ABSTRACT
In a previous paper (RSC Adv., 2015, 5, 66886-66893), we showed that the combination of silver nanoparticles (NanoAg) with doxycycline (DO) culminated in an increased bactericidal activity towards E. coli. Herein we further investigated the metabolic changes that occurred on Staphylococcus aureus upon exposure to NanoAg with the help of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) coupled with multivariate data analysis. It has been discovered that the combination of DO with NanoAg produced metabolic changes in S. aureus that were not simply the overlap of the treatments with DO and NanoAg separately. Our results suggest that DO and NanoAg act synergistically to impede protein synthesis by the bacteria.
ABSTRACT
BACKGROUND: Gold nanoparticles (GNPs) are regarded as potential platforms for drug delivery. However, their interaction with live organisms must be understood prior to their utilization as drug carriers. The present study reports the anti-inflammatory, analgesic and anti-tumor effects of GNPs. The biodistribution of GNPs and their effect on various tissues have also been studied. METHODS: GNPs were synthesized through an environmentally friendly route and characterized with TEM and UV-vis. After HT-29 cells had been exposed to GNPs, apoptosis was assessed with Annexin V and propidium iodide staining and caspase-3 activity determined with a confocal laser scanning microscope. GNPs were administrated to male and female Swiss mice for posterior assessment of their anti-inflammatory and analgesic properties. The biodistribution of GNPs and their impact on tissues were studied with UV-vis and histopathological analysis, respectively. RESULTS: Cell apoptosis was observed in a dose-dependent manner for GNPs concentrations ranging from 40µg/mL to 80µg/mL (p<0.05). The best anti-inflammatory activity was observed at the dose of 1500µg/kg, which caused a reduction of 49.3% in leukocyte migration. GNPs showed peripheral analgesia at the dose of 1500µg/kg and have been found in liver, spleen, kidney and lungs. Histopathological examination revealed extravasation of red blood cells in lungs. CONCLUSION: The study draws attention to gold nanoparticles as a resource for technological innovation in the anti-inflammatory, analgesic and anti-tumor fields. GNPs have biological effects that deserve investigation to assess their full interaction with organic systems.
