Channeled scaffolds implanted in adult rat brain.

Scaffolds with aligned channels based on acrylate copolymers, which had previously demonstrated good compatibility with neural progenitor cells were studied as colonizable structures both in vitro with neural progenitor cells and in vivo, implanted without cells in two different locations, in the cortical plate of adult rat brains and close to the subventricular zone. In vitro, neuroprogenitors colonize the scaffold and differentiate into neurons and glia within its channels. When implanted in vivo immunohistochemical analysis by confocal microscopy for neural and endothelial cells markers demonstrated that the scaffolds maintained continuity with the surrounding neural tissue and were colonized by GFAP-positive cells and, in the case of scaffolds implanted in contact with the subventricular zone, by neurons. Local angiogenesis was evidenced in the interior of the scaffolds' pores. New axons and neural cells from the adult neural niche abundantly colonized the biomaterial's inner structure after 2 months, and minimal scar formation was manifest around the implant. These findings indicate the biocompatibility of the polymeric material with the brain tissue and open possibilities to further studies on the relevance of factors such as scaffold structure, scaffold seeding and scaffold placement for their possible use in regenerative strategies in the central nervous system. The development of neural interfaces with minimized glial scar and improved tissue compatibility of the implants may also benefit from these results. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A 100A:3276-3286, 2012.