High-throughput, label-free stem cell sorting using shear-rate discrimination
Stem cells are typified by their ability to differentiate into a wide range of specific cell types, including nerve cells, brain cells, and other cells that do not typically regenerate in the human body. This pluripotency holds great promise for regenerative medicine, possibly enabling the repair of damaged or defective tissues in adults and children. A great promise for stem cells is the production of very large quantities of stem cells differentiated into new heart muscle cells, skin cells, nerve cells, or other types of cells that are needed to repair these tissues.
Controlling what type of cells stem cells differentiate into, and separating those that have differentiated into distinct types, from those that have not differentiated, is a key element in using stem cells as therapeutic elements. Control is typically explored using a wide range of different chemical and physical environments, and is proving a highly complex and challenging area of research. Distinguishing and purifying the results of these control experiments, both in research and in possible clinical application, will clearly be a significant and important part of the eventual therapeutic use of stem cells.
The technologies we propose to develop would enable the very high throughput and highly specific separation of differentiated and non-differentiated stem cells into separate groups, so that very highly purified samples of any particular type would then be available for further development or for direct therapeutic use. The instruments are based on technology that would allow very inexpensive, disposable, yet highly sensitive stem cell identification and purification, making the instruments readily and cheaply available to both the researcher and the clinician. It is based on very novel and disruptive technology, quite distinct from the methods presently used for these applications, providing a route to much simpler and faster instruments, and more rapid results, than present methodologies.
We will develop a high-throughput human stem cell sorter, using a combination of microfluidics, biofunctionalization, and radiofrequency velocimetry. The resulting device will provide a label-free method to sort billions of stem cells per hour, based on their surface protein expression. The end product will be a small, hand-held unit that includes disposable components, whose operation will be simple, with software-definable discriminants driving multi-axis sorting decisions. Such a device will have immediate applications to the identification and purification of heterogeneous stem cell populations, and to the identification and removal of cancer stem cells.
The benefits to California of this research are multi-dimensional. To begin, the technology produced through this research will have a direct impact on stem cell research and use, an area to which California has clearly made a strong commitment; commercial and academic research efforts within California would benefit directly from this tool.
Second, the technology produced here will likely form the basis of a commercial enterprise to produce and further develop this technology. This enterprise will most likely be based in California, and if successful would provide employment, new technology, and tax revenue to the state.
Third, the participation of the two PIs, bringing highly distinct expertise in biophysics (Cleland), and cellular biology (Kosik), will provide a unique combination of backgrounds and technologies that will likely generate new ideas and more applications for this type of instrumentation.
Fourth, the research efforts of the two postdoctoral scientists and a graduate student will train three new professionals in this cross-disciplinary area, students that will doubtless continue to work on closely related areas of work and further develop the concepts and technology that will enable future progress.
Finally, this will further the development and unification of microfluidic technology with electronics, an area of technology that will likely expand further over the next decade.