Breakthrough discoveries made by a materials engineer and his team at City University of Hong Kong (CityU) hold great promise for the future of cancer treatment and energy saving.
The achievements, made by a research team that include members from their Department of Physics, Department of Materials Science and Engineering and researchers from Nanjing University.
Their results from the study of photoluminescence and light scattering mechanisms, as well as the plasmonic properties of micro-nanostructures may lead to new methods of treatment.
The important findings have earned the team the prestigious First Class Award (Natural Science) at the 2017 Higher Education Outstanding Scientific Research Output Awards (Science and Technology) of the Ministry of Education, China.
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In addition, Professor Paul Chu Kim-ho, who led the CityU team, was included in the 2017 list of Highly Cited Researchers in materials science for the second year running, according to Clarivate Analytics.
One of the applications of Chu's findings involves the use of intense heat triggered by a photothermal process to kill cancer cells, offering an efficient and targeted way to treat cancer.
Chu goes on to explain that photothermal therapy, an emerging cancer treatment, involves the targeted delivery of photothermal agents to tumours, and subsequent light irradiation to produce a high local temperature that can kill tumour cells.
He compared the strategy to a “Trojan horse” carrying “bombs”. “When the ‘bombs’ interact with near-infrared light, the temperature rapidly increases, killing the tumours,” he said.
Chu and his team have discovered two effective types of carriers with photothermal agents: Bi2Se3-laden-macrophages and Nile blue dye with black phosphorus.
When trial experiments were carried out on mice, the technique was able to completely destroy and remove the tumours in them, with no recurrence.
“Both carriers possess good biocompatibility, and most of the material can be excreted from the body within 25 days to eliminate potential cytotoxicity,” Chu added.
He concluded that photothermal therapy is minimally invasive and fast-acting, and can easily be combined with other therapeutic approaches.
Another important discovery made by Chu and his team is thermochromic smart coating, a material that can control solar radiation transmission dynamically and automatically in varying temperatures and brightness.
The smart coating blocks heat when the temperature rises to 28 degrees Celsius or above with strong luminosity, but is heat transparent in weak irradiation conditions or at a temperature of 20 degrees Celsius or under.
Ultimately, it works as a transparent blind to control heat transmission and minimise the need for air conditioning.
“We have combined the properties of titanium nitride nanoparticles and vanadium dioxide. The former absorbs light quickly and increases the local temperature, while the latter shifts phases depending on different temperatures to block or allow heat through. Therefore, the coating is suitable for windows in buildings or vehicles,” explained Chu.
“The fundamental knowledge gained from this research has enabled us to develop new materials and technology to combat cancer and save energy effectively,” he added.