Bone repair using periodontal ligament progenitor cell-seeded constructs

The success of tissue-engineering therapies is dependent on the ability of scaffolds to guide differentiation of progenitor cells. here we present a new approach using a biomimetic construct composed of hydroxyapatite modified with an in vitro-derived extracellular matrix (ha-ecm) and seeded with periodontal ligament progenitor cells (pdlcs). the study aimed to investigate the effect of ha-ecm on osteogenic differentiation of pdlcs and in vivo evaluation of the pdlc-seeded ha-ecm constructs using a rat calvarial critical-sized defect model. after flow-cytometric phenotyping of pdlcs for typical mesenchymal stem cell markers,the pdlcs were cultured on ha-ecm or ha alone in osteogenic media and assessed by mtt,alkaline phosphatase (alp) assays,and real-time qpcr at different time intervals after seeding. new bone formation induced by pdlc-seeded constructs was assessed by histomorphometric analysis at 12 weeks post-operatively. the pdlcs seeded on ha-ecm showed significantly higher alp activity and up-regulation of bone-related genes. the treatment with pdlc-seeded ha-ecm significantly improved calvarial bone repair,with the highest amount of newly formed bone elicited by cell-seeded constructs cultured for 14 days. our results highlight the pdlc-seeded ha-ecm constructs as a promising tool for craniofacial bone regeneration. © 2012 international & american associations for dental research.