%0 Journal Article %T Evaluation of Cytotoxic Effects of Different Concentrations of Porous Hollow Au Nanoparticles (PHAuNPs) on Cells %A Smitha Rao %A Chienwen Huang %A Uday Tata %A Peter Wu %A Nikhil Arora %A Jinsung Ahn %A Victor K. Lin %A Yaowu Hao %A J.-C. Chiao %J Journal of Nanotechnology %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/631248 %X Nanoparticles (NPs) have been introduced as a suitable alternative in many in vivo bioapplications. The risks of utilizing nanoparticles continue to be an ongoing research. Furthermore, the various chemicals used in their synthesis influence the cytotoxic effects of nanoparticles. We have investigated the cytotoxicity of Porous Hollow Au Nanoparticles (PHAuNPs) on cancer cell lines PC-3, PC-3ML, and MDA-MB-231 and the normal cell line PNT1A. Cell proliferation for the different cells in the presence of different concentrations of the PHAuNPs was assessed after 24 hours and 72 hours of incubation using MTT assay. The study also included the cytotoxic evaluation of pegylated PHAuNPs. Identical cell seeding densities, particle concentrations, and incubation times were employed for these two types of Au nanoparticles. Our results indicated that (1) impact on cell proliferation was concentration dependent and was different for the different cell types without cellular necrosis and (b) cellular proliferation might be impacted more based on the cell line. 1. Introduction Nanoparticles (NPs) exhibit unique properties compared to their constituent bulk materials. These include quantum confinement in semiconductor particles, surface plasmon resonance [1¨C8] in metal particles, and superparamagnetism in magnetic particles. Such unique properties allow the use of nanoparticles in a wide variety of applications. Nanoparticles such as fullerenes, liquid crystals, liposomes, Au nanoparticles, and quantum dots have been demonstrated in biomedical applications [5, 6], chemotherapy [7, 8], drug delivery [8¨C11], imaging [11] and cosmetics [12¨C14]. Gold nanoparticles (AuNPs) have been subjects of intensive research in the last decade. In vivo applications of AuNPs include photothermal ablation treatment and optical imaging. Imaging utilizes the surface plasmon resonance (SPR) effect of AuNPs, a strong enhancement of absorption, and scattering of light in resonant with the SPR frequency. AuNPs possess two additional important merits for in vivo applications: (1) they are generally considered as biocompatible; (2) they can be easily functionalized with well-established thiol-Au linkage. However, the SPR wavelength for solid AuNPs lies around 520 nm, which excludes their in vivo applications since this wavelength is strongly absorbed by tissues and blood. In the last decade, several engineered Au nanoparticles such as nanoshells and nanocages have been developed to tune SPR wavelength of these nanoparticles to near-infrared region that is commonly regarded as a ˇ°clear windowˇ± %U http://www.hindawi.com/journals/jnt/2014/631248/