Abstract 5269: Cell matrix interactions in a 3D alginate cell culture system
Authors: Dornish John Michael , Andersen Therese , Markusssen Christine , Melvik Jan Egil 
Published: August 2012

Abstract
The use of 3-dimensional (3D) matrices for cell culture is gaining popularity as a substitute for traditional 2D cell culture as it can enable formation of multi-cellular structures and a more biologically relevant cell-cell contact such as found in tissues, organs and tumors. NovaMatrix®-3D is an alginate-based cell culture system comprising an alginate foam matrix and an alginate immobilizing solution. Cells are entrapped throughout the alginate foam by first suspending them in a solution of sodium alginate that is applied to the foam. As the foam absorbs the suspension, in situ gelation occurs as calcium ions are donated from the foam cross-linking the added alginate forming a hydrogel in the pores of the foam comprising the cells. Cells do not have receptors that recognize alginate molecules and this may stimulate formation of spheroids. However, some cells require signaling molecules and matrix interaction in order to proliferate. This was evaluated by culturing cells in the presence of alginate to which the peptide sequence RGD (Arg-Gly-Asp) was covalently attached (RGD-alginate) thereby facilitating a signaling cascade via integrin-RGD interaction. Various cell lines were first cultured in 2D then prepared as a suspension in 0.5 - 1% alginate or RGD-alginate in cell culture medium. An aliquot of each cell suspension was added to γ-sterilized NovaMatrix®-3D foams. NHIK 3025 (human cervix carcinoma), OVCAR-3 (human ovarian adenocarcinoma), SKOV-3 (human ovarian carcinoma), NIH:3T3 (murine fibroblasts), C2C12 (murine myoblasts), V79-379A (hamster lung fibroblast) and MDCK (Madin Darby canine kidney) were used and single cells were immobilized in the alginate foams. Cell localization within the foam was visualized using confocal microscopy to identify fluorescently labeled (CellTrace™ CFSE) cells. Cell proliferation was measured by counting cells after de-gelling the foam using sodium citrate. Cell proliferation and spheroid formation occurred during three weeks of culture in foams with or without RGD-alginate for NHIK 3025, SKOV-3, 3T3 and V79-379A indicating that these cell lines do not require the presence of RGD within the alginate matrix for cell growth. However, during the same period, cell proliferation was only seen in the foams containing RGD-alginate for OVCAR-3, MDCK and C2C12. The proliferation rate was affected by the RGD density. Cells that did not proliferate in pure alginate were still metabolically viable as shown by live-dead staining. This cell culture model enables 3D cell culture, formation of spheroids and isolation of intact cellular structures. Cell-matrix interaction can be controlled by type and concentration of signaling molecules covalently attached to the alginate immobilization solution making NovaMatrix®-3D a versatile cell culture system. Portions of this work have been funded with the support from METOXIA project no.222741 under the 7th Research Framework Programme of the European Union.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5269. doi:1538-7445.AM2012-5269