Antiproliferative and Antimigratory Activity of Poly-gallic Acid in Cancer Cell Lines.

BACKGROUND/AIM: Enzyme-mediated grafting of poly (gallic acid) (PGAL) and L-arginine and a-L-lysine onto PGAL produces reactive oxygen species (ROS)-suppressor multiradical molecules with low cytotoxicity, high thermostability and water solubility with cancer treatment potential. This study examined the anticancer effects of these molecules in hepatic (HepG2, ATCC HB-8065), breast (MCF7, ATCC HTB-22), and prostate (PC-3, ATCC CRL-1435 and DU 145, ATCC HTB-81) cancer cell lines, as well as in fibroblasts from healthy human skin as control cells. MATERIALS AND METHODS: PGAL was synthesized by the oxidative polymerization of the naturally abundant GA using laccase from Trametes versicolor. Insertions of amino acids L-arginine and α-L-lysine on the PGAL chain were carried out by microwave. The cells of dermal fibroblast (Fb) were obtained from primary skin cultures and isolated from skin biopsies. The cancer cells lines of hepatic (HepG2), breast (MCF7), and prostate (PC-3, DU 145) were obtained from ATCC. The viability of the cancer cells and the primary culture was obtained by the MTT assay. Proliferation was demonstrated by crystal violet assay. Cell migration was determined by Wound healing assay. Finally, cell cycle analysis was carried out with cells. RESULTS: The results show that 200 µg/ml of PGAL cultured in vitro with prostate cancer cells decreased viability, proliferation, and migration, as well as arrested cells in the G1 and S phases of the cell cycle. In contrast, the dermal fibroblasts and the hepatic line remained unaffected. The random grafting of L-Arg and a-L-Lys onto the PGAL chain also decreased the viability of prostate cancer cells. CONCLUSION: PGAL and PGAL-grafted amino acids are potential adjuvants for prostate cancer treatment, with improved physicochemical characteristics compared to GA.

Ibuprofen removal by a microfiltration membrane bioreactor during the startup phase.

The behavior of ibuprofen (IBU) during the startup phase of a microfiltration membrane bioreactor (MBR) was determined. A full-scale experimental installation treating real urban wastewater was used for the study. The MBR was composed of an anoxic and an aerobic bioreactors working in pre-denitrification configuration, followed of a membrane reactor. A full mass balance was carried out to estimate the contribution of biotransformation and sorption to biomass to the overall removal of the IBU. During the startup phase of the MBR system there were significant oscillations of the operational variables, mainly of the sludge retention time (SRT); nevertheless, the capacity of the system for IBU removal was very high, with yields of over 94%, despite reaching minimum SRT values of 4.15 d. The main IBU removal occurs in the aerobic reactor, both in the liquid phase and the one associated with the sludge, while in the anoxic bioreactor the removal was scarce, although a certain transfer of IBU from the liquid phase to the sludge took place under anoxic conditions. Despite the high IBU removal yields during startup, the SRT was the most influential variable in IBU removal, an effect observed in all bioreactors, particularly in the anoxic one.

Carbamazepine behaviour and effects in an urban wastewater MBR working with high sludge and hydraulic retention time.

The behaviour and fate of carbamazepine (CBZ) in urban wastewater treatment by a membrane bioreactor (MBR) and its possible effects on the system's efficiency, and on mixed microbial communities, has been studied. The experimental microfiltration MBR system, with capacity to treat 10.8 m(3) d(-1) of urban wastewater, operated with a pre-denitrification configuration with high sludge and hydraulic retention time. The CBZ concentration assayed was higher than in the usual urban wastewater, in order to provoke a strong biomass reaction. Influent, effluent, and all bioreactors of the MBR system were analysed in order to calculate a CBZ balance. Bench-scale experiments and respirometric analyses were performed, with and without the presence of CBZ, to evaluate its influence on the bacterial activity. The respirometric assays showed variations in the oxygen uptake rate (OUR) in the presence of CBZ. Negative effects were detected in the MBR bacterial community during the initial period of dosing. However, the effects were not permanent and the biomass spiked with CBZ had behaviour similar to that of the biomass without CBZ after a few hours. Biodegradation was not detected during the MBR treatment. The system showed an inefficient elimination of CBZ (less than 10%) with a high concentration in the effluent. The small percentage of CBZ removal was associated with the sludge retention and eliminated by the purge. All CBZ present in the influent was accounted for, and even an increase in the total amount of CBZ was registered in the permeate. During and after the experimental process, CBZ did not significantly affect the efficiency of the MBR system, and the quality of the effluent was not affected by the dosing of CBZ in terms of COD and nitrogen removal.

Removal of low concentrations of phenanthrene, fluoranthene and pyrene from urban wastewater by membrane bioreactors technology.

The fate and removal of phenanthrene (Phen), fluoranthene (F) and pyrene (Py) in urban wastewater treatment by membrane bioreactor (MBR) with low influent polycyclic aromatic hydrocarbons (PAHs) concentration were studied. A full experimental ultrafiltration MBR with a pre-denitrification configuration and capacity to treat 20 m(3)/d was employed. The system was operated with real urban wastewater, to which a concentration of PAHs was added. A constant purge was achieved in order to obtain 12 d of sludge retention time and the hydraulic retention time was 34 h. Concentration of PAHs was determined by Gas Chromatography and Mass Spectrometry with Twister, and mass balance on the MBR system were calculated. Data were supplemented by respirometric analyses, isolation of PAHs degrading microorganisms and bench-scale experiments. All effluent samples presented concentrations of PAHs, with removal levels of 91% and 92% for F and Py respectively, while for Phen performance did not surpass 82%. In spite of the high hydrophobicity of the tested compounds, their accumulation in the biomass was scarce and the sludge presented a low PAH concentration. The experiments reveal that PAHs removal is mainly due to air stripping, with biodegradation and adsorption making an insignificant contribution.