Study On Insulin Secretion, Ion Channel Activity And New Type Of Adsorption Materials

Diabetes is a chronic metabolic diseases induced by inadequate insulin secretionabsolutely or relatively, which results in the disorders of sugar, fats and proteinsdirectly and of vitamin, water and electrolyte metabolic secondary, and breaksoxidation balance. With the number of diabetic patients increasing and longevityextending of human, it has theoretical meaning and clinical value to study themechanism of chronic complications and find effective treatment. Insulin secretionand activity of volume-regulated anion channel (VRAC) have been studied.Mesoporous SBA-15 silica molecular sieves have high ordered channel structurewith large pore diameter and area and excellent thermal stability. Consequently, it canbe well controlled for adsorption/desorption processes. Recently, mesoporous silicamaterials as matrix, especially mesoporous SBA-15 silica molecular sieves, have beenmodified by different functional groups. The modified materials normally exhibitdifferent properties for a variety of applications. The thesis presented the preparation,characterization and application of C₈-SBA-15, C₁₈-SBA-15, p-tert-butyl-calix[4]arene-SBA-15 and magnetic Fe-SBA-15.1) The effects of different dosage water-soluble vitamins have been studied oninsulin secretion of pancreatic islets induced by different glucose concentration. In theconcentration range from 0.25 to 1μnmol/L, B₁ and B₆ had no effect on insulinrelease. Biotin and Pantothenic acid could stimulate insulin release induced at 16.7mmol/L glucose. Nicotinic acid stimulated insulin release at 16.7 mmol/L glucose.Folic acid, vitamin B₂, the mixture of B vitamins and vitamin C inhibited insulinrelease at 16.7 mmol/L glucose.2) The study of aspartate outflow from pancreatic islets is aim to assess relationshipbetween the activity of volume-regulated anion channels and insulin secretion frompancreatic islets. Aspartate outflow and insulin release decreased with VRAC blockerDCPIB. Aspartate outflow and insulin secretion decreased at high chlorideconcentration and increased at low chloride concentration. At high sucroseconcentration, aspartate outflow didn't change, and insulin secretion decreased. 3) The activity of volume-regulated anion channels has been studied viahepatocytes uptaking aspartate. At high chloride concentration, it stimulatedhepatocytes uptaking aspartate. It inhibited hepatocytes uptaking aspartate at 1μmol/LDCPIB.4) SBA-15 was modified octyl and octadecyl groups rapidly and effectively. Themodified alkyl SBA-15 was characterized by fourier transform infrared (FT-IR)spectroscopy, powder X-ray diffraction (XRD), nitrogen adsorption-desorptionmeasurements, scanning electron microscopy (SEM) and transmission electronmicroscopy (TEM). At last, dynamic adsorption experiments have studied theadsorption capacity of the modified materials to phthalate esters. The maximumdynamic adsorption capacity of C₈-SBA-15 and C₁₈-SBA-15 were 9.65, 10.52 mg/g,and were 3.9 and 4.3 times higher than SBA-15 particles for diethyl phthalate,respectively.5) p-tert-butyl-calix[4]arene-SBA-15 was prepared and characterized by FT-IR,XRD and nitrogen adsorption-desorption measurements and used adsorption fordiethylstilbestrol (DES) and bisphenol A (BPA) by dynamic adsorption experiments.The maximum dynamic adsorption capacity of p-tert-butyl-calix[4]arene-SBA-15were 71, 16 mg/g, and were 34.8 and 2.9 times higher than SBA-15 particles for DESand BPA, respectively.6) Magnetic Fe-SBA-15 was prepared via wet impregnation of iron ion, calcinationand reduction by hydrogen, characterized by FT-IR, XRD, nitrogenadsorption-desorption measurements, SEM, TEM, vibrating sample magnetometer(VSM), atomic absorption spectrometry (AAS) and X-ray photoelectron spectroscopy(XPS) and used for adsorption by magnetic separation. Analytical data for 5 mL watersolution with 1 ppm benzene, toluene, and ethyl benzene on 20 mg magneticFe-SBA-15 materials revealed removal of 90.6%, 88.7% and 85.4%, respectively.