Ultrasound used to target stem cell therapy

Episode # 93
Uploaded: April 2, 2012
Running Time: 03:11

CROWN: From the National Institutes of Health in Bethesda, Maryland, this is CLINICAL CENTER RADIO.

NIH researchers have been carefully reviewing stem cell therapy as an alternative therapy for injuries and disease treatment. Part of this research includes the study of bone marrow stromal cells. These cells are believed to stimulate new bone growth and help regulate the immune system. But as with all cell therapy, the tracking and targeted delivery of the transfused cells have been critical pieces of the puzzle. Dr. Joseph Frank, chief of the Clinical Center’s Radiology and Imaging Sciences Laboratory of Diagnostic Radiology Research, recently announced that he and his team have developed a new method to label transplanted cells so they can be tracked by magnetic resonance imaging, or MRI. Now he has unveiled a new discovery – a noninvasive method of using pulsed, focused ultrasound to precisely target stem cell delivery.

FRANK: The technique is essentially a noninvasive approach. We’re just scanning across the skin in an area, directing it where we want to. We can put multiple pulses in the area that we want and change the microenvironment of the tissue. Essentially, we’re developing what we could commonly call a molecular zip code for that cell to be able to home to that area and then migrate across. 

CROWN: Dr. Frank explains that the ultrasound works by causing the tissue to temporarily release natural chemicals, such as cytokines, integrins, and growth factors, to which the cells are attracted. It doesn’t hurt the tissue and, in fact, the tissue is only affected for a short period of time – about 24-36 hours. This may make is feasible to do multiple applications over a relatively short period of time.

FRANK: So the concept is that we can come back multiple times. And, in fact, when we do daily combinations of the pulsed focused ultrasound with the stem cell infusion, we actually have highly significant differences in the number of cells after three days compared to just a single course of stem cells.

CROWN: Traditional non-invasive methods of cell therapy typically have less than 3 percent success rate of the transplanted cells reaching their target.  Dr. Frank’s study showed that using pulsed, focused ultrasound prior to cell therapy multiplied cell delivery up to eight to 10 times that of traditional methods. However, Dr. Frank explains that more cells may not be better. Researchers are still trying to better understand issues such as optional dosing and timing.

FRANK: You can always put more cells in by putting a catheter into a vessel and directing it the area that you want or directly injecting it. The concept now is that I can noninvasively without damaging the tissue put more cells in the tissue. And is that going to be better for repair?  Is the going to be better for regenerative medicine?

CROWN: From America's Clinical Research Hospital, this has been CLINICAL CENTER RADIO. In Bethesda, Maryland, I'm Ellen Crown, at the National Institutes of Health, an agency of the United States Department of Health and Human Services.

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