A simple technique of constructing nano-roughened polydimethylsiloxane surface to enhance mesenchymal stem cell adhesion and proliferation

Polydimethylsiloxane (PDMS) is one of the most popular molding materials for fabricating biomedical microdevices with many prominent features. Currently, many efforts have been devoted to using PDMS-based platform to construct 2-D cell sheet or 3-D tissue scaffold. However, cell growth on native PDMS is not favorable due to its inherent hydrophobicity, which usually results in cells dislodged from the substrate during prolonged cultivation. Additionally, traditional chemical surface modification approaches are generally complicated and time-consuming. To modify the surface property of PDMS, a simple approach based on chemical etching of a polystyrene mold and rapid prototyping was developed in this work to obtain a nano-roughened PDMS substrate in a controllable manner. Fibronectin was then coated on the treated PDMS substrate, generating a more biocompatible interface to stabilize cell adhesion. Surface properties were characterized in terms of topography, wettability and protein adsorption. Compared to native PDMS control, the surface wettability and protein adsorption on nano-roughened PDMS substrates were considerably improved. More importantly, this simple strategy could facilitate long-term cell adhesion and proliferation, enabling prolonged cellular studies in PDMS-based lab-on-a-chip devices.