Sponges

Marine sponges are one of the most prolific sources of chemical compounds with pharmaceutical importance. To establish a supply of such compounds large enough for clinical development, in vitro production methodology was investigated. Since all sponge cells do not divide in culture, it was hypothesized that the fusion of rapidly dividing cells of a sponge that does not produce any compounds of interest with cells of a nondividing but compound-producing sponge would result in a hybridoma that produces the compound of interest. In this study, hybridomas have been produced with cells of two marine sponges, Axinella corrugata, which produces the antitumor compound stevensine, and Geodia neptuni, which divides rapidly in a nutrient medium optimized for sponge cell culture. Successful hybridization and subsequent cell division and in vitro stevensine production may unlock the potential for sustainable mass production of other sponge-derived compounds.

Marine sponges are economically and environmentally valuable, but restoration, commercial, and biomedical demands exceed what wild populations and aquaculture can provide. In vitro culture of sponge cells is a promising alternative, but has remained elusive until recent breakthroughs involving improved nutrient medium M1 in two-dimensional culture. The advantages of three-dimensional over two-dimensional cell culture have been increasingly recognized. Here we report the successful 21-day culture of cells from the marine sponge Geodia neptuni using multiple three-dimensional cell culture methods: FibraCel© disks, thin hydrogel layers, gel micro droplets, and spheroid cell culture. These methods performed comparably to two-dimensional control cultures, and each method offers advantages for restoration or in vitro applications using sponge cells. Further optimization of these methods may lead to the ability to culture fully functioning sponges from dissociated, cryopreserved cells, which will reduce the need for wild harvest of sponge tissues for commercial, restoration, and biomedical purposes.