Tuberculosis is one of the world’s deadliest infectious diseases. It’s a major issue (worldwide, there are 10.4 million cases of TB and 1.7 million deaths every year). It’s cunning (Mycobacterium tuberculosis is able to multiply within a body’s own immune cells, macrophages, cells which are otherwise designed to kill bacteria), and treatment is exhausting. Treatment can last for months, and the drugs used require a gruelling regimen and can be toxic.
But there may be a new hope for TB treatment on the horizon: nanomedicine.
“Nanomedicine is the use of nanotechnology to either diagnose or treat a disease,” explains Associate Professor Admire Dube, Associate Professor of Pharmacy at the University of the Western Cape (UWC). “By creating and manipulating structures in the nanometre size range, we can devise medical solutions that are limited only by our imaginations.”
Dube is one of many scientists exploring the potential of nanotechnology for a better world. The nanoparticles used in nanomedicine are about 800 times smaller than the thickness of human hair, can be loaded with a variety of types of drugs such as proteins, DNA or even extracts from plants, and can be administered into the human body through swallowing, inhaling, injections or via the skin.
“Typically, nanoparticles are packed with drugs, and these nanoparticles can be designed to target only the site of the disease, and release the drug there,” Dube says. “Multiple drugs can be loaded in a single nanoparticle or a mixture of nanoparticles, (each containing a single type of drug), can be administered into the body to target disease sites and deliver drugs to those sites.”
Nanoparticles are able to make the drugs more available at the sites of infection by protecting them from breakdown prior to reaching the site. And there’s a greater uptake of the nanoparticles into infected sites. With better targeting, patients would need to take less medication for a shorter duration, with fewer side effects and less waste. And (hopefully) treatment would be cheaper.
As Dube puts it: “Nanomedicine is one of the most exciting applications of nanotechnology and promises to address several of mankind’s healthcare needs.”
There are currently about 50 nanomedicines worldwide which are in use by doctors to treat diseases - most of these for the treatment of cancers. Many researchers believe that nanomedicine could help TB patients enormously as well, and Dube’s research at UWC is focused on just that - examining the application of nanoparticles towards the treatment of tuberculosis, especially to achieve immunotherapy, targeted drug delivery and/or access across biological barriers.
“We engineer nanoparticles targeted to macrophages and use these nanoparticles to deliver high doses of drugs into these macrophages,” he explains. “Since these are immune cells, we also engineer the nanoparticles to activate these macrophages (known as immunotherapy) and therefore we can deliver a double, lethal punch to Mycobacterium tuberculosis.”
This form of immunotherapy holds great promise: it could prevent the generation of drug resistant TB strains, since the body’s own immune system is used to kill the bacteria. And since nanomedicines can be inhaled, they can be localised in the lungs – the centre of TB infection.
“It’s hoped that these TB-specific nanomedicines will make it to human trials over the next few years,” Dube remarks, “and that they will prove to be safe and effective – and start doing the important work of tackling this debilitating disease.”
Nanomedicine: A Better, Healthier World
Dube first became interested in nanomedicine when he read of the multitude of possibilities offered by nanotechnology for addressing health problems.
“Nanomedicine is a very exciting field from a technological perspective, and opens up many possibilities for innovation to address specific patient health needs,” Dube remarks. “Nanomedicine also provides unique opportunities for scientists from different backgrounds to come and work together to solve medical problems, and such teams usually include pharmacists, medical doctors, biotechnologists, chemists, physicists and material scientists.”
Born in Zimbabwe, Dube completed his Masters degree in Pharmacy at UWC in Cape Town, finished his PhD in Pharmaceutical Sciences in Australia, and performed postdoctoral research in the United States - so he knows a thing or two about nanomedicine and pharmacy around the globe.
He hopes to inspire other young scientists to pursue careers in academia and research in nanomedicine.
“I have a strong desire to see the development of an effective nanomedicine therapy for persons suffering from tuberculosis in South Africa,” he says. “Nanomedicine offers multiple opportunities to develop such therapies - and really, one’s imagination is the limit.”