UC Irvine

Cell signaling is an integral factor of life that determines important functions for survival. From all types of unicellular to multicellular organisms, cells must communicate between each other in a number of ways through soluble factors in chemical signaling and through cell-to-cell direct contact. A relatively recent discovery of direct juxtacrine signaling is the idea of tunneling nanotubes. These transient connections between cell membranes are formed within minutes and can last for hours, transporting all types of cytoplasmic molecules across these narrow bridges. Tunneling nanotubes are fragile, and very difficult to find in a traditional cell culture environment and in tissue samples. Although many microfabricated platforms exist to study cellular communications, there are no dedicated platforms for the explicit study of these delicate connections.

With this project, we propose the fabrication of an optically clear platform that would allow for the study of tunneling nanotubes. Using negative photoresist SU-8 on a glass substrate, we test various methods to build the platform by limiting UV exposure or by transferring patterned layers between substrates. Despite surface modifications and alternative techniques, we continued to encounter delamination of the layers from the glass and were ultimately unsuccessful in attempts to fabricate our platform. However, we explore a possible future direction in creating nanochannels by molding PDMS from a nano-indented surface. These nanochannels can then be enclosed by bonding the PDMS to another layer featuring chambers for cell seeding.