The effects of gelatin-dopamine coating on polydimethylsiloxane substrates on pluripotency maintenance and myocardial differentiation of cultured mouse embryonic stem cells.

Polydimethylsiloxane (PDMS) is a common biomaterial in the fabrication of microfluidic devices due to its various beneficial properties. However, its inherent highly hydrophobic surfaces often limit PDMS-based microfluidic devices for myocardial differentiation of pluripotent stem cells. In order to improve cell interactive properties of PDMS, gelatin-dopamine was synthesized by grafting dopamine onto a gelatin backbone. The conjugation of dopamine onto gelatin was verified using proton nuclear magnetic resonance spectroscopy (1H NMR). Compared with gelatin coating, coating with gelatin-dopamine greatly reduced the water contact angle of the PDMS substrates and resulted in higher protein adsorption on the PDMS surfaces. In addition, the gelatin-dopamine coated PDMS surfaces also improved the embryonic stem cell (ESC) adhesion, proliferation and differentiation as compared to gelatin modified surfaces. The effects of gelatin-dopamine coating on the ESC-derived embryoid body (EB), myocardial differentiation on PDMS surfaces were also investigated. Compared with the PDMS surface coated with gelatin, the EB spread-out areas and myocardial differentiation efficiency greatly increased on the gelatin-dopamine coated PDMS surface. Interestingly, the lower concentration of gelatin-dopamine coating was more favorable for ESC pluripotent maintenance, while the higher concentration was more likely to support ESC myocardial differentiation. These results indicate that gelatin-dopamine is an effective coating material to improve ESC long-term culture and myocardial differentiation on PDMS substrates.