New polymers shatter to release drugs at specific target

A new delivery platform called chain-shattering polymers, developed by researchers at the University of Illinois, could hold the key to the more controlled release of drugs at localized sites and tissues.

By integrating a drug into the structure of a polymer, Jianjun Cheng and his team in Urbana-Champaign were able to release predictable amounts of the drug by shattering the chain, a method they published in the journal Angewandte Chemie. The polymer consists of alternating units of the drug and a "suicidal" chemical residue with a protecting agent. When the protecting agent is exposed to either ultraviolet light or a peroxide trigger, the chemical breaks away, freeing the drug at the intended location, which could be a tumor, skin lesion or other tissue, according to a report in Chemical & Engineering News.

Courtesy of Angewandte Chemie

The Illinois researchers used a design by Rutgers University's Kathryn Uhrich that incorporated aspirin directly into the polymer chain, but they used the cancer drug camptothecin and were able to release 80% of the agent in 10 minutes.

"This is the only polymeric nanomedicine I know that has nearly perfect control over composition, structure and release profile," Cheng told C&EN.

There's still a ways to go before the effectiveness and safety of chain-shattering polymers can be proven in vivo, C&EN reports, including an investigation into the side effects of polymer degradation.

- here's the C&EN report
- and here's the abstract