Chemotherapy treatment produces significant side effects. A new operator (Ultrasound Works against Cancer) that concentrates on the tumor tissue and works there with ultrasound waves does not have this problem.
Platinum complexes are among the most commonly used cancer drugs. They are successful, but they have negative effects. An international study by Dr. Johannes Karges from the Department of Chemistry and Biochemistry of the Ruhr University in Bochum, Germany, has developed a complex that binds to tumor tissue and works there with ultrasonic waves. Therefore, its destructive effects appear where it is really needed.
“Whereas previous studies rely on switches that can only penetrate a few millimeters into the body, we have developed a treatment system with ultrasound input that penetrates several centimeters into the body,” he said. Karges says. This can make treatment possible with fewer side effects, even for larger and deeper tumors. The researchers published their findings in the journal Angewandte Chemie International Edition on March 24, 2023.
Harmless and good for the body
Platinum(II) complexes cisplatin, oxaliplatin and carboplatin are among the most commonly used anticancer drugs. Their clinical progress is offset by adverse effects, such as nausea, vomiting, kidney damage and bone marrow suppression. To overcome these limitations, much research effort has been devoted to the development of so-called platinum (IV) complex pro drugs in the past decades.
Johannes Karges explains: “These drugs are stable and inactive, so they are harmless. “In a solid body, they should stay that way. In cancerous tissue, however, they are quickly converted into therapeutically active platinum (II) compounds.
Energy is required for the reduction of the iron complex. Previous studies have reported activation in ultraviolet, blue, or red light. “The problem is that light can penetrate the body less than a centimeter and therefore does not reach many tumors,” explains Johannes Karges. To overcome this limitation, his team for the first time combined platinum complex (IV) pro drugs with sonosensitizers that can be selectively activated by ultrasound irradiation.
Nanoparticles accumulate in tumors
To create an effective therapeutic complex, the researchers combined platinum (IV) complex prodrugs and sonosensitizers together with hemoglobin to create nanoparticles. Johannes Karges reports: “We could see that the particles accumulated in the intestinal tissue of mice after being injected into the bloodstream, thus supporting targeted therapy.” “After ultrasound irradiation, the platinum (IV) prodrug is activated at the tumor site, resulting in the release of cisplatin, which is toxic to cells, and almost completely eradicates the tumor.”
Benefits of Ultrasound
These results may pave the way for the development of new methods and agents for the treatment of large or deep tumors. Ultrasound can penetrate more than an order of magnitude deeper into tissue than near infrared light. In addition, ultrasound therapy is considered to be safe and easy to use. Another advantage is that hospitals often have the necessary equipment. “Our work is still basic research,” emphasizes Johannes Karges. “It is impossible to predict if and when a treatment based on this can be given in clinical practice.”
Source: Ruhr-University Bochum.
