RESUMEN
Graphene oxide (GO) nanosheets can be functionalized with reactive pentafluorophenyl ester via esterification of the carboxylic groups. The resulting reactive GO nanosheets provide a versatile platform for grafting of amino-containing polymers or biomolecules via ester-amine coupling. Coupling of poly[(9,9-dioctylfluorene)-alt-(4-amino-phenylcarbazole)] (PFCz-NH(2) ), amino-terminated hyperbranched polyglycerol (HPG-NH(2) ), and lysozyme (Lyz) was illustrated. The Al/GO-g-PFCz/ITO sandwich thin-film device exhibits bistable electrical switching and rewritable memory effects. The GO-g-Lyz nanohybrids exhibit high bactericidal efficacy against S. aureus and E. coli, while the GO-g-HPG nanohybrids exhibit reduced cytotoxicity toward 3T3 fibroblasts.
Asunto(s)
Antibacterianos/química , Materiales Biocompatibles/química , Grafito/química , Nanoestructuras/química , Óxidos/química , Polímeros/química , Animales , Antibacterianos/farmacología , Materiales Biocompatibles/farmacología , Escherichia coli/efectos de los fármacos , Grafito/farmacología , Ratones , Células 3T3 NIH , Óxidos/farmacología , Polímeros/farmacología , Staphylococcus aureus/efectos de los fármacosRESUMEN
Here, we are the first to report a novel approach to preparing well-defined poly(ethylene glycol) (PEG) fluorescent nanogels, with well-defined molecular structures and desired functionalities via reverse (mini)emulsion copper(I)-catalyzed azide-alkyne cycloaddition (REM-CuAAC). Nanogels with hydroxyl groups and Ga-porphyrin complex (Ga-porphyrin-OH nanogels), as well as with Ga-porphyrin complex and folate functional groups (Ga-porphyrin-FA), are successfully prepared. Nanogels of 30 and 120 nm in diameter are obtained and they exhibit an emission maxima within the wavelength range 700-800 nm. The nanogels could find uses in near infrared (NIR) imaging attributable to their fluorescence and their functionality for cell affinity.
Asunto(s)
Química Clic/métodos , Compuestos Organometálicos/química , Polietilenglicoles/síntesis química , Polietileneimina/síntesis química , Polímeros/síntesis química , Porfirinas/química , Emulsiones/química , Fluorescencia , Estructura Molecular , Nanogeles , Tamaño de la Partícula , Polietilenglicoles/química , Polietileneimina/química , Polímeros/químicaRESUMEN
Coatings based on thin films of agarose-poly(ethylene glycol) (Agr-PEG) cross-linked systems are developed as environmentally-friendly and fouling-resistant marine coatings. The Agr-PEG cross-linked systems were prepared via thermal azide-alkyne cycloaddition (AAC) using azido-functionalized Agr (AgrAz) and activated alkynyl-containing poly(2-propiolamidoethyl methacrylate-co-poly(ethylene glycol)methyl ether methacrylate) P(PEMA-co-PEGMEMA) random copolymers as the precursors. The Agr-PEG cross-linked systems were further deposited onto a SS surface, pre-functionalized with an alkynyl-containing biomimetic anchor, dopamine propiolamide, to form a thin film after thermal treatment. The thin film-coated SS surfaces can effectively reduce the adhesion of marine algae and the settlement of barnacle cyprids. Upon covalent cross-linking, the covalently cross-linked Agr-PEG films coated SS surfaces exhibit good stability in flowing artificial seawater, and enhanced resistance to the settlement of barnacle cyprids, in comparison to that of the surfaces coated with physically cross-linked AgrAz films.
Asunto(s)
Alquinos/química , Azidas/química , Polietilenglicoles/química , Sefarosa/química , Acero Inoxidable/química , Adsorción/efectos de los fármacos , Animales , Incrustaciones Biológicas/prevención & control , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Reactivos de Enlaces Cruzados/química , Reacción de Cicloadición , Metacrilatos/química , Microalgas/química , Microscopía Electrónica de Rastreo , Microscopía Fluorescente , Polímeros/química , Polímeros/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie , Temperatura , Thoracica/químicaRESUMEN
This feature article provides an overview of the preparation of functional nanofibers by combined electrospinning, controlled radical polymerization and 'Click Chemistry'. A combination of the powerful capability of controlled radical polymerization and 'Click Chemistry' for the synthesis of functional macromolecules and on surface modification as well as their wide applicability to electrospinning materials, functional nanofibers with a crosslinked structure, core-shell structures, and switchable surface properties etc. were prepared. In addition, the applications of the functional nanofibers in antibacterial fields and controlled release are also explored.
Asunto(s)
Nanofibras/química , Polímeros/química , Antibacterianos/química , Antibacterianos/farmacología , Compuestos Azo/química , Química Clic , Ciclodextrinas/química , Nanofibras/ultraestructura , Propiedades de SuperficieRESUMEN
Electrospinning has been recognized as a feasible process for fabrication of continuous fibers with diameters ranging from several micrometers down to a few nanometers. This article presents an overview of recent progress in functional polymeric nanofibers prepared by electrospinning. Except of functional nanofibers fabricated from electrospinning of functional polymers, nanofibers from a combined technology such as coaxial electrospinning, electrospinning with living radical polymerization, and electrospinning with surface modification, would also be introduced in this review. Furthermore, the functionality and application of nanofibers would also be highlighted.