Photodynamic therapy is often used to treat brain tumors because of its specificity—it can target very small regions containing cancerous cells while sparing the normal cells around it from damage. It works by injecting a drug called a photosensitizer into the bloodstream, where it gathers in cells, and then exposing the drug-filled cells to light. When the photosensitizer is exposed to this light, it emits what is known as a reactive oxygen species (ROS) that causes the cells to die. The method is precise because photosensitizers preferentially gather in cancerous cells over normal cells. As such, when they are exposed to the light, the normal cells will be spared from damage.
Photodynamic therapy is often used to treat brain tumors because of its specificity—it can target very small regions containing cancerous cells while sparing the normal cells around it from damage. It works by injecting a drug called a photosensitizer into the bloodstream, where it gathers in cells, and then exposing the drug-filled cells to light. When the photosensitizer is exposed to this light, it emits what is known as a reactive oxygen species (ROS) that causes the cells to die. The method is precise because photosensitizers preferentially gather in cancerous cells over normal cells. As such, when they are exposed to the light, the normal cells will be spared from damage.
This method is far from perfect, however. Although the chemical components used to build the photosensitizer, such as polypyridyl Ru-complexes, are stable, biocompatible, and highly efficient in emitting ROS—and more ROS means more effective tumor cell death—the additional components added to it to boost emissions lead to poor solubility in water. Thus the compound is difficult to wield for effective drug delivery since the molecules tend to clump together rather than dissolve uniformly and thus move cleanly through blood, which is over 90% water. As such, there is room to improve the photodynamic therapy method, and researchers at the Okinawa Institute of Science and Technology Graduate University (OIST) have posited a new way of constructing a photosensitizer by adding the natural amino acid taurine into the Ru-complex’s chemical makeup. The study is published in the journal Chemical Communications.
Read more at Okinawa Institute of Science and Technology (OIST) Graduate University
Image: Death of brain cancer cells after photodynamic therapy. (Credit: Okinawa Institute of Science and Technology Graduate University (OIST))
