Hybrid Bilayered Sponges For Dynamic Osteoarthritic 3D In vitro Model

Osteoarthritis (OA), a prevalent chronic condition with a striking impact on life quality, represents an enormous societal burden that increases greatly as populations’ age. Yet no approved pharmacological intervention, biologic therapy or procedure prevents the progressive destruction of the OA joint. Bilayered structures have been suggested for osteochondral applications (Oliveira et al 2006). Since OA is an inflammatory and degenerative disorder affecting cartilage and subchondral bone, we followed this bilayered strategy for the creation of an OA in vitro model. Moreover, we considered relevant recreating a 3D controlled subchondral bone and cartilage integrated environment as a drug screening platform. Methacrylated gelatin (GelMA) and methacrylated gellan gum (MAGG) are being reported as supporting materials for tissue engineering applications (Silva-Correia et al 2013, Tasoglu et al 2014). However too fast or slow degradation are problems associated respectively to the first and second polymers. In this study we created 6 hybrid formulations as scaffolds solving this problem and compared the performance against each individual material culturing human adipose-derived stem cells from Hoffa’s body. The best formulation was selected for osteochondral co-differentiation. Regarding this goal, a dual-chamber bioreactor was designed for the co-differentiation in a single 3D structure (Canadas et al 2014). A dynamic platform was created inducing cell homogenization and improving secreted and fresh culture media exchanges in the 3D cell culture. Ultimately, OA will be induced circulating TNF-alpha on top chamber and the phenotype will be evaluated in both subchondral- and cartilage-layers.