Patterning alginate hydrogels using light-directed release of caged calcium in a microfluidic device
This paper describes a simple reversible hydrogel patterning method for 3D cell culture. Alginate gel is formed in select regions of a microfluidic device through light-triggered release of caged calcium. In the pre-gelled alginate solution, calcium is chelated by DM-nitrophen (DM-n) to prevent cross-linking of alginate. After sufficient UV exposure the caged calcium is released from DM-n causing alginate to cross-link. The effect of using different concentrations of calcium and chelating agents as well as the duration of UV exposure is described. Since the cross-linking is based on calcium concentration, the cross-linked alginate can easily be dissolved by EDTA. We also demonstrate application of this capability to patterned microscale 3D co-culture using endothelial cells and osteoblastic cells in a microchannel.
KeywordsMicrofluidics Alginate Hydrogel Endothelial cells Osteoblastic cells Caged calcium
- S.R. Sershen, G.A. Mensing, M. Ng, N.J. Halas, D.J. Beebe, J.L. West, Adv. Mat. 17, 1366–1368 (2005)Google Scholar