (p<.05) increased (51±19 on day 2 compared to 77±25 cells on day 5). The results showed that the cell viability on PLLA scaffolds significantly increased compared to control groups. Moreover, cell viability was significantly increased 5days after culturing (262.3±50.2) as compared to 2days culture in Vitro (174.2±28.3, p<.05). Scanning electron micrographs also showed that the NSPCs adhered and differentiated on PLLA scaffolds. We found that the neural cell markers, microtubule-associated protein 2 (MAP2) and glial fibrillary acidic protein (GFAP), were expressed in NSPCs seeded on random PLLA scaffolds after 21days of cultivation. These results suggest that the PLLA nano-scaffolds, due to their biocompatible property, are an appropriate structure for the proliferation, differentiation, and normal growth of NSPCs.