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1.
Angew Chem Int Ed Engl ; 58(30): 10260-10265, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31145525

RESUMO

Fluorescent polymersomes with both aggregation-induced emission (AIE) and CO2 -responsive properties were developed from amphiphilic block copolymer PEG-b-P(DEAEMA-co-TPEMA) in which the hydrophobic block was a copolymer made of tetraphenylethene functionalized methacrylate (TPEMA) and 2-(diethylamino)ethyl methacrylate (DEAEMA) with unspecified sequence arrangement. Four block copolymers with different DEAEMA/TPEMA and hydrophilic/hydrophobic ratios were synthesized, and bright AIE polymersomes were prepared by nanoprecipitation in THF/water and dioxane/water systems. Polymersomes of PEG45 -b-P(DEAEMA36 -co-TPEMA6 ) were chosen to study the CO2 -responsive property. Upon CO2 bubbling vesicles transformed to small spherical micelles, and upon Ar bubbling micelles returned to vesicles with the presence of a few intermediate morphologies. These polymersomes might have promising applications as sensors, nanoreactors, or controlled release systems.

2.
Fitoterapia ; 128: 20-25, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29723562

RESUMO

Five new amide alkaloids (1-3, 5-6) were isolated from the seeds of Clausena lansium together with one new natural product (4) and four known analogues (7-10). The structures of the new amide alkaloids were elucidated based on a comprehensive spectroscopic data analysis including 1D and 2D NMR as well as HRESIMS, and by comparison with the literature. The bioactivity results showed that compound 8 expressed potent nematicidal activity against Panagrellus redivevus, with IC50 value of 0.12 mM, while compounds 3 and 5 presented moderate nematicidal activity with IC50 values of 2.75 and 3.93 mM, respectively (abamectin as the positive control with IC50 value of 1.05 mM).


Assuntos
Alcaloides/isolamento & purificação , Amidas/isolamento & purificação , Anti-Helmínticos/isolamento & purificação , Clausena/química , Sementes/química , Alcaloides/farmacologia , Amidas/farmacologia , Animais , Anti-Helmínticos/farmacologia , Estrutura Molecular , Tylenchida/efeitos dos fármacos
3.
ACS Nano ; 12(4): 4025-4035, 2018 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-29617555

RESUMO

Fluorescent polymersomes are interesting systems for cell/tissue imaging and in vivo study of drug distribution and delivery. We report on bright fluorescent polymersomes with aggregation-induced emission self-assembled by a series of tetraphenylethylene (TPE)-containing amphiphilic biodegradable block copolymers, where the hydrophilic block is a polyethylene glycol and hydrophobic block is a TPE-substituted trimethylenecarbonate polymer P(TPE-TMC). Their self-assemblies in water were prepared by nanoprecipitation using dioxane or tetrahydrofuran as co-solvent, and the self-assembling processes were studied in detail by cryo-electron microscopy, dynamic light scattering, and spectrofluorometer. The polymersomes are formed via the closure of bilayer lamellae self-assembled first by amphiphilic block copolymers. The polymersome membrane affords a nanosize bright fluorescent system with self-assembly induced emission in the thickness scale of 10-15 nm. The control of the whole size of polymersome is achieved by the choice of co-solvent for self-assembling and by the design of a suitable hydrophilic/hydrophobic ratio of block copolymers. These polymersomes can be potentially used as a stable fluorescent tool to monitor the transportation and distribution of drugs and bioconjugates in living cells.

4.
Soft Matter ; 11(21): 4218-25, 2015 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-25892050

RESUMO

Shape memory hydrogels offer the ability to recover their permanent shape from temporarily trapped shapes without application of external forces. Here, we report a novel dual-responsive shape memory hydrogel with characteristic thermoplasticity. The water-insoluble hydrogel is prepared by simple ternary copolymerization of acrylamide (AM) and acrylic acid (AA) with low amounts of a cationic surfmer, in the absence of organic crosslinkers. Through either ionic/complex binding of carboxyl groups via trivalent cations or salt-dependent hydrophobic association, the hydrogel can memorize a temporary shape successfully, which recovers its permanent form in the presence of a reducing agent or deionized water. Besides, the unique thermoplasticity of the hydrophobic polyampholyte hydrogel allows the change of its permanent shape upon heating and the fixation after cooling, which is in strong contrast to the conventional chemically cross-linked shape memory hydrogels. This fascinating feature undoubtedly enriches the shape memory hydrogel systems. Thus, we believe that the facile strategy could provide new opportunities with regard to the design and practical application of stimulus-responsive hydrogel systems.


Assuntos
Hidrogéis/química , Acrilamida/química , Acrilatos/química , Compostos Férricos/química , Hidrogéis/síntese química , Interações Hidrofóbicas e Hidrofílicas , Polimerização , Reologia , Cloreto de Sódio/química
5.
Chem Commun (Camb) ; 51(33): 7234-7, 2015 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-25813408

RESUMO

This work reports the self-assembly of anion-exchangeable vesicles from an amphiphilic hyperbranched polymeric ionic liquid (HBPIL). By a simple one-step anion exchange with methyl orange, the obtained HBPILs could self-assemble into pH-indicative and colorful vesicles in water with color changes directly visible to the naked eye in response to solution pH. In addition, by another step of anion exchange with bovine serum albumin (BSA), the BSA-coated vesicles could also be readily prepared.

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