The effect of controlled growth factor delivery on embryonic stem cell differentiation inside fibrin scaffolds

Abstract

The goal of this project is to develop 3-D biomaterial scaffolds that present cues to direct differentiation of embryonic stem cell derived neural progenitor cells (ESNPCs) seeded inside into mature neural phenotypes, specifically neurons and oligodendrocytes. Release studies were performed to determine the appropriate conditions for retention of neurotrophin-3 (NT-3), sonic hedgehog (Shh), and platelet derived growth factor (PDGF) by an affinity-based delivery system (ABDS) incorporated into fibrin scaffolds. Embryoid bodies (EBs) containing neural progenitors were formed from mouse ES cells, using a 4 − /4+ retinoic acid treatment protocol, and then seeded inside of fibrin scaffolds containing the drug delivery system. This delivery system was used to deliver various growth factor doses and combinations to the cells seeded inside of the scaffolds. Controlled delivery of NT-3 and PDGF simultaneously increased the fraction of neural progenitors, neurons, and oligodendrocytes while decreasing the fraction of astrocytes obtained compared to control cultures seeded inside of unmodified fibrin scaffolds with no growth factors present in the media. These results demonstrate that such a strategy can be used to generate an engineered tissue for the potential treatment of spinal cord injury and could be extended to study of differentiation in other tissues.