Micromachined biocapsules for cell-based sensing and delivery.

In recent years, rapid advancements have been made in the biomedical applications of micro- and nanotechnology. While the focus of such technology has primarily been on in vitro analytical and diagnostic tools, more recently, in vivo therapeutic and sensing applications have gained attention. The long-term integration of cells with inorganic materials provides the basis for novel delivery and sensing platforms. Our recent work has focused on the ability to maintain cells long term in nanoporous silicon-based microenvironments. This paper describes the creation of monodisperse, nanoporous, biocompatible, silicon membranes as a platform for the delivery of cells. Studies described herein focus on the interaction of silicon-based substrates with cells of interest in terms of viability, proliferation, and functionality. Such microfabricated nanoporous membranes can be used both in vitro for cell-based assays and in vivo for immunoisolation and drug delivery applications.