Scientists on the trail of health risks in everyday products say pure gold nanoparticles in cosmetics, pharmaceuticals and other medical substances may accelerate aging, increase wrinkling and slow the wound-healing process.
The analysis, centered at Stony Brook University in Stony Brook, N.Y., grows out of a collaboration among diverse scientific enterprises — human skin research, chemical engineering and materials science. The latter discipline, devoted to studying properties of matter, has zeroed in on nanoparticles as an active field of investigation.
Nanoparticles are infinitesimally — almost unimaginably — small flecks of matter, and are being used in a growing array of products.
Stony Brook scientists wanted to find out how they affected human cells.
“Since they have been considered inert and essentially harmless, it was assumed that pure gold nanoparticles would also be safe,” said Tatsiana Mironava, a visiting professor of chemical and molecular engineering. “Evidence to the contrary is beginning to emerge.”
The series of experiments conducted at Stony Brook appear in the current issue of the journal Nanotoxicology.
Miriam Rafailovich, distinguished professor of materials science, said the research was carried out in lab dishes, a so-called in vitro study of human cells.
“Gold nanoparticles are in cosmetics because they have such interesting colors. You can get yellows and browns, all the way down to blues and purples,” Rafailovich said.
The tiny flecks, she added, are also in pharmaceuticals and MRI contrast agents.
When examining the effects of gold nanoparticles on human cells in the laboratory, Rafailovich and her collaborators found that certain fat-derived stromal cells — a type of adult stem cell — were not only easily and instantly penetrated, but the flecks accumulated with no pathway for elimination.
Dr. Marcia Simon, director of the university’s Living Skin Bank, a facility that develops skin tissue for burn victims, said the particles disrupted cell functions such as movement, replication and collagen contraction. Most disturbing, the scientists said, was their discovery that the particles interfered with gene regulation and inhibited the ability of fat cells to mature and carry out critical functions. The gold also enhanced wrinkling.
Still, said Simon, the findings should be taken with a dose of caution. As yet, there have been no studies in an animal model, which are slated to occur soon to help explain the tissue findings.