| Abstract |
This study evaluated size-dependent effects of gold nanoparticle (AuNP) on matrix metalloproteinase (MMP) inhibition, cytotoxicity and genotoxicity. Polyvinylpyrrolidone (PVP) coated AuNPs of three different diameters (small = 33.2 nm, medium = 51.4 nm and large = 65.0 nm) were used in this study. MMP assays were conducted to evaluate the interaction of MMPs with nanoparticles (NPs). The cytotoxic and genotoxic effects of NPs were examined in RAW264 macrophages. Morphological analysis was conducted by fluorescence and transmission electron microscopy. Smaller NPs most effectively inhibited MMP activity, compared with larger ones. This MMP inhibition was attributed to chelation of the carboxyl group of PVP with the active site Zn2+ of the enzyme. However, no cytotoxic or genotoxic effects were observed at any concentration of either size AuNPs. In cells, NPs were localized mainly to lysosomes without penetration into nuclei or mitochondria. AuNPs are biocompatible because of the stability of the core metal (Au) even in the acidic or enzymatic environment of lysosomes. The surfactant (PVP) and core metal (Au) are involved in MMP inhibition and cytotoxicity, respectively. The relationship between MMP inhibition and cytotoxicity was, therefore, influenced by associations with different components of the AuNPs.
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