Golden Bullet Nanocages and Laser Light Kills Cancer Cells
Researchers are exploring a way to kill cancer cells that is non toxic and uses what is described as a golden bullet for cancer. Scientists, using gold nanocages, have found that a combination of gold and laser light kills cancer tumors.
Researchers from Washington University in St. Louis injected gold nanocages – the golden bullets - into mice. The nanoparticles congregate around cancerous tumors. Next they used photodynamic therapy to barely warm surrounding tissue. The warmth of the laser used during photothermal therapy to treat cancer converted light to heat, targeting and killing the cancer cells.
Michael J. Welch, Ph.D., professor of radiology and developmental biology in the School of Medicine explains, “We saw significant changes in tumor metabolism and histology, which is remarkable given that the work was exploratory, the laser ‘dose’ had not been maximized, and the tumors were ‘passively’ rather than ‘actively’ targeted."
The researchers say the gold nanoparticles are efficient at absorbing light and converting it into heat, making it the most important aspect of photothermal therapy. The gold is nontoxic and has been used for more than a century to treat patients with arthritis. Welch says “People know what gold does in the body and it’s inert, so we hope this is going to be a nontoxic approach” that can kill cancer cells in humans.
One of the problems with putting bare nanoparticles into humans is the attack that would be launched by the immune system from proteins that would deposit on the particles. For the mouse experiment researchers coated the silver bullet nanocages with PEG, a nontoxic chemical contained in laxatives. The PEG layer acted as a disguise long enough for the injected nanoparticles to accumulate in cancer tumors where they penetrate thin leaky tumor walls where they can be targeted and destroyed.
The potential cancer treatment using gold nanocages, aka the silver bullet of cancer, will be continued through a $2,129,873 grant from the National Cancer Institute. The scientists plan on exploring the use of cancer fighting drugs inside the nanocages to give cancer a one two punch. The cancer treatment is promising, given the dreaded side effects of chemotherapy drugs.