HIV implant targets disease for up to a year

US researchers have developed an injectable implant that delivers multiple drugs to prevent and treat HIV and other conditions over long periods of time.

HIV
SEM cross-section images of the implant after drug release for 30 days (Credit: UNC School of Medicine)

The device is the result of a seven-year collaboration between various departments of the University of North Carolina and North Carolina State University. It is comprised of three elements – an organic solvent, a polymer and the drugs themselves. These three components form a liquid with the consistency of honey which solidifies once injected, as the solvent diffuses into the body leaving the polymer and the drugs behind. Adjusting the ratio of polymer to drugs determines the rate of release into the body. It’s believed the implant could enhance long term treatment and prevention of HIV with antiretrovirals where medication regimes often require patients to take multiple drugs at the same time each day.

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In the study, published in Nature Communications, six antiretroviral drugs were tested, with all keeping their physical and chemical properties within the formulation and upon release. All six were also released from the implant at effective levels for a sustained amount of time ranging from one month to a year. The researchers also claim the implant can be surgically removed within one week of implantation and for several months after. Such a situation might arise if a patient reacted badly to the implant, or if a woman became pregnant.

“There is no FDA-approved or marketed technology for long-acting prevention of HIV, and we are the first to use this delivery method with multiple antiretroviral drugs,” said study first author Rahima Benhabbour, assistant professor in the UNC_NCSU Joint Department of Biomedical Engineering.

“To have an HIV prevention treatment that consists of an injection once or twice a year would make an incredible impact for patients. This technology is not only promising for HIV, but for any kind of condition that requires a daily intake of medication. We’re talking about a safe, removable, long-lasting injection that takes away the burden of adhering to a daily medication regimen.”

Human error, access to drugs and the stigma surrounding HIV are just some of the issues that stand in the way of successful antiretroviral treatment. But the effectiveness of the medication is dependent on strict adherence to the drug regimen. The new implant overcomes these obstacles and promises accurate dosages over sustained periods of time.

“In sub-Saharan Africa where prevalence of HIV is highest, accessibility to these medications can be difficult, and there is much stigma associated with the virus,” Benhabbour said. “It is a very big deal for someone who doesn’t have HIV to go out of their way to not only access the drugs, but then associate themselves with HIV by taking a pill every day.”