Stem cells, especially human pluripotent stem cells (hPSCs), hold significant promise for modeling developmental and disease processes, drug and toxicity screening, and cell-based regenerative medicine. While many potent biochemical signals have been identified that can mediate stem cell functions, emerging new evidence suggests that biomechanical stimuli, including substrate rigidity and external forces, also play pivotal roles in the fate decisions of stem cells. Thus, to achieve a controllable, reproducible, and scalable culture system for stem cell self-renewal and differentiation, it is necessary to fully understand and leverage the mechanosensitive properties of stem cells to develop engineered material systems with controlled dynamic and instructive mechanical properties to direct stem cell behaviors. Furthermore, a paradigm-shifting research direction will use the principles of cellular mechanosensing to improve cell transplantation efficacy and to design physiologically relevant disease models for personalized, precision diagnostics.
My research applies and integrates fundamental engineering principles, such as manufacturing, biomechanics, materials science, and micro/nanoengineering, to understand and harness the mechanobiology of stem cells for modeling currently incurable human diseases and for applications in regenerative medicine.
Current research in our lab focuses on developing enabling tools to regulate microenvironment of stem cells. For example, we used poly(dimethylsiloxane) (PDMS) micropost arrays (PMAs) with tunable height and Young's modulus to control substrate rigidity, and demonstrated that leveraging the intrinsic mechanosensitivity of human pluripotent stem cells (hPSCs), the purity and yield of functional motor neurons derived from hPSCs are drastically improved. Also, we developed a novel acoustic tweezing cytometry (ATC) technique that utilizes ultrasound excitation of membrane-bound gaseous microbubbles to generate controllable subcellular mechanical stimulations to live single cells and simultaneously probe intracellular contractile forces and rheological cell properties. Leveraging the tools we developed, we aim to discover novel mechanotransduction mechanisms and fabricate advanced tissue/organ in vitro models to study the developmental processes and disease progressions.
Learn more at blogs.umass.edu/ybsun/
- BS University of Science and Technology of China
- PhD University of Michigan, Ann Arbor