A Silk Fibroin and Peptide Amphiphile-Based Co-Culture Model for Osteochondral Tissue Engineering

New biomaterials with the properties of both bone and cartilage extracellular matrices (ECM) should be designed and used with co-culture systems to address clinically applicable osteochondral constructs. Herein, a co-culture model is described based on a trilayered silk fibroin-peptide amphiphile (PA) scaffold cultured with human articular chondrocytes (hACs) and human bone marrow mesenchymal stem cells (hBMSCs) in an osteochondral cocktail medium for the cartilage and bone sides, respectively. The presence of hACs in the co-cultures significantly increases the osteogenic differentiation potential of hBMSCs based on ALP activity, RT-PCR for osteogenic markers, calcium analyses, and histological stainings, whereas hACs produces a significant amount of glycosaminoglycans (GAGs) for the cartilage region, even in the absence of growth factor TGF-β family in the co-culture medium. This trilayered scaffold with trophic effects offers a promising strategy for the study of osteochondral defects.