You can kill a cancer cell by sneaking nanoparticles inside it, or in its vicinity. When light shines on the nanoparticles, they absorb the light energy and give it back as heat — the heat kills the cancer cells. This mechanism is well understood, but the challenges are in designing a nanoparticle that is good at absorbing light and emitting heat, and is also small enough to crawl into the cancer cell.

Now a team of researchers led by Prof Jaya Prakash, Department of Instrumentation and Applied Physics, IISc, Bengaluru, has developed a hybrid nanoparticle of gold and copper sulphide for this purpose. Copper sulphide pinpoints the cancer cells and the gold destroys them, when light hits the nanoparticles.

A big challenge was to make the nanoparticle tiny enough to sneak into the cancer cell. To overcome this, the researchers used a novel ‘reduction’ method, using Tannic acid and sodium citrate to form gold nanoseeds, which were then deposited on a copper sulphide surface. The nanoparticle they got was 8 nm in size.

“The researchers believe that the nanoparticles’ small size would also allow them to leave the human body naturally without accumulating, although extensive studies have to be carried out to determine if they are safe to use inside the human body,” says a write-up in IISc’s in-house publication, Kernel.

“The researchers have tested their nanoparticles on lung cancer and cervical cancer cell lines in the lab. They now plan to take the results forward for clinical development,” Kernel says.