Gary Yu

Faculty Mentor: John Pacella

Research:

Gary Yu’s research project investigates the relationship between therapeutic ultrasound conditions and thrombolytic efficacy in ultrasound-mediated microbubble cavitation therapy (UTMC). UTMC is a theranostic platform which aims to reduce microvascular thrombi burden in settings of acute myocardial infarction through ultrasound cavitation of injected lipid microbubbles. Insight into physical mechanisms of thrombus dissolution will optimize clinically relevant outcomes, including microthrombus penetration, size reduction, and time course for treatment. Variations in ultrasound conditions may generate either inertial or stable MB cavitation, which result in different microthrombi interactions. Characterization of MB behaviors, including micro- jetting, pitting of microthrombi surfaces, and formation of daughter bubbles, may inform therapeutic enhancements of SRP.

Additionally, Gary Yu’s project investigates the validation of erythrocyte nitric oxide synthase as a therapeutic target for UTMC therapy. It has been demonstrated that shear stress upregulates activity of erythrocyte nitric oxide synthase, leading to significant vasodilation and nitric oxide release in a hypoxic environment. Preliminary data has also confirmed that UTMC therapy causes shear stress on the local endothelial environment through microbubble oscillation. Given the interaction between intravascular microbubbles and erythrocytes in the vascular space, microbubbles likely exert shear forces on erythrocytes, allowing the leveraging of the hypoxic tendency of erythrocyte nitric oxide synthase activity as an additional mechanism for UTMC therapy to address microvascular obstruction in acute myocardial infarction, an inherently ischemic state. 

Publications:

• Deng, Y., Sun, A. X., Overholt, K. J., Yu, G. Z., Fritch, M. R., Alexander, P. G., ... & Lin, H. (2019). Enhancing chondrogenesis and mechanical strength retention in physiologically relevant hydrogels with incorporation of hyaluronic acid and direct loading of TGF-β. Acta biomaterialia, 83, 167-176.
• Yu, G. Z., Chou, D. T., Hong, D., Roy, A., & Kumta, P. N. (2017). Biomimetic Rotated Lamellar Plywood Motifs by Additive Manufacturing of Metal Alloy Scaffolds for Bone Tissue Engineering. ACS Biomaterials Science & Engineering. 

Presentations:

• Gary Yu, Filip Istvanic, Xucai Chen, Mehdi Nouraie, John Pacella. Ultrasound-targeted microbubble cavitation with sodium nitrite synergistically enhances nitric oxide production and microvascular perfusion. Abstract for oral presentation. 2019. The 24^th European Symposium on Ultrasound Contrast Imaging.
• Gary Yu, Janice Peake, and Kent Pinkerton. Exposure to environmental tobacco smoke can exacerbate house dust mite allergen-induced allergic lung inflammation in guinea pigs. In: The 14th International Congress of Immunology, Kobe, Japan, August 26, 2010.
• Gary Yu, Francois Yu, Xucai Chen, Linda Laverly, John J. Pacella. Improving Reperfusion Kinetics and Efficacy with Sodium Nitroprusside in Sonoreperfusion Therapy. Abstract for poster presentation. 2017. American Heart Association Fellows Research Day.
• Francois T.H. Yu, Gary Yu, Xucai Chen, Linda Laverly, Flordeliza Villanueva and John J. Pacella. The Effect of Pulse Length on Perfusion Kinetics Following Sonoreperfusion Therapy. Abstract for poster presentation. 2017. European symposium on Ultrasound Contrast Imaging, Rotterdam.
• Hang Lin, Aaron X. Sun, Gary Yu, Alexander Peter, Rocky Tuan. Customized Fabrication of Osteochondral Tissue for Articular Joint Surface Repair. Abstract for poster presentation. 2018. Orthopedic Research Society Annual Meeting.

Mr. Yu's current research focuses on development and characterization of ultrasound-targeted microbubble cavitation therapy (UTMC), which involves ultrasound stimulation of injected lipid microbubbles.