We hypothesized that pulmonary clearancevs.retention of metal oxide nanoparticles (NPs) is controlled not only by activity of phagocytes and other physiological mechanisms but also by the NP solubilization which, in some cases, may even prevail thus making the impact of these NPs on lungs quite feeble. To test this hypothesis, airborne Fe₂O₃NPs with the mean diameter of 14±4nm produced by sparking from 99.99% pure iron rods were fed into a nose-only exposure device. Rats were inhaling these NPs for 4 h a day, 5 days a week during 3, 6 or 10 months at the mean concentration of 1.14±0.01mg/m³.

Fig. 1. Structure of the multi-compartmental model for the kinetics of retention and elimination of the Fe₂O₃-NPs deposited in the pulmonary region of the lung. Here: ω is a function of particle deposition in the pulmonary region, and k_jiis a rate constant of particle translocation from compartment Xi into compartment Xj. Dotted lines are conventional boundaries between anatomical regions.

We obtained transmission electron microscopy images of NPs within alveolocytes. Besides, the Fe₂O₃肺和内容lung-associated淋巴点头es measured by the Electron Paramagnetic Resonance (EPR) spectroscopy was gradually increasing with time. However, it proved much lower as compared with respective values known for the micrometric standard quartz dust DQ12 (having particle sizes of less than 5 µm) at similar exposure conditions.

We demonstrated that free pulmonary cell responses to both particulates were virtually the same, but Fe₂O₃NPs collected from the inhaled air, even though insoluble in water, dissolved markedly in the cell free broncho-alveolar lavage fluid supernatant and in the sterile bovine blood serum. This may be considered anin vitromodel of theirin vivosolubilization.

We have identified parameters of the multicompartmental system model describing the toxicokinetics of inhaled nanoparticles after their deposition in the lower airways as a process controlled by their (a) high ability to penetrate through the alveolar membrane; (b) active endocytosis; (c)in vivo解散。这个模型满意地模仿练习perimental Fe₂O₃and thus corranorated our initial hypothesis demonstrating that, as concerns iron oxide NPs of the dimensions used, the dissolution-depending mechanisms proved to be dominant.

Sutunkova M.P.¹,Katsnelson B.A.¹,Privalova L.I.¹,Gurvich V.B.¹,Konysheva L.K.¹,Shur V.Ya.²,Shishkina E.V.²,Minigalieva I.A.¹,Solovjeva S.N.¹,Grebenkina S.V.¹,Zubarev I.V.^2
1The Ekaterinburg Medical Research Center for Prophylaxis and
Health Protection in Industrial Workers of the Rospotrebnadzor, Ekaterinburg, Russia
²The Ural Center for Shared Use “Modern Nanotechnology”,
Ural Federal University, Ekaterinburg, Russia

Publication

On the contribution of the phagocytosis and the solubilization to the iron oxide nanoparticles retention in and elimination from lungs under long-term inhalation exposure.
Sutunkova MP, Katsnelson BA, Privalova LI, Gurvich VB, Konysheva LK, Shur VY, Shishkina EV, Minigalieva IA, Solovjeva SN, Grebenkina SV, Zubarev IV
Toxicology. 2016 Jul 1

Read offline:

Related Articles:

	Imaging metal nanoparticle adsorption on graphene aerogelsThe functionalization of porous carbon aerogels and sponge-like materials with metal nanoparticles (NPs) has shown significant promise for several applications, including energy storage and harvesting and environmental remediation. Methods for…
	Low phosphate after modern intravenous iron? Fibroblast…Iron is an essential substance with a number of roles in the body. Anaemia caused by low iron (iron deficiency anaemia) can worsen disease outcomes and reduce the quality of…
	How mitochondria "sense" and respond to changes in oxygen…Mitochondria – intracellular organelles – are our organism’s “powerhouse”, the main oxygen sensors that play the signaling role as modulators of oxygen consumption and regulators of the rate of oxygen…
	The stress of dieting: what a rat model may tell us about…In the United States, obesity and concomitant diseases such as hypertension and diabetes have soared in older adults—and obesity is especially pronounced in women after menopause. Numerous strategies are used…
	Am I at risk of developing diabetes if exposed to…The answer is: it depends. Of course, there is no trivial answer to an open question like that when referring to scientific investigation. But we can make you think better…
	Atmospheric and genetic parameters influence Rhinovirus…Rhinoviruses are a diverse set of very small and common viruses, repeatedly infecting humans in the course of a single year. For most people, infection usually results in mild common…