Three of the pigs who received nanoparticles delivered by microbubbles (as opposed to intracellularly or with a patch attached to the heart) experienced blood clots, the researchers reported.
Right now, drug-eluting stents appear to be quite successful in treating atherosclerosis, said Fisher, but the new technique might one day be helpful in two particular subgroups: People who form clots after receiving a drug-eluting stent and who now require long-term anti-platelet therapy, and diabetic patients who are difficult to treat with angioplasty and stenting.
However, studies with animals that show promise don't always guarantee that the benefits will be seen in humans.
The Ural State Medical Academy in Yekaterinburg, Russian Federation, funded the study, with help from private investors.
A second study, from German researchers, used stem cells to heal tissue after a heart attack, although that research, Fisher said, "is a few steps more removed from clinical practice [than the nanoparticle study]."
Thirty rats were outfitted with miniature plastic scaffolds coated with stem cells engineered to overexpress different types of cytokines. Cytokines are cells produced by the immune system that facilitate communication between cells.
Other rats were given a cytokine-related gene and still others received stem cells without the scaffolding.
Rats who were implanted with scaffolding plus genetically modified stem cells saw greater improvements in blood pressure function than those in the control group, according to the report by Dr. Matthias Siepe, assistant professor and staff surgeon at the department of cardiovascular surgery, Medical University Center in Freiburg, Germany, and colleagues.
Both trials are preliminary, though, noted Dr. Darwin J. Prockop, director of the Texas A&M Health Science Center College of Medicine Institute for Regenerative Medicine at Scott & Whi
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