RESUMO
Although the programmed degradation of biocompatible films finds applications in various fields including biomedical and bionanotechnological areas, coating methods have generally been limited to be substrate-specific, not applicable to any kinds of substrates. In this paper, we report a dopamine derivative, which allows for both universal coating of various substrates and stimuli-responsive film degradation, inspired by mussel-adhesive proteins. Two dopamine moieties are linked together by the disulfide bond, the cleavage of which enables the programmed film degradation. Mechanistic analysis of the degradable films indicates that the initial cleavage of the disulfide linkage causes rapid uptake of water molecules, hydrating the films, which leads to rapid degradation. Our substrate-independent coating of degradable films provides an advanced tool for drug delivery systems, tissue engineering, and anti-fouling strategies.
Assuntos
Adesivos/química , Dissulfetos/química , Dopamina/química , Indóis/química , Nanotecnologia/métodos , Polímeros/química , Proteínas/química , Animais , Materiais Biocompatíveis/química , Bivalves , Soluções Tampão , Materiais Revestidos Biocompatíveis/química , Doxorrubicina/química , Sistemas de Liberação de Medicamentos , Glutationa/química , Levodopa/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Engenharia Tecidual/métodos , Água/químicaRESUMO
We report in-plane enyne metathesis and subsequent Diels-Alder reactions on self-assembled monolayers (SAMs) terminating in vinyl and acetylenyl groups on gold. After the formation of SAMs of vinyl and acetylenyl group-containing dithiols on gold, in-plane enyne metathesis of the vinyl and acetylenyl groups, leading to the formation of 1,3-diene, was achieved on the SAMs, and Diels-Alder reactions were then successfully performed with tetracyanoethylene, maleic anhydride, and maleimide. The reactions were confirmed by FT-IR spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary-ion mass spectrometry. In-plane enyne metathesis developed herein would offer a versatile platform for the functionalization of surfaces with mild reaction conditions and a high compatibility in functional groups.
RESUMO
In order to develop therapeutic agents against neurodegenerative diseases, we designed novel antioxidants containing N-t-butyl-N-hydroxylaminophenyl moieties and evaluated in vitro and in vivo neuroprotective properties as well as anti-ischemic effects.
