SIR: Microbubbles with stem cells can stimulate new blood vessels in the leg
Bone marrow stem cells suspended in X-ray-visible microbubbles can help in treating peripheral arterial disease (PAD) patients by increasing the number of blood vessels, according to research presented at the Society of Interventional Radiology's 35th Annual Scientific Meeting in Tampa, Fla.  this week.

"Using an animal model, we found that stem cells in x-ray–visible microbubbles dramatically improve the ability to build new blood vessels when a blood vessel in the upper leg has been suddenly closed or occluded," said Dara L. Kraitchman, VMD, PhD, associate professor at School of Medicine, Johns Hopkins University in Baltimore. "With this treatment, the body was able to provide a more normal blood supply to the toes—possibly offering the hope of dramatically reducing—or avoiding—amputation. Treatment could also be personalized for individual patients," she added.

Kraitchman and colleagues created x-ray visible capsules, by encapsulating rabbit mesenchymal stem cells (MSCs) by alginate poly-L-lysine alginate method with the addition 12 percent PFOB (PFOB-MSCs).

The researchers found that microencapsulation protected PFOB-MSCs from early cell destruction in a rabbit PAD model, thereby enhancing viability and improving arteriogenic response for the treatment of PAD.

Kraitchman and colleagues believe that these microbubble stem cells could be administered when an interventional radiologist is performing a dye study to look at a patient's arteries and the treatment could be repeated, if needed.

"The future hope is to use adult stem cells extracted from a healthy donor's bone marrow and inject the cells into the patients' legs where circulation problems exist, stimulating the growth of new or more blood vessels in the leg, thus improving circulation," noted Kraitchman.

"We are continuing to test the treatment in animals and attempting to perfect methods using non-invasive imaging, such as magnetic resonance imaging (MRI), ultrasound and blood pressure measurements, which could be used to follow up patients without exposing them to X-rays or needing to enter a blood vessel to inject dye to see the newly formed vessels," said Kraitchman. "We are also fusing the x-ray imaging results with other imaging techniques like MRI to provide a better picture of where to place the stem cells," she added.