"We loaded insulin in layers of microgel films in the lab and released bursts of insulin by applying heat to the films. They were extremely stable and could continue to release the drug for more than one month at a time," said L. Andrew Lyon, associate professor at Georgia Tech's School of Chemistry and Biochemistry.

The results add to a decade's worth of work in controlled and targeted drug delivery. Lyon's usage of using films assembled from microparticles allows more control over drug release than films previously made in monolithic form.

The insulin tests, said Lyon, serve as proof of a concept that this method of drug delivery is worth further investigation. Currently, the films release their cargo at 31 C, six degrees below human body temperature, but Lyon's group is working on pushing the release point to a temperature slightly above that of the human body. Once implanted, the pharmaceutical-loaded films could be placed on chips with resistive heaters and scheduled to release drugs according to a time schedule or another trigger.

"One potential use is tying the implant to a blood glucose monitor using radio frequency (RF) technology," said Lyon. "When the monitor detects that a diabetic patient has high blood sugar, it could send a signal to the chip to heat the film and release insulin into the bloodstream."

Patients undergoing hormone therapy, chemotherapy or other treatments requiring periodic medication could conceivably get their dosages this way.

"Of course using these films to deliver medications in humans would require many more trials, said Lyon. "We believe we've taken an important step in new methods of drug delivery."