Straight to the heart

A new kind of non-inflammatory drug-delivery vehicle for the treatment of heart disease is reported online this week in Nature Materials. Michael Davis and colleagues demonstrate that ‘polymeric microspheres’ could be a useful form of drug transportation for a range of conditions.

Many polymer-based drug-delivery materials break down in the body to form acidic by-products that cause local inflammation in the target tissue. In the treatment of inflammatory diseases, such as cardiac dysfunction following heart attacks, this inflammation is detrimental to the recovery of the tissue.

Davis and his team show that polymer microspheres loaded with a known drug can be injected directly into the heart and, because of the neutral and non-inflammatory breakdown products of the polymer, they do not worsen the already inflamed section of the heart. This improved treatment of cardiac dysfunction is a result of the controlled release of the encapsulated drug from the polymer particles, allowing the diseased area to experience a sustained amount of the drug over several days. In comparison, the direct injection of the drug without the polymer shows no such beneficial effect.

The use of a polymer delivery vehicle with non-inflammatory decomposition products could have applications in inflammatory diseases of other organs, including liver, lung and bowel.