Simple poly(dimethylsiloxane) surface modification to control cell adhesion

Poly(dimethylsiloxane) (PDMS) has a long history of exploitation in a variety of biological and medical applications. Particularly in the past decade, PDMS has attracted interest as a material for the fabrication of microfluidic biochip. The control of cell adhesion on a PDMS surface is important in many microfluidic applications such as cell culture or cell-based chemicals/drug testing. Unlike many complicated approaches, this study reports simple methods of PDMS surface modification to effectively inhibit or conversely enhance cell adhesion on a PDMS surface using Pluronic surfactant solution and poly-L-lysine, respectively. This research basically succeeded our prior work to further confirm the long-term capability of 3% Pluronic F68 surfactant to suppress cell adhesion on a PDMS surface over a 6-day cell culture. Microscopic observation showed that the treated PDMS surface created an unfavorable interface, where chondrocytes seemed to clump together on day 2 and 6 after chondrocyte seeding, and there was no sign of chondrocyte spreading. On the opposite side, results demonstrated that the poly-L-lysine-treated surface significantly increased fibroblast adhesion by 32% in contrast to the untreated PDMS, which is comparable to the commercial cell-culture-grade microplate. However, fibronectin treatment did not have such an effect. All these fundamental information is found useful for any PDMS-related application.