pH-sensitive resist materials for combined photolithographic patterning of proteins and fluid lipid bilayers

Abstract

Photolithography of a pH-sensitive photoresist polymer was performed to pattern both lipid bilayers and proteins onto the same surface. The motivation behind this was to create a substrate mimicking an array of antigen- presenting cells. The substrate would consist of signaling ligand, biotin anti- CD3, bound to a lipid bilayer in a regular array of patches. The fluidity of the lipid bilayer would impart mobility to the signaling ligand. It was found that under appropriate substrate fabrication conditions, lipid bilayers and their associated ligand do segregate to the desired signaling patches. Additionally, the bilayer in these regions is fluid, and is potentially bioactive. This bodes well for our system as a future platform to study the actions of the helper T cell and antigen- presenting cell at the immunological synapse.