Channeled polymeric scaffolds with polypeptide gel filling for lengthwise guidance of neural cells

Abstract

CNS damages are often irreversible since neurons of the central nervous system are unable to regenerate after an injury. As a new strategy within the nervous system tissue engineering, multifunctional systems based on two different biomaterials to support axonal guidance in damaged connective tracts have been developed herein. These systems are composed of a channeled scaffold made of ethyl acrylate and hydroxyethyl acrylate copolymer, P(EA-co-HEA), with parallel tubular micropores, combined with an injectable and in situ gelable self-assembling polypeptide (RAD16-I) as pores filler. The polymer scaffold is intended to provide a three-dimensional context for axon growth; subsequently, its morphology and physicochemical parameters have been determined by scanning electron microscopy, density measurements and compression tests. Besides, the hydrogel acts as a cell-friendly nanoenvironment while it creates a gradient of bioactive molecules (nerve growth factor, NGF) along the scaffolds channels; the chemotactic effect of NGF has been evaluated by a quantitative ELISA assay. These multifunctional systems have shown ability to keep circulating NGF, as well as proper short-term in vitro biological response with glial cells and neural progenitors.