Scientists are reporting development of a new form of aspirin - taken daily by about 60 million people in the United States alone to reduce the risk of heart attack and stroke - that could extend aspirin's benefits to people who may not respond to the drug. Their advance toward coping with "aspirin resistance" appears in the journal ACS Nano.

Shiqi Peng, Ming Zhao and colleagues note that aspirin lowers cardiovascular disease risk by keeping blood cells called platelets from clumping and forming clots. But some experts believe that aspirin doesn't work for millions of people, who may switch to more costly, potent prescription drugs with more serious side effects. Scientists have tried to address aspirin resistance by combining it with other drugs. But Peng and Zhao say that the problem remains. Their research group decided to modify aspirin in an effort to make it work for more people.

They linked aspirin to a carrier consisting of a fragment of protein that can transport aspirin directly to damaged parts of blood vessels where clots form. Experiments with laboratory rats, stand-ins for humans in such early tests, showed that the carrier delivered aspirin to areas of blood vessels where clots were forming. It released aspirin inside the developing clot and stopped the clot-formation process.

Article: Nanosized Aspirin-Arg-Gly-Asp-Val: Delivery of Aspirin to Thrombus by the Target Carrier Arg-Gly-Asp-Val Tetrapeptide, DOI: 10.1021/nn402171v.