Gold Nanospheres Show Promise in 'Boiling' Out Cancer
Source: U.S. News & World Report (3/23/09)
". . .doctors expose the tumors to near infrared light, causing the nanospheres to heat up and destroy the cancer while leaving healthy tissue alone."
The treatment uses gold nanospheres guided directly to the melanoma cells by a special protein fragment called a peptide placed inside the nanosphere. Using a technique known as photoablation therapy (PAT), doctors expose the tumors to near infrared light, causing the nanospheres to heat up and destroy the cancer while leaving healthy tissue alone.
Studies done on mice with melanoma tumors found the peptide-laced nanoparticles were eight times more effective in killing the cancer than those without the peptide guidance system, according to researchers who were to present the findings at an American Chemical Society meeting in Salt Lake City.
According to the U.S. National Cancer Institute, more than 62,000 cases of melanoma were diagnosed in the United States in 2008, and more than 8,400 people die each year from the disease.
The findings are significant because PAT can accidentally destroy healthy skin cells if the light exposure is not administered carefully and closely monitored. Though the use of metal nanoparticles that are smaller than a speck of dust has improved the technique, researchers have been trying to perfect them to destroy the most cancer with the least damage to healthy cells.
The peptide-loaded nanospheres developed by Zhang appear to have superior ability to find and enter their target and absorb cancer-destroying light. At thousands of times smaller than the width of a human hair, they are smaller than most other metal nanoparticles used in PAT and would appear to be safer because gold generally causes fewer negative reactions than other metals that come in contact with the human body, Zhang said.