(375f) Gramicidin Channel Incorporated Bilayer Supported on Hierarchical Porous Inorganic Membrane

A Cell membrane is a dynamic two-dimensional lipid bilayer structure, with proteins embedded in it responsible for transport of species across the membrane. Recently, there has been great interest in assembling the lipid bilayer on a substrate. This can be further incorporated with ion-channel proteins that can be utilized for selective transport of ions across the membrane. These membranes have applications in biotechnology such as biosensors and drug delivery. They also serve as a model system for studying cell membrane processes. One of the crucial factors in formation of lipid bilayer is choosing the support that provides the stability to the membrane as well as maintains the cellular environment. We have engineered a porous inorganic support with a hybrid octadecyltrichlorosilane (C18)-lipid bilayer that mimics the cellular environment with aqueous environment present on both sides of the membrane. The composite inorganic porous structure consisting of an alumina support, mesoporous gamma- alumina and microporous silica has been synthesized. The C18 monolayer was covalently attached to the surface of silica and lipid monolayer was deposited onto the surface using solution-diffusion and vesicle deposition methods. Flow of ions across the membrane was detected by pH change and conductivity measurements. The C18-lipid hybrid bilayer formed the barrier for ion transport. Incorporation of protein, Gramicidin D, into the bilayer caused the increased flow of ion indicating the functional form of ion-channel in C18-lipid hybrid bilayer. Porous inorganic support showed promising result as a substrate to support lipid bilayer and incorporate ion-channels.