RESUMO
Neural stem cells (NSCs) cultured in vitro were implanted within three-dimensional (3D) and self-assembly hydrogel from IKVAV-containing peptide. The cytocompatibility of hydrogel with NSCs was explored. Neural cells harvested from the cerebral cortex of neonatal mice were dissociated mechanically and cultivated in serum-free media, and were immunohistochemically examined for Nestin, NSE (neuron specific enolase) and GFAP (Glial fibrillary acidic protein); the self-assembly hydrogel from 1 wt% amphiphilic peptide was formed with the addition of DMEM/F12 and observed under transmission electron microscope (TEM); 1 x 10(5) /ml NSCs implanted within hydrogel (3D culture system) and seeded onto the surface of coverslips covered with polylysine (two-dimensional culture system, 2D culture system) respectively were incubated without serum at 37 degrees C in 5% CO2 and 95% air. Then the cells in 3D culture system and 2D one were double-labeled with DAPI/Brdu and observed under fluorescence microscope. The Nestin-positive cells were found, and they were able to differentiate into NSE-positive neuron- like cells and GFAP-positive glial-like cells, TEM showed that the hydrogel derived from 1 wt% peptide solution was composed of nanofiber network with the fiber diameters ranging from 3 to 6 nm and the fiber length warying from 100 nm to 1.5 microm, NSCs labeled with Brdu in 2D system were thinly scattered, and those in 3D system formed many neurospheres; the positive rate in 3D was much higher than that in 2D system (P < 0.001). The self-assembly hydrogel from the amphiphilic peptide containing IKVAV sequence had good cyto-compatibility and promoted the proliferation of NSCs.
