This Small Business Innovation Research Phase I project will create a microcarrier with immobilized growth factors for adherent cultured cells. This advancement in cell culture biomaterials promises to remove the variability associated with growth factors in liquid media while increasing cell culture workflow efficiency. The project is to identify an efficient reaction mechanism for coupling protein, including animal serum and purified fibroblast growth factor (FGF), to the surface of a previously developed magnetic alginate microcarrier. The resulting product is anticipated to have significant benefits over traditional flask culture methods and will provide enabling technology to next generation drug discovery and therapeutics as primary and stem cells become the cell types of choice. The broader impact/commercial potential of this project is the use of immobilized growth factors to advance the basic understanding of cell-substrate interactions. Currently, the major cost for culturing primary and stem cells is the cell growth media, which contains costly purified growth factors. Reducing the amount of growth factors necessary for culture will directly reduce the cost per cell. Furthermore, this product will prove valuable for therapeutic applications including cell-based therapies in which cGMP growth factors would be especially costly. Finally, a growth factor-conjugated microsphere will be a useful basic research platform for understanding the role of "immobilized" growth factors in vivo, which is important for creating bio-scaffolds and regenerative implants