Marine collagen-chitosan-fucoidan/chondroitin sulfate cryo-biomaterials loaded with primary human cells envisaging cartilage tissue engineering.

Cartilage repair after a trauma or a degenerative disease like osteoarthritis (OA) continues to be a big challenge in current medicine due to the limited self-regenerative capacity of the articular cartilage tissues. To overcome the current limitations, tissue engineering and regenerative medicine (TERM) and adjacent areas have focused their efforts on new therapeutical procedures and materials capable of restoring normal tissue functionalities through polymeric scaffolding and stem cell engineering approaches. For this, the sustainable exploration of marine origin materials has emerged in the last years as a natural alternative to mammal sources, benefiting from their biological properties (e.g., biocompatibility, biodegradability, no toxicity, among others) for the development of several types of scaffolds. In this study, marine collagen(jCOL)-chitosan(sCHT)-fucoidan(aFUC)/chondroitin sulfate(aCS) were cryo-processed (-20 °C, -80 °C, and -196 °C) and a chemical-free crosslinking approach was explored to establish cohesive and stable cryogel materials. The cryogels were intensively characterized to assess their oscillatory behavior, thermal structural stability, thixotropic properties (around 45 % for the best formulations), injectability, and surface structural organization. Additionally, the cryogels demonstrate an interesting microenvironment in in vitro studies using human adipose-derived stem cells (hASCs), supporting their viability and proliferation. In both physic-chemical and in vitro studies, the systems that contain fucoidan in their formulations, i.e., C1 (jCOL, sCHT, aFUC) and C3 (jCOL, sCHT, aFUC, aCS), submitted at -80 °C, are those that demonstrated most promising results for future application in articular cartilage tissues.