BENGALURU: A relatively new treatment for cancer could become safer and less expensive, thanks to research at the Indian Institute of Science.
Photodynamic therapy (PDT), using light to treat cancer, is emerging as an alternative to harsh treatments such as chemotherapy or radiation.
In PDT, a drug called a photosensitiser is injected into cancer cells in a non-reactive or dormant form.
When exposed to light of a specific wavelength, the drug gets activated and then triggers the release of a reactive oxygen molecule, which kills the cancer cells.
Researchers at IISc have designed a trio of compounds that can be triggered by light to become toxic to cancer cells.
These target the cells’ mitochondria — their “energy factories” — setting off a chain reaction that turns on cell death pathways and kills the cancer cells.
Better Drugs: The newly-designed compounds could potentially lead to novel mitochondria-targeting cancer drugs that are safe, controlled and efficient.
Prof Akhil R Chakravarty, Department of Inorganic and Physical Chemistry, Babu Balaji, a graduate student, Prof Anjali Karande, Department of Biochemistry, Babita Balakrishnan, a post-doctoral scholar, and Shravanakumar Perumalla, a graduate student, designed the new compounds, a novel blend of organic and metallic components.
Biological studies were carried out with the help of Prof Anjali Karande’s research group.
Chain Reaction: Positively charged elements in the compounds’ structure help them travel across the negatively charged mitochondrial membrane and accumulate inside. When exposed to light, the stable ferrocene in the mix switches to an unstable ferrocenium molecule, triggering the release of reactive oxygen species (ROS). ROS are destructive molecules that start off a chain reaction, eventually killing the cancer cells, a process called apoptosis or programmed cell death.
“Organic (carbon-containing) drugs derived from porphyrin, a cyclic molecule, are currently used in PDT to treat certain lung and esophageal cancers. The new ferrocene-complexes, however, could substitute for these expensive porphyrin-based drugs,” Chakravarty said.
Current Drawbacks: Porphyrin-based drugs are also known to have harmful side effects on the skin, liver and kidney.