Study of protein membranes formed by interfacial crosslinking using microfluidic flow

Abstract

Microfluidic membranes are used in myriad applications, including use in microbioreactors. They serve as bio-catalyst surfaces or allow cell adhesion. However, creating such membranes requires complex manufacturing processes including multi-step self assemble. Recently, a nylon membrane was produced in situ in a flow channel [17]. This process is completed rapidly (within a few minutes), but such membranes are essentially only gas permeable. Control of the thickness and inclusion of porosity is important for effective membrane permeably for general solute transfer and could be sensitive for a given size range of molecules. In the present work, a simplified in situ fabrication technique has been used to produce a robust and novel protein micro-membrane. The proteins studied were BSA and fibrinogen with an acyl chloride to achieve protein crosslinking. Three acyl chloride crosslinkers were tested each crosslinker also generated unique surface morphologies and cross section morphological structures. Permeability of these membranes was tested by diffusion studies using dye molecules as well as the electrochemically active. A simplified approach of using ethanol to further modify the porosity of the membrane was established. Antibacterial membranes were achieved by exposing the protein membranes to copper sulphate solution. Tensile tests on the membranes showed that there was variation in membrane strength that was related to the crosslink or molecule type, and was also related to porosity.