Nanopatterning of advanced research tools to harness the mechanobiology of cell-matrix interaction for stem cell expansion

点击翻译按钮获取中文摘要

Pluripotent stem cells (PSC), which can give rise to different cell types of all three germ layers, are excellent models to study tissue development and lineage commitment in vitro. While conventional culture conditions for PSCs focus on biochemical definition, biophysical cues that are present in the stem cell niche are not incorporated in vitro. Our previous studies have demonstrated the significant influence of topography on stem cell fate determination through the involvement and restructuring of focal adhesion. Yet the biophysical regulation of PSC pluripotency maintenance and lineage commitment in the in vitro niche remains a mystery. We hypothesize that 1) biophysical cues such as nanotopography regulate pluripotency maintenance via a focal adhesion-signaling pathway; 2) a suitable biophysical environment and biochemical factor can work synergistically to enhance human PSC maintenance; and 3) advanced nanofabrication techniques can fabricate nanopatterned tools and 3D bioreactors for stem cell expansion. Nanofabrication technologies enable breakthroughs in microelectronics, optics, and in vitro biological systems to study cell-matrix interaction. However, 2 key factors limit the application of nanotopography for stem cell-biology studies and industrial scale-up of cell expansion: the properties of the patterning materials, and conventional 2D patterned culture surfaces, respectively. Therefore, in the proposed research program, we aim to 1) develop nanopatterned research tools with tunable mechanical properties and refractive index to enable the study of cell-matrix interactions through super-resolution microscopy; 2) investigate the cell-matrix interaction during pluripotency maintenance to harness the optimal biophysical conditions that enhance PSC expansion; 3) develop a 3D nanopatterned bioreactor for PSC expansion; and 4) apply bioreactor and nanotopography tools in scaling up the production of PSC for research. Our innovative approaches and research program will develop new research tools to study stem cells. With the new tools, the program will lead to new insights in stem cell biology research by providing a deeper understanding of the biophysical regulation of PSC lineage commitment. This will be a significant contribution to the stem cell and mechanobiology research communities. A minimalistic, biophysically- and biochemically-defined niche for stem cell expansion will also provide an effective means to meet the rigorous demand for consistent and reproducible cells needed for different applications such as biological studies or drug development. Ultimately, this program will yield new, potentially patentable devices and concepts that are applicable to many research areas and will help grow Canada's biotechnology industries. It will also produce the next generation of bioengineers for these vital academic and industrial communities.