(170a) Engineering Multifunctional Microfluidic Platform for Stem Cell Study

The microenvironment in living tissues comprises numerous cells, extracellular matrix (ECM) proteins and a variety of soluble and ECM bound factors. The ECM with which cells interact often includes topography at the nanoscale and provides, in concert with the spatio-temporally arranged signaling molecules and mechanical stimuli, cues for cell adhesion, migration, proliferation and differentiation. Knowledge of the effect of topographical, mechanical and chemical cues on cell behavior is crucial to understanding many fundamental biological questions and to designing medical devices. It is thus important to engineer microfluidic platform with precise control over topographical and chemical cues for cell study. Based on polymer thin film technology, we have developed a cost-effective technique to generate a large nanopatterned surface from small nanostructured patterns, so that enough cells can be seeded for subsequent biochemical and molecular biology analyses. Taking advantage of polymer thin film and microcontact printing technologies, a simple assembly technique using curable thin film has been developed to seal polymeric microfluidics. Using pre-designed stencils, the specific nanopatterned surface can be modified with biomolecules. Preliminary studies with human mesenchymal stem cells (hMSCs) on the multifunctional microfluidic platform show that the nanotopography, flow-induced mechanical stress and chemical cue play a role in attachment, migration, spreading, and gene expression of hMSCs. This platform provides a powerful tool to influence the fate of stem cells and expand specific stem cell phenotypes for clinical applications.