Lower Glutathione Content Research Articles

Redox-responsive CpG-dextran conjugate enhances anti-tumour immunity following intratumoral administration

Conjugation of a therapeutic agent to a polymer for enhanced delivery into target cells followed by its intracellular triggered release has proved to be an effective drug delivery approach. This approach is applied to the delivery of the immune–stimulatory unmethylated cytosine-phosphate-guanine (CpG) oligonucleotide for an anti-tumour immune response after intratumoral administration. On average four CpG-1668 molecules were covalently linked to a 40-kDa amino-functionalised dextran polymer via either a non-reversible (CpG-dextran) or an intracellular redox-responsive disulfide linkage (CpG-SS-dextran). Dynamic light scattering analysis showed that both conjugates had a similar particle size and surface charge of 17 nm and −10 mV, respectively. Agarose gel electrophoresis analysis showed that CpG-SS-dextran was stable in the extracellular low glutathione (GSH) concentration range (i.e. 10–20 μM) and was cleaved at the higher intracellular GSH concentration (5 mM), while CpG-dextran was stable in both GSH concentrations. Uptake and activation assays on bone-marrow-derived dendritic cells showed no significant difference between free CpG, CpG-dextran and CpG-SS-dextran. In a mouse subcutaneous colorectal tumour model the CpG-SS-dextran showed a statistically significantly greater inhibition of tumour growth (p < 0.03) and prolonged survival (p < 0.001) compared to CpG-dextran or free CpG. These results demonstrate that the redox-triggered intracellular release of CpG from a dextran polymer carrier has promise for intratumoral therapeutic vaccination against cancer.

Decreased glutathione synthesis in granulosa cells, but not oocytes, of growing follicles decreases fertility in mice†.

Prior studies showed that mice deficient in the modifier subunit of glutamate cysteine ligase (Gclm), the rate-limiting enzyme in synthesis of the thiol antioxidant glutathione, have decreased ovarian glutathione concentrations, chronic ovarian oxidative stress, poor oocyte quality resulting in early preimplantation embryonic mortality and decreased litter size, and accelerated age-related decline in ovarian follicle numbers. Global deficiency of the catalytic subunit of this enzyme, Gclc, is embryonic lethal. We tested the hypothesis that granulosa cell- or oocyte-specific deletion of Gclc recapitulates the female reproductive phenotype of global Gclm deficiency. We deleted Gclc in granulosa cells or oocytes of growing follicles using Gclc floxed transgenic mice paired with Amhr2-Cre or Zp3-Cre alleles, respectively. We discovered that granulosa cell-specific deletion of Gclc in Amhr2Cre;Gclc(f/-) mice recapitulates the decreased litter size observed in Gclm-/- mice but does not recapitulate the accelerated age-related decline in ovarian follicles observed in Gclm-/- mice. In addition to having lower glutathione concentrations in granulosa cells, Amhr2Cre;Gclc(f/-) mice also had decreased glutathione concentrations in oocytes. By contrast, oocyte-specific deletion of Gclc in Zp3Cre;Gclc(f/-) mice did not affect litter size or accelerate the age-related decline in follicle numbers, and these mice did not have decreased oocyte glutathione concentrations, consistent with transport of glutathione between cells via gap junctions. The results suggest that glutathione deficiency at earlier stages of follicle development may be required to generate the accelerated follicle depletion phenotype observed in global Gclm null mice.

The Perspective of Chemodynamic Therapy Combination with Plasma in Cancer Treatments

Chemodynamic therapy is (CDT) a novel emerging cancer treatment based on the Fenton-Fenton like reactions. During the Fenton chemical process, hydrogen peroxide in the presence of iron is converted to hydroxyl radical which is a highly reactive species to induce cell damage. The tumor optimal conditions for the occurrence of the Fenton-Fenton like reaction are: a high concentration of hydrogen peroxide, low pH level, and low Glutathione concentration. The requirement for these conditions limit us to achieving the best results from cancer chemodynamic therapy, thus combination with other treatments may be necessary. Here, using current research and a cell model, firstly we introduce the limitations of chemodynamic therapy in cancer treatment and then propose that cold atmospheric plasma could be a suitable candidate for combination with chemodynamic therapy to overcome these limitations.

Applying smartphone camera, spectrophotometry, or ocular analysis-based dipsticks for the detection of glutathione level as a cancer biomarker

This study provides simple sensitive and selective spot tests and spectrophotometric methods for quantifying l-glutathione (GSH) as a cancer biomarker. The dipsticks are based on filter paper containing a Cu(II)-murexide complex which was prepared in phosphate buffer pH 6.0 and then incorporated inside a filter paper matrix. On addition of GSH, the spots' color progressively changed from yellow to orange through pink to violet before gradually vanishing. The indicator is released when GSH is injected because GSH displaces murexide dye from the murexide-Cu2+ complex. This enables the determination of glutathione in human serum visually using the reflectometric Red-Green-Blue (RGB) interpretation of the dipstick image data. In the spectrophotometric method, the Cu2+-murexide complex absorbance band is gradually red-shifted upon interaction with different concentrations of glutathione due to the displacement reaction.Glutathione can be determined from 0.01 to 500 μg mL−1 visually and from the evaluation of the smartphone images. The limit of detection for glutathione determination using dipsticks is 0.01 μg mL−1, which is the lowest value to date. This technique has been successfully used with positive outcomes to identify low concentrations of glutathione in samples of human serum.

Severe Hemolytic Anemia and Metabolic Acidosis at Birth with Glutathione Synthetase Deficiency and Progressive Neurological Symptoms on Follow-Up.

BACKGROUND Glutathione synthetase deficiency (GSD) is a rare autosomal recessive disorder caused by glutathione synthetase (GSS) gene variants that occur in 1 in 1 million individuals. The severe form of GSD is characterized by hemolytic anemia, metabolic acidosis with 5-oxoprolinuria, progressive neurological symptoms, and recurrent bacterial infections. This case report presents a male Japanese infant with severe hemolytic anemia and metabolic acidosis at birth caused by GSD, who developed progressive neurological symptoms on follow-up. CASE REPORT A Japanese male term infant developed severe hemolytic anemia and metabolic acidosis in the early neonatal period. We suspected GSD based on his symptoms and a high 5-oxoproline urine concentration. We began correcting his metabolic acidosis and administering vitamins C and E supplements. The patient required blood transfusion twice during the acute phase for hemolytic anemia. After age 1 month, he maintained good control of metabolic acidosis and hemolytic anemia. A definitive diagnosis of GSD was made based on high concentrations of 5-oxoproline in urine, low concentrations of glutathione and GSS activity in erythrocytes, and genetic testing. Several episodes of febrile convulsions were started at age 11 months, but none occurred after 2 years. At the last follow-up at age 25 months, metabolic acidosis and hemolytic anemia were well controlled, but he had mild neurodevelopmental delay. CONCLUSIONS This case report shows that GSD can present with severe hemolytic anemia and metabolic acidosis at birth, and manifest with subsequent neurological impairment despite early diagnosis and treatment. Therefore, a careful long-term follow-up that includes neurological evaluation is essential for patients with GSD.

L-2-Oxothiazolidine-4-Carboxylate, a Cysteine Precursor, Stimulates Growth and Normalizes Tissue Glutathione Concentrations in Rats Fed a Sulfur Amino Acid-Deficient Diet

The efficiency of L-2-oxothiazolidine-4-carboxylate, a cysteine precursor, in stimulating glutathione synthesis and growth was evaluated in growing rats. Animals were fed a sulfur amino acid-deficient diet (0.25% L-methionine and no cysteine) supplemented with L-2-oxothiazolidine-4-carboxylate (0.35%) for 3 wk and compared with age-matched animals receiving the sulfur amino acid-deficient diet alone. Rats fed the sulfur amino acid-deficient diet had lower glutathione concentrations in bronchoalveolar lining fluid, lung, lymphocytes, and liver than rats fed a sulfur amino acid-deficient diet supplemented with L-2-oxothiazolidine-4-carboxylate. Rats fed the supplemented diet had normal tissue and bronchoalveolar lining fluid glutathione levels. Central venous plasma glutathione concentrations, mostly reflecting liver excretion, were less affected by L-2-oxothiazolidine-4-carboxylate supplementation. Rats fed L-2-oxothiazolidine-4-carboxylate supplementation had normal weight gain compared with a much lower weight gain in animals fed the sulfur amino acid-deficient diet alone. Thus, L-2-oxothiazolidine-4-carboxylate increased tissue glutathione concentrations and stimulated growth in rats. The lung glutathione status of the rats was reflected by glutathione concentrations in lymphocytes and the bronchoalveolar lining fluid, but not by the central venous plasma glutathione concentrations.

Exhaled breath condensate markers of oxidative stress in male storekeepers of chemical stores in the Ariaria international market Aba Abia state Nigeria.

In most developing countries, stores, where chemical substances are sold, are poorly ventilated, and best practices are not followed. This can result in the contamination of the ambient air inside the stores with toxicological implications for the lungs. This work aimed at determining the risk of pulmonary disease in chemical storekeepers in the Ariaria international market Aba by the evaluation of exhaled breath condensate (EBC) biomarkers of oxidative stress. A gas monitor was used for gas sampling while an Aerocet analyzer was used for particulate matter determinations. Exposed filter paper was used for the sampling of heavy metals in the air, and the determination was done using atomic absorption spectrophotometry. The exhaled breath condensate was collected with a refrigerated condenser, and the markers of oxidative stress were determined spectrophotometrically. Concentrations of particulate matter (PM1, PM2.5, PM4, PM7, PM10) were elevated in all the chemical stores studied. Our findings also showed that the indoor air of the chemical stores studied was polluted with SO2, NO2, NH3 and H2S, as their concentrations were respectively higher than the WHO standard values. Concentrations of all the heavy metals present in the ambient air of the chemical stores were also higher than the Nigerian Environmental Standard and Regulation Enforcement Agency (NESREA) standard values. Chemical storekeepers at the Ariaria international market exhaled increased concentrations of thiobarbituric acid reactive substances (TBARS), H2O2, and lower concentrations of glutathione (GSH). The pH values of the exhaled breath condensates were decreased and slightly acidic. It therefore means that the storekeepers were exposed to polluted ambient air inside the stores. This resulted to airway oxidative stress in the storekeepers as reported herein. Therefore, storekeepers of chemical stores in the Ariaria international market, Aba Nigeria were at risk of pulmonary disease(s).

A Decreased Response to Resistin in Mononuclear Leukocytes Contributes to Oxidative Stress in Nonalcoholic Fatty Liver Disease.

Deregulation of immune response and oxidative stress contribute to nonalcoholic fatty liver disease (NAFLD) pathogenesis. Resistin is a physiological modulator of inflammation and redox homeostasis of different cell types. Increased resistin serum concentration and the direct association between resistin hepatic expression and NAFLD severity suggest that resistin participates in NAFLD pathogenesis. To evaluate resistin-induced regulation of redox homeostasis in mononuclear leukocytes from NAFLD patients and controls. We evaluated basal and resistin-mediated modulation of reactive oxygen species (ROS) and glutathione content by flow cytometry, and antioxidant enzyme activities by spectrophotometry. Peripheral blood mononuclear cells (PBMC) from NAFLD patients showed higher ROS content and glutathione peroxidase activity and lower glutathione content, superoxide dismutase and glutathione reductase activities than control PBMC. Resistin decreased ROS levels and superoxide dismutase activity and increased glutathione reductase and catalase activities in PBMC from controls but not from patients. Resistin decreased glutathione content in PBMC from control and NAFLD patients, with greater effect on patient cells. Basal and resistin-modulated ROS levels were directly associated with obesity-related risk factors for NAFLD. Hepatic myeloid cells and T-lymphocytes from NAFLD patients showed higher basal ROS content than cells from controls. Resistin decreased ROS levels in hepatic T-lymphocytes from controls but not from patients. Resistin regulates redox homeostasis in mononuclear leukocytes. A decreased response to resistin in leukocytes from NAFLD patients is associated with an impaired redox homeostasis.

Controllable preparation of sea urchin-like Au NPs as a SERS substrate for highly sensitive detection of the toxic atropine.

Branched Au nanoparticles (Au NPs) can significantly enhance the Raman signal of trace chemical substances, and have attracted the interest of researchers. However, there are still challenges to accurately prepare the morphology of branched Au NPs. In this work, we have successfully prepared sea urchin-like Au NPs and Au nanowires by using the seed-mediate growth method, with cetyltrimethylammonium bromide (CTAB) and glutathione as ligands, and ascorbic acid as a reducing agent. Using Au NPs with a tetrahexahedron (THH) morphology as seeds, and by simply changing the concentration of glutathione, we explored the growth process of sea urchin-like Au and Au nanowires. At low concentrations of glutathione, Au NPs will preferentially grow along the edges and corners of the THH Au seed, forming a core/satellite structure. As the concentration of glutathione increases, Au NPs will grow along the direction of glutathione, forming sea urchin-like Au NPs. To further increase the concentration of glutathione, we will prepare Au nanowires. In addition, we use the prepared Au NPs as a substrate material for surface-enhanced Raman (SERS) high-sensitivity detection. By using 4-aminothiophenol (4-ATP) as the test molecule, we evaluated the SERS effect of the prepared Au NPs with different morphologies. The results showed that sea urchin-like Au NPs have the best enhancement effect. The lowest concentrations of Rhodamine 6G and 4-ATP were 10−10 M and 10−12 M, respectively, using sea urchin Au NPs as the base material. Furthermore, we conducted a highly sensitive SERS detection of the poison atropine monohydrate, and the lowest detected concentration was 10−10 M.

Cardiovascular Risk Assessment in Children With Chronic Cholestatic Liver Diseases.

Chronic cholestatic liver diseases are often associated with disturbed lipid metabolism, which may potentially increase cardiovascular (CV) risk but the evidence is scarce. The aim of the study was to assess factors associated with increased CV risk in children with Alagille syndrome (AGS) and biliary atresia (BA). We investigated 17 patients with AGS, ages 11.0 years (8.4-13.4) and 19 with BA, ages 13.5 years (10.4-15.1) in whom we performed thorough biochemical assessment including lipid profiles and oxidative stress biomarkers, blood pressure (BP)-systolic, diastolic and mean, carotid intima-media thickness (cIMT), and pulse wave velocity (PWV). There were abnormal lipid profiles in 82% of children with AGS and 52.6% with BA. In AGS group, we observed significantly higher levels of TC, LDL C, APO B, lower glutathione concentration and glutathione peroxidase activity and lower blood pressure, lower cIMT (P = 0.02), cIMT-SDS (P = 0.04), and PWV (P = 0.04). We, however, observed elevated blood pressure in 2/19 patients with BA and none-with AGS (BA vs AGS: P = 0.12), whereas cIMT-SDS was increased only in 2/17 patients with AGS and in 6/19 with BA (P = 0.24), and abnormal PWV-SDS values were detected in 3/17 of AGS and 8/19 of BA patients (P = 0.15). Neither presence of dyslipidemia nor Lp-X correlated with vascular parameters. Children with BA and AGS may present with increased cardiovascular risk factors but vascular parameters are not directly related to lipid abnormalities. cIMT and BP should be considered for clinical practice in these cholestatic disorders so as to determine individuals with potential CV risk.

PH and redox dual-responsive polymeric micelles with charge conversion for paclitaxel delivery

Here we demonstrate a type of pH and redox dual-responsive micelles, which were self-assembled in aqueous solution by an amphiphilic polymer, methoxypoly(ethylene glycol)-cystamine-poly(L-glutamic acid)-imidazole (mPEG-SS-PGA-IM). Considering tumor cells or tissues exhibiting low pH values and high glutathione (GSH) concentration, mPEG-SS-PGA-IM micelles possessed the charge conversion at pH of tumor tissues, which can facilitate cellular uptake of tumor cells. Furthermore, mPEG-SS-PGA-IM micelles can escape from endo/lysosomes based on the proton sponge effect, following degraded by higher concentration of GSH in cytoplasm. CLSM images of HCT116 cells indicated that mPEG-SS-PGA-IM micelles can escape from endo/lysosomes and enter cytoplasm. MTT assay showed that (paclitaxel) PTX-loaded mPEG-SS-PGA-IM micelles had higher cytotoxicity against HCT116 cells compared with PTX-loaded mPEG-PBLG and mPEG-SS-PBLG micelles. These results indicated that these mPEG-SS-PGA-IM micelles, as novel and effective pH- and redox-responsive nanocarriers, have great potential to both improve drug targeting efficiency while also enhancing the antitumor efficacy of PTX.

Multifunctional Core-Shell Glyconanoparticles for Galectin-3-Targeted, Trigger-Responsive Combination Chemotherapy.

Galectin-3 (gal-3) plays a crucial role in various cellular events associated to tumor metastasis and progression. In this direction, gal-3 binding core-shell glyconanoparticles based on citrus pectin (CP) have been designed for targeted, trigger-responsive combination drug delivery. Depolymerization via periodate oxidation in heterogeneous medium yielded low-molecular weight dialdehyde oligomers (CPDA) of CP with a gal-3 binding property (Kd = 160.90 μM). CPDA-based core-shell nanoparticles prepared to enhance the gal-3 binding specificity via a multivalent ligand presentation have shown to reduce homotypic cellular aggregation, tumor cell binding with endothelial cells, and endothelial tube formation, the major steps involved in the progression of cancer. Immune-fluorescence and flow cytometric analysis confirmed significant reduction in gal-3 expression on MDA-MB 231 cancer cells upon incubation with nanoparticles. An on-demand tumor microenvironment-responsive release of drugs at low pH and high concentrations of glucose and glutathione prevailing in tumor milieu was achieved by introducing a cleavable Schiff's base, a boronate ester, and disulfide linkages within the shell of the nanoparticles. Nanoparticles with encapsulated sulindac in the core and doxorubicin (DOX) in the shell demonstrated target specificity and enhanced internalization with synergistic cytotoxic effects with a 30-fold reduction in IC50 in DOX-resistant, triple-negative MDA-MB 231 breast cancer cells. Nanoparticles were radiolabeled with 131I radioisotopes with ≥80% efficiency while retaining its gal-3 binding property. Biodistribution studies of radiolabeled placebo nanoparticles and drug-loaded CPDA nanoparticles demonstrated proof of concept of gal-3 targeting seen as preferential accumulation in the gal-3-expressing tissues of the gastric tract. The CPDA core-shell nanoparticles are thus promising platforms for gal-3 targeting and inhibition of gal-3-mediated processes involved in cancer progression with a potential of radiolabeling for in vivo monitoring or delivering therapeutic doses of radiation and on-demand triggered, target-specific drug release.

Fabrication of Mixed Polymeric Micelles Based on Stimuli-Responsive Amphiphilic Copolymers for Drug Delivery and Controlled Release

In this report, mixed polymeric micelles (MPMs) system self-assembled from two kinds of cholesterol-grafted amphiphilic block copolymers cholesterol modified poly ([Formula: see text]-amino esters)-grafted disulfide poly (ethylene glycol) methyl ether (PAE(-ss-mPEG)-[Formula: see text]-Chol) and poly([Formula: see text]-amino ester)-g-poly(ethylene glycol) methyl ether-cholesterol (PAE-[Formula: see text]-mPEG-Chol) were prepared for drug delivery and controlled release with pH and redox-responsibilities. The self-assembly of two block copolymers was evaluated by measurement of critical micelle concentration (CMC) values using fluorescence spectroscopy. The hydrodynamic diameter, polydispersity index (PDI) and zeta-potential of MPMs in aqueous were recorded by dynamic light scattering (DLS) at different conditions. Doxorubicin (DOX) was efficiently encapsulated in the micellar core by the hydrophobic interaction. The drug loading content (LC) and encapsulation efficacy (EE) of MPMs with different formulations were evaluated. The DOX was released due to the swelling and disassembly of MPMs induced by low pH and high glutathione (GSH) concentrations. The in vitro results demonstrated that drug release rate and cumulative release were obviously dependent on pH values and reducing agents. The results showed that the MPMs could be the potential anticancer drug delivery carriers with pH/redox-triggered drug release profile.

Fucoidan protects against subacute diazinon-induced oxidative damage in cardiac, hepatic, and renal tissues.

Fucoidans (FUC) are organic sulfated polysaccharides from natural seaweeds with multiple biological actions. The current study was performed to assess the chemoprotective, antioxidant, and anti-inflammatory effects of FUC from Laminaria japonicum against diazinon (DZN)-induced injuries to rat cardiac, hepatic, and renal tissues. Forty male Wistar rats were assigned into five groups, receiving saline, oral FUC 200mg/kg/day, subcutaneous DZN 20mg/kg/day, DZN plus FUC 100mg/kg/day, or DZN plus FUC 200mg/kg/day (each treatment was given daily for 4weeks). Data analysis showed that DZN-intoxicated rats exhibited significantly higher (p < 0.05) serum levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, urea, creatine, creatine kinase, creatine kinase-MB, lactate dehydrogenase, cholesterol, interleukin-6, and tumor necrosis factor-α, as well as lower levels of acetylcholinesterase, compared to control rats. In addition, DZN intoxication was associated with significantly higher (p < 0.05) cardiac, hepatic, and renal tissue concentrations of malondialdehyde and nitric oxide, as well as lower glutathione concentrations, and activities of glutathione peroxidase, superoxide dismutase, and catalase enzymes in comparison to control rats. Treatment with FUC (at 100 or 200mg/kg/day) ameliorated all the aforementioned alterations in a dose-dependent manner. In conclusion, FUC from Laminaria japonicum ameliorated DZN-induced oxidative stress, pro-inflammatory effects, and injuries to the cardiac, hepatic, and renal tissues. These effects may be related to the antioxidant and anti-inflammatory effects of FUC.

The vaginal metabolome and microbiota of cervical HPV-positive and HPV-negative women: a cross-sectional analysis.

Characterise the vaginal metabolome of cervical HPV-infected and uninfected women. Cross-sectional. The Center for Health Behavior Research at the University of Maryland School of Public Health. Thirty-nine participants, 13 categorised as HPV-negative and 26 as HPV-positive (any genotype; HPV+ ), 14 of whom were positive with at least one high-risk HPV strain (hrHPV). Self-collected mid-vaginal swabs were profiled for bacterial composition by 16S rRNA gene amplicon sequencing, metabolites by both gas and liquid chromatography mass spectrometry, and 37 types of HPV DNA. Metabolite abundances. Vaginal microbiota clustered into Community State Type (CST) I (Lactobacilluscrispatus-dominated), CST III (Lactobacillusiners-dominated), and CST IV (low-Lactobacillus, 'molecular-BV'). HPV+ women had higher biogenic amine and phospholipid concentrations compared with HPV- women after adjustment for CST and cigarette smoking. Metabolomic profiles of HPV+ and HPV- women differed in strata of CST. In CST III, there were higher concentrations of biogenic amines and glycogen-related metabolites in HPV+ women than in HPV- women. In CST IV, there were lower concentrations of glutathione, glycogen, and phospholipid-related metabolites in HPV+ participants than in HPV- participants. Across all CSTs, women with hrHPV strains had lower concentrations of amino acids, lipids, and peptides compared with women who had only low-risk HPV (lrHPV). The vaginal metabolome of HPV+ women differed from HPV- women in terms of several metabolites, including biogenic amines, glutathione, and lipid-related metabolites. If the temporal relation between increased levels of reduced glutathione and oxidised glutathione and HPV incidence/persistence is confirmed in future studies, anti-oxidant therapies may be considered as a non-surgical HPV control intervention. Metabolomics study: Vaginal microenvironment of HPV+ women may be informative for non-surgical interventions.

Gradient Redox-Responsive and Two-Stage Rocket-Mimetic Drug Delivery System for Improved Tumor Accumulation and Safe Chemotherapy.

Recent drug delivery nanosystems for cancer treatment still suffer from the poor tumor accumulation and low therapeutic efficacy due to the complex in vivo biological barriers. To resolve these problems, in this work, a novel gradient redox-responsive and two-stage rocket-mimetic drug nanocarrier is designed and constructed for improved tumor accumulation and safe chemotherapy. The nanocarrier is constructed on the basis of the disulfide-doped organosilica-micellar hybrid nanoparticles and the following dual-functional modification with disulfide-bonded polyethylene glycol (PEG) and amido-bonded polyethylenimine (PEI). First, prolonged circulation duration in the bloodstream is guaranteed due to the shielding of the outer PEG chains. Once the nanocarrier accumulates at the tumoral extracellular microenvironment with low glutathione (GSH) concentrations, the first-stage redox-responsive behavior with the separation of PEG and the exposure of PEI is triggered, leading to the improved tumor accumulation and cellular internalization. Furthermore, with their endocytosis by tumor cells, a high concentration of GSH induces the second-stage redox-responsiveness with the degradation of silsesquioxane framework and the release of the encapsulated drugs. As a result, the rocket-mimetic drug carrier displays longer circulation duration in the bloodstream, higher tumor accumulation capability, and improved antitumor efficacy (which is 2.5 times higher than that with inseparable PEG). It is envisioned that the rocket-mimetic strategy can provide new solutions for improving tumor accumulation and safety of nanocarriers in further cancer chemotherapy.

The role of low concentrations of some sulfuric antioxidants on the semen characteristics of rams

This study aims to investigate the effect of low concentrations of sulfuric antioxidants on sperm of rams. This study was conducted in the field of sheep and goats of the Department of Livestock in the collage of Agricultural Engineering Sciences, University of Baghdad. The semen was collected using the artificial vagina at weekly rate (Pooled semen) and was subjected to different tests and then was divided into seven treatments but different concentrations of cysteine (0.5, 1mM) and glutathione (0.5, 1mM) and taurine (0.5, 1mM).The sample of the semen was diluted with Tris dilution (10: 1). The results showed that the low concentrations of glutathione, cysteine and taurine resulted in an improvement in the motility and integrity of the plasma membrane, dead sperm, DNA damage and survival sperm during the conservation period (0, 24, 48 hours).

Nanoscale Metal-Organic-Frameworks Coated by Biodegradable Organosilica for pH and Redox Dual Responsive Drug Release and High-Performance Anticancer Therapy.

Responsive nanocarriers with biocompatibility and precise drug releasing capability have emerged as a prospective candidate for anticancer treatment. However, the challenges imposed by the complicated preparation process and limited loading capacities have seriously impeded the development of novel multifunctional drug delivery systems. Here, we developed a novel and dual-responsive nanocarrier based on a nanoscale ZIF-8 core and an organosilica shell containing disulfide bridges in its frameworks through a facile and efficient strategy. The prepared ZIF-8@DOX@organosilica nanoparticles (ZDOS NPs) exhibited a well-defined structure and excellent doxorubicin (DOX) loading capability (41.2%) with pH and redox dual-sensitive release properties. The degradation of the organosilica shell was observed after 12 h incubation with a 10 mM reducing agent. Confocal imaging and flow cytometry analysis further proved that the nanocarriers can efficiently enter cells and complete intracellular DOX release under the low pH and high glutathione concentrations, which resulted in an enhanced cytotoxicity of DOX for cancer cells. Meanwhile, subcellular localization experiments revealed that the ZDOS NPs entered cells mainly by endocytosis and then escaped from lysosomes into the cytosol. Moreover, in vivo assays also demonstrated that the ZDOS NPs exhibited negligible systemic toxicity and significantly enhanced anticancer efficiencies compared with free DOX. In summary, our prepared pH and redox dual-responsive nanocarriers provide a potential platform for controlled release and cancer treatment.

Dual pH/Redox-Responsive Mixed Polymeric Micelles for Anticancer Drug Delivery and Controlled Release.

Stimuli-responsive polymeric micelles (PMs) have shown great potential in drug delivery and controlled release in cancer chemotherapy. Herein, inspired by the features of the tumor microenvironment, we developed dual pH/redox-responsive mixed PMs which are self-assembled from two kinds of amphiphilic diblock copolymers (poly(ethylene glycol) methyl ether-b-poly(β-amino esters) (mPEG-b-PAE) and poly(ethylene glycol) methyl ether-grafted disulfide-poly(β-amino esters) (PAE-ss-mPEG)) for anticancer drug delivery and controlled release. The co-micellization of two copolymers is evaluated by measurement of critical micelle concentration (CMC) values at different ratios of the two copolymers. The pH/redox-responsiveness of PMs is thoroughly investigated by measurement of base dissociation constant (pKb) value, particle size, and zeta-potential in different conditions. The PMs can encapsulate doxorubicin (DOX) efficiently, with high drug-loading efficacy. The DOX was released due to the swelling and disassembly of nanoparticles triggered by low pH and high glutathione (GSH) concentrations in tumor cells. The in vitro results demonstrated that drug release rate and cumulative release are obviously dependent on pH values and reducing agents. Furthermore, the cytotoxicity test showed that the mixed PMs have negligible toxicity, whereas the DOX-loaded mixed PMs exhibit high cytotoxicity for HepG2 cells. Therefore, the results demonstrate that the dual pH/redox-responsive PMs self-assembled from PAE-based diblock copolymers could be potential anticancer drug delivery carriers with pH/redox-triggered drug release, and the fabrication of stimuli-responsive mixed PMs could be an efficient strategy for preparation of intelligent drug delivery platform for disease therapy.

Enzymatic glutaredoxin-dependent method to determine glutathione and protein S-glutathionylation using fluorescent eosin-glutathione

Glutathione is an abundant low-molecular-weight thiol, up to 10 mM in mammalian cells, and exists in three major forms: reduced sulphydryl (GSH), glutathione disulfide (GSSG) or bound to Cys residues in proteins (PSSG). The ratio GSH/GSSG has been used as an indicator of the cells redox level but this parameter can also be estimated by the quantification of PSSG. In fact, PSSGs have the advantage of being more stable than GSSG.Here we present a highly sensitive fluorescent-based method for detection of low concentrations of glutathione in complex samples such as cell lysates, tissues and plasma. The method is based on our previously described protocol to study Glutaredoxin (Grx) activity. The whole procedure was optimized to measure the fluorescence increase of the di-eosin-glutathione disulfide (Di-E-GSSG) reduced by Grx in the presence of Glutathione Reductase and NADPH, keeping GSH as the limiting factor to drive the reaction.The methods to selectively measure PSSG are expensive and not widely accessible, therefore we optimized our glutaredoxin protocol to quantify this post-translational modification using common laboratory equipments.Overall, our method has simplicity and rapidity combined with high sensitivity as its main advantages; therefore, it may be particularly suitable for large-scale clinical studies.