Characterization of sterilization techniques on a microfluidic oxygen delivery device

A microfluidic oxygen delivery device was designed to regulate the exposure of cells in culture to oxygen, facilitating experiments involving oxygen-dependent cell processes. Most of the device is composed of the biocompatible elastomer PDMS (polydimethylsiloxane), including the thin gas-permeable membrane which serves as a diffusive interface between a flowing gas source and the cell culture media. Because cell cultures require a sterile environment, the device must be sterile as well. This study was designed to investigate the effects of common sterilization techniques on the diffusive properties of the device. Devices were sterilized repetitively with autoclaving, UV light, Dri-Clean detergent soaks, or ethanol soaks. Diffusion of oxygen across the device membranes was periodically measured using fluorescent microscopy. After 32 treatments no significant changes were seen in oxygen diffusion over time or in sterilization groups compared to control, meaning that the utility of the device is not adversely affected by repetitive sterilization.