Effect of Self-assembling Peptide, Chondrogenic Factors, and Bone Marrow Derived Stromal Cells on Osteochondral Repair

Objective—The goal of this study was to test the ability of an injectable self-assembling peptide (KLD) hydrogel with or without chondrogenic factors (CF) and allogeneic bone marrow stromal cells (BMSCs) to stimulate cartilage regeneration in a full-thickness, critically-sized, rabbit cartilage defect model in vivo. We used CF treatments to test the hypotheses that CF would stimulate chondrogenesis and matrix production by cells migrating into acellular KLD (KLD+CF) or by BMSCs delivered in KLD (KLD+CF+BMSCs). Design—Three groups were tested against contralateral untreated controls: KLD, KLD+CF, and KLD+CF+BMSCs, n=6–7. TGF-β1, dexamethasone, and IGF-1 were used as chondrogenic factors (CF) pre-mixed with KLD and BMSCs before injection. Evaluations included gross, histological, immunohistochemical and radiographic analyses. Results—KLD without CF or BMSCs showed the greatest repair after 12 weeks with significantly higher Safranin-O, collagen II immunostaining, and cumulative histology scores than untreated contralateral controls. KLD+CF resulted in significantly higher aggrecan immunostaining than untreated contralateral controls. Including allogeneic BMSCs+CF markedl