title: Biocompatibility of amorphous silica nanoparticles: Size and charge effect on vascular function, in vitro.
abstract: Synthetic amorphous silica is gaining popularity as the material of choice in the fabrication of nanoparticles for use in imaging diagnostics, medical therapeutics, and tissue engineering because of its biocompatible nature. However, recent evidence suggests that silica nanoparticles (SiNPs) show a concentration- and size-dependent toxic effect that is cell specific. We investigated the direct influence of SiNP uptake on the vasodilator responses of rat aortic vessels, in vitro, using fabricated SiNPs of defined size (97 ± 7.60 and 197 ± 7.50 nm) and charge (positive and nonmodified). Dilator responses to cumulative doses of endothelial-dependent [acetylcholine (Ach); 0.01 µM-1.0 mM] and endothelial-independent (sodium nitroprusside; 0.01-10 µM) agonists were determined before and 30 Min after incubation in SiNPs (at 1.1 × 10(11)  nanoparticles/mL). Acute exposure to SiNPs led to their rapid uptake by the lining endothelial cells (as verified by transmission electron microscopy). SiNP uptake had no significant influence on dilator responses, although a greater degree of attenuation was evident after uptake of the 100 nm and positively charged SiNPs (significant at the highest 1.0 mM Ach concentration between positive and nonmodified 200 nm SiNPs; P < 0.05). In summary, our findings suggest that SiNP surface interactions, rather than mass, affect vasodilator function of aortic vessels.
authors: The School of Healthcare Science, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, UK.
authors: Naveed
authors: N
authors: Akbar
authors: Teba
authors: T
authors: Mohamed
authors: Debra
authors: D
authors: Whitehead
authors: May
authors: M
authors: Azzawi
mesh_terms: D000818:Animals; D001011:Aorta / Q000502:physiology*; D001672:Biocompatible Materials / Q000737:chemistry / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D008297:Male; D008422:Materials Testing; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D051381:Rats; D017208:Rats, Wistar; D012822:Silicon Dioxide / Q000737:chemistry / Q000378:metabolism*; D014664:Vasodilation
chemical_list: D001672:Biocompatible Materials; D012822:Silicon Dioxide