Coating materials enhance urochordate primary cell culture adherence.

Marine invertebrate cell cultures are a potential source for diverse biotechnological applications, given the wide range of bioactive compounds they synthesize and accumulate. Yet, the number of established marine invertebrate cell culture systems remains limited compared with those of insects and vertebrates, particularly with respect to adherent cell cultures. Here we studied the in vitro adherence of circulating blood cells from the colonial ascidian Botryllus schlosseri. Two experimental approaches were employed, seeding blood cells either alone (setup 1) or in combination with tissue fragments (setup 2), using three basal media (DMEM, DMEM/F-12, RPMI) on culture plates coated with either Poly-L/D-lysine, gelatin, collagen, or laminin. Each experiment lasted for up to 3 d. Setup 1 results reveal that Botryllus cells remain viable and can adhere to coated surfaces in all tested media. Collagen- and laminin-coated plates supported longer-term cultures, whereas Poly-D (or L)-lysine coatings were more suitable for short-term studies. Among the basal media, RPMI and DMEM/F12 most effectively supported cell attachment. Setup 2 plates consistently showed higher cell adherence compared to setup 1, suggesting that tissue-derived factors may enhance attachment. Overall, circulating Botryllus cells demonstrate the capacity for substrate adhesion in vitro, offering a foundation for the development of adherent cell cultures.