Development of nanostructured biomedical micro-drug testing device based on in situ cellular activity monitoring.

Integration of micro and nanofabrication techniques with biotechnology has resulted in the development of in vitro analytical and diagnostic tools for biomedical applications. The focus of such technology has primarily been on therapeutic and sensing applications. The long-term integration of cells with inorganic materials provides the basis for novel sensing platforms. This paper describes the creation of, nanoporous, biocompatible, alumina membranes as a platform for incorporation into a cell based device targeted for in situ recording of cellular electrical activity variations due to the changes associated with the surrounding microenvironments more specifically due to the effect of therapeutic drugs. Studies described herein focus on the interaction of nanoporous alumina substrates embedded in silicon, patterned with cells of interest. The cells that have been used to develop the in vitro test platform are primary hippocampal neurons. Demonstrated here, is the fidelity of such a system in terms of determination of cell viability, proliferation, and functionality. The response of the cells to the "drug" molecules is electro-optically characterized in an in situ manner. The capability of such, micro fabricated nanoporous membranes as in vitro drug testing platforms, is first theoretically estimated using two dimensional finite element modeling of the diffusion of the molecules of interest through the nanoporous substrate using CFDRC. It is then experimentally established, using glucose and immunoglobulin G (IgG).