No abstract

No abstract

Background Chlorin e6 trisodium salt (Ce6) is a newly developed hydrophilic photosensitizer designed to mediate anticancer photodynamic therapy (PDT). The response of different cancer types and strategies to boost anticancer efficiency of Ce6-PDT are poorly studied. Objectives This study aimed to investigate the response of different cancer types to Ce6-PDT, identify the unresponsive ones, and develop a nanosystem for response enhancement. Methods Sk-Br-3, MCF-7, U87, and HF-5 cells were tested in 2D cell cultures. Ce6 uptake, PDT-mediated phototoxicity, ROS production, caspase 3/7 levels, and cell death mode were examined. Furthermore, U87 spheroids were treated with Ce6-PDT. Mesoporous silica nanoparticles (MSN) were synthesized and loaded with Ce6. Cellular uptake and phototoxicity of MSN-Ce6 were compared to free Ce6 in vitro and in vivo. Results Ce6 was detectable in the cell cytoplasm within 15 min. U87 cells showed the highest Ce6 cellular uptake. Upon Ce6-PDT, U87 cells were the most responsive ones with an 11-fold increase in ROS production. Here, 5 µM Ce6 and 4 J/cm2 were enough to reach IC50. Ce6-PDT induced both necrotic and caspase-dependent apoptotic cell death and 75% reduction of spheroids volume. Also, MCF-7 and HF-5 cells responded well to Ce6-PDT treatment. Sk-Br-3 breast cancer cells, on the other hand, were the least responsive ones with 80% viability after treatment (5 µM Ce6, 8 J/cm2). However, MSN-Ce6 conjugates increased Sk-Br-3 cellular uptake of Ce6 sevenfold decreasing the IC50 irradiation dose by an order of magnitude. In a very aggressive breast cancer rat model, MSN-Ce6-PDT treatment led to suppression of tumor volume by 50% and elevation of both Bax and caspase 3 by 90% compared to the control while the corresponding values for Ce6-PDT were 30% and 70%, respectively. Conclusion The newly developed hydrophilic chlorin and even more its MSN conjugate show high activities in anticancer PDT.

Cotton leaf worm, Spodoptera littoralis (Boisduval, 1833), is one of the most dangerous pests in Egypt, causing economically significant losses of different crops. The present study was aimed to evaluate toxicological, biological and biochemical effects of two nanocomposites, Silver (Ag) and graphene oxide (GO) nanomaterials over magnesium chlorophillin (Mg-Chl/Ag and Mg-Chl/GO) at three concentrations (1, 10, 100 ml/L) against 2nd instar larvae of S. littoralis. The results showed that larval mortality rate was positively correlated with the increase of concentrations of the tested nanocomposites and time after exposure. The mortality rate in nanographene oxide composite were higher than nano silver. LC50 (lethal concentration of 50% of a group of test larvae) values were 10.27 and 16.14 mg/L at Mg-Chl/Ag and Mg-Chl/GO compound at 2 h exposure to light. Some biological aspects of S. littoralis resulted from the treated 2nd instars larvae with two nanocomposites were recorded. Larval, pupal durations, pupation, adult emergence rate and pupal weight were significantly lower in all concentrations compared to untreated larvae. All tested samples showed decrease in total carbohydrates, total proteins and total lipids. Obtained results suggest that using silver and graphene oxide nanomaterials over the magnesium chlorophillin would be a useful component for controlling S. littoralis.

The application of polyurethane foam for the preconcentration of Cypermethrin, Malathion and Parathion insecticides was examined by the static mode of extraction. The retention of the tested species from aqueous media with the polyether polyurethane foam suggests that the solvent extraction and the cation chelation mechanism might be operative. Quantitative retention and recovery of the tested insecticides by the foam column mode of separation were carried out and satisfactory recovery percentages (up to 99.10±3.12%) were obtained. The number and the height equivalent of the theoretical plate of the foam columns were found in the range of 165 -170±4 and 1.85 -1.93±0.26 mm, respectively at 10 cm3/ min flow rate. Separation of the binary mixtures of Malathion-Cypermethrin and Parathion-Cypermethrin insecticides from the aqueous media was achieved successfully. The helical structure of the foam sorbents offfers rapid, versatile and effective separations and preconcentration of different compounds from fluid samples over conventional bulk-type granular sorbents. KeywordsPolyurethane foam, organophosphorous insecticide, pyrethroid insecticide, Parathion, MalathionAs a consequence of the activities of modern industries and agriculture many man-made pollutants have found their way into the environment, without the availability of much knowledge on their possible harmful effect on the environment. 1'2 The insecticides can enter water systems from agriculture land, direct entry from crop spraying, industrial and sewage effluent, dust and rain fall. The presence of these compounds in the aquatic environment has been known to cause severe health problems to animals and humans.3The most common reported extraction procedures for the removal or reduction of these pollutants are limited and are too expensive for routine analysis where many large volume samples are concentrated on site prior to quantitative analysis.4-9 The classical paper of Bowen1° and the pioneering studies of Braun and Farag11,12 on the application of polyurethane foam (PuF) sorbents to trace elements led to revealing the potentialities of their geometrical form: spherical membrane-shaped geometry in extraction chromatography. [10][11][12][13][14][15][16][17][18][19][20][21][22] In this paper, the extraction of some insecticides by polyether based polyurethane foam from large volume water samples is reported.The influence of various parameters on the retention of the tested species was carried out to determine whether the sorption on the polyurethane foams takes place by solvent extraction mechanism or by other mechanisms. ExperimentalReagents and materials All of the chemicals used were of analytical reagent grade. Open-cell polyether based polyurethane foam was supplied by Greiner K. G. Schaum (Stoffwerk, Kremsmunster, Austria). Foam cubes of approximately 1 cm3 were cut from a polyurethane foam sheet. The foam cubes were washed with HCl (10%v/v) and distilled water. The acid-free foam cubes were then washed with acetone in a Soxhlet extractor for 6 h and...