Researchers at the Indian Institute of Science (IISc) have developed a method that uses visible light on a particular kind of molecule to kill cancerous cells. 

Presently, the common methods used to treat cancer are radiation, chemotherapy and surgery.

Add to this - Photodynamic therapy (PDT) or Photochemotherapy, a technique that uses drugs that are activated only when a certain wavelength of visible light is applied. The drug, a photosensitising agent, is applied topically  or intravenously, depending on where the cancer is located. The agent is engineered to preferentially accumulate in the cancerous cells. When visible light of a particular wavelength is applied, the drug gets triggered and kills only the cancerous cells, leaving healthy cells intact.

The team of Prof Akhil R Chakravarty from the Department of Inorganic and Physical Chemistry and Prof Anjali Karande from the Department of Biochemistry have synthesised a new molecule that can be used in PDT and kills cancer cells selectively.

The molecule has demonstrated specific chemical properties that makes it a potent killer of cancerous cells. The molecule accumulated specifically in the cancer cells’ mitochondria, a part of the cell that generates energy, causing damage to the mitochondrial DNA and resulting in cell death. The molecule only gets activated when visible light (of 400-700 nanometres wavelength) was applied. It was also demonstrated to be essentially non-toxic in normal cells.

Controlling the activity of the drug through exposure to light or the PTD therapy is an entirely new approach to cancer therapy, said a release from the IISc. As a result of its potent and multiple mechanisms in killing cancer cells selectively, and with limited side effects to healthy tissue, the molecule holds much promise as a novel cancer therapy drug, it added.

In all its forms, cancer kills as many as seven lakh people every year in India and millions all over the world. It occurs when normal cells go rogue,  tweaking functions that make it easier for the cancerous cells to multiply and invade normal tissues, affecting the organs’ functions.