RESUMO
Rose bengal-grafted chitosan (RB-CHI), synthesized through dehydration between amino and carboxyl functional groups under mild conditions, was coated onto the outer layer of preformed biodegradable microcapsules consisting of sodium alginate and chitosan. The fabricated photosensitive microcapsules were characterized by optical microscopy, scanning electron microscopy, and confocal laser scanning microscopy. The assembled materials maintained intact spherical morphology and thus showed good ability to form thin films. Electron spin resonance spectroscopy allowed direct observation of the generation of singlet oxygen ((1)O(2)) from photosensitive microcapsules under light excitation at about 545 nm. Furthermore, with increasing light radiation, the content of (1)O(2) increased, as detected by a chemical probe. In vitro cellular toxicity assays showed that RB-CHI-coated photosensitive microcapsules exhibit good biocompatibility in darkness and high cytotoxicity after irradiation, and could provide new photoresponsive drug-delivery vehicles.
Assuntos
Alginatos/química , Neoplasias da Mama/química , Cápsulas , Quitosana/química , Nanotecnologia/métodos , Rosa Bengala/química , Oxigênio Singlete/química , Sistemas de Liberação de Medicamentos , Espectroscopia de Ressonância de Spin Eletrônica , Feminino , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Humanos , Microscopia Confocal , Microscopia Eletrônica de Varredura , Espectrofotometria InfravermelhoRESUMO
Fourteen solid coordination compounds of rare earth(Sm3+, Eu3+, Tb3+ and Dy3+ and Ln3+ (La3+, Gd3+ and Y3+)-doped Tb3+ with p-tert-butyl-calix[8] arene (LH8) have been synthesized and characterized. Elemental analysis, rare erth complexometry, 1H NMR spectra and TG-DTA have been studied. The results suggest that the complexes have the composition of [RE2 (LH2)(DMSO)5]DMSO, [RE2 (LH2) (DMF)5] 2DMF, [LnTb (LH2) (DMSO)5] DMSO and [LnTb (LH2) (DMF)5] 2DMF respectively. Fluorescence spectrum suggests that the Tb3+ complexes have characteristic luminescence, and its fluorescence intensity is enhanced after doping with La3+, Gd3+ and Y3+. The influence of the doping ions and two neutral ligands (DMSO and DMF) has also been discussed. In addition, the fluorescence lifetime of some complexes has been investigated.
