Porcine bone scaffolds adsorb growth factors secreted by MSCs and improve bone tissue repair

An ideal tissue-engineered bone graft should have both excellent pro-osteogenesis and pro-angiogenesis properties to rapidly realize the bone regeneration in vivo. To meet this goal, in this work a porcine bone scaffold was successfully used as a Trojan horse to store growth factors produced by mesenchymal stem cells (MSCs). This new scaffold showed a time-dependent release of bioactive growth factors, such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), in vitro. The biological effect of the growth factors-adsorbed scaffold on the in vitro commitment of MSCs into osteogenic and endothelial cell phenotypes has been evaluated. In addition, we have investigated the activity of growth factor-impregnated granules in the repair of critical-size defects in rat calvaria by means of histological, immunohistochemical, and molecular biology analyses. Based on the results of our work bone tissue formation and markers for bone and vascularization were significantly increased by the growth factor-enriched bone granules after implantation. This suggests that the controlled release of active growth factors from porcine bone granules can enhance and promote bone regeneration.