Studies On The Attachment Of Marine Sponge Cells On Microcarriers

Sponge (Porifera) is one of the most important marine organisms as a source ofmarine natural products. Sponge cell culture in vitro has attracted great interests tosolve the "Supply Problem"of sponge biomass in the process of sponge-derived drugdevelopment. This work aimed to investigate the characteristics of attachment ofsponge cells on the microcarriers and the potential to develop a new sponge cellculture in vitro technology using microcarriers. It is expected to provide theexperimental and theoretical basis for sponge cell culture on microcarriers.The cell attachment characteristics were evaluated. It was found that cell affinity, thesurface charge and the wetting property all effected the attachment of sponge cells.The two types of cells are confirmed as archaeocytes and epithelial cells by Opticalmicroscope and TEM. BrdU assay further indicated that the microcarriers alsoenriched the actively-dividing archaeocytes cells, leaving less dividing cells amongthe unattached cell populations.The suitable temperarure and pH are 18℃and pH8.2. The attachment of spongecells on microcarriers fit a first-order kinetic equation between the attachment ratioof sponge cells and inoculated cell density. The cell attachment ratio is greatly relatedto the cell density and the ratio of cell/microcarrier.Both microcarrier-attached cells and cell aggregation exist in the system of spongecell culture with microcarriers. The cell attachment on microcarriers is much fasterthan cell aggregation. The diameter of cell aggregates increased during the period ofcultivation. It was observed that cell aggregates could attach on microcarrier, andseveral microcarriers could adhere on primmorphs. At the same time, vacant ratio ofmicrocarriers increased. Finally the system is composed of large primmorphs andclumps of microcarriers.In both 24-well plates and shake flasks, the cultivation of sponge cells withmicrocarrier was initially investigated. The MTT assay showed that the cell viabilitywith microcariers was significantly higher than that without microcarrers after 3 daysof cultivation.An optimum inoculated density of microcarriers may exist.