RESUMO
In the present study, magnetic glass ceramics in the system Fe2O3 â TiO2 â P2O5 â SiO2 â MO (M=Mg, Ca, Mn, Cu, Zn or Ce) are prepared. The effect of adding different cations on the thermal behavior, developed phases, microstructure and magnetic properties is studied using differental thermal analysis (DTA), X-ray diffraction analysis (XRD), transmission electron microscope (TEM), FT-infrared transmission (FT-IR) and vibrating sample magnetometer (VSM) respectively. The magnetic glass ceramics are tested as delivery systems for 5-fluorouracil. Modeling and analysis of release kinetics are addressed. The application of Higuchi square root of time model and the first order release model indicated that, 5-FU is released by diffusion controlled mechanisms, and that its released rate depends greatly on the concentration of loaded drug during the loading stage. The obtained results suggested that, the prepared magnetic glass ceramics can be used for cancer treatment by hyperthermia and/or by localized delivery of therapeutic doses of 5-fluorouracil.
Assuntos
Cerâmica/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Fluoruracila/química , Magnetismo , Materiais Biocompatíveis , Cristalização , Compostos Férricos/química , Fluoruracila/farmacologia , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Compostos de Fósforo/química , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Titânio/química , Difração de Raios XRESUMO
The liver plays a major role in urea and glutamine metabolism where it maintains ammonia and bicarbonate homeostasis under physiological and pathological conditions. Glutamine assessment in different liver diseases showed deviations from normal serum values. In the present study, glutamine level in serum [serum glutamate values] (SGV) and liver tissue homogenates (liver homogenate glutamine values] (LHGV) in patients with schistosomal hepatic fibrosis with and without conventional supportive medical therapy and anti-schistosomal therapy were correlated. LHGV in liver tissue homogenates from cases were higher than those of matched controls. SGV of patients with late hepatic schistosomiasis were greater than those with early stages of the disease. All patients, whether in early or late schistosomal hepatic fibrosis, showed reduction of SGV after treatment. We came to the conclusion that in patients with schistosomal hepatic fibrosis, whether early or late, there is a derangement of glutamine metabolism which could be corrected partially by the conventional supportive medical therapy. Again, estimation of glutamine in serum could be considered an early and reliable parameter for the assessment of liver function in patients with schistosomal hepatic fibrosis.