(395d) Novel Cell Patterning Platform Employing Photocaged RGDS Peptides On a Hydrogel

Cell behaviors, including proliferation, differentiation, and migration, are known to be influenced to a large extent by the nature of the surrounding microenvironment. In the body, cells grow within well defined tissue architectures, and not in the randomly placed fashion achieved with traditional cell culture techniques. Currently, cell micropatterning platforms can provide us with tools to control the spatial localization of cells on biomaterial constructs. However, the vast majority of cell micropatterning techniques focus on the patterning of a single cell type; in order to truly fabricate the highly controlled microenvironments found in multicellular organisms, it becomes necessary to develop simple, easily accessible techniques to control the spatial localization of multiple cell types on a single construct. Furthermore, the utilization of natural extracellular matrix (ECM) materials in these patterning techniques can allow for increased biocompatibility. With this degree of control in the manufacturing of biocompatible surfaces we can hope to conduct novel studies in cell biology or to optimize cell behavior and function towards the development of new cell based devices and tissue engineering constructs.

To address these issues, we have developed a novel cell patterning platform. Our patterning technique employs hyaluronic acid as the base material, a polymer naturally found in the ECM surrounding cells and present in all connective tissues of the body. We also make use of the RGDS peptide sequence, a recognition site within the cell-adhesive ECM protein, fibronectin. In order to create a cell pattern, we have fabricated a cell non-adhesive cross-linked hyaluronic acid hydrogel bound to caged RGDS peptides. We covalently bound 2-nitrobenzyl to the RGDS peptides via a photolabile bond which could be severed upon exposure to light in the near-UV range. These photocaged peptides bound to the gel formed a cell-nonadhesive surface. Patterned cell adhesive regions were created on the hydrogel surface upon exposure to near-UV light through a patterned photomask. As a proof of concept, lined patterns of 3T3 fibroblast cells were created on the hydrogel surface, and fibroblasts were seen to adhere and grow along the patterned regions for at least 2.5 days. Our current work is aiming towards the application of this technique to the patterning of multiple cell types.

Our hydrogel surface cell patterning technique and its subsequent characterization shall be discussed in the meeting, along with cell culture work and cell patterns achieved to date.