A “smart” ring device for women has been developed to help prevent HIV transmission in situations where condom use is not possible.
The intravaginal ring (IVR) can be inserted into the female genital tract, where it will deliver medications known to decrease the transmission of HIV. Although condom usage is still recognised as the best prevention method for HIV transmission, researchers from the University of Waterloo have been working to design an alternative option for sex workers and women in situations where condom use is not possible.
The researchers examined how effectively their IVR delivered two medications – hydroxychloroquine (HCQ), an FDA-approved medication, and a nanomedicine gene therapy developed by the team in previous research.
The results from the study were published in the journal Drug Delivery and Translation Research.
Professor Emmanuel Ho, from the University of Waterloo’s School of Pharmacy and study author, said: “We’ve specifically engineered a combination IVR that can deliver two unique medications targeting different aspects of the HIV infection process.
“Before, only one drug could be delivered from an intravaginal ring.”
Segmented design
The ring is made of medical-grade plastic and contains two separate sections. One section is solid and coated in a pH-sensitive polymer that releases the customised gene-therapy treatment specifically during sexual intercourse. The other half is a hollow ring with small pores that releases HCQ gradually over 25 days.
The HCQ is the first line of defence to reduce the immune cell activation – meaning HIV cells have fewer host target cells to interact with. Doing this buys time for the gene therapy treatment which comes in specifically during sexual intercourse to further suppress the expression of cellular receptors that HIV cells attach to.
The left half of the Intravaginal ring is a solid section that releases gene-therapy. The right half of the ring is a hollow portion that releases hydroxychloroquine.
The team, which has previously partnered with the University of Nairobi in Kenya on related research, recognises the importance of using medications as cautiously as possible given potentially limited healthcare resources.
Activated by pH change
The system is designed to be placed in the vaginal tract but only act when there is sexual intercourse. The presence of semen increases the pH of the genital tract. Therefore, researchers designed the “smart” gene-therapy segment of the IVR to detect that change in pH and to release the nanomedicine at that point in time only.
Yannick Traore, a recent Waterloo PhD graduate and lead author on the study, said: “This IVR system will help women to protect themselves against HIV infection and greatly reduce drug usage when it is not necessary.
“We are hoping that this will reduce the cost of drug therapy and also prevent users from developing drug resistance.”
The study confirmed that the segmented design of the IVR is effective. In lab tests, the HCQ segment successfully released the drug slowly and effectively over 25 days and the gene therapy segment responded to the presence of seminal fluid simulant by releasing 20 times more nanomedicine than was released in an environment of only vaginal fluid simulant. Researchers will now test the IVR in animal models.
