Drug-embedded microparticles bolster heart function in anim...(articles half is gone after a week of j...)

"These are actually cells we're trying to reach with the drug, because they're involved in the inflammatory response in the heart," he says. "The macrophages can surround and eat the particles, or fuse together if the particles are too big."

Davis says polyketals have an advantage over other biodegradable polymers, in that they break down into neutral, excretable compounds that aren't themselves inflammatory.

Polyesters such as PLGA (polylactic-co-glycolic acid) are approved for use in sutures and grafts. However, when they are made into particles small enough to be broken down in the body, polyesters cause inflammation exactly what the drugs are supposed to stop, he says.

When the particles were injected into rats' hearts, the researchers could see an inhibition of the MAP kinase enzyme lasting for a week. However, the effect on heart function was greater after 21 days. Davis says this result suggests that the main way the particles helped the heart was to prevent the scarring that sets in after the initial tissue damage of a heart attack.

He and Murthy are exploring polyketal particles as delivery vehicles for drugs or proteins in several organs: heart, liver, lungs and spinal cord.

'/>"/>