GOLD NANOPARTICLES ARMED WITH SPECIAL PEPTIDE ARE EFFICIENT CANCER KILLERS
Treating cancer is a complex task often requiring difficult decisions by both physician and patient. Cancer treatment usually includes at least one of three: surgical, radiation and/or chemotherapy. But what if there was a way to stop cancer in its tracks using a more accurate and effective method.
Researchers from Brown University and the University of Rhode Island worked together to come up with a way to deliver gold nanoparticles to cancer cells using a novel method. Using gold nanoparticles in radiation treatment is not a new concept, and has proven more effective than radiation alone in multiple studies. Gold, apart from being a coveted precious metal, is also extremely useful in medicine because it has the unique property of absorbing 100 times more radiation than tissue. It is known that through the Auger effect, these nanoparticles release electrons, which cause damage to cancer cells.
The most recently published study in PNAS (Proceedings of the National Academy of Sciences) has taken nanogold particles to the next level using a special acidophilic peptide called pHLIP (pH low insertion peptide). At neutral pH (7.0) pHLIPs form weak bonds with cell membranes, but at slightly acidic pH (<7.0) they form a stable transmembrane bond, which is important because cancer cells are slightly acidic. Interestingly, pHLIPs, at low pH, actually insert therapeutic or diagnostic agents, in this case gold nanoparticles, into cells acting like a nanosyringe to amplify the effectiveness of radiation treatment.
Schematic representation of pHLIPcargo interactions with the membrane of cells in healthy and diseased tissue.
In the study, the team of researchers compared standard radiation treatment, radiation and gold alone and radiation with goldpHLIPs. The results showed that irradiated cancer cells had a 24% lower survival rate when using goldpHLIPS compared to standard radiation therapy. Also, scientists were able to demonstrate a 21% lower survival rate of cancer cells using goldpHLIPS compared to gold alone.
Using the acid-seeking pHLIPs with gold nanoparticles has the potential to reduce radiation dose and sideeffects while simultaneously increasing cancer killing effectiveness. The researchers plan on further studies to investigate efficacy in rodent models.
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