Osteochondral tissue engineering constructs with a cartilage part made of poly(L-lactic acid) starch blend and a bioactive poly(L-lactic acid) composite layer for subchondral bone

Articular cartilage has an inadequate natural rebuilding capacity. Tissue engineering has shown to have potential to provide an effective alternative to engineer the damaged cartilage. In this study, an integrated porous bi-layered scaffold was developed aiming to mimic the requirements of cartilage and underlying subchondral bone. The osteochondral approach explored in this work was to include a common polymeric component in both cartilage and bone components, which maximised the integration at the interface by mean of a melt-based processing route. A blend of starch and poly(L-lactic acid),PLLA, was used in the cartilage side, which was found to possess an adequate water uptake capability. For the bone region, to induce bioactivity, PLLA had been reinforced with hydroxyapatite (HA) and bioactive glass (BG). The surfaces of the constructs were investigated as a function of soaking time in a simulated body (SBF) fluid using scanning electron microscopy (SEM) and FTIR. The SEM - FTIR indicated a bone-like apatite formation and the surface coverage by apatite layer increased with increasing soaking time, whereas the cartilage-layer did not exhibit the formation of any apatite like layer.