Sea urchins and mechanically adaptable connective tissues: alternative sources for biomaterial design

Sea urchins, as all echinoderms (starfish, sea cucumber, etc.), possess connective tissues that undergo drastic changes in their mechanical properties (Mutable Collagenous Tissues: MCTs). Mammalian connective tissues rarely undergo significant changes within a physiological timescale, the only major exception being the destiffening then restiffening of the mammalian uterine cervix at the end of pregnancy. In contrast, MCT can switch reversibly between stiff and compliant conditions in timescales of seconds to minutes following nervous stimulation. Considering this, MCT could be an inspiration for new matrices capable of changing their molecular and structural conformation in response to external stimuli. Furthermore, elucidating the molecular mechanism underlying MCT mutability could have implications for veterinary and biomedical science, particularly regarding the pathological plasticization or stiffening of connective tissue structures. The MIMESIS (Marine Invertebrate Models & Engineered Substrates for Innovative bio-Scaffolds) project has being developed within this scientific context. This contribution presents a review of the distinctive features of MCT together with the first results aimed to the production of MCT-derived matrices as cell culture /tissue regeneration substrates.