Here, we report the development of an electric field-assisted methodology for constructing 3D C2C12 cell sheets with the potential for cell surface modification. In this method, a conducting polymer, polypyrrole (Ppy), is electrodeposited via biotin doping, and then chemical conjugation of biotinylated bone morphogenetic protein 2 (BMP2) is achieved using a biotin-streptavidin cross-linker. Subsequently, C2C12 cells are cultured on BMP2-immobilized Ppy surfaces to induce interactions between cell surface receptors and bound BMP2 ligands. Following these procedures, layers of BMP2-immobilized cells can be easily detached from the Ppy surface by applying an electrical potential. This novel method results in high affinity, ligand-bound cell sheets, which exhibit homogeneous coverage with membrane-bound proteins and signal activation that occurs via maximal receptor accessibility. Using this strategy to engineer the cell surface with desirable ligands results in structures that mimic in vivo tissues; thus, the method reported here has potential applications in regenerative medicine and tissue engineering.
Keywords: bone morphogenetic protein 2; cell sheet; conducting polymer; electrical stimulation; osteogenesis.