Precious alien metals can kill cancer cells

Iridium, the alien metal brought to Earth by the dinosaur-killing meteorite, could cure cancer,Mirrorjust reported. This is the rarest element in the world. When using lasers to bombard this metal, researchers obtained a toxic form of oxygen that can kill cancer cells but is harmless to healthy cells.

Experimental results show that iridium enters the nucleus of cancer cells by binding to the protein albumin in the blood, promising to revolutionize the treatment of the most dangerous diseases. Iridium only becomes toxic when exposed to light in photodynamic therapy. This therapy activates the metal to kill cells through oxidation, in which the diseased cells' own oxygen is converted into a lethal form. Meanwhile, healthy tissue is not affected.

"It's exciting that this large protein can enter cancer cells and carry the metal iridium, which selectively kills them when activated by visible light. If this technology can be applied clinically, it could be very effective against difficult-to-treat cancers and reduce the side effects of chemotherapy," said Professor Peter Sadler, from the Department of Chemistry at the University of Warwick, UK. According to Professor Sadler, the next step is pre-clinical testing on animals.

Professor Sadler's international team used a special organic coating to bind iridium to albumin, causing the protein to glow. Using powerful microscopes, they tracked the albumin's path into lab-grown lung cancer tumors and found it destroyed the tumors.

Photodynamic therapy relies on chemical compounds called photosensitizers that produce oxidizing agents when activated by lasers. It is being used to treat many types of cancer, including skin, breast, and lung cancers. When the photosensitizer is exposed to a specific wavelength of light, it produces a form of oxygen that can kill nearby cells. Doctors target the cancer cells they want to attack using an optical fiber that carries the light signal.

Research published in Angewandte Chemie International Edition found that iridium-containing compounds are excellent light-sensitive agents. Furthermore, albumin can deliver it into the nucleus of cancer cells, where all the genetic material is stored. Iridium can be activated by red laser light, allowing cancer cells to be destroyed from within. The laser technique destroys tumors with much greater precision than radiotherapy and chemotherapy.

Iridium was found in the Chicxulub crater in the Yucatan Peninsula 66 million years ago when the 11km-wide meteorite killed 70% of all living things, including dinosaurs. Professor Sadler believes rare metals like iridium could help fight drug resistance.