scholarly journals Behaviour of Titanium Dioxide Particles in Artificial Body Fluids and Human Blood Plasma

2021 ◽  
Vol 22 (19) ◽  
pp. 10614
Author(s):  
Eva Korábková ◽  
Věra Kašpárková ◽  
Daniela Jasenská ◽  
Dita Moricová ◽  
Eliška Daďová ◽  
...  

The growing application of materials containing TiO2 particles has led to an increased risk of human exposure, while a gap in knowledge about the possible adverse effects of TiO2 still exists. In this work, TiO2 particles of rutile, anatase, and their commercial mixture were exposed to various environments, including simulated gastric fluids and human blood plasma (both representing in vivo conditions), and media used in in vitro experiments. Simulated body fluids of different compositions, ionic strengths, and pH were used, and the impact of the absence or presence of chosen enzymes was investigated. The physicochemical properties and agglomeration of TiO2 in these media were determined. The time dependent agglomeration of TiO2 related to the type of TiO2, and mainly to the type and composition of the environment that was observed. The presence of enzymes either prevented or promoted TiO2 agglomeration. TiO2 was also observed to exhibit concentration-dependent cytotoxicity. This knowledge about TiO2 behavior in all the abovementioned environments is critical when TiO2 safety is considered, especially with respect to the significant impact of the presence of proteins and size-related cytotoxicity.

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Louise Ann Clark ◽  
Jochen Beyer ◽  
Andis Graudins

Background. Intravenous lipid emulsion (ILE) is recommended as a “rescue” treatment for local anaesthetic (LA) toxicity. A purported mechanism of action suggests that lipophilic LAs are sequestered into an intravascular “lipid-sink,” thus reducing free drug concentration. There is limited data available correlating the effects of ILE on LAs.Aims. To compare the in vitro effect of ILE on LA concentrations in human blood/plasma and to correlate this reduction to LA lipophilicity.Method. One of four LAs (bupivacaine-most lipophilic-4 mg/L, ropivacaine-6 mg/L, lignocaine-14 mg/L, and prilocaine-least lipophilic-7 mg/L) was spiked into plasma or whole blood. ILE or control-buffer was added. Plasma was centrifuged to separate ILE and total-LA concentration assayed from the lipid-free fraction. Whole blood underwent equilibrium dialysis and free-LA concentration was measured. Percent reduction in LA concentration from control was compared between the LAs and correlated with lipophilicity.Results. ILE caused a significant reduction in total and free bupivacaine concentration compared with the other LAs. Ropivacaine had the least reduction in concentration, despite a lipophilicity similar to bupivacaine. The reduction in LA concentration correlated to increasing lipophilicity when ropivacaine was excluded from analysis.Conclusion. In this first in vitro model assessing both free- and total-LA concentrations exposed to ILE in human blood/plasma, ILE effect was linearly correlated with increasing lipophilicity for all but ropivacaine.


Blood ◽  
2011 ◽  
Vol 118 (6) ◽  
pp. 1699-1709 ◽  
Author(s):  
Isabelle Ligi ◽  
Stéphanie Simoncini ◽  
Edwige Tellier ◽  
Paula Frizera Vassallo ◽  
Florence Sabatier ◽  
...  

Abstract Low birth weight (LBW) is associated with increased risk of cardiovascular diseases at adulthood. Nevertheless, the impact of LBW on the endothelium is not clearly established. We investigate whether LBW alters the angiogenic properties of cord blood endothelial colony forming cells (LBW-ECFCs) in 25 preterm neonates compared with 25 term neonates (CT-ECFCs). We observed that LBW decreased the number of colonies formed by ECFCs and delayed the time of appearance of their clonal progeny. LBW dramatically reduced LBW-ECFC capacity to form sprouts and tubes, to migrate and to proliferate in vitro. The angiogenic defect of LBW-ECFCs was confirmed in vivo by their inability to form robust capillary networks in Matrigel plugs injected in nu/nu mice. Gene profile analysis of LBW-ECFCs demonstrated an increased expression of antiangiogenic genes. Among them, thrombospondin 1 (THBS1) was highly expressed at RNA and protein levels in LBW-ECFCs. Silencing THBS1 restored the angiogenic properties of LBW-ECFCs by increasing AKT phosphorylation. The imbalance toward an angiostatic state provide a mechanistic link between LBW and the impaired angiogenic properties of ECFCs and allows the identification of THBS1 as a novel player in LBW-ECFC defect, opening new perspectives for novel deprogramming agents.


1976 ◽  
Vol 81 (1) ◽  
pp. 70-72
Author(s):  
S. V. Kaznacheev ◽  
V. A. Kozlov ◽  
E. M. Petrova ◽  
V. P. Lozovoi

2020 ◽  
Vol 10 (02) ◽  
pp. 238-243
Author(s):  
Ghassaq T. Al-Ubaidi ◽  
Ahmed A. Abbas ◽  
Ali A. Taha ◽  
Qasim S. Sharhan

The necessity of nicotine analysis in blood plasma is increasing along with the increased number of smokers and nicotine poisoning cases. One of the analytical methods for nicotine is using high-performance liquid chromatography (HPLC) with ultraviolet (UV) detector because it has been commonly owned by instance in Indonesia. To guarantee accuracy, an analytical method can be used, and it must be validated. This research was the purpose of finding out the validity of the nicotine analysis method in human blood plasma (in vitro) using HPLC with UV detection. Blood plasma samples remained treated with centrifugation procedure by protein denaturation method using acetonitrile. The compounds were analyzed using methanol and buffer acetate 0.01 M (pH 5) 85:15 v/v as a mobile phase on an octadecylsilane column 250 mm, with UV detection at 254 and 260 nm, and flow rate 0.6 mL/minute. Parameter of analytical methods that were validated includes selectivity, accuracy, precision, repeatability, linearity, limit of detection (LoD), limit of quantification (LoQ), and system suitability. According to the result, the selectivity was 2.479, repeatability expressed by its variation coefficient = 0.701%, linearity at range 5–22 μg/mL expressed by coefficient correlation (r) = 0.996. Based on the chromatogram’s area under a curve, the LoD value was found 2.021 μg/mL, LoQ value was 6.737 μg/mL, the accurate percentage was 112.49 to 114.12%, and precision (% CV) was 2.15 to 3.95%. The system suitability from retention time and chromatogram’s area under curve showed % CV 0.70 and 1.64%. According to the experiment result, all parameters meet the requirements of validation criteria.


1992 ◽  
Vol 114 (3) ◽  
pp. 1315-1317
Author(s):  
Yu. K. Napolov ◽  
N. U. Borsukova ◽  
N. L. Shimanovskii

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
K. Rahme ◽  
G. Minassian ◽  
M. Sarkis ◽  
M. Nakhl ◽  
R. El Hage ◽  
...  

Gold nanoparticle (AuNP) physicochemical characteristics, mainly size and charge, modulate their biodistribution, cytotoxicity, and immunorecognition as reported fromin vitroandin vivostudies. While data fromin vitrostudies could be biased by several factors including activation of cells upon isolation and lack of sera proteins in the microenvironment of primary generated cell lines,in vivostudies are costly and time-consuming and require ethics consideration. In this study, we developed a simple and novelin vivo-like method to test for NP immunorecognition from freshly withdrawn human blood samples. AuNPs with a size range of 30 ± 5 nm coated with cationic poly(L-lysine) (PLL) dendrigraft and slightly negative poly(vinyl alcohol) (PVA) were synthesized in water. PLL-capped AuNPs were further coated with poly(ethylene glycol) (PEG) to obtain nearly neutrally charged PEG-AuNPs. Physicochemical properties were determined using zeta potential measurements, UV-Vis spectroscopy, dynamic light scattering (DLS), and scanning electron microscopy (SEM). Gel electrophoretic separation, zeta potential, and DLS were also used to characterize our NPs after human blood plasma treatment. PLL-AuNPs showed similar variation in charge and binding affinity to plasma proteins in comparison with PVA-AuNPs. However, PLL-AuNPs.protein complexes revealed a drastic change in size compared to the other tested particles. Results obtained from the neutrophil function test and pyridine formazan extraction revealed the highest activation level of neutrophils (~70%) by 50 μg/mL of PLL-AuNPs compared to a null induction by PEG- and PVA-AuNPs. This observation was further verified by flow cytometry analysis of polymorphonuclear cell size variation in the presence of coated AuNPs. Overall, ourin vivo-like method, to test for NP immunorecognition, proved to be reliable and effective. Finally, our data supports the use of PEG-AuNPs as promising vehicles for drug delivery, as they exhibit minimal protein adsorption affinity and insignificant charge and size variation once introduced in whole blood.


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