Nanotoxicity of TiO2 nanoparticles to erythrocyte in vitro

Titanium dioxide (TiO(2)) has been considered as non-toxic mineral particles widely used in the fields like cosmetics, food and drug. When the scale come to nanometer, TiO(2) nanoparticles (nano-TiO(2)) exhibits multiple specific characteristics coupled with unknown risks on health. The purpose of this study was to systematically research the influence of nano-TiO(2) on erythrocyte. The results indicated that the erythrocytes treated with nano-TiO(2) underwent abnormal sedimentation, hemagglutination and dose dependent hemolysis, totally differing from those treated with micro-TiO(2). The ghost cells were firstly investigated by using ultra-thin cell section in the case under nano-TiO(2). The mechanism of such adverse effects is (1) the attachment around erythrocyte change the surface native properties and ultimately lead to hemoagglutination; (2) the content leak to the outside of erythrocyte through the breakage induced by both the nano-TiO(2) trans-membrane and the oxidative stress under nano-TiO(2). Our findings imply that nano-TiO(2) may have potential toxicity to human being health.     

Nanotoxicity of pure silica mediated through oxidant generation rather than glutathione depletion in human lung epithelial cells

Though, oxidative stress has been implicated in silica nanoparticles induced toxicity both in vitro and in vivo, but no similarities exist regarding dose–response relationship. This discrepancy may, partly, be due to associated impurities of trace metals that may present in varying amounts. Here, cytotoxicity and oxidative stress parameters of two sizes (10 nm and 80 nm) of pure silica nanoparticles was determined in human lung epithelial cells (A549 cells). Both sizes of silica nanoparticles induced dose-dependent cytotoxicity as measured by MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] and lactate dehydrogenase (LDH) assays. Silica nanoparticles were also found to induce oxidative stress in dose-dependent manner indicated by induction of reactive oxygen species (ROS) generation, and membrane lipid peroxidation (LPO). However, both sizes of silica nanoparticles had little effect on intracellular glutathione (GSH) level and the activities of glutathione metabolizing enzymes; glutathione reductase (GR) and glutathione peroxidase (GPx). Buthionine-[S,R]-sulfoximine (BSO) plus silica nanoparticles did not result in significant GSH depletion than that caused by BSO alone nor N-acetyl cysteine (NAC) afforded significant protection from ROS and LPO induced by silica nanoparticles. The rather unaltered level of GSH is also supported by finding no appreciable alteration in the level of GR and GPx. Our data suggest that the silica nanoparticles exert toxicity in A549 cells through the oxidant generation (ROS and LPO) rather than the depletion of GSH.     

Differential interferences with clinical chemistry assays by gold nanorods,and gold and silica nanospheres

Abstract

Nanomaterials are known to cause interference with several standard toxicological assays. As part of an in vivo study of PEG-coated gold nanorods in mice, nanorods were added to reference serum, and results for standard clinical chemistry parameters were compared with serum analyzed without nanorods. PEG-coated gold nanorods produced several concentration-dependent interferences. Comparisons were then made with PEG-coated gold and silica nanospheres. Interferences were observed for both materials that differed from gold nanorods. Removal of the particles from serum by centrifugation prior to analysis resolved most, but not all of the interferences. Additional clinical chemistry analyzers were used to further investigate trends in assay interference. We conclude that PEG-coated gold and silica nanoparticles can interfere with standard clinical chemistry tests in ways that vary depending upon material, shape, and specific assay methodology employed. Assay interferences by nanomaterials cannot always be predicted, underscoring the need to verify that nanomaterials under study do not interfere with methods used to evaluate potential biological effects.     

Clinical pharmacology of gold

Since the dawn of civilization, elemental gold and gold compounds have been revered and utilized by Shamen and medical practitioners alike for many varied pathological problems. In the 20(th) century following the observations of Jacques Forestier, injectable gold compounds were successfully used for the treatment of rheumatoid arthritis. Of the many compounds developed, gold sodium thiomalate has been the most extensively studied by basic scientists and by clinicians. In the1980s, the oral gold compound auranofin showed promise as a therapeutic contender to injectable gold, but the clinical side effect profile and fear of long term effects of immune suppression by auranofin, resulted in gold sodium thiomalate continuing as the preferred gold compound for rheumatoid treatment. However, the increased use and demonstration of effectiveness of low dose Methotrexate (MTX) in rheumatoid treatment over the last 20 years has resulted in a significant decline in the use of injectable gold sodium thiomalate, this despite the claims and evidence that it remains a useful agent in the management of rheumatoid arthritis. Several authors still contend that the injectable gold compounds can still play a valuable role, and indeed may be the correct first choice in the management of rheumatoid arthritis.     

载阿霉素金纳米粒的制备和细胞毒性研究

目的 构建载阿霉素（DOX）的甲氧基聚乙二醇（mPEG）修饰的金纳米粒AuNPs-mPEG@DOX，以降低DOX的毒副作用。方法 制备AuNPs-mPEG@DOX，通过粒径、电位和紫外可见光吸收光谱（UV-Vis）进行表征。考察连接巯基的DOX（HS-DOX）投药浓度对AuNPs-mPEG@DOX吸附率和载药量的影响。建立未吸附HS-DOX含量测定的高效液相色谱法（HPLC），对专属性、线性、精密度、稳定性和加样回收率进行考察。采用CCK-8法检测AuNPs-mPEG@DOX对MCF-10A和MCF-7细胞的毒性作用。结果 成功制备了AuNPs-mPEG@DOX，粒径为（46.12±0.49） nm，电位为（18.60±1.51） mV，最大吸收波长为530 nm。建立了可用于检测AuNPs-mPEG@DOX未吸附HS-DOX含量的HPLC方法，测定最佳投药浓度11.18 μg/ml，HS-DOX条件下的吸附率为（9.21±2.88）%，载药量为（2.01±0.62）%。细胞毒性实验表明AuNPs-mPEG@DOX可明显降低DOX对正常乳腺细胞的毒副作用；DOX在≥4.75 μmol/L时，AuNPs-mPEG@DOX与游离DOX对乳腺肿瘤细胞的细胞毒性作用一致。结论 AuNPs-mPEG@DOX可有效降低DOX的毒副作用，为后续AuNPs连接药物降低其毒副作用的研究提供参考。     

Distribution of gold in human platelets after in-vitro interaction and during chrysotherapy with gold sodium thiomalate

We have studied the distribution of gold in platelets from patients with rheumatoid arthritis (RA) undergoing chrysotherapy and, in vitro, in platelets reacted with gold sodium thiomalate. In vitro, electron dense fibrillar particles within membrane bound structures were detected in preparations containing 50 μg/ml or more of Au. Energy dispersive spectroscopy confirmed the presence of gold and sulphur in these particles. Gold was detected in platelets from RA patients by neutron activation analysis, but not by electron microscopy.     

Anti-glycation activity of gold nanoparticles

Anti-glycation activity of gold nanoparticles (GNPs) has been reported for the first time. Nonenzymatic glycation of alpha-crystallin leads to formation of cataract, or opaque aggregate of proteins. In this article we report prevention of glycation of alpha-crystallin by conjugation with GNPs. Formation of advanced glycosylic end products is prevented even if a strong glycating agent such as fructose is used. In addition, the nanoconjugation can provide some important information on the structural distribution of this dynamic chaperone protein. Because GNPs are biocompatible, their reported anti-glycation activity may have ophthalmological implications.     

Ecotoxicity and uptake of polymer coated gold nanoparticles

Abstract

Bioconjugated gold nanoparticles (Au NPs) are a promising tool for pharmaceutical applications. However, the ecotoxicity of these types of NPs has hardly been studied. We investigated the ecotoxicity and uptake of 4–5 nm Au NPs to which two types of polymer coatings were attached. One coating was an amphiphilic polymer only and the other an amphiphilic coating to which 10 kDa polyethylene glycol chains were attached. In both 72 h algal growth inhibition tests with the alga Pseudokirchneriella subcapitata and in 24 h resazurin cytotoxicity tests with the rainbow trout gill cell line RTGill-W1, the pegylated Au NPs were found less toxic compared to the amphiphilic coated particles. No uptake or direct interaction between particles and algal cells was observed. However, uptake/adsorption in fish gill cells reached up to >10⁶ particles/cell after 1 h and particles were eliminated for ≥96% after 24 h depuration. Both particle types were found within membrane enclosed vesicles in the cytoplasm of RTgill-W1 cells.     

Clinical pharmacokinetics of oral and injectable gold compounds

The pharmacokinetics of oral gold (auranofin) in some respects resemble, and in other respects differ from, those of existing parenteral gold compounds such as gold sodium thiomalate (GST). This may in part relate to physicochemical differences as GST is a water-soluble polymeric compound in vitro whereas auranofin is lipid-soluble and characteristically monomeric. Furthermore, intramuscularly administered gold is greater than 95% bioavailable, whereas only 20 to 30% of an orally administered dose of auranofin is absorbed. Following a standard 50mg intramuscular injection of GST, serum gold concentrations rise sharply, peaking between 4 and 8 mg/L in approximately 2 hours and declining to an average of 3 mg/L by 7 days. With repeated injections of GST stable serum concentrations of gold (3 to 5 mg/L) are eventually achieved (usually within 5 to 8 weeks) although absolute concentrations may vary widely between patients. On the other hand, long term treatment with auranofin is associated with lower and more stable serum concentrations of gold (0.5 to 0.7 mg/L), on the standard dosing regimen of 6 mg daily. Both compounds are retained within the body for prolonged periods. However, the amount of gold retained with auranofin is significantly less compared with GST (less than 5% of a tracer dose of auranofin--about 20% of the absorbed dose--is retained by 100 days whereas the retention for a single labelled dose of GST over a similar interval is greater than 50%). Excretory patterns of GST and auranofin also differ. Most of an absorbed dose of GST (greater than 70%) is excreted by the kidneys whereas only 50% of an absorbed (15% of an administered) dose of auranofin is excreted in the urine. Both compounds are avidly bound by plasma proteins and auranofin shows a particularly strong association with circulating cellular elements. In human subjects, parenterally administered gold is widely distributed among bodily tissues, showing a predilection for tissues of the reticuloendothelial system as well as the kidney and adrenal cortex. Comparable studies in humans are not available for auranofin but animal studies have shown comparatively less affinity for the liver, kidney and spleen. Valuable insight has been gained in analysing the comparative pharmacokinetics of oral and injectable gold compounds. Unfortunately, attempts to correlate pharmacokinetic findings with clinical response or pharmacodynamic changes, as a whole, remain largely unsuccessful with these agents.     

Anti-cancer potential of gold complexes

A full range of gold compounds is currently being investigated for their potential as anti-tumor agents. Gold(I) compounds related to the anti-arthritic drug [Formula: see text] continue to attract attention, especially those carrying biologically active molecules with anti-tumor activity in their own right. Tetrahedrally coordinated gold(I) compounds, that possibly target mitochondria, are under development with a particular focus upon moderating their hydrophilicity. A resurgence of interest in square-planar gold(III) compounds has occurred in the last decade. A wide variety of species: mono- and di-nuclear, neutral and charged, coordination and organometallic, etc. are being developed. Supporting many investigations are studies of mechanistic aspects of gold compounds but a clear understanding of the mechanism of action of these compounds has yet to be delineated.     

Inter-strand cross-links and single-strand breaks produced by gold(I) and gold(III) coordination complexes

The ability of gold coordination complexes to bind to DNA and produce inter-strand cross-links in DNA was assessed in an assay system based on the fluorescence properties of the DNA intercalative dye, ethidium bromide. Results from these studies using a variety of gold(I) and gold(III) complexes suggest that the ability of gold complexes to bind to and produce inter-strand cross-links in DNA is not dependent on the oxidation state of gold in the complex but is influenced by the nature of the coordinating ligands. Those complexes in which the gold was ligated through one or more weakly coordinating ligands showed evidence for DNA binding. However, only those complexes with two or more of these relatively weak coordinating ligands produced inter-strand cross-links. Both the amount of binding to and cross-linking of DNA by these compounds were decreased by treatment of the gold-DNA complex with 2-mercaptoethanol and other thiol containing agents. As shown by agarose gel electrophoresis, 2-mercaptoethanol caused a dissociation of the gold-DNA complexes and a regeneration of closed circular superhelical pBR322 DNA. DNA strand breakage also resulted from treatment of a number of gold-DNA complexes with 2-mercaptoethanol; this was observed with the gold compounds which were shown to produce inter-strand cross-links in DNA. The amount of DNA strand breakage produced by treatment of gold-DNA complexes with 2-mercaptoethanol was influenced by the initial conformation of the DNA; gold-DNA complexes which resulted from the binding of gold compounds to covalently closed superhelical DNA were more sensitive to the breakage induced by 2-mercaptoethanol treatment than those complexes in which closed circular, relaxed DNA was used as substrate. The DNA breakage was not reduced in partially anaerobic conditions or by free-radical scavengers, suggesting that it is not mediated by oxygen. The results are discussed with respect to the potential for the interaction of gold complexes with intracellular DNA and chromatin and their biological implications.     

Characterization of gold in urine and bile following administration of gold sodium thiomalate with chelating agents to rats.

Gold was characterized in the urine and bile of rats treated with D-penicillamine (D-PEN), 2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercaptopropane sulphonate (DMPS), or N-(2-mercapto-2-methylpropanoyl)-L-cysteine (bucillamine) immediately after gold sodium thiomalate (AuTM) injection by both gel chromatographic and electrophoretic methods. It is suggested that the gold in the urine and bile after AuTM administration was predominantly bound to high molecular weight compounds. The characterization of gold in the urine after administration of AuTM with D-PEN, DMSA, or DMPS showed that most of the gold was bound to the chelating agents. In the treatment with the chelating agents such as D-PEN and DMPS, the gold was mainly excreted as a gold-chelating agent compound in the bile and a minor portion of the gold was present in the form of a gold-L-cysteine compound and high molecular weight compounds. DMSA treatment showed that a major portion of the gold was bound to high molecular weight compounds in the bile and a minor portion of the gold was present in the forms of gold-DMSA and gold-L-cysteine compounds. The administration of AuTM and bucillamine indicated that the gold was mainly present as a gold-Me-bucillamine compound in the urine and a gold-bucillamine compound in the bile.     

Mining for therapeutic gold

A comprehensive and collaborative strategy to enable the investigation of new uses of approved and abandoned drug compounds could advance translational research.     

Labeling and tracking cells with gold nanoparticles

Gold nanoparticles (AuNPs) have garnered much attention as contrast agents for computerized tomography (CT) because of their facile synthesis and surface functionalization, in addition to their significant X-ray attenuation and minimal cytotoxicity. Cell labeling using AuNPs and tracking of the labeled cells using CT has become a time-efficient and cost-effective method. Actively targeted AuNPs can enhance CT contrast and sensitivity, and further reduce the radiation dosage needed during CT imaging. In this review, we summarize the state-of-the-art use of AuNPs in CT for cell tracking, including the precautionary steps necessary for their use and the difficulty in translating the process into clinical use.     

Review on gold nanoparticles and their applications

Gold nanoparticles are widely used in many fields as preferred materials for their unique optical and physical properties, such as surface plasmon oscillations for labeling, imaging, and sensing. Recently, many advancements were made in biomedical applications with better biocompatibility in disease diagnosis and therapeutics. Au-NPs could be prepared and conjugated with many functionalizing agents, such as polymers, surfactants, ligands, dendrimers, drugs, DNA, RNA, proteins, peptides and oligonucleotides. This review addressed the use of gold nanoparticles and the surface functionalization with a wide range of molecules, expanding and improving gold nanoparticles in targeting drugs for photothermal therapy with reduced cytotoxic effcts in various cancers, gene therapy and many other diseases. Overall, Au-NPs would be a promising vehicle for drug delivery and therapies.