Recommended if funds allow
Statement of Benefit to California:
SYNOPSIS: In this proposal, the PI proposes to induce optimal cardiomyocyte differentiation from hESCs using microsystems wherein ESCs/hEBs are seeded on polymeric scaffolds, allowing rapid exchange in a high throughput fashon of chemical stimuli, tested in combination with electrical and mechanical stimuli, and monitored optically and by electrophysiological measurements. Such variable stimuli may then lead to differentiation to specific subpopulations of cardiomyocytes, including atrial, ventricular and pacemaker cells. INNOVATION AND SIGNIFICANCE: The creation of cardiomyocytes from hESCs is significant as no other stem cells, perhaps except stem cells within the heart itself, have been proven to differentiate to cardiocytes, and cardiac diseases are a significant health problem in the developing and Western world. The innovative nature of this proposal is to not only use chemical stimuli but also electrical and mechanical stimuli to reach this goal. Although chemical or electrical stimulation have been used individually, detailed studies of combinations of the two types of stimulation are new. A unique microtechnology platform will be used to enable simultaneous differentiation and analysis of multiple embryoid bodies (EB). STRENGTHS: The proposal addresses an important topic. The investigative team has a strong engineering and electrophysiology background. The proposed research uses an innovative microplatform approach to combine chemical with electrical and mechanical stimuli in a high throughput format to induce specific differentiation from ESCs to different cell types in the heart. The strategy for guiding differentiation is well described. The approach proposed for enriching for cardiomyocytes is convincing and feasible. The platform seems ready for use. It is a clever idea to use a patch clamp on a chip platform for electrical and chemical stimulation of EBs to enhance cardiomyocyte differentiation. The advantages of the proposed system over existing methods of electrical and chemical stimulation is convincing. WEAKNESSES: Although the investigators provide significant information regarding the possible role of non-chemical stimuli, and although chemical stimuli may aid in cardiac differentiation, very little discussion is given on the exact nature of the factors to be used. To induce specific differentiation, it will likely require that a series of cardiac specific growth factors and cytokines are provided in specific combinations and sequence. Methods for single cell level stripping of cells from EBs seems a bit vague in description and seems challenging to accomplish. DISCUSSION: The PI previously developed an interesting microfluidic device for patch clamp measurements and now proposes a variation on this as a platform for chemical, electrical and mechanical stimulation of hESC/EB to differentiate them into cardiomyocytes. This is a clever use of previously developed technology. There was discussion as to whether EBs were a feasible cell type for this use with agreement that they could be appropriate. There was a question over whether the fully differentiated cardiomyocytes would be clinically useful, and it appears that in mouse the answer is yes, and thus possibly could be useful in humans as a patch or as single cells.