Single-crystalline gold nano- and microplates with triangular or hexagonal shapes are synthesized by reduction of HAuCl(4) in lyotropic liquid crystal (LLC) mainly made of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymers and water after adding a small amount of capping agents, cetyltrimethylammonium bromide (CTAB) or tetrabutylammonium bromide (TBAB). During the growth of such plates, capping agents play the crucial role. It is found that there is an optimal value of CTAB or TBAB concentration for producing microplates. The selective adsorption of CTAB or TBAB on certain crystallographic facets may be the key point of the supposed mechanism. Although LLC does not really act as a template, it provides an ordered structure confining CTAB as well as the nascent metal nuclei, which enhances the oriented attachment of nuclei and thus the consequent growth of single-crystal plates.
Lyotropic liquid crystalline phases of an amphiphilic block copolymer are constructed and characterized in an ionic liquid with comparison of component and temperature effects.
Inflammation
is a protective response to stimuli trauma, which
can also lead to severe tissue injury. The existing anti-inflammatory
drugs, such as corticosteroids and glucocorticoids, generally exhibit
side effects and poor accumulation in inflammatory tissue. Hence,
a theranostic nanoplatform with serial reactive oxygen species (ROS)
responsiveness and two-photon AIE bioimaging has been constructed
for dimensional diagnosis and accurate therapy of inflammation. Prednisolone
(Pred) is bridged to a two-photon fluorophore (TP) developed
by us via a ROS sensitive bond to form a diagnosis-therapy compound TPP, which is then loaded by the amphipathic polymer PMPC–PMEMA
(PMM) through self-assembling into the core–shell structured
micelles (TPP@PMM). With a particle size of 57.5 nm, TPP@PMM can realize
the accumulation in the inflammatory site via the oedematous tissue
and the accurate release of anti-inflammatory drug Pred through the
serial response to the local overexpressed ROS. The micellar structure
is first interrupted by the ROS triggered hydrophobic-to-hydrophilic
conversion of PMEMA, which allows the release of TPP.
Then the ROS responsive bond in TPP is subsequently broken,
resulting in the accurate delivery of Pred and the inflammation therapy.
Furthermore, TPP@PMM can be traced in vivo with a
distinct two-photon imaging due to the AIE active fluorophore TP. The theranostic TPP@PMM reveals high-resolution inflammation
diagnosis and efficient anti-inflammatory activity owing to the two-photon
fluorophore and the serial ROS responsiveness and has been proven
to achieve the efficient treatment of acute lung injury, arthritis,
and atherosclerosis. Therefore, TPP@PMM holds considerable promise
as a potential strategy for acute and chronic inflammation theranostics.
Phase diagrams of two ionic liquids: hydrophobic 1-butyl-3-methylimidazolium hexafluorophosphate (bmim-PF(6)) and relatively hydrophilic 1-butyl-3-methylimidazolium tetrafluoroborate (bmim-BF(4)) in aqueous solutions of Brij 97 were determined at 25 degrees C. Two hexagonal liquid crystalline phases formed in bmim-PF(6)- and bmim-BF(4)-containing ternary systems were investigated by means of small-angle X-ray scattering (SAXS) and rheological techniques, with comparison of composition and temperature effects. From analysis of the SAXS data, bmim-PF(6) is dominantly penetrated between the oxyethylene chains of surfactant molecules, whereas bmim-BF(4) is mainly located in the water layer of hexagonal phases. The strength of the network of hexagonal phase formed in the Brij 97/water/bmim-BF(4) system is appreciably stronger than that of the Brij 97/water/bmim-PF(6) system, indicated by the smaller area of the surfactant molecule at the interface and the higher moduli (G', G' '). Temperature has a converse effect on the lattice parameters of the two hexagonal phases.
Intelligent polymeric micelles for antitumor drug delivery and tumor bioimaging have drawn a broad attention because of their reduced systemic toxicity, enhanced efficacy of drugs, and potential application of tumor diagnosis. Herein, we developed a multifunctional polymeric micelle system based on a pH and redox dual-responsive mPEG-P(TPE- co-AEMA) copolymer for stimuli-triggered drug release and aggregation-induced emission (AIE) active imaging. These mPEG-P(TPE- co-AEMA)-based micelles showed excellent biocompatibility and emission property, exhibiting great potential application for cellular imaging. Furthermore, the antitumor drug doxorubicin (DOX) could be encapsulated during self-assembly process with high loading efficiency, and a DOX-loaded micelle system with a size of 68.2 nm and narrow size distribution could be obtained. DOX-loaded micelles demonstrated great tumor suppression ability in vitro, and the dual-responsive triggered intracellular drug release could be further traced. Moreover, DOX-loaded micelles could efficiently accumulate at the tumor site because of enhanced permeability and retention effect and long circulation of micelles. Compared with free DOX, DOX-loaded micelles exhibited better antitumor effect and significantly reduced adverse effects. Given the efficient accumulation targeting to tumor tissue, dual-responsive drug release, and excellent AIE property, this polymeric micelle would be a potential candidate for cancer therapy and diagnosis.
Self-assembled vesicles, structurally equivalent to some hydrotropes, have been obtained from a Zn2+-fluorous surfactant or in the mixture of Zn2+-fluorous surfactant/zwitterionic surfactant in room-temperature ionic liquids (RTILs). The existence of bilayers arranged in vesicles in RTILs would be very exciting, open several new possibilities as reaction media, and increase our understanding of the physical and chemical factors for self-assembling systems in RTILs.
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