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Effect of anions on fluorescence quenching of Rhodamine B–Pluronic F127 complex
摘要： Pluronic F127 has been widely used for controlled release of drugs. The aggregation behaviour and solubilisation properties of pluronics can be affected by addition of salts. This work reports the studies on the changes in micellar assemblies of F127 due to addition of inorganic anions (KCl, KBr, KI and KNO3) in Pluronic F127–Rhodamine B system. This was monitored by using UV–vis spectroscopy, fluorescence spectroscopy and fluorescence lifetime spectra. The change in fluorescence spectrum due to the presence of quenchers was attributed to the change in microenvironment of the micelle. The quenching depends on the ability of the fluorophore to transfer energy to the quencher. Out of all four salts, KI was observed to be the best quencher for the above system.
关键词： Rhodamine B (Rh B),quenchers,spectroscopy studies,Pluronic F127,micelle
更新于2025-09-23 15:23:52
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Surfactant templated oriented 1-D nanoscale platinum and palladium systems on a modified silicon surface
摘要： A templating method has been improved to form oriented one-dimensional metal nanostructures on a silicon surface. To achieve this, the silicon surface is modified with 3-aminopropyl trimethoxysilane. The cationic surfactant cetyltrimethylammonium bromide is used as a micellar template. The average width of the obtained Pt strips is 35 nm, the average width of the obtained Pd strips is 60 nm.
关键词： Platinum group,Atomic force microscopy,Surface modification,Nanostructured materials,Micelle templates
更新于2025-09-23 15:23:52
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Lignosulfonate: a Convenient FRET Platform for the Construction of Ratiometric Fluorescence pH-Sensing Probe
摘要： Lignin is a kind of natural fluorescent polymer material. However, the application based on the fluorescent property of lignin was rarely reported. Herein, a non-covalent lignin-based Fluorescence Resonance Energy Transfer (FRET) system was readily constructed by physical blending method with spirolactam Rhodamine B (SRhB) and lignosulfonate (LS) as the acceptor and donor groups, respectively. The FRET behavior, self-assembly and energy transfer mechanism of SRhB/LS composite were systematically studied. It was demonstrated that LS could be used as a convenient aptamer as energy donor to construct water-soluble ratiometric sensors because of its inherent property of intra-micelle energy transfer cascades. Our results not only presented a facile and general strategy for producing lignin-based functional material, but also provided a fundamental understanding about lignin fluorescent to promote the functional and high-valued applications of lignin fluorescence characteristic.
关键词： lignin,ratiometric sensor,FRET,intra-micelle energy transfer cascade
更新于2025-09-23 15:23:52
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Multispectral optoacoustic tomography (MSOT) for imaging the particle size-dependent intratumoral distribution of polymeric micelles
摘要： Purpose: This study proposes the utilization of multispectral optoacoustic tomography (MSOT) to investigate the intratumoral distribution of polymeric micelles and effect of size on the biodistribution and antitumor efficacy (ATE). Materials and methods: Docetaxel and/or optoacoustic agent-loaded polymeric micelles (with diameters of 22, 48, and 124 nm) were prepared using amphiphilic block copolymers poly (ethylene glycol) methyl ether-block-poly (D,L lactide) (PEG2000–PDLLAx). Subcutaneous 4T1 tumor-bearing mice were monitored with MSOT imaging and IVIS? Spectrum in vivo live imaging after tail vein injection of micelles. The in vivo results and ex vivo confocal imaging results were then compared. Next, ATE of the three micelles was found and compared. Results: We found that MSOT imaging offers spatiotemporal and quantitative information on intratumoral distribution of micelles in living animals. All the polymeric micelles rapidly extravasated into tumor site after intravenous injection, but only the 22-nm micelle preferred to distribute into the inner tumor tissues, leading to a superior ATE than that of 48- and 124-nm micelles. Conclusion: This study demonstrated that MSOT is theranostically a powerful imaging modality, offering quantitative information on size-dependent spatiotemporal distribution patterns after the extravasation of nanomedicine from tumor blood vessels.
关键词： intratumoral distribution,MSOT,multispectral optoacoustic tomography,in vivo imaging,tumor model,particle size,polymeric micelle
更新于2025-09-23 15:23:52
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Amphiphilic nanoaggregates with bimodal MRI and optical properties exhibiting magnetic field dependent switching from positive to negative contrast enhancement
摘要： Mixed micelles based on amphiphilic gadolinium(III)-DOTA and europium(III)-DTPA complexes were synthesized and evaluated for their paramagnetic and optical properties as potential bimodal contrast agents. Amphiphilic folate molecule for targeting the folate receptor protein, which is commonly expressed on the surface of many human cancer cells, was used in the self-assembly process in order to create nanoaggregates with targeting properties. Both targeted and non-targeted nanoaggregates formed mono-disperse micelles having distribution maxima of 10 nm. The micelles show characteristic europium(III) emission with quantum yields of 2% and 1.1% for the non-targeted and targeted micelles respectively. Fluorescence microscopy using excitation at 405 nm and emission at 575-675 nm was employed to visualize nanoaggregates in cultured HeLa cells. The uptake of folate-targeted and non-targeted micelles is already visible after 5 hour incubation, and was characterized with the europium(III) emission which is clearly observable in the cytoplasm of the cells. The very fast longitudinal relaxivity r1 of ca. 26 s-1 mM-1 per gadolinium(III) ion was observed for both micelles at 60 MHz and 310 K. Upon increasing the magnetic field to 300 MHz the nanoaggregates exhibited a large switching to transversal relaxivity with r2 value of ca. 52 s-1 mM-1 at 310 K. Theoretical fitting of the 1H NMRD profiles indicate that the efficient T1 and T2 relaxations are sustained by the favorable magnetic and electron-configuration properties of the gadolinium(III) ion, rotational correlation time and coordinated water molecule. These nanoaggregates could have versatile application as a positive contrast agent at currently used magnetic imaging field strengths and a negative contrast agent in higher field applications, while at the same time offering the possibility for the loading of hydrophobic therapeutics or targeting molecules.
关键词： bimodal contrast agents,gadolinium,nanoaggregates,optical imaging,micelle,high field MRI
更新于2025-09-23 15:22:29
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Tracing Boron with Fluorescence and PET Imaging of Boronated Porphyrin Nanocomplex for Imaging Guided Boron Neutron Capture Therapy
摘要： Boron neutron capture therapy (BNCT) induces high-energy radiation within cancer cells while avoiding damage to normal cells that without uptake of BNCT drugs, which is holding great promise to provide excellent control over locally invasive malignant tumors. However, lack of quantitative imaging technique to determine local boron concentration has been a great challenge for nuclear physicians to apply accurate neutron irradiation during the treatment, which is a key factor that has limited BNCT’s application in clinics. To meet this challenge, this study describes coating boronated porphyrins with a biocompatible Poly(lactide–co-glycolide)–monomethoxy-poly(polyethylene-glycol) (PLGA-mPEG) micelle for selective tumor accumulation and reduced toxicity comparing with previously reported boronated porphyrin drugs. Fluorescence imaging and PET imaging were performed, unveiling the potential imaging properties of this boronated porphyrin nanocomplex (BPN) to locate tumor region and to determine tissue-localized boron concentration which facilitates treatment planning. By studying the pharmacokinetics of BPN with Cu-64 PET imaging, the treatment plan was adjusted from single bolus injection to multiple times of injections of smaller doses. As expected, high tumor uptake of boron (125.17±13.54 ppm) was achieved with an extraordinarily high tumor to normal tissue ratio: tumor to liver, muscle, fat and blood were 3.24±0.22, 61.46±20.26, 31.55±10.30 and 33.85±5.73, respectively. At last, neutron irradiation with BPN showed almost complete tumor suppression, demonstrating that BPN holds a great potential for being an efficient boron delivery agent for imaging-guided BNCT.
关键词： copper-64,boron neutron capture therapy,theranostics,positron emission tomography,micelle
更新于2025-09-23 15:21:21
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Solubilization of a Hydrophobic Prodrug and the Ultrasound Irradiation Effect to TiO<sub>2</sub> Nanoparticles-Incorporated Polyion Complex Micelles
摘要： Sonodynamic therapy (SDT) using ultrasound irradiation instead of photoactivation as in photodynamic therapy, has emerged as a promising treatment for various types of cancer. We have focused on titanium dioxide nanoparticles (TiO2 NPs) as a sonosensitizer which can generate reactive oxygen species by sonication. TiO2 NPs-incorporated polyion complex micelles were developed for the delivery into the cells. Here, carmofur being a hydrophobic prodrug was solubilized into the micelles. From in vitro experiments, it was confirmed that carmofur-solubilized micelles effectively suppress the cell viability due to the additive effect of the anticancer effect of 5-fluorouracil produced by hydrolysis of carmofur and the SDT effect.
关键词： Sonodynamic Therapy,TiO2 Nanoparticle,Polyion Complex Micelle,Prodrug
更新于2025-09-19 17:15:36
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Photochemical Processes in Molecular Polymethine Dye Probes in the Presence of Bile Salts
摘要： Primary photochemical processes in polymethine dye probes 3,3′-di(γ-sulfopropyl)-4,5,4′,5′-dibenzo-9-ethylthiacarbocyanine betaine (DEC) and 3,3′,9-trimethylthiacarbocyanine iodide (Cyan 2) in micellar systems of bile-acid salts (BASs) sodium cholate, deoxycholate, and taurocholate and sodium dodecyl sulfate (SDS) as a reference are studied by flash photolysis. Signals due to photoisomerization of dye trans-isomers and dark reverse isomerization of the resulting cis-photoisomers are observed during pulse photolysis of air-saturated aqueous dye solutions in the presence of BAS and SDS micelles. The lifetimes of the photoisomers are 60–190 μs. Pulse photolysis of Cyan 2 and DEC solutions without oxygen and with BAS and SDS micelles induced photoisomerization and transition of the dyes into an excited triplet state followed by the reverse transition (intersystem crossing) into the initial singlet state. Triplet–triplet absorption spectra of these dyes isomers in polar (EtOH, i-PrOH) and nonpolar (dioxane) solvents were obtained for comparison using triplet–triplet energy transfer from anthracene. The conclusion was drawn that the photochemical behavior of the dyes in BAS and SDS micellar systems were similar.
关键词： triplet state,surfactants,polymethine dye probes,bile-acid salts,trans–cis photoisomerization,micelle
更新于2025-09-19 17:15:36
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Micelle-Assisted Formation of Nanoparticle Superlattices and Thermally Reversible Symmetry Transitions
摘要： Nanoparticle superlattices (NPSLs) are of great interests as materials with designed emerging properties depending on the lattice symmetry as well as composition. The symmetry transition of NPSLs depending on environmental conditions can be an excellent ground for making new stimuli-responsive functional materials. Here, we report a spherical micelle-assisted method to form exceptionally ordered NPSLs which are inherently sensitive to environmental conditions. Upon mixing functionalized gold nanoparticles (AuNPs) with a nonionic surfactant spherical micellar solution, NPSLs of different symmetries such as NaZn13, MgZn2, and AlB2-type are formed depending on the size ratio between micelles and functionalized AuNPs, and composition. The NPSLs formed by the spherical micelle-assisted method show thermally reversible order-order (NaZn13–AlB2) and order-disorder (MgZn2–isotropic) symmetry transitions, which are consistent with the Gibbs free energy calculations for binary hard-sphere model. This approach may open up new possibilities for NPSLs as stimuli-responsive functional materials.
关键词： small-angle x-ray scattering,nanoparticle superlattice,spherical micelle,stimuli-responsive symmetry transition
更新于2025-09-19 17:15:36
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Reverse micelle facilitated synthesis of nanostructured polyaniline as the counter electrode materials in dye-sensitized solar cells
摘要： We report a reverse-micelle emulsion polymerization of nanostructured PANI using a nonionic surfactant Polyglyceryl-2-Dipolyhydroxystearate (PGPH) at various concentrations from 2% to 6% (v/v). SEM images show that the obtained morphologies are irregular agglomerates at low PGPH concentration and relatively regular granules at high PGPH concentration. FTIR and Raman spectra show that the synthesized PANI is in the form of Emeraldine salt (PANI ES) with electrical conductivity around 10?3 S cm?1. Photovoltaic current-voltage (J-V) measurements show the highest power conversion efficiency is achieved at 1.71% at 6% (v/v) of PGPH.
关键词： dye-sensitized solar cell,Counter-electrode materials,nanostructured polyaniline,emulsion polymerization,reverse micelle,polyglyceryl-2-dipolyhydroxystearate
更新于2025-09-19 17:13:59