RESUMO
Cancer is one of the most important issues in modern medicine and the most common cause of death after cardiovascular diseases in many countries. Brain cancer is one of the most common causes of cancer death among men and women, ranking third. Chemotherapeutic drugs that aim to prevent uncontrolled proliferation of cells in tissues of the body and induce apoptosis of tumor cells are prominent candidates for development. Since cisplatin has an apoptosisinducing role, it is widely used as an anticancer agent. In this research, toxicity of cisplatin was studied with the C6 rat glioma cell lined using the MTT method. In addition, nanoparticles underwent SEM microscopic imaging. Particle average size, size distribution, polydispersity index (PDI) and zeta potential of poly butyl cyanoacrylate nanoparticles were found to be 222 nm, 0.470 ± 0.04 and 5.1 ± 0.2 mV, respectively. The results showed that nanoconjugates of cisplatin have more cytotoxic effects on C6 cells than the free drug (P<0.05), pointing to an enhanced potential of the synthesized nano-particles as a new nanocarrier for chemotherapy.
RESUMO
The interaction of proteins with glucose results in their non-enzymatic glycation and influences their structural and functional properties. Human serum albumin (HSA) interacts with glucose forming glycated HSA. However, the glucose binding sites and the thermodynamic characteristics of the glycated HSA require further delineation. Here, the binding properties of HSA and glucose were studied utilizing fluorescent techniques. HSA was incubated with glucose in the 0-300mM range at 27 or 37 degrees C. The interaction of HSA with glucose showed two sets of binding sites. The first set consists of two sites with positive cooperativity and the second set consists of nine identical non-cooperative sites. The percentage of glycated HSA (gly%) and the moles of glucose bound to moles of HSA (r) were utilized to obtain binding constants and thermodynamic parameters based on the Wyman binding potential. The enthalpy of binding, obtained by van't Hoff relation, presented exothermicity up to 7mM glucose (126mg/dl, normal range) and endothermic propensity at higher glucose concentrations (>7mM, diabetic range). The start of endothermic propensity was consistent with the diabetic range of glucose concentration and indicates unfolding of HSA. The Gibbs free energy and entropy of binding further supports the unfolding of HSA. Therefore, glucose interacts with multiple sites on HSA affecting its biochemical and biophysical properties. This may interfere with HSA normal function contributing to diabetic complications.
