Cytotoxic effects caused by N,N-diethyl-meta-toluamide and radiation in Perna perna mussels

The aim of this study was to evaluate the biological effects of ionizing radiation in combination with DEET on marine aquatic biota. It was studied the exposure of irradiated and non-irradiated marine mussels to different concentrations of DEET. It was compared the recoverability of mussels which were exposed to DEET after suffering another stressful action by the ionizing radiation. The cytotoxicity by the neutral red retention time assay was used to verify the DEET effect on the lysosomal membrane of Perna perna mussels hemocytes in non-irradiated and irradiated organisms. The organisms were irradiated at 3, 11 and 107 Gy doses of 60Co gamma rays and exposed to 0.1; 1.0 and 20.0 μg L-1 DEET. The results were obtained 24, 48 and 72h after irradiation. It was observed statistic significance at concentrations of 1.0 and 20.0 μg L-1 in non-irradiated mussels for all exposure times. In mussels irradiated with 3 Gy and 11 Gy it was observed that the retention time was not significantly different from trials in which the organisms were not irradiated. The 107 Gy dose caused some adverse effects to organisms showing a significant reduction in the number of cells compared with the other doses. The present study showed cytotoxic effect of DEET to Perna perna mussels at concentrations above 0.1 μg L-1 a value very close to the concentrations identified in the environment suggesting attention to this concentration range

Evaluation of resveratrol toxicity in the embryolarval stage of Danio rerio fish

Human beings concern about healthy life has driven researchers to study new compounds capable of reaching that desire. Resveratrol (3, 4 ‘, 5-trihydroxystilbene) a phenolic compound, is one of these substances which presents a variety of pharmacological actions, as antioxidant potential, anti-inflammatory capacity, protection against heart and cancer diseases. Despite the resveratrol health benefits studies, there is a little evidence of its toxicity in the literature in aquatic organisms, and especially the data on the concentration of resveratrol in the environment, making the present study fundamental for information about resveratrol ecotoxicity in the aquatic system. The aim of this study was to evaluate the toxicity of resveratrol in embryos and larvae of Danio rerio (zebrafish). The in vitro cytotoxicity and ecotoxicity assays were performed. The IC50 obtained in the NCTC-L929 cell line cytotoxicity assay was 38.5 mg L-1. The LC50 (96h) obtained in fish embryo toxicity test was 75.3 mg L-1 and the mean value of resveratrol LC50 (168h) obtained in the short-term chronic ecotoxicity assays performed with zebrafish larvae was 51.4 mg L-1. This work provided data on the toxicity of resveratrol in the embryonic stage of fish of the species Danio rerio and the toxic effects are dependent on its concentration

Resveratrol and radiation biological effects

Resveratrol is a phytoalexin, a phenolic compound present in wines and several plants. This compound is related to a broad spectrum of biological activities such as antioxidant and anticarcinogenic effects that are very important in prevention of cancer, cardiovascular diseases and other diseases caused by oxidative processes. Over the last years, biological effects of ionizing radiation in the presence of resveratrol have been studied in different cell cultures. The aim of this study was to verify the effect of gamma radiation on mouse connective tissue cells (NCTC clone 929) in culture in the presence of trans-resveratrol. Cell viabilities were analyzed by neutral red uptake assay. The results demonstrated in vitro the radioprotective effect of trans-resveratrol on cell culture and it was more pronounced when cell culture was irradiated at 500-800 Gy doses in the presence of resveratrol concentrations between 12.5 and 25 μM. These results provide evidence that trans-resveratrol alters the cellular response to ionizing radiation, expanding the knowledge of resveratrol biological properties in physiological and pathological processes, contributing to the development of future studies about the possibility of including resveratrol and its derivatives in dietary supplements given to cancer patients during radiotherapy

Characterization of PVDF/HAP composites for medical applications

Biomaterials (composites and blends) play a major role in the health of modern society. This paper reports on the preparation and characterization of polyvinylidene fluoride (PVDF) and hydroxyapatite (HAP) composites, analyzing the incorporation of HAP in PVDF and investigating their mechanical properties and cytotoxicity (biocompatibility) for use in bone restoration and filling. The material was prepared in film form by the casting method. PVDF pellets were dissolved in dimethylacetamide (DMA), a HAP/DMA emulsion was prepared. The materials were mixed in proportions of 100/00, 90/10, 80/20, 70/30, 60/40, 50/50, 40/60, 30/70 in weight and left to dry in an oven, resulting in homogeneous, flexible films which were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X ray diffractometry (XRD), contact angle measurement, and by mechanical and cytotoxicity tests.247251Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Avaliação da biocompatibilidade de vidro e vitrocerâmica do sistema SNCP (SiO2-Na2O-CaO-P2O5)

This article reports research results related to bioactivity and cytotoxicity tests using neutral red uptake method for glass powders and bulk glass ceramics belonging to the SNCP (SiO2-Na2O-CaO-P2O5) system. The obtained materials showed bioactivity when immersed in SBF promoting the surface deposition of HAp. When analyzed as powders, cytotoxicity was evidenced in the processed materials but not when bulk samples were tested

Cytotoxicity evaluation of Amoxicillin and Potassium Clavulanate in Perna perna mussels

Pharmaceutical compounds are identified in environmental matrices in the order of magnitude of ng L-1 to μg L-1. Among the drugs, antibiotics have been receiving special attention due to the problems caused to aquatic biota. The aim of this study was to evaluate the cytotoxicity of Amoxicillin and Potassium Clavulanate, in isolated and associated forms, to marine mussels Perna perna through neutral red retention time assay (NRRT), which assesses the stability of lisossomal membrane of test-organisms hemocytes. Amoxicillin caused cytotoxicity to the mussels in concentrations of OEC= 1 ng L-1, IC25-24h= 0.44 ng L-1, IC25-48h= 1.19 ng L-1 and IC25-72h= 0.85 ng L-1, Potassium Clavulanate was cytotoxic at concentrations of OEC= 10 ngL-1 in 24h; 50 ng L-1 and 100 ng L-1 at 48h and 72h. The inhibitory concentration values (IC25) were: 3.11 ng L-1, 3.45 ng L-1 and 3.43 ng L-1 at 24h, 48h and 72h respectively. In the test conducted with the combination of drugs, all concentrations were cytotoxic to mussels in 48h. In 72h only 40 ng L-1 Amoxicillin + 10 ng L-1 Potassium Clavulanate and 200 ng L-1 Amoxicillin + 50 ng L-1 Potassium Clavulanate were cytotoxic. The IC25 for Amoxicillin was 1.67 ng L-1 in 48h and 1.36 ng L-1 in 72h. For Potassium Clavulanate was 0.42 ng L-1 in 48h and in 72h was 0.34 ng L-1

Processamento e caracterização de espumas vitrocerâmicas do sistema sncp (Sio2-Na2o-Cao-P2 O5) Processing and characterization of sncp (Sio2-Na2o-Cao-P2o5) glass-ceramic foams

<abstract language="eng">Glass-ceramics foams prepared from glasses of the SiO2-Na2O-CaO-P2O5 by replication process were obtained and characterized in terms of their chemical and physical properties by X-ray fluorescence, X-ray diffraction, laser diffraction, thermal analysis, density, mechanical strength, microstructural and cytotoxic analysis. The results showed that it is possible to produce glass-ceramic foams by the replication method with optimized properties but cytotoxic analysis indicates that the glass-ceramic foams are not bioactive materials. Mechanical strength values varying from 0.5 to 1.0 MPa and from 0.8 to 2.3 MPa were reached for mean particle sizes of 10 and 6 µm, respectively

Influence of gamma radiation onto polymeric matrix with papain

Papain is a proteolytic enzyme that has been widely used as debridement agent for scars and wound healing treatment. However, papain presents low stability, which limits its use to extemporaneous or short shelf-life formulations. The purpose of this study was to entrap papain into a polymeric matrix in order to obtain a drug delivery system that could be used as medical device. Since these systems must be sterile, gamma radiation is an interesting option and presents advantages in relation to conventional agents: no radioactive residues are formed: the product can be sterilized inside the final packaging and has an excellent reliability. The normative reference for the establishment of the sterilizing dose determines 25 kGy as the inactivation dose for viable microorganisms. A silicone dispersion was selected to prepare membranes containing 2% (w/w) papain. Irradiated and non-irradiated membranes were simultaneously assessed in order to verify whether gamma radiation interferes with the drug-releasing profile. Results showed that irradiation does not affect significantly papain release and its activity. Therefore papain shows radioresistance in the irradiation conditions applied. In conclusion, gamma radiation can be easily used as sterilizing agent without affecting the papain release profile and its activity onto the biocompatible device is studied. (C) 2009 Elsevier Ltd. All rights reserved

Characterization of PVDF/HAP composites for medical applications

Biomaterials (composites and blends) play a major role in the health of modern society. This paper reports on the preparation and characterization of polyvinylidene fluoride (PVDF) and hydroxyapatite (HAP) composites, analyzing the incorporation of HAP in PVDF and investigating their mechanical properties and cytotoxicity (biocompatibility) for use in bone restoration and filling. The material was prepared in film form by the casting method. PVDF pellets were dissolved in dimethylacetamide (DMA), a HAP/DMA emulsion was prepared. The materials were mixed in proportions of 100/00, 90/10, 80/20, 70/30, 60/40, 50/50, 40/60, 30/70 in weight and left to dry in an oven, resulting in homogeneous, flexible films which were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X ray diffractometry (XRD), contact angle measurement, and by mechanical and cytotoxicity tests.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq