Formation of a Stable Gelatin Layer on Polydimethylsiloxane (PDMS) Surface for Cell Culture

Abstract

The purpose of this work was to develop a simple and robustmethod that would allow a stable gelatin layer to form on PDMS that is suitable for cell culturing. Treating the cured PDMS layer with (3-(2-aminoethylamino) propyl) trimethoxysilane and then casting 2 layers of 2% (w/v) gelatin on the surface created a stable layer. The water contact angle of the formed layer system is in close agreement with reported water contact angle values for standard gelatin layers. The pH of water on the gelatincoated PDMS was within physiological pH range but slightly basic. A relative hardness test showed that the hardness of the film was unchanged after silanization, allowing the PDMS to retain its mechanical properties. A fluorescence test for soluble gelatin indicated that less than 8% of gelatin was released from the surface after a 24 hour period of PBS soaking at 37° C, which is nearly identical to the amount of gelatin that came off a standard gelatin coated coverslip. MOVAS-1 cells were grown for 96 hours on the modified surfaces in a manner identical to control coverslips coated with gelatin. These results validate the use of a silanizing agent, such as (3-(2-aminoethylamino) propyl) trimethoxysilane, as an interfacing method between PDMS and gelatin, and allows appropriate films that are robust to be formed,thereby allow for cell growth and proliferation on a PDMS base material.