Coated silver nanoparticles: synthesis,cytotoxicity, and optical properties

Coated silver nanoparticles (AgNPs) have recently become a topic of interest due to the fact that they have several applications such as in electronic, antimicrobial, industrial, optical, and medical fields as biosensors and drug delivery systems. However, the use of AgNPs in medical fields remains somewhat limited due to their probable cytotoxic effect. Researchers have succeeded in reducing the toxicity of silver particles by coating them with different substances. Generally, the coating of AgNPs leads to change in their properties depending on the type of the coating material as well as the layer thickness. This review covers the state-of-the-art technologies behind (a) the synthesis of coated AgNPs including coating methods and coating materials, (b) the cytotoxicity of coated AgNPs and (c) the optical properties of coated AgNPs.

Coated silver nanoparticles (AgNPs) have recently become a topic of interest due to the fact that they have several applications such as in electronic, antimicrobial, industrial, optical, and medical fields as biosensors and drug delivery systems.     

Effect of novel water soluble curcumin derivative on experimental type- 1 diabetes mellitus (short term study)

ABSTRACT: BACKGROUND: Diabetes mellitus type 1 is an autoimmune disorder caused by lymphocytic infiltration and beta cells destruction. Curcumin has been identified as a potent inducer of heme-oxygenase-1 (HO-1), a redoxsensitive inducible protein that provides protection against various forms of stress. A novel water soluble curcumin derivative (NCD) has been developed to overcome low in vivo bioavailability of curcumin. The aim of the present work is to evaluate the anti diabetic effects of the "NCD" and its effects on diabetes-induced ROS generation and lipid peroxidation in experimental type- 1 diabetes mellitus. We also examine whether the up regulation of HO-1 accompanied by increased HO activity mediates these antidiabetic and anti oxidant actions. Materials and methods Rats were divided into control group, control group receiving curcumin derivative, diabetic group, diabetic group receiving curcumin derivative and diabetic group receiving curcumin derivative and HO inhibitor ZnPP. Type-1 diabetes was induced by intraperitoneal injection of streptozotocin. Curcumin derivative was given orally for 45 days. At the planned sacrification time (after 45 days), fasting blood samples were withdrawn for estimation of plasma glucose, plasma insulin and lipid profile . Animals were sacrificed; pancreas, aorta and liver were excised for the heme oxygenase - 1 expression, activity and malondialdehyde estimation. RESULTS: NCD supplementation to diabetic rats significantly lowered the plasma glucose by 27.5% and increased plasma insulin by 66.67%. On the other hand, the mean plasma glucose level in the control group showed no significant difference compared to the control group receiving the oral NCD whereas, NCD supplementation to the control rats significantly increased the plasma insulin by 47.13% compared to the control. NCD decreased total cholesterol, triglycerides, LDL cholesterol and increased HDL cholesterol levels. Also, it decreased lipid peroxides (malondialdehyde) in the pancreas, aorta and liver. CONCLUSION: The (NCD) by its small dose possesses antidiabetic actions and that heme oxygenase induction seems to play an important role in its anti-diabetic effects. NCD also improves the lipid profile and oxidative status directly, proved by decreasing lipid peroxides (malondialdehyde) in pancreas, liver & aorta. The new water soluble curcumin derivative still retains the essential potencies of natural curcumin.     

In vitro and in vivo biofilm adhesion to esthetic coated arch wires and its correlation with surface roughness

Objective:To evaluate the in vitro ability of esthetic coated rectangular arch wires to retain oral biofilms and in vivo biofilm formation on these wires after 4 and 8 weeks of clinical use and to correlate the findings with the surface roughness of these wires.Materials and Methods:Three brands of esthetic coated nickel-titanium (NiTi) arch wires were selected. Arch wires retrieved after 4 and 8 weeks of intraoral use were obtained from 30 orthodontic patients. Surface roughness (SR) was assessed with an atomic force microscope. In vitro adhesion assays were performed using Streptococcus mutans (MS), Staphylococcus aureus, and Candida albicans. The amount of bacterial adhesion was quantified using the colony-count method. Paired t-test, analysis of variance, post hoc Tukey''s test, and Pearson''s correlation coefficient test were used for statistical analysis at the .05 level of significance.Results:In vitro bacterial adhesion showed significant differences between wires in terms of MS adhesion (P  =  .01). All wires showed significant increases in SR (P  =  .001 after 4 weeks and .007 after 8 weeks) and biofilm adhesion (P  =  .0001 after 4 weeks and .045 after 8 weeks) after intraoral exposure. A significant positive correlation (P  =  .001 after 4 weeks and .05 after 8 weeks) was observed between these two variables in vivo, but the correlation was not significant for in vitro bacterial adhesion.Conclusions:SR and biofilm adhesion increased after intraoral use at all time intervals. There was a positive correlation between SR and biofilm adhesion in vivo only.     

Revising the criteria for the predictors of variceal haemorrhage outcome

Background and study aimsThere are many criteria and definitions used to evaluate the failure to control and prevent variceal bleeding. Baveno criteria were developed in Baveno consensus workshops I–III. Some of these criteria are fairly difficult to apply and do not adequately reflect common situations that are observed in clinical practice. Therefore, new criteria were developed at the Baveno-IV workshop. In the present study, we aimed to evaluate the validity of Baveno II–IV criteria in the prediction of bleeding recurrence among patients with liver cirrhosis who presented with bleeding oesophageal varices.Patients and methodsFifty patients with liver cirrhosis and acute variceal bleeding were divided into two groups according to treatment response. Group I consisted of 44 patients for whom treatment to control bleeding was successful, and Group II included 6 patients for whom treatment failed. Baveno criteria were used in the evaluation of treatment outcome in these patients.ResultsThe overall accuracy of Baveno II and III criteria was 87.3% within the first 6 h and 76.5% after 6 h, with a mean accuracy 81.9%. The overall accuracy of Baveno IV criteria in this study was 83%. The criterion of death was also very specific (100%), with 100% PPV, but its sensitivity was very low (16.7%).ConclusionBaveno IV criteria are less complicated, much easier to apply and have nearly the same accuracy as Baveno II/III criteria. However, there are some criteria that need to be modified, such as the adjusted blood requirement index (ABR1), among others.     

Detection of Epithelial-Mesenchymal Transition Markers in High Grade Bladder Cancer and Special Variants of Urothelial Carcinoma

Transitional cell carcinoma is considered the most predominant type of bladder cancer. Bladder can cer can also be found as squamous cell carcinoma that accounts for 5% of the total bladder cancer due to its etiology. The biomarkers associated with grade, prognosis, and stage of the disease are not well proved and known however, many studies have pointed to the association between SNAL/SLUG and Twist2 to the overall survival in patients with bladder cancer. These biomarkers were found to have a crucial role in inhibiting cadherin mediators specifically E-cadherin which are found normally in high level to integrate cell adhesion and normal function of the bladder. This research aims to detect SNAL/SLUG and Twist2 biomarkers in specimens of patients with bladder cancer and to detect their impact on E-cadherin, a tumor suppressor mediator responsible for improving survival and prevent metastasis. Materials and Methods: Using 150 archival tissue blocks from human bladder cancer cases to detect expression of SNAIL/SLUG and Twist2 in relation to loss of E-cadherin by immunohistochemical method. Results: Our results have revealed that in squamous cell carcinoma 40 specimens showed marked Twist 2 expression, and 30 specimens showed marked snail/slug biomarkers expression while poorly differentiated cancer cases showed marked expression of Twist 2 in 60 specimens and marked expression of Snail/slug marked expression in 50 specimens. Both were associated with E-cadherin loss. Among the 100 specimens with transitional cell carcinoma, 70 specimens showed divergent differentiation with 7 subtypes each showed different medium to high expression of Snail/Slug and Twist 2 biomarkers with the loss of E-cadherin. E-cadherin was strongly associated with the inverse increase in SNAL/SLUG and Twist2 biomarkers in urothelial carcinoma. Conclusion: Detection of SNAIL/SLUG and Twist 2 biomarkers in urothelial cancer is an important predictor for the loss of E-cadherin, a cornerstone in urinary bladder cell adhesion and its loss in urothelial carcinoma may contribute to cancer invasion and poor prognosis.     

Evaluation of the Radiation Shielding Properties of a Tellurite Glass System Modified with Sodium Oxide

In this study, the X-ray and gamma attenuation characteristics and optical properties of a synthesized tellurite–phosphate–sodium oxide glass system with a composition of (85 − x)TeO₂–10P₂O₅–xNa₂O mol% (where x = 15, 20, and 25) were evaluated. The glass systems we re fabricated by our research group using quenching melt fabrication. The shielding parameters of as-synthesized systems, such as the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), effective atomic number (Z_eff), half-value layer (HVL), tenth value layer (TVL), mean free path (MFP), and effective electron density (N_eff) in a wide energy range between 15 keV and 15 MeV, were estimated using well-known PHY-X/PSD software and recently developed MIKE software. Herein, the optical parameters of prepared glasses, such as molar volume (V_M), oxygen molar volume (V_O), oxygen packing density (OPD), molar polarizability (αm), molar refractivity (R_m), reflection loss (R_L), and metallization (M), were estimated using MIKE software. Furthermore, the shielding performance of the prepared glasses was compared with that of commonly used standard glass shielding materials. The results show that the incorporation of sodium oxide into the matrix TeO₂/P₂O₅ with an optimum concentration can yield a glass system with good shielding performance as well as good optical and physical properties, especially at low photon energy.