RESUMO
Contaminated soil has become a growing issue in recent years. The most common technique used to remove contaminants (such as metals) from the soil is the soil washing process. However, this process produces a final effluent containing chelating agents (i.e., ethylenediaminedisuccinic acid, also known as EDDS) and extracted metals (i.e., Cu, Fe, and Zn) at concentrations higher than discharge limits allowed by the Italian and Brazilian environmental law. Therefore, it is necessary to develop further treatments before its proper disposal or reuse. In the present study, soil washing tests were carried out through two sequential paths. Moreover, different artificial sunlight-driven photocatalytic treatments were used to remove Cu, Zn, Fe, and EDDS from soil washing effluents. Metal concentrations after the additional treatment were within the Brazilian and Italian regulatory limits for discharging in public sewers. The combined TiO2-photocatalytic processes applied were enough to decontaminate the effluents, allowing their reuse in soil washing treatment. Ecotoxicological assessment using different living organisms was carried out to assess the impact of the proposed two-step photocatalytic process on the effluent ecotoxicity. Graphical Abstract á .
Assuntos
Descontaminação/métodos , Processos Fotoquímicos , Poluentes do Solo/química , Poluentes do Solo/isolamento & purificação , Solo/química , Luz Solar , Catálise , Etilenodiaminas/química , Etilenodiaminas/isolamento & purificação , Etilenodiaminas/toxicidade , Metais Pesados/química , Metais Pesados/isolamento & purificação , Metais Pesados/toxicidade , Poluentes do Solo/toxicidade , Succinatos/química , Succinatos/isolamento & purificação , Succinatos/toxicidadeRESUMO
N, N, N', N'-tetramethylethylenediamine (TEMED) is extensively used for initiating polymerization of acrylamide and bisacrylamide gel for electrophoresis and for inorganic complex structure formation. The present study evaluates the toxicological effect of TEMED on structures of rat brain acetylcholinesterase (AChE) activity. In vitro study showed that the Ki values for striatum, cortex, cerebellum and hypothalamus were found to be 1.24, 1.4, 1.45 and 1.47 mM. Kinetics studies indicated that TEMED caused mixed type of inhibition that is a combination of competitive and noncompetitive inhibition in striatum, cortex, hypothalamus and cerebellum. The result showed that km increased and V max decreased with increase in TEMED concentration. The IC50 values calculated for striatum, cortex, cerebellum and hypothalamus were found to be as 0.92, 0.92, 1.44 and 1.42 mM. The present study indicates that TEMED is a toxicant for brain via inhibition of AChE. Therefore, proper precaution should be made during its handling.
Assuntos
Acetilcolinesterase/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Etilenodiaminas/toxicidade , Acetilcolinesterase/metabolismo , Animais , Encéfalo/enzimologia , Cerebelo/efeitos dos fármacos , Cerebelo/enzimologia , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/enzimologia , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/enzimologia , Relação Dose-Resposta a Droga , Feminino , Hipotálamo/efeitos dos fármacos , Hipotálamo/enzimologia , Concentração Inibidora 50 , Ratos , Ratos WistarRESUMO
Poloxamines (X-shaped poly(ethylene oxide)-poly(propylene oxide) (PEO-PPO) diblocks connected to a central ethylenediamine group) were N-methylated and N-allylated with the aim of widening their versatility as drug nanocarriers. The self-aggregation properties of various derivatives, covering a wide range of molecular weights and EO/PO ratios, were thoroughly investigated. The cytocompatibility of different modified poloxamines was compared to that of the pristine counterparts by MTT and LDH assays. The most hydrophilic varieties were highly cytocompatible even at concentrations of 5%. Toward the optimization of the oral pharmacotherapy of the Human Immunodeficiency Virus (HIV) infection in pediatric patients, the encapsulation and in vitro delivery of efavirenz (EFV), a lipophilic first-line antiretroviral drug, were evaluated. Pristine and N-alkylated poloxamines behaved as highly efficient EFV solubilizers enhancing the aqueous solubility of the drug between 166 and 7426-times. EFV promotes self-micellization of poloxamines; their tiny structural modification (i.e., just one methyl- or allyl-group) being able to regulate drug/micellar core interaction. Despite the physical stability of the micelles against dilution in physiological mimicking fluids, the N-alkylated derivatives were slightly more prone to disassembly promoting EFV release from the micellar reservoir. For all the derivatives evaluated, the in vitro release fitted zero-order kinetics and was sustained for at least 24 h. These findings point out N-alkylated poloxamines as promising nanocarriers for oral or parenteral drug delivery.