BREAKTHROUGHS BLOG

November 21, 2016

Research Roundup: Long-lasting pills, HIV testing, and starving bacteria of iron

Senior Program Assistant
GHTC

Researchers at Massachusetts Institute of Technology and Harvard Medical School have designed a star-shaped pill that releases medicines over the course of two weeks. The long-acting pill has six arms that can be folded into a capsule. Once the capsule reaches the stomach, its outer layer is dissolved, causing the six arms to pop out. Due to its size, the expanded pill is able to remain in the stomach until its arms detach and are digested one by one. The research team used the antimalarial ivermectin to test this delivery system in pigs. The medicine was continually released for two weeks—an impressive feat as oral medicines rarely last longer than a day. Long-acting medicines can significantly improve adherence to complicated treatment regimens. The researchers are now using the platform to develop drugs for neuropsychiatric disorders, HIV/AIDS, diabetes, and epilepsy.

Someday soon, one drop of blood and a USB stick could be all that’s required to determine a patient’s HIV viral load. The system uses an electronic chip to detect the virus and transform it into an electronic signal, which is then picked up by the USB, enabling users to access their results off by computer. The device was used to evaluate nearly 1,000 blood samples and proved to be accurate 95 percent of the time, providing results in 21 minutes on average. Current techniques to assess viral load take three days. Patients in remote areas often have to wait much longer because their samples must be transported to laboratories. The HIV virus can develop resistance to antiretroviral treatment, resulting in increasing levels of the virus in the blood. Patients could use this tool to regularly monitor their viral load, ensuring early detection of resistance.

During infection, bacteria deploy minute molecules—siderophores—to steal iron from human cells. Microbes need iron to reproduce and interfering with this process could debilitate bacteria, preventing infection. Scientists have sought to develop vaccines that train the immune system to respond to the presence of siderophores; however, the molecules are too small to prompt an adequate immune response. Now, two independent groups of researchers have demonstrated that attaching siderophores to large proteins boosts the immune response. One team used siderophores from the strain of E. coli that causes urinary tract infections, while the other used the strain of Salmonella that causes food poisoning. Both teams vaccinated mice and then exposed them to the bacteria several weeks later. While neither vaccine provided complete protection, infections were much less severe in vaccinated mice. Mice that were vaccinated against E. coli had one-tenth the bacterial load in their urine and kidneys and less inflammation in their kidneys and bladders. The Salmonella-based vaccine triggered the production of antibodies against the siderophores, resulting in a bacterial load 20,000-fold fewer in vaccinated mice.

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