Tebello Nyokong, a South African chemist, is developing nanomaterials containing photosensitive dyes for use with lasers to attack certain types of cancerous cells. Photodynamic therapy is a non-invasive, low-toxicity method of causing cell death used to treat a wide range of medical conditions, including several forms of cancer. Dye particles are ingested, injected or applied in a cream, and after they have built up in the body, a laser is applied to targeted cells, either externally or via an endoscope.
When the photosensitive dye is excited by a laser, it can react with the oxygen in cell tissue to produce a highly reactive form of oxygen molecule called singlet oxygen, which can destroy cancerous cells. In a February paper4, Nyokong and her colleagues reported on a new photosensitive dye, finding it was suitable candidate for further research to treat breast cancer.
Nanomaterial research requires extremely expensive equipment to understand matter on an atomic or molecular level, says Nyokong, who is director of the Institute for Nanotechnology Innovation at Rhodes University in Makhanda, South Africa.“Nanomaterials are so tiny, you need high-powered equipment to see their composition, the surface of this material, and whether they have any pores to absorb the drug or not.”
Nyokong says she is proud to have established a state-of-the-art facility for nanotechnology “in the middle of nowhere”: Makhanda is about 750 kilometres from South Africa’s legislative capital, Cape Town, and 975 km by road from its largest city, Johannesburg.
Nyokong battles to find adequate funding. African nations largely fail to allocate adequate resources for scientific research, she argues in a paper5 published in March, and adds that funding challenges are compounded by system failures in payments of grants.
She works with up to 40 postgraduate students and postdoctoral researchers from across Africa. One of her collaborators, Bokolombe Pitchou Ngoy, now a professor at the University of Kinshasa in the Democratic Republic of the Congo, says Nyokong likes to promote the work of young scientists, particularly women.
Another former colleague, Edith Amuhaya, now an assistant professor in chemistry at the United States International University-Africa in Nairobi, Kenya, was a postdoctoral researcher at the institute, where she collaborated with Nyokong. She describes her former colleague as “hands-on”, despite managing a vast lab, with many students.
The institute’s research builds on work that Nyokong has been doing since she was first awarded two lasers by the National Laser Centre. Given mere hours in 2003 to write an application for the lasers, today those lasers have been updated and replaced many times over. “It changed the course of my research,” she says. “I could not do the research on exploring my molecules for the possibility of use in photodynamic therapy without the lasers.”
Now research facilities across South Africa send materials to the institute for analysis, and its own research is forging new paths.
Research is now under way with researchers in Canada and Kenya to explore the use of photodynamic therapy to treat bacterial, fungal and viral infections.
Nyokong says she remains frustrated that industry take-up in South Africa of novel scientific research continues to be slow. Her team has worked on developing a film or screen to protect pilots’ eyes from exposure to laser beams while landing, but moving the project forward had been difficult. “I want to work with someone to push this into mass production,” she says. “I need fresh ideas, because I’m training fresh minds.”