Gold nanoparticles (AuNPs) have unique electronic and chemical properties and hence are used in many applications. However, their potential health risk(s) and interactions with cells are not fully known. Most previous studies have focused determining the cell proliferation after short exposures, less than 24 hours. Since skin is the primary source of contact with nanoparticles, we studied the effects of AuNPs concentration and size, separately on keratinocytes, dermal fibroblasts and adipocytes. Our results indicate that the effect on cell proliferation is minimal with keratinocytes, regardless of particle size. On the other hand, both dermal fibroblasts and adipocytes are highly sensitive to dose. It was found that 45nm AuNPs penetrate dermal fibroblasts via clathrin mediated endocytosis, while the smaller 13nm enter via phagocytosis. In contrast to dermal fibroblasts the uptake in adipocytes was less dependent on particle size. Also TEM data indicated that only adipocytes with low particle contraction inside, had produced lipid. In the case of dermal fibroblasts, we probed the effects of the particles on the production of collagen and fibronectin and found that the expression of the collagen and fibronectin was diminished by the cells exposed to AuNPs. Finally we are investigating whether recovery from nanoparticle damage is possible once the source is removed. We found nearly full recovery as a function of AuNPs size, concentration and exposure time.
Journal: TechConnect Briefs
Volume: 3, Nanotechnology 2010: Bio Sensors, Instruments, Medical, Environment and Energy
Published: June 21, 2010
Pages: 199 - 201
Industry sector: Medical & Biotech