The smart sea urchin: towards innovative biomimetic matrices for tissue engineering

The natural world has provided ideas and solutions for different human applied fields. In particular, the marine environment has been a valuable source of naturally-derived or -inspired compounds and products with high social impact such as antiviral and anticancer drugs, broadly used reporter gene (GFP), cosmetics. By applying a modern biomimetic approach, we want to take inspiration from echinoderm dynamic connective tissues (Mutable Collagenous Tissue, MCTs) for the development of novel “intelligent” dynamic materials and compounds for biomedical and pharmaceutical applications. MCTs undergo extremely rapid and reversible changes in their passive mechanical properties (stiffness, tensile strength, viscosity). These changes are dictated by the interactions between collagen fibrils, regulated by specific effectors/molecules. By studying in detail MCT functioning and combining different disciplines (functional biology, engineering) we want to develop MCT-inspired biomaterials displaying mutable mechanical properties or compounds addressed to the treatment of connective tissue pathologies. Bioengineers or pharmacologist will use this “technology”, depending on the final applications of the developed products (scaffold for tissue regeneration or cell culture rather than plasticizing or strengthening agents in connective tissue pathology treatment). Benefits will be addressed to a wide part of the society.The development of a dynamic intelligent scaffold, made of a new alternative collagen source, and capable of adapting its stiffness/structural integrity according to the needs of a growing tissue may chance the scenario of biomaterials in regenerative medicine and tissue engineering, since it would leads towards more physiologically-responsive biomaterials. The possibility of manipulate the scaffold cohesive forces regulating its structural plasticity entails unestimable applicative advantages. The biodegradabilty of the scaffold material (such as in the case of collagen) represents a further remarkable advantage. In strictly applicative and practical terms, main innovative results and perspectives will raise from the development of a new dynamic crosslinking method to assembly collagen fibres, namely through synthetic sequences derived from MCT mutability effectors. These latter (or their possible human homologous/recombinant protein) may represent a source of bioactive compounds for in situ manipulation of human connective tissue.A dynamic scaffold adapting its mechanics to the needs of a growing tissue would positively impact the world of tissue regeneration and cell cultures by providing innovative substrates. Furthermore, these could be obtained from safer and cheap collagen source (sea urchins) obtained from “waste material” of the food industry. Sea urchin gonads are collected as food whereas the rest of the body is discharged and is potentially available for collagen extraction. Understanding the key-mechanisms behind the tuneable mechanical properties of MCT could inspire the development of appropriate treatments for human connective tissues to partially restore this evolutionary lost capacities, thus markedly impacting the pharmaceutical and cosmetic fields. The MCT-inspired material could impact also the food/photography/adhesive industry with the production of gelatines/new adhesives having intermediate properties between thermoplastic collagen-based glues and permanent plastic adhesives. Furthermore, understanding the mechanisms governing MCTs is also essential in order to preserve echinoderm biodiversity and the marine ecosystem.