By Rob Goodier
NEW YORK (Reuters Health) – A refillable implant could someday passively administer pre-exposure prophylaxis drugs to HIV patients.
Now in animal trials, the device has successfully released a stream of tenofovir diphosphate and emtricitabine triphosphate without the need for pumps, valves or a power supply, according to research presented February 21 at the American Society of Mechanical Engineers’ NanoEngineering for Medicine and Biology Conference in Houston, Texas.
“The constant drug release is achieved through the use of nanochannels, which are engineered in size to be slightly larger (but still comparable) to the size of drug molecules that are released,” Alessandro Grattoni, Nanomedicine Chair at Houston Methodist Research Institute in Houston, Texas, who led the research, told Reuters Health by email.
“In other words, drug molecules, driven by a difference in concentration, are released from the implant reservoir to the body by diffusion across the narrow nanochannels,” Grattoni says.
Grattoni and his team implanted test devices loaded with either tenofovir or emtricitabine. Over the course of 21 days, the researchers measured a preventative dose of tenofovir, but not of emtricitabine. The conclusion was that larger nanochannels are needed and new tests are ongoing.