FTIR imaging analysis of bioactive microsphere incorporated stem cell sheets for osteochondral defect repair

Several tissue engineering approaches have been proposed for articular cartilage repair, but to date there is no consensus on the optimal method. Self-assembling microsphere-incorporated cell sheets have been developed recently for cartilage tissue engineering applications, as they provide an environment for the chondrogenic induction of human mesenchymal stem cells (hMSCs). In the current study, early articular cartilage repair was assessed in a rabbit osteochondral defect model treated with self-assembling hMSC sheets incorporated with bioactive polymer microspheres. Histological sections were evaluated by FTIR imaging for molecular composition. We found that the incorporation of transforming growth factor β1 to the microspheres improved the quality of repair tissue based on increased repair tissue, and increased collagen maturity, at one and three months post-repair. Evaluation of repair tissue at longer timepoints will assess whether these preliminary results will extend to the quality of more mature repair tissue.