276c Microengineered Co-Culture Substrates: Investigating Cell-Cell Interactions Using Selectively Degradable Hydrogels

Andreia S. Ribeiro1, Filipa Maia2, Ozlem Yasar3, Binil Starly3, and Jennie B. Leach1. (1) Chemical and Biochemical Engineering, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, (2) Departamento de Engenharia Química, Faculdade de Engenharia da Universidade do Porto, Porto, 4000, Portugal, (3) School of Industrial Engineering, University of Oklahoma, Norman, OK 73019

Interactions between neighboring cells regulate cell behavior as well as tissue function. Tools to investigate heterologous cell-cell interactions in vitro are therefore critically important for the development of new diagnostic and drug screening tools. Layered manufacturing based technologies have enabled the development of novel tools to study cell-cell and cell-material interaction for applications in tissue engineering. Among these techniques, microfabrication and stereolithography provide powerful means to pattern cells, but typically rely on immobilized adhesive domains that permit stronger affinity of one cell type for a specific biochemical group relative to a second cell type. While successful, these techniques generally cannot be applied to co-cultures of similar cell types (e.g., two types of neurons) that do not demonstrate selective adhesion to biochemical cues. In this work, we aim to demonstrate a new co-culture patterning approach based on the selective degradation of patterned gels thus allowing the culture of any two cell types for investigating cell-cell interactions in vitro. Using maskless projection micro-stereolithography (µSL), we developed defined multi-component micropatterned architectures of poly (ethylene glycol) dimethacrylate (PEG-DM) and carboxymethylcellulose-aminoethyl methacrylate (CMC-MA) on glass substrates. Since both polymer surfaces are resistant to cell and protein adsorption, the first cell type can only adhere to the free glass spaces. The degradation of the CMC-MA patterns by the enzyme cellulase provides new adhesive regions on the substrate where a second cell type can adhere. This technique allows control of cell-cell contact and spacing between two different cell types at the microscale and will be used as a new tool to investigate heterologous cell-cell interactions in co-culture systems.