Improving the Function and Engraftment of Transplanted Pancreatic Islets Using Pulsed Focused Ultrasound Therapy

This is the authors' abstract. We don't add key points for this paper.

This study demonstrates that pulsed focused ultrasound (pFUS) therapy can non-invasively enhance the function and engraftment of pancreatic islets following transplantation. In vitro , we show that islets treated with pFUS at low (peak negative pressure (PNP): 106kPa, spatial peak temporal peak intensity (I sptp ): 0.71 W/cm 2 ), medium (PNP: 150kPa, I sptp : 1.43 W/cm 2 ) or high (PNP: 212kPa, I sptp : 2.86 W/cm 2 ) acoustic intensities were stimulated resulting in an increase in their function (i.e. insulin secretion at low-intensity: 1.15 ± 0.17, medium-intensity: 2.02 ± 0.25, and high-intensity: 2.54 ± 0.38 fold increase when compared to control untreated islets; P < 0.05). Furthermore, we have shown that this improvement in islet function is a result of pFUS increasing the intracellular concentration of calcium (Ca 2+ ) within islets which was also linked to pFUS increasing the resting membrane potential ( V m ) of islets. Following syngeneic renal sub-capsule islet transplantation in C57/B6 mice, pFUS (PNP: 2.9 MPa, I sptp : 895 W/cm 2 ) improved the function of transplanted islets with diabetic animals rapidly re-establishing glycemic control. In addition, pFUS was able to enhance the engraftment by facilitating islet revascularization and reducing inflammation. Given a significant number of islets are lost immediately following transplantation, pFUS has the potential to be used in humans as a novel non-invasive therapy to facilitate islet function and engraftment, thereby improving the outcome of diabetic patients undergoing islet transplantation.