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Nepafenac-Loaded Cyclodextrin/Polymer Nanoaggregates: A New Approach to Eye Drop Formulation
摘要： The topical administration route is commonly used for targeting therapeutics to the eye; however, improving the bioavailability of drugs applied directly to the eye remains a challenge. Different strategies have been studied to address this challenge. One of them is the use of aggregates that are formed easily by self-assembly of cyclodextrin (CD)/drug complexes in aqueous solution. The aim of this study was to design a new eye drop formulation based on aggregates formed between CD/drug complexes. For this purpose, the physicochemical properties of the aggregates associated with six CDs and selected water-soluble polymers were analysed. Complex formation was studied using differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR) and 1H nuclear magnetic resonance spectroscopy (1H-NMR). Results showed that HPβCD performed best in terms of solubilization, while γCD performed best in terms of enhancing nanoaggregate formation. Formation of inclusion complexes was con?rmed by DSC, FT-IR and 1H-NMR studies. A mixture of 15% (w/v) γCD and 8% (w/v) HPβCD was selected for formulation studies. It was concluded that formulations with aggregate sizes less than 1 μm and viscosity around 10–19 centipoises can be easily prepared using a mixture of CDs. Formulations containing polymeric drug/CD nanoaggregates represent an interesting strategy for enhanced topical delivery of nepafenac.
关键词： cyclodextrin,self-assemble,nepafenac,aggregate,polymer,complexation,ocular drug delivery
更新于2025-09-23 15:22:29
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Roll-to-roll fabrication of touch-responsive cellulose photonic laminates
摘要： Hydroxypropyl-cellulose (HPC), a derivative of naturally abundant cellulose, can self-assemble into helical nanostructures that lead to striking colouration from Bragg reflections. The helical periodicity is very sensitive to pressure, rendering HPC a responsive photonic material. Recent advances in elucidating these HPC mechano-chromic properties have so-far delivered few real-world applications, which require both up-scaling fabrication and digital translation of their colour changes. Here we present roll-to-roll manufactured metre-scale HPC laminates using continuous coating and encapsulation. We quantify the pressure response of the encapsulated HPC using optical analyses of the pressure-induced hue change as perceived by the human eye and digital imaging. Finally, we show the ability to capture real-time pressure distributions and temporal evolution of a human foot-print on our HPC laminates. This is the first demonstration of a large area and cost-effective method for fabricating HPC stimuli-responsive photonic films, which can generate pressure maps that can be read out with standard cameras.
关键词： mechano-chromic,Hydroxypropyl-cellulose,pressure mapping,self-assemble,photonic laminates,Bragg reflections,roll-to-roll fabrication,helical nanostructures
更新于2025-09-23 15:21:21
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Position Dependence of Emission Wavelength of a SiO2 Colloidal Photonic-Crystal Laser
摘要： In this paper, a wavelength tunable colloidal-crystal laser with monodispersed silica particles was demonstrated. Silica particles were synthesized through the modified St?ber process and self-assembled into the colloidal photonic-crystal structure, which was then used to form the optic cavity of a wavelength tunable laser device. Due to Bragg’s diffraction of the colloidal photonic-crystal and the coffee ring effect, the forbidden energy gap of light varied with different lattice sizes at different positions of the colloidal photonic-crystal. When the pumping pulsed laser irradiated on the gain medium of the sample, the fluorescence was restricted and enhanced by the colloidal photonic-crystal. Lasing emission with a single peak occurred when the energy of the pumping laser exceeded the threshold energy. The threshold energy and the full-width at half-maximum (FWHM) of the proposed laser were 7.63 μJ/pulse and 2.88 nm, respectively. Moreover, the lasing wavelength of the colloidal photonic-crystal laser could be tuned from 604 nm to 594 nm, corresponding to the various positions in the sample due to the coffee ring effect.
关键词： St?ber process,colloidal-crystal laser,wavelength tunable,self-assemble,silica particles
更新于2025-09-19 17:13:59
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Fabrication, Investigation, and Application of Light-Responsive Self-Assembled Nanoparticles
摘要： Light-responsive materials have attracted increasing interest in recent years on account of their adjustable on-off properties upon specific light. In consideration of reversible isomerization transition for azobenzene (AZO), it was designed as a light-responsive domain for nanoparticles in this research. At the same time, the interaction between AZO domain and β-cyclodextrin (β-CD) domain was designed as a driving force to assemble nanoparticles, which was fabricated by two polymers containing AZO domain and β-CD domain, respectively. The formed nanoparticles were confirmed by Dynamic Light Scattering (DLS) results and Transmission Electron Microscope (TEM) images. An obvious two-phase structure was formed in which the outer layer of nanoparticles was composed of PCD polymer, as verified by 1HNMR spectroscopy. The efficient and effective light response of the nanoparticles, including quick responsive time, controllable and gradual recovered process and good fatigue resistance, was confirmed by UV-Vis spectroscopy. The size of the nanoparticle could be adjusted by polymer ratio and light irradiation, which was ascribed to its light-response property. Nanoparticles had irreversibly pH dependent characteristics. In order to explore its application as a nanocarrier, drug loading and in vitro release profile in different environment were investigated through control of stimuli including light or pH value. Folic acid (FA), as a kind of target fluorescent molecule with specific protein-binding property, was functionalized onto nanoparticles for precise delivery for anticancer drugs. Preliminary in vitro cell culture results confirmed efficient and effective curative effect for the nanocarrier on MCF-7 cells.
关键词： nanocarrier,nanoparticle,drug delivery,light-responsive property,self-assemble
更新于2025-09-16 10:30:52
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Self-assembled peptide functionalized gold nanopolyhedrons with excellent chiral optical properties
摘要： Due to the unique optical properties of gold nanomaterials, the preparation of gold nanomaterials with excellent chirality has received extensive attention. In order to develop a simple fabrication method for three-dimensional chiral Au nanostructure with a size of several hundred nanometers, chiral gold nanoparticles were developed to transfer chirality of a peptide to gold nanoparticles. In this study, the controlled synthesis of asymmetric gold nanopolyhedrons was achieved. The asymmetric gold nanopolyhedrons prepared via peptide-directed growth can exhibit strong circular dichroism (~±50 mdeg) couplets in the visible range (500-600 nm). And the morphology of chiral Au nanododecahedrons-peptide particles showed distorted and asymmetric properties. In order to prove that the size and spatial structure of gold nanopolyhedrons have an influence on their chiral optical properties, the Au nanotrioctahedrons-peptide particles were prepared by using Au nanotrioctahedrons with different morphologies. Au nanotrioctahedrons-peptide particles also exhibited circular dichromatic couplets in the visible region.
关键词： circular dichroism,peptide,self-assemble,gold nanopolyhedrons,chiral
更新于2025-09-12 10:27:22
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Self-assembled highly porous rugby-like hierarchical ZnO thin film formaldehyde gas sensor
摘要： A new rugby-like ZnO thin film was self-assembled via a hydrothermal method and the influences of the hydrothermal temperature on crystal growth and gas sensing properties of ZnO thin films were investigated. The results showed that the highly porous rugby-like ZnO crystals were self-assembled via thin fan-shape sheets with abundant nanopores formed by interconnected the smaller nanoplates when the hydrothermal temperature was 140 (cid:1)C. Its specific surface area value reached 45.0 m2 g(cid:3)1. The sensor exhibited an excellent gas sensing response, a good selectivity towards formaldehyde and quick response characteristics at the optimum working temperature of 250 (cid:1)C.
关键词： self-assemble,zinc oxide,gas sensing property,rugby-like hierarchical nanostructure
更新于2025-09-12 10:27:22
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Synthesis and Self-Assemble Nanofibers of Tetra Phenoxy Substituted Nickel Phthalocyanine
摘要： Tetra phenoxy substituted nickel phthalocyanine nanofibers were synthesized in large scale by self-assemble. The FESEM and HRTEM micrographs indicated that the sizes of the fibers are 20-60 nm in width and 0.2-5 μm in length. The formation mechanism of nickel phthalocyanine fibers was discussed and studied by XRD and UV-visible spectra. The nickel phthalocyanine nanofibers have potential application on organic function devices.
关键词： Nickel phthalocyanine,Nanofibers,Synthesis,Self-assemble
更新于2025-09-11 14:15:04