Ultraviolet-induced Surface Grafting of Octafluoropentyl Methacrylate on Polyether Ether Ketone for Inducing Antibiofilm Properties

Since octafluoropentyl methacrylate is an antifouling polymer, surface modification of polyether ether ketone with octafluoropentyl methacrylate is a practical approach to obtaining anti-biofilm biocompatible devices. In the current study, the surface treatment of polyether ether ketone by the use of ultraviolet irradiation, so as to graft (octafluoropentyl methacrylate) polymer chains, was initially implemented and then investigated. The Fourier-transform infrared and nuclear magnetic resonance spectra corroborated the appearance of new signals associated with the fluoroacrylate group. Thermogravimetric curves indicated enhanced asymmetry in the polymer structure due to the introduction of the said new groups. Measuring the peak area in differential scanning calorimetry experiments also showed additional bond formation. Static water contact angle measurements indicated a change in wettability to the more hydrophobic surface. The polyether ether ketone–octafluoropentyl methacrylate surface greatly reduced the protein adsorption. This efficient method can modulate and tune the surface properties of polyether ether ketone according to specific applications

Cytotoxicity of Two Experimental Epoxy Resin-Based Sealers

Introduction: Many endodontic sealers are available, but search for the ideal sealer continues. This study aimed to assess the cytotoxicity of two experimental endodontic sealers in comparison with AH-26 resin sealer. Methods and Materials: This in vitro study was conducted on conventional and experimental root canal sealers: AH-26, an epoxy resin experimental sealer A (ES-A) composed of calcium tungstate, zirconium oxide, aerosil, bismuth oxide, titanium oxide, hexamine and an epoxy resin and experimental sealer B (ES-B) with compositions similar to ES-A except for the presence of imidazoline as a catalyst. The experimental sealers containing nano-particles were mixed with 37.5% of an epoxy resin. The extraction of five samples of each experimental sealer (A, B) and AH-26 sealer were subjected to MTT assay in the form of set and fresh at 1, 24 and 72 h with 1, 10, 100% dilution according to the International Standard ISO:10993-2012. Data were analyzed using the one-way ANOVA. Results: The set ES-A had the least cytotoxicity from the first hour but the cytotoxicity of ES-B and AH-26 extraction decreased over time. In fresh form, except for 100% concentration, ES-A showed the least cytotoxicity compared to the other two sealers. Conclusion: All three sealers had high cytotoxicity in 100% concentration but had low cytotoxicity in 10% and 1% concentrations.Keywords: Cytotoxicity; Endodontics; Epoxy Resin; Seale

Physical Properties and Chemical Characterization of Two Experimental Epoxy Resin Root Canal Sealers

Introduction: The aim of this in vitro study was to evaluate the setting time, flow, film thickness, solubility, radiopacity and characterization analysis of three epoxy resin based sealers including two experimental sealers and AH-26. Methods and Materials: Five samples of each material were evaluated for setting time, flow, film thickness, solubility and radiopacity according to ISO 6876 Standard. Characterization of sealers was performed under the scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Statistical evaluation was performed using the Kruskal-Wallis test. Results: In this study, AH-26 showed more radiopacity and flow compared to two other experimental sealers (P<0.05). However, both sealers had lower setting time than AH-26 (P<0.05). No statistical differences were found regarding film thickness, solubility and radiopacity (P>0.05). The characterization analysis exhibited relatively similar microstructure of AH-26 sealer to the experimental root canal sealers. Conclusion: According to the result of this study, all tested root canal sealers had acceptable properties based on ISO 6876 standard criteria.Keywords: Epoxy Resin; Fourier Transform Infrared; Root Canal Sealer; Scanning Electron Microscopy; X-Ray Energy Dispersive Spectroscopy

Cancer stem cells (CSCs) in cancer progression and therapy

Cancer stem cells (CSCs) are self-renewable cell types that are identified in most types of liquid and solid cancers and contributed to tumor onset, expansion, resistance, recurrence, and metastasis after therapy. CSCs are identified from the expression of cell surface markers, which is tumor-type dependent. The transition between CSCs with cancer cells and other non-CSCs occurs in cancers, which is possibly under the control of signals from CSCs and tumor microenvironment (TME), including CSC niche. Cancer-associated fibroblasts are among the most influential cells for promoting both differentiation of CSCs and dedifferentiation of non-CSCs toward attaining a CSC-like phenotype. WNT/β-catenin, transforming growth factor-β, Hedgehog, and Notch are important signals for maintaining self-renewal in CSCs. An effective therapeutic strategy relies on targeting both CSCs and non-CSCs to remove a possible chance of tumor relapse. There are multiple ways to target CSCs, including immunotherapy, hormone therapy, (mi)siRNA delivery, and gene knockout. Such approaches can be designed for suppressing CSC stemness, tumorigenic cues from TME, CSC extrinsic and/or intrinsic signaling, hypoxia or for promoting differentiation in the cells. Because of sharing a range of characteristics to normal stem/progenitor cells, CSCs must be targeted based on their unique markers and their preferential expression of antigens. © 2018 Wiley Periodicals, Inc

Different Methods of Measuring Neutron Dose/Fluence Generated During Radiation Therapy with Megavoltage Beams

Medical linear accelerators (linacs) are the most frequently applied radiation therapy machines in the locoregional treatment of cancers by producing either high-energy electron or photon beams. However, with high-energy photons (>8 MeV), interaction of these photons with different high-Z nuclei of materials in components of the linac head unavoidably generates neutrons. On the other hand, the average energy of these generated neutrons has almost the highest radiation-weighting factor. Therefore, the produced neutrons should not be neglected. There are various tools for the measurement of neutron dose/fluence generated in a megavoltage linac, including thermoluminescent dosimeters, solid-state nuclear track detectors, bubble detectors, activation foils, Bonner sphere systems, and ionization chamber pairs. In this review article, each of the above-mentioned dosimetric methods will be described in detail

Investigating the Efficiency of Functionalized PAMAM-GO Nano-Composite for Nitrate Removal from Aqua Solutions

Due to the high solubility of nitrate in water, conventional treatment methods fail to remove it. This research investigated for the first time in national and global level, the efficiency of functionalized PAMAM-Go nanocomposite for nitrate removal from aquatic solutions. GO was synthesized by modified Hummers method. AFM images were used to characterize the GO and the AGO. Experiments were performed in a batch reactor and the main factors of pH, reaction time, and concentration of PAMAM_GO were investigated. The highest removal efficiency was obtained as 84% at 5 mL/L functionalized PAMAM_GO, pH of 3 and 25 min reaction time. The results showed that nitrate removal by functionalized PAMAM-Go nanocomposite is directly correlated with nanocomposite concentration and contact time while it is inversely correlated with pH and initial concentration of nitrate. It seems that ion exchange between nitrate and chloride is the main mechanism of nitrate removal by functionalized PAMAM_GO nano composite according to functionalization of PAMAM-Go using hydrochloric acid. This method can be used as a suitable method for in situ treatment of nitrate and many  pollutants in water and wastewater, due to its easy operation, no need for high levels of expertise and sophisticated equipment, no need for large space of construction, low initial investment, low price, availability of raw materials, simple synthesis of graphene oxide and  easy  to functionalize

The role of melatonin on doxorubicin-induced cardiotoxicity: A systematic review

Purpose: Doxorubicin, as an effective chemotherapeutic drug, is commonly used for combating various solid and hematological tumors. However, doxorubicin-induced cardiotoxicity is considered as a serious adverse effect, and it limits the clinical use of this chemotherapeutic drug. The use of melatonin can lead to a decrease in the cardiotoxic effect induced by doxorubicin. The aim of this review was to evaluate the potential role of melatonin in the prevention of doxorubicin-induced cardiotoxicity. Methods: This review was conducted by a full systematic search strategy based on PRISMA guidelines for the identification of relevant literature in the electronic databases of PubMed, Web of Science, Embase, and Scopus up to January 2019 using search terms in the titles and abstracts. 286 articles were screened in accordance with our inclusion and exclusion criteria. Finally, 28 articles were selected in this systematic review. Results: The findings demonstrated that doxorubicin-treated groups had increased mortality, decreased body weight and heart weight, and increased ascites compared to the control groups; the co-administration of melatonin revealed an opposite pattern compared to the doxorubicin-treated groups. Also, this chemotherapeutic agent can lead to biochemical and histopathological changes; as for most of the cases, these alterations were reversed near to normal levels (control groups) by melatonin co-administration. Melatonin exerts these protection effects through mechanisms of anti-oxidant, anti-apoptosis, anti-inflammatory, and mitochondrial function. Conclusion: The results of this systematic review indicated that co-administration of melatonin ameliorates the doxorubicin-induced cardiotoxicity. © 2019 Elsevier Inc

Efficiency Evaluation of Nitrate Removal from Synthetic Solutions by Dendrimer- Graphene Oxide Nano-Composite Activated with HCl

High soluability of nitrate ions in water cause the dysfunction of many existing treatment methods in the removal of this very dangerous ion from aqueous media. On the other hand,  due to the need for in situ treatment methods, in particular for groundwater, the replacement of old inefficient methods with new compounds is required. In this study, for the first time, the efficiency of activated dendrimer- graphene oxide for nitrate removal from an aquatic solution was investigated. Experiments were performed in a batch reactor and the main factors of pH, reaction time, and concentration of PAMAM-GO were investigated. The highest removal efficiency was obtained as 90% at 0.025mg/L activated dendrimer- graphene oxide, pH of 7.5 and 15 min reaction time. The results showed that nitrate removal by activated dendrimer-graphene oxide is correlated with nanocomposite concentration, contact time, pH and initial concentration of nitrate. It seems that ion exchange between nitrate and chloride is the main mechanism of nitrate removal by activated dendrimer-graphene oxide according to functionalization of activated dendrimer-graphene oxide using hydrochloric acid. This method can be used as a suitable method for in situ removal of nitrate from water and wastewater due to the desirable ability of the nanocomposite and its optimal compatibility with the environment

Biological properties of Pegylated PLA (PLA-PEG-PLA) and its capability for intracellular delivery of poor soluble peptide drug, gramicidin

Poly lactic acid-co-poly ethylene glycol-co-Poly lactic acid (PLA-PEG-PLA) co-polymer was synthesized and after determination of its biological properties was used for intracellular delivery of poor soluble peptide drug, gramicidin. Toxicity of this polymer on LNCaP cell line was determined by MTT assay. Treatment of cells with fluorescein isothiocyanate (FITC) loaded nanoparticles and fluorescence microscopy indicates ability of this carrier for intracellular delivery. PLA-PEG-PLA nanoparticles containing poor soluble peptide drug, gramicidin, was prepared by solvent evaporation method. In order to confirm loading of gramicidin on PLA-PEG-PLA nanoparticles, FT-IR, spectrofluoremeteric, circular dichroism (CD), and scanning electron microscopy (SEM) studies were carried out. Our studies revealed treatment of prostate cancer cell line, LNCaP, with gramicidin loaded nanoparticles was more effective than gramicidin alone in killing cancer cells

Disruption of the redox balance with either oxidative or anti-oxidative overloading as a promising target for cancer therapy

Abstract Oxidative stress acts as a double edged sword by being both a promoter and a suppressor of cancer. Moderate oxidative stress is beneficial for cancer cell proliferative and invasiveness features, while overexposure of the cells to oxidative insults could induce cancer cell apoptosis and reduce hypoxia along with modulating the immune system for regression of tumor. Cancer cells and cancer stem cells have highly efficient redox systems that make them resistant to oxidative insults. The redox disruptive approach is an area of current research and key for oxidative targeted cancer therapies. This disruption is applicable by using either oxidative or anti oxidative overloading strategies, specifically on cancer cells without influencing normal cells or tissues around tumor. The activity of tumor suppressor cells within tumor microenvironment is needed to be maintained in patients receiving such approaches. KEYWORDS: cancer, oxidative stress, reactive oxygen species (ROS), redo