Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Mais filtros

Base de dados
Intervalo de ano de publicação
J Mater Chem B ; 9(48): 9961-9970, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34870667


Bacterial infection has increasingly affected people's lives, therefore it is significant to explore novel antibacterial agents and strategies for efficient disinfection. Herein, we designed ZIF-8 based composites ICG@ZIF-8/PDA/Ag, which encapsulate photothermal agent indocyanine green (ICG) and grow polydopamine (PDA) on their surface for in situ reduction to generate Ag nanoparticles. With 20 min of 808 nm laser irradiation at 1.5 W cm-2, 100 µg mL-1 ICG@ZIF-8/PDA/Ag exhibited 100% bactericidal effects toward E. coli and S. aureus bacteria resulting from both hyperthermia of ICG and PDA and chemical toxicity of the released Ag and Zn ions. When the bacterial incubation period was extended to 12 h, the minimum bactericidal concentration (MBC) of ICG@ZIF-8/PDA/Ag was reduced to 6.25 µg mL-1, and this extremely low MBC was due to the long-term chemo-photothermal combinational effect induced by NIR irradiation. Additionally, the composites successfully promote the healing of S. aureus infected wounds on mice. This work constructed photo-responsive antibacterial composites that realize chemo-photothermal synergistic therapy.

Antibacterianos/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/síntese química , Antibacterianos/química , Relação Dose-Resposta a Droga , Verde de Indocianina/química , Verde de Indocianina/farmacologia , Indóis/química , Indóis/farmacologia , Raios Infravermelhos , Teste de Materiais , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Polímeros/química , Polímeros/farmacologia , Prata/química , Prata/farmacologia , Zeolitas/química , Zeolitas/farmacologia
ACS Omega ; 6(39): 25720-25728, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34632228


In this work, we demonstrated a facile approach for fabrication of Au nanoflowers (Au NFs) using an amino-containing organosilane, 3-aminopropyltriethoxysilane (APTES), as a shape-directing agent. In this approach, the morphology of the Au particles evolved from sphere-like to flower-like with increasing the concentration of APTES, accompanied by a red shift in the localized surface plasmon resonance peak from 520 to 685 nm. It was identified that the addition of APTES is profitable to direct the preferential growth of the (111) plane of face-centered cubic gold and promote the formation of anisotropic Au NFs. The as-prepared Au NFs, with APTES on their surface, presented effective catalytic and surface-enhanced Raman scattering (SERS) performances, as evidenced by their applications in catalyzing the dimerization of p-aminothiophenol and monitoring the reaction process via in situ SERS analysis.

ACS Appl Bio Mater ; 3(12): 9109-9116, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-35019588


Abnormal concentrations of glutathione (GSH) are important indicators of many human diseases such as cancers, liver damage, AIDS, and Alzheimer's disease. In this work, a kind of bovine serum albumin (BSA)@Au core-shell particles were fabricated using 110 nm BSA aggregates as a template, onto which gold shells composed of Au nanoparticles (NPs) were grown through a seeded growth approach. The morphology of the Au shells deposited on BSA aggregates was tuned from sparse to dense distribution of Au NPs by increasing the concentration of silver ions contained in the growth solutions. Surface plasmon resonance (SPR) peaks of BSA@Au particles were tunable in the range from 550 to 620 nm, corresponding to evolution in color from red to blue due to the enhanced plasmonic coupling among the Au NPs in the shell. The blue BSA@Au particles were qualified for colorimetric detection of GSH since GSH may act as a swelling agent for BSA@Au particles by breaking the intermolecular disulfide bonds in BSA aggregates. With an increased amount of GSH presented, the color of BSA@Au particles evolved from blue to red attributed to gradual swelling of BSA@Au particles and thus increased the distance among the Au NPs in the shell, which was readily recognized by naked eyes or recorded by ultraviolet-visible (UV-vis) spectroscopy. This colorimetric method exhibited good selectivity and anti-interference capability in the analysis of GSH in real samples. In addition, a solid sensing system for the detection of GSH was designed and fabricated by dispersing BSA@Au particles into an agarose hydrogel.

RSC Adv ; 9(48): 28228-28233, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-35530466


In this work, we demonstrated a facile, one-pot approach for preparation of gold nanoflowers by using tetrachloroauric acid as a gold precursor, ascorbic acid as a reductant, and bovine serum albumin (BSA) as a ligand. It was found that the morphology of the as-prepared gold nanoparticles (Au NPs) was dependent on the concentration of BSA introduced into the reaction solutions. It is identified that BSA directed the preferential growth along the 〈111〉 direction, which contributed to the anisotropic growth of Au NPs and thus the formation of Au nanoflowers. An increased concentration of BSA reduced the reactivity of the gold precursor, leading to the formation of Au nanoflowers with increased size, which could also be obtained by decreasing the amount of reductant added. The Au nanoflowers were ultra-stable in the presence of chloride ions under acidic pH, making them suitable for selective detection of oppositely charged dyes via surface-enhanced Raman scattering according to the isoelectric point (∼4.7) of BSA capped on their surface.

Langmuir ; 33(23): 5879-5890, 2017 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-28514596


In this work, we investigated the kinetic balance between ammonia-catalyzed hydrolysis of tetraethyl orthosilicate (TEOS) and subsequent condensation over the growth of silica particles in the Stöber method. Our results reveal that, at the initial stage, the reaction is dictated by TEOS hydrolysis to form silanol monomers, which is denoted as pathway I and is responsible for nucleation and growth of small silica particles via condensation of neighboring silanol monomers and siloxane network clusters derived thereafter. Afterward, the reaction is dictated by condensation of newly formed silanol monomers onto the earlier formed silica particles, which is denoted as pathway II and is responsible for the enlargement in size of silica particles. When TEOS hydrolysis is significantly promoted, either at high ammonia concentration (≥0.95 M) or at low ammonia concentration in the presence of LiOH as secondary catalyst, temporal separation of pathways I and II makes the Stöber method reminiscent of in situ seeded growth. This knowledge advance enables us not only to reconcile the most prevailing aggregation-only and monomer-addition models in literature into one consistent framework to interpret the Stöber process but also to grow monodisperse silica particles with sizes in the range 15-230 nm simply but precisely regulated by the ammonia concentration with the aid of LiOH.