Influence of IP-injected ZnO-nanoparticles in Catla catla fish: hematological and serological profile.

This study reports an effort to synthesize biocompatible zinc oxide nanoparticles using sol-gel method and its influence on hematological and serological profile of Catla catla fish. Hexagonal wurtzite structure and crystallite size of ZnO-NPs was identified by using XRD in the range of 19 to 20 nm. Moreover, the irregular and non-uniform surface of these NPs was found using SEM. The different stretched and vibrational mode (ZnO, OH, CO, and H-O-H) was identified by using FTIR analysis. UV-visible spectroscopy confirmed absorbance of the blue shift in the range 340 nm. Bioassay of ZnO-NPs on Catla catla was performed and nano ZnO was given through intraperitoneal injections at 0, 25, 50, 75, and 100 µg/g body weight doses. Analysis of fish blood samples indicated an increase in WBCs and leukocytes while the differential effect on monocytes. On the other hand in response to varying ZnO concentrations, an increase in RBCs, hemoglobin, and HCT was evident. Serum analysis revealed an increase in urea concentration while a reduction in creatinine, ALT, and AST. In an overall assessment, nano-ZnO supplementation at 25 to 100 µg/g body weight differentially affected hematological and serum biochemical profile of thaila fish. Graphical abstract.

RETRACTED: Designing of carbon based fluorescent nanosea-urchin via green-synthesis approach for live cell detection of zinc oxide nanoparticle.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of Editor following concerns raised by a reader. There are significant concerns regarding the originality of the electron micrographs displayed in Fig. 1 (panels B-G, especially C). The concern is that these multi-particle images are comprised of copies of the same particles. These problems with the data presented cast doubt on all the data, and accordingly also the conclusions based on that data, in this publication. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process

Assessment of the toxic potential of engineered metal oxide nanomaterials using an acellular model: citrated rat blood plasma.

Citrated Sprague-Dawley rat blood plasma was used as a biologically relevant exposure medium to assess the acellular toxic potential of two metal oxide engineered nanomaterials (ENMs), zinc oxide (nZnO), and cerium oxide (nCeO2). Plasma was incubated at 37 °C for up to 48 h with ENM concentrations ranging between 0 and 200 mg/L. The degree of ENM-induced oxidation was assessed by assaying for reactive oxygen species (ROS) levels using dichlorofluorescein (DCF), pH, ferric reducing ability of plasma (FRAP), lipase activity, malondialdehyde (MDA), and protein carbonyls (PC). Whereas previous in vitro studies showed linear-positive correlations between ENM concentration and oxidative damage, our results suggested that low concentrations were generally pro-oxidant and higher concentrations appeared antioxidant or protective, as indicated by DCF fluorescence trends. nZnO and nCeO2 also affected pH in a manner dependent on concentration and elemental composition; higher nZnO concentrations maintained a more alkaline pH, while nCeO2 tended to decrease pH. No other biomarkers of oxidative damage (FRAP, MDA, PC, lipase activity) showed changes at any ENM concentration or time-point tested. Differential dissolution of the two ENMs was also observed, where as much as ∼31.3% of nZnO was instantaneously dissolved to Zn2+ and only negligible nCeO2 was degraded. The results suggest that the direct oxidative potential of nZnO and nCeO2 in citrated rat blood plasma is low, and that a physiological or immune response is needed to generate appreciable damage biomarkers. The data also highlight the need for careful consideration when selecting a model for assessing ENM toxicity.

A comprehensive toxicity study of zinc oxide nanoparticles versus their bulk in Wistar rats: Toxicity study of zinc oxide nanoparticles.

The purpose of this study was to characterize the zinc oxide nanoparticles (ZnO-NPs) and their bulk counterpart in suspensions and to access the impact of their acute oral toxicity at doses of 300 and 2000 mg/kg in healthy female Wistar rats. The hematological, biochemical, and urine parameters were accessed at 24 and 48 h and 14 days posttreatment. The histopathological evaluations of tissues were also performed. The distribution of zinc content in liver, kidney, spleen, plasma, and excretory materials (feces and urine) at 24 and 48 h and 14 days posttreatment were accessed after a single exposure at dose of 2000 mg/kg body weight. The elevated level of alanine amino transferase, alkaline phosphatase, lactate dehydrogenase, and creatinine were observed in ZnO-NPs at a dose of 2000 mg/kg at all time points. There was a decrease in iron levels in all the treated groups at 24 h posttreatment as compared to control groups but returned to their normal level at 14 days posttreatment. The hematological parameters red blood cells, hemoglobin, hematocrit, platelets, and haptoglobin were reduced at 48 h posttreatment at a dose of 2000 mg/kg ZnO-NPs and showed hemolytic condition. All the treated groups were comparable to control group at the end of 14 days posttreatment. The zinc concentration in the kidney, liver, plasma, feces, and urine showed a significant increase in both groups as compared to control. This study explained that ZnO-NPs produced more toxicological effect as compared to their bulk particles as evidenced through alteration in some hemato-biochemical parameters and with few histopathological lesions in liver and kidney tissues.

Surface modification of zinc oxide nanoparticles with amorphous silica alters their fate in the circulation.

Nanoparticle (NP) pharmacokinetics and biological effects are influenced by many factors, especially surface physicochemical properties. We assessed the effects of an amorphous silica coating on the fate of zinc after intravenous (IV) injection of neutron activated uncoated (65)ZnO or silica-coated (65)ZnO NPs in male Wistar Han rats. Groups of IV-injected rats were sequentially euthanized, and 18 tissues were collected and analyzed for (65)Zn radioactivity. The protein coronas on each ZnO NP after incubation in rat plasma were analyzed by SDS-PAGE gel electrophoresis and mass spectrometry of selected gel bands. Plasma clearance for both NPs was biphasic with rapid initial and slower terminal clearance rates. Half-lives of plasma clearance of silica-coated (65)ZnO were shorter (initial - <1 min; terminal - 2.5 min) than uncoated (65)ZnO (initial - 1.9 min; terminal - 38 min). Interestingly, the silica-coated (65)ZnO group had higher (65)Zn associated with red blood cells and higher initial uptake in the liver. The (65)Zn concentrations in all the other tissues were significantly lower in the silica-coated than uncoated groups. We also found that the protein corona formed on silica-coated ZnO NPs had higher amounts of plasma proteins, particularly albumin, transferrin, A1 inhibitor 3, α-2-hs-glycoprotein, apoprotein E and α-1 antitrypsin. Surface modification with amorphous silica alters the protein corona, agglomerate size, and zeta potential of ZnO NPs, which in turn influences ZnO biokinetic behavior in the circulation. This emphasizes the critical role of the protein corona in the biokinetics, toxicology and nanomedical applications of NPs.

Comparative absorption, distribution, and excretion of titanium dioxide and zinc oxide nanoparticles after repeated oral administration.

BACKGROUND: The in vivo kinetics of nanoparticles is an essential to understand the hazard of nanoparticles. Here, the absorption, distribution, and excretion patterns of titanium dioxide (TiO2) and zinc oxide (ZnO) nanoparticles following oral administration were evaluated. METHODS: Nanoparticles were orally administered to rats for 13 weeks (7 days/week). Samples of blood, tissues (liver, kidneys, spleen, and brain), urine, and feces were obtained at necropsy. The level of Ti or Zn in each sample was measured using inductively coupled plasma-mass spectrometry. RESULTS: TiO2 nanoparticles had extremely low absorption, while ZnO nanoparticles had higher absorption and a clear dose-response curve. Tissue distribution data showed that TiO2 nanoparticles were not significantly increased in sampled organs, even in the group receiving the highest dose (1041.5 mg/kg body weight). In contrast, Zn concentrations in the liver and kidney were significantly increased compared with the vehicle control. ZnO nanoparticles in the spleen and brain were minimally increased. Ti concentrations were not significantly increased in the urine, while Zn levels were significantly increased in the urine, again with a clear dose-response curve. Very high concentrations of Ti were detected in the feces, while much less Zn was detected in the feces. CONCLUSIONS: Compared with TiO2 nanoparticles, ZnO nanoparticles demonstrated higher absorption and more extensive organ distribution when administered orally. The higher absorption of ZnO than TiO2 nanoparticles might be due to the higher dissolution rate in acidic gastric fluid, although more thorough studies are needed.

Bioavailability of zinc oxide added to corn tortilla is similar to that of zinc sulfate and is not affected by simultaneous addition of iron.

BACKGROUND: Corn tortilla is the staple food of Mexico and its fortification with zinc, iron, and other micronutrients is intended to reduce micronutrient deficiencies. However, no studies have been performed to determine the relative amount of zinc absorbed from the fortified product and whether zinc absorption is affected by the simultaneous addition of iron. OBJECTIVE: To compare zinc absorption from corn tortilla fortified with zinc oxide versus zinc sulfate and to determine the effect of simultaneous addition of two doses of iron on zinc bioavailability. METHODS: A randomized, double-blind, crossover design was carried out in two phases. In the first phase, 10 adult women received corn tortillas with either 20 mg/kg of zinc oxide added, 20 mg/kg of zinc sulfate added, or no zinc added. In the second phase, 10 adult women received corn tortilla with 20 mg/kg of zinc oxide added and either with no iron added or with iron added at one of two different levels. Zinc absorption was measured by the stable isotope method. RESULTS: The mean (+/- SEM) fractional zinc absorption from unfortified tortilla, tortilla fortified with zinc oxide, and tortilla fortified with zinc sulfate did not differ among treatments: 0.35 +/- 0.07, 0.36 +/- 0.05, and 0.37 +/- 0.07, respectively. The three treatment groups with 0, 30, and 60 mg/kg of added iron had similar fractional zinc absorption (0.32 +/- 0.04, 0.33 +/- 0.02, and 0.32 +/- 0.05, respectively) and similar amounts of zinc absorbed (4.8 +/- 0.7, 4.5 +/- 0.3, and 4.8 +/- 0.7 mg/day, respectively). CONCLUSIONS: Since zinc oxide is more stable and less expensive and was absorbed equally as well as zinc sulfate, we suggest its use for corn tortilla fortification. Simultaneous addition of zinc and iron to corn tortilla does not modify zinc bioavailability at iron doses of 30 and 60 mg/kg of corn flour.

Chemical stability of ZnO nanostructures in simulated physiological environments and its application in determining polar directions.

The in vitro chemical stability and etching of ZnO nanostructures in simulated physiological solution (SPS) were studied using electron microscopy. Calcium hydrogen phosphate thin layers were observed to be uniformly deposited on the surfaces of ZnO nanomaterials in SPS. Electron diffraction and high-resolution transmission electron microscopy revealed that the calcium hydrogen phosphate layers were amorphous and had excellent interfacial contact with the nanocrystals. ZnO nanostructures fabricated by thermal evaporation were found to survive much longer in SPS than those fabricated using a hydrothermal solution method. The shapes of the voids formed in the ZnO nanostructures by the etching in SPS can be used to deduce the polar directions of ZnO nanostructures.

Blood-lead levels of monkeys treated with a lead-containing (N2) root canal cement: a preliminary report.

The effect of a root canal filling material on the level of lead in blood of rhesus monkeys was examined by anodic stripping voltometry. Blood-lead levels after root canal treatment with N2 cement were elevated when compared to preoperative controls. Lead 210 was incorporated into the leadfree N2 cement to identify the source of lead. Analyses of blood samples for 210Pb indicated that the lead originated from the filling material.