The microalga Volvox carteri as a cell supportive building block for tissue engineering

Abstract Background V. carteri f. nagariensis constitutes, in its most simplified form, a cellularized spheroid built around and stabilised by a form of primitive extracellular matrix (ECM). Methods Based on its structure and its ability to support surface cell adhesion most likely induced by the composition of its algal ECM, we have developed a modular approach to soft tissue engineering by compact-stacking of V. carteri –based living building blocks. Results A primary biocompatibility assessment demonstrated the algal suspension cytocompatibility, its histogenesis promoting properties, and that it did not induce an inflammatory response in vitro . These results allowed us to consider the use of such algal suspension for soft tissue augmentation and to initiate the study of its in vivo biocompatibility. V. carteri exhibited cellular fate-directing properties, causing fibroblasts to take on an alkaline phosphatase + stem-cell-like phenotype and both human adipose-derived stem cells and mouse embryonic stem cells to differentiate into preadipocytes to adipocytes. The ability of V. carteri to support histogenesis and adipogenesis was also observed in vivo by subcutaneous tissue augmentation of athymic mice, highlighting the potential of V. carteri to support or influence tissue regeneration. Conclusions Our conclusion present for the first time V. carteri as an innovative and inspiring biomaterial for tissue engineering and soft tissue regeneration. Its strategies in terms of shape, structure and composition can be central in the design of a new generation of bio-inspired heterogeneous biomaterials recapitulating more appropriately the complexity of the body tissues when guiding their regeneration.