Tailoring PDMS microfluidic channel surfaces for improved cell adhesion

Microfluidic on-chip platforms for cell biomechanics investigations have become very popular in the field of fundamental cell and tissue engineering. Polydimethylsiloxane (PDMS) is widely used fabrication material for such biological microfluidic applications because of its versatile nature, optical transparency, ease to replicate fine microarchitechtures and tunable mechanical properties by varying base to crosslinker ratio. However, the hydrophobic surface of native PDMS often provides unfavourable conditions for cellular attachment. Although plasma-treatment and protein physisorption methods enhances the initial cell adhesion but they are short-lived. This paper focuses on tailoring a biocompatible PDMS surface for long-term cell culture by using (3-Aminopropyl)triethoxysilane as a linking agent between PDMS and protein. Characterization of APTES+Gelatin treated PDMS surfaces has revealed changes in surface wettability, surface free energy and surface roughness as compared to pristine PDMS surface. These physico-chemical changes contribute to enhanced endothelial cell attachment and proliferation. This tailored PDMS surface can significantly prolong the cell-culture compatibility of PDMS-based microfluidic devices for mechano-biological studies and in vitro organ modeling.