Nanoparticles found in everyday items can inhibit fat storage: Gold nanoparticles accelerate aging

Together with co-author Dr. Marcia Simon, Professor of Oral Biology and Pathology at Stony Brook University, and Director of the University's Living Skin Bank, a world-class facility that has developed skin tissue for burn victims and various wound therapies, the researchers tested the impact of nanoparticles in vitro on multiple types of cells, including adipose (fat) tissue, to determine whether their basic functions were disrupted when exposed to very low doses of nanoparticles. Subcutaneous adipose tissue acts as insulation from heat and cold, functions as a reserve of nutrients, and is found around internal organs for padding, in yellow bone marrow and in breast tissue.

They discovered that the human adipose-derived stromal cells -- a type of adult stem cells -- were penetrated by the gold nanoparticles almost instantly and that the particles accumulated in the cells with no obvious pathway for elimination. The presence of the particles disrupted multiple cell functions, such as movement; replication (cell division); and collagen contraction; processes that are essential in wound healing.

According to the researchers, the most disturbing finding was that the particles interfered with genetic regulation, RNA expression and inhibited the ability to differentiate into mature adipocytes or fat cells. "Reductions caused by gold nanoparticles can result in systemic changes to the body," said Professor Mironava. "Since they have been considered inert and essentially harmless, it was assumed that pure gold nanoparticles would also be safe. Evidence to the contrary is beginning to emerge."

This study is also the first to demonstrate the impact of nanoparticles on adult stem cells, which are the cells our body uses for continual organ regeneration. It revealed that adipose derived stromal cells involved in regeneration of multiple organs, including skin, nerve, bone, and hair, ignored appropriate cues and failed to differentiate when exposed to nanoparticles. The presence of gold nanoparticles also reduced adiponectin, a protein involved in regulating glucose levels and fatty acid breakdown, which helps to regulate metabolism.

"We have learned that careful consideration and the choice of size, concentration and the duration of the clinical application of gold nanoparticles is warranted," said Professor Mironava. "The good news is that when the nanoparticles were removed, normal functions were eventually restored."

"Nanotechnology is continuing to be at the cutting edge of science research and has opened new doors in energy and materials science," said co-author, Miriam Rafailovich, PhD, Chief Scientist of the Advanced Energy Center and Distinguished Professor of Materials Science and Engineering at Stony Brook. "Progress comes with social responsibility and ensuring that new technologies are environmentally sustainable. These results are very relevant to achieving these goals."

The research, funded by the National Science Foundation Materials Research Science and Engineering Centers (MRSEC) and Polymer Programs, was a collaboration of Stony Brook University and New York State Stem Cell Science (NYSTEM). The paper was also co-authored by Michael Hadjiargyrou, Professor and Chairperson, Department of Life Sciences at New York Institute of Technology (NYIT) and former Professor in the Department of Biomedical Engineering at Stony Brook.