Microfluidic Approaches to Profile Single-Cell Phenotypes and Pattern Tissue Microenvironments

The phenotype of a cell is governed by its microenvironment, which includes the extracellular matrix surrounding the cell, its interactions with neighboring cells such as fibroblasts, immune cells, etc., and the sensing of biochemical and biomechanical cues within the microenvironment. The profiling of cellular microenvironments enables novel insights into the development, diagnosis, and treatment of various disease states. By using microfluidic methods, it is possible to pattern microenvironments and create chemical gradients and biomechanical cues that mimic the tissue microenvironment, as well as study cell phenotypes with single-cell sensitivity to profile subpopulations. The specific aims of this thesis include: (Aim 1) Developing microfluidic patterned cell-laden hydrogels for the delivery of biomechanical cues (Chapter 2) and chemical gradient cues (Chapter 3) to the tissue microenvironment. (Aim 2) Developing single-cell label-free profiling approaches using impedance cytometry, to study phenotypes of interest from specific microenvironments, such as the activation of macrophages in intervertebral disc injury (Chapter 4) and circulating-like pancreatic cancer cell subpopulations (Chapter 5).