RÉSUMÉ
UiO-66 (University of Oslo 66) is a kind of promising material that can improve the release and bioavailability of poorly water-soluble bioactive compounds of traditional Chinese medicine. However, the loading of quercetin in raw UiO-66 was not ideal. In this study, UiO-66-BH (UiO-66-blend-heating) was obtained by heating UiO-66 and KOH solution following blended them. UiO-66-BH maintained the outline of octahedral structure of UiO-66 but with obvious rough and uneven pores on the surface. UiO-66-BH had good adsorption of quercetin with saturation adsorption was 138.92 mg·g-1, the adsorption process belonged to single molecular layer adsorption and was controlled by chemisorption. UiO-66-BH can control the release of quercetin in simulated gastrointestinal fluid, and the drug concentration was significantly higher than that of free quercetin after long-term release (36% vs 9%). Compared with quercetin, the ABTS (2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt) radical scavenging activity of UiO-66-BH@quercetin drug delivery system decreased, while the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity remained almost unchanged. The drug delivery system showed a strong antioxidant effect similar to quercetin. The findings indicated that UiO-66-BH could control release of quercetin and was expected to be used as a drug carrier material for some insoluble active components of traditional Chinese medicine such as quercetin.
RÉSUMÉ
A magnetic metal organic framework (MMOF) was synthesized and used to separate Sr2+ in aqueous solution. The shape and structure of prepared Fe3O4@UiO-66-NH2 were characterized, and the absorbed concentration of strontium was determined through inductively coupled plasma mass spectrometry. The results indicated that Fe3O4 and UiO-66-NH2 combined through chemical bonding. The experimental adsorption results for separation of Sr2+ in aqueous solution indicated that the adsorption of Sr2+ to Fe3O4@UiO-66-NH2 increased drastically from pH 11 to pH 13. The adsorption isotherm model indicated that the adsorption of Sr2+ conformed to the Freundlich isotherm model (R2 = 0.9919). The MMOF thus inherited the superior qualities of magnetic composites and metal organic frameworks, and can easily be separated under an external magnetic field. This MMOF thus has potential applications as a magnetic adsorbent for low level radionuclide 90Sr.