Surface modification of polydimethylsiloxane by exposure of active oxygen and ultraviolet lights to improve cell adhesion

Abstract

Polydimethylsiloxane (PDMS) is used as a flexible cell culture substrate in medical and biological research fields. It has been demonstrated that surface modification by oxygen plasma irradiation was performed to improve cell adhesion, because PDMS has poor cell adhesiveness. However, the surface modification effect was not sufficient due to the flexibility of PDMS. In this study, active oxygen and UV lights were exposed to PDMS surface to improve the cell adhesion. The active oxygen was generated by a UV lamp emitting at wavelengths of 185 nm and 254 nm. The surface modification effect of PDMS before and after exposure of active oxygen and UV lights were evaluated. As a result, although the surface roughness did not change before and after exposure of active oxygen and UV lights, the wettability was improved. In addition, temporal change of PDMS surface after exposure of active oxygen and UV lights was smaller than that after plasma irradiation. Because the formation of silicon oxide layer on the surface was confirmed, it was considered that this layer prevented the penetration of polar groups getting into the PDMS substrate. Furthermore, osteoblast-like cells on the PDMS after exposure of active oxygen and UV lights were adhered and extend well. Therefore, it was demonstrated that a stable surface modification of PDMS surface was achieved by exposure of active oxygen and UV lights.

Keywords

• polydimethylsiloxane (pdms)
• surface modification
• active oxygen
• ultravioret lights
• cell adhesion