Post-surgical patch releases non-opioid painkiller directly to the wound

The polymer itself, comprised of poly(ester urea) homopolymers and co-polymers, is also special, Becker said.

"Most polymers that are used in medicine swell, and everything comes out at once," Becker said. But this polymer erodes slowly, and its painkiller dose and longevity can be controlled simply by varying the surface area and thicknesses. "The film is about like a piece of paper."

"If you can get four or five days of pain control out of the patch and not have to take those other pain drugs, not only do you avoid some of the side effects and risks of addiction, you're concentrating therapy where you need it," Becker said.

Rat studies also showed that the painkiller stayed in tissues close to the patch site, rather than dissolving into circulating plasma.

Becker said the patch should be able to provide three or four days of wound-pain management, which is the critical period for post-surgical pain. The implantable film would be particularly useful in endoscopic procedures and instances where the physicians and patients would like to avoid opioid exposure such as Cesarean births and pediatric surgeries. In studies with mice that mimic the neuropathic pain of diabetes, the pain patch was placed against a nerve and provided a four-day nerve block.