AIMS: Capped silver nanoparticles that can be coupled to a variety of molecules and biomolecules are of great interest owing to their potential applications in biomedicine. However, there are no data about their toxicity or functional effects on a key innate immune response, such as IL-6 secretion, after the engagement of the main group of pathogen-associated molecular patterns receptors, that is, the Toll-like receptors (TLRs). MATERIALS & METHODS: N-(2-mercaptopropionyl)glycine (tiopronin)-capped silver (Ag@tiopronin) nanoparticles of a narrow sized distribution ( approximately 5 nm) were synthesized and characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, Raman, (1)H-NMR and total correlation spectroscopy. Cytotoxicity was determined by lactate deshidrogenase and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium assays in Raw 264.7 macrophages. IL-6 was measured by ELISA. RESULTS & DISCUSSION: Ag@tiopronin nanoparticles have a narrow size distribution ( approximately 5 nm), high solubility and stability in aqueous environment with no cytotoxicity in terms of mitochondrial function or plasma-membrane integrity at concentrations as high as 200 microg/10(6) cells. Ag@tiopronin nanoparticles were not proinflammatory agents, but remarkably they specifically impaired the IL-6 secretion mediated by TLR2, TLR2/6, TLR3 or TLR9 stimulation in co-treatment experiments. However, in pretreatment experiments, nanoparticles enhanced the susceptibility of macrophages to inflammatory stimulation mediated by TLR2/1 and TLR2/6 specific ligands while severely impairing the IL-6 secretion activated by the TLR3 or TLR9 ligands. CONCLUSIONS: Contrary to what is found for bare silver nanoparticles, Ag@tiopronin nanoparticles are noncytotoxic to macrophages. Ag@tiopronin nanoparticles showed differential effects on TLR signaling of a high degree of specificity, without proinflammatory effects by themselves. These effects have to be borne in mind when using bioconjugates of Ag@tiopronin nanoparticles for future medical applications.
AIMS: Capped silver nanoparticles that can be coupled to a variety of molecules and biomolecules are of great interest owing to their potential applications in biomedicine. However, there are no data about their toxicity or functional effects on a key innate immune response, such as IL-6 secretion, after the engagement of the main group of pathogen-associated molecular patterns receptors, that is, the Toll-like receptors (TLRs). MATERIALS & METHODS:N-(2-mercaptopropionyl)glycine (tiopronin)-capped silver (Ag@tiopronin) nanoparticles of a narrow sized distribution ( approximately 5 nm) were synthesized and characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, Raman, (1)H-NMR and total correlation spectroscopy. Cytotoxicity was determined by lactate deshidrogenase and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium assays in Raw 264.7 macrophages. IL-6 was measured by ELISA. RESULTS & DISCUSSION: Ag@tiopronin nanoparticles have a narrow size distribution ( approximately 5 nm), high solubility and stability in aqueous environment with no cytotoxicity in terms of mitochondrial function or plasma-membrane integrity at concentrations as high as 200 microg/10(6) cells. Ag@tiopronin nanoparticles were not proinflammatory agents, but remarkably they specifically impaired the IL-6 secretion mediated by TLR2, TLR2/6, TLR3 or TLR9 stimulation in co-treatment experiments. However, in pretreatment experiments, nanoparticles enhanced the susceptibility of macrophages to inflammatory stimulation mediated by TLR2/1 and TLR2/6 specific ligands while severely impairing the IL-6 secretion activated by the TLR3 or TLR9 ligands. CONCLUSIONS: Contrary to what is found for bare silver nanoparticles, Ag@tiopronin nanoparticles are noncytotoxic to macrophages. Ag@tiopronin nanoparticles showed differential effects on TLR signaling of a high degree of specificity, without proinflammatory effects by themselves. These effects have to be borne in mind when using bioconjugates of Ag@tiopronin nanoparticles for future medical applications.
Authors: Zaira González-Sánchez; Victoria Areal-Quecuty; Alvaro Jimenez-Guerra; Daniel Cabanillas-Balsera; Francisco Javier Gil; Eugenio Velasco-Ortega; David Pozo Journal: Int J Mol Sci Date: 2022-04-13 Impact factor: 6.208
Authors: Cintia Roodveldt; Adahir Labrador-Garrido; Elena Gonzalez-Rey; Christian C Lachaud; Tim Guilliams; Rafael Fernandez-Montesinos; Alicia Benitez-Rondan; Gema Robledo; Abdelkrim Hmadcha; Mario Delgado; Christopher M Dobson; David Pozo Journal: PLoS One Date: 2013-11-13 Impact factor: 3.240