Osteochondral (OC) tissue engineering have the potential of producing sufficient numbers of grafts, tailor-made mechanical properties and topology of the graft essential for the repair/regeneration of OC defects.OC defects are lesions of the articular cartilage and underlying subchondral bone often derived from trauma related injuries or osteoarthritis, causing joint pain and deformity, impaired function, limited range of motion and stiffness. Although current clinical options are effective for the treatment of OC defects, advanced therapeutic options that simultaneously preserve the native tissue structure and address a proper regeneration of bone and cartilage defects are therefore fundamental, namely in respect to neurovascular regeneration in large defects. The main purpose for OC tissue engineering is to recreate a monolithic scaffold consisting of a cartilaginous layer and an osseous layer, for regeneration of cartilage and bone, respectively, involving different combinations of materials morphologies and properties in both parts of the scaffolds.

Nanostructures materials involving biopolymeric matrices and bioresorbable nanofillers have been considered as a strategy for tissue engineering and regeneration due to their ability to provide enhanced mechanical performance and suitable transduction of the mechanical stimuli to the cellular level. Biopolymers hold significant similarities with the ECM, chemical versatility, and good biological performance without toxicity or immunological reactions, while bioresorbable fillers, such as tricalcium phosphate (TCP) exhibit remarkably biocompatibility, bioresorbability and osteoconductivity. This study aims to develop nanostructures composed of biopolymers (silk fibroin) and TCP nanopowders incorporating different ions (e.g. Sr, Zn, Mn), for OC regeneration. These scaffolds present great bioresorbability and osteointegration, and high mechanical strength. In particular, Sr and Zn play vital roles in the formation, growth, and repair of bone, thus promoting osteogenesis and angiogenesis. Porous nanocomposite structures with distinct cartilage and bone sides were produced using salt-leaching technique followed by freeze-drying. The scaffolds presented macroporosity highly interconnected and microporosity with sizes around 500 µm, and 1-10 µm, respectively. Current studies are on-going to evaluate the scaffolds in vitro degradation and ions release profiles, and mechanical properties.