A University of Waterloo professor and his team are in the midst of developing a device to reduce the risk of transmitting HIV.
Emmanuel Ho, an associate professor at UW’s School of Pharmacy, along with his team, is researching an intravaginal ring (IVR) which is inserted into the female genital tract and delivers two different medications. This is an innovative design compared to previous ring devices as they have only been able to deliver a single medication.
HIV is an immunodeficiency virus, meaning it will attack and severely weaken the immune system of the host. This allows for other diseases to thrive which may eventually kill the host. Therefore, medications used to stop the transmission of the virus aim to target the immune cells themselves.
“[This device] is different from other rings available since we are combining chemotherapy and gene therapy that can further enhance the blockage of HIV to its target cells. Also, the device is designed to deliver the medication only when needed in an effort for a smarter way to control the drug release,” said Yannick Traore, a PhD graduate and primary author of the study.
The device can release two types of medications because of its design. One half of the ring is hollow with small pores to allow the release of hydroxychloroquine (HCQ) over a 25-day period, while the other half of the ring is solid, with a pH sensitive coating which will allow the ring to release a nanomedicine gene therapy during intercourse.
The first medication used is HCQ. HCQ is a drug that will decrease T cell activity and reduce the possibility that HIV cells will interact with them. This drug is FDA-approved and safe to use.
“The concentration of hydroxychloroquine used will just reduce the activation of T cells and not suppress their activity completely,” Traore said.
The gene therapy contains nanoparticles which decrease the expression of a T cell surface receptor called CCR5. CCR5 is a receptor for cellular signals, but HIV cells will also use this receptor to get into the T cells. Therefore, T cells not expressing the CCR5 receptor cannot be infiltrated by the virus.
“From our knowledge, the suppression of CCR5 expression from the immune cells does not affect the cell functions,” Traore said. Therefore, other essential T-cell functions can still be active without this receptor present.
The nanoparticles are only released when the outer coating of the ring detects a pH change during intercourse. “To avoid unnecessary gene knockdown and potential toxicity, it makes sense to only use the gene therapy when it is necessary and it will be cost-effective, especially if we want to use this device in developing countries where HIV is more prevalent,” Traore explained.
Currently ,the device has passed all laboratory testing to date and is ready for animal studies. If approved, the device would help many women around the world.
“The intravaginal ring, in general, will empower more women to protect themself against HIV if they are not able to negotiate condom usage with their male partners,” Traore said.
