Mesangial cell (MC) phenotypic transition is crucial for the progression of diabetic nephropathy. A major stimulus mediating high glucose-induced MC phenotypic transition is TGF-β1. Our current study focuses on microRNA-215 (miR-215) and investigates its role in TGF-β1-mediated MC phenotypic transition. Using real-time quantitative PCR (qRT-PCR) and northern blotting, we determined that the miR-192/215 family is dramatically upregulated under diabetic conditions both in vitro and in vivo. Gain- and loss-of-function approaches demonstrated that miR-215 inhibition significantly inhibited TGF-β1-induced mouse mesangial cell (MMC) phenotypic transition, whereas miR-215 upregulation promoted MMC phenotypic transition. Interestingly, these changes were not detected in cells that were treated with TGF-β1 and miR-192 mimics or inhibitors. These results suggest that miR-215 participates in TGF-β1-induced MMC phenotypic transition. Luciferase reporter assays were used to identify whether catenin-beta interacting protein 1 (CTNNBIP1) is a direct target of miR-215, which was predicted by bioinformatic analysis. Mechanistic studies revealed that CTNNBIP1 suppresses Wnt/β-catenin signaling and that miR-215 promotes β-catenin activation and upregulates α-SMA and fibronectin expression in TGF-β1-treated MMCs by targeting CTNNBIP1. In addition, in vivo miR-215 silencing with a specific antagomir significantly increased CTNNBIP1 protein expression, resulting in reduced β-catenin activity and decreased α-SMA and fibronectin expression in db/db mouse kidney glomeruli. Taken together, our findings indicate that miR-215 plays an essential role in MC phenotypic transition by regulating the CTNNBIP1/β-catenin pathway, which is related to the pathogenesis of diabetic nephropathy.

We study the scattering properties of coated nanoparticles with high-permittivity core and nonlocal plasmonic shell with full-wave nonlocal Mie theory. Both electric and artificial magnetic resonances of different orders are supported simultaneously for such coated particles. By properly engineering the aspect ratio, we can achieve not only the overlapping of electric dipole (ED) and magnetic dipole (MD) modes but also that of electric quadrupole (EQ) and magnetic quadrupole (MQ). We numerically demonstrate that there are two overlapping ways to obtain the superscattering state for core–shell nanoparticles. Furthermore, we show that the nonlocality becomes less important in the scattering of coated nanoparticles with ultrathin shell thickness but large total size due to the fact that nonlocality is essentially a surface effect.

No abstract

Methyl methacrylate (MMA)-styrene (St) copolymer nanocapsules containing cologne essential oil for fragrant fabrics treatment were prepared by miniemulsion polymerization. The morphology, chemical composition and thermal properties were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and thermal gravimetric analysis (TGA). The nanocapsules had relatively small size (ca. 136 nm of mean particle diameter), regular sphericity and uniform particle size distribution. The encapsulation efficiency and loading capacity of the nanocapsules were 85.4% and 42.7%, respectively. The nanocapsules had good thermostability. The release experiments showed that 6.8% cologne essential oil still existed after being washed 15 times in the fabrics treated with nanocapsules, indicating that the fabrics treated with nanocapsules had good washing durability.

We theoretically study the effective third-order nonlinear response and optical bistability of the 3D graphene based composite consisting of graphene wrapped dielectric nanoparticles embedded in dielectric host at terahertz frequencies. Taking into account the nonlinear conductivity of graphene, we derive the analytical expressions for the effective third-order nonlinear coefficient in weakly nonlinear limit. Moreover, for strong applied fields, the criterion for achieving optical bistability in such a graphene coated sphere, as well as the switching thresholds of optical bistability are discussed. We find that both and optical bistability are strongly dependent on the Fermi energy of graphene and it is possible to achieve very low switching thresholds under the normal graphene dissipation. We further propose a scheme to study the transmittance of this nonlinear composite slab. These results reveal novel regime of the optical bistability of the transmittance of light. We show that this kind of graphene-wrapped composite, which has tunable and low threshold optical bistability, can be the best candidate for unique nonlinear optical materials.

We demonstrate tunable pulling and pushing optical forces on plasmonic nanostructures around Fano resonance. The plasmonic nanostructure containing a spherical core with optical gain and a metallic shell shows much larger optical pulling force than a pure gain sphere. One can obtain large field enhancement and giant pulling force at the emerged quadrupole mode. The introduction of optical pump compensate the dissipative loss from metal shell, thus enable the strong coupling between a narrow quadrupole mode and a board dipole mode, giving rise to Fano resonance. The giant negative forces origin from the reversal of electric field at Fano resonance, which lead to pulling force on bound currents and charges. Meanwhile, the separation of the Lorentz force helps to reveal the nature of the pulling forces in gain system. We have shown that by applying the Lorentz force density formula, it is possible to obtain the correct value of the force inside our complex inhomogenous structure made up of dispersive and lossy metamaterial irrespective of the electromagnetic momentum density. Our results provide a practical way to manipulate nanoparticles and give deep insight into light-matter interaction.

Equivalent permittivity and permeability for metallic nanowires with spatial dispersion are derived analytically. The extinction cross section based on the local full-wave theory with our equivalent permittivity and permeability is found to be in agreement with the one based on the nonlocal full-wave theory. When the electromagnetic wave is incident on the nanocylinder with nonlocal permittivity, multiple Fano resonances exist because of the interference of different longitudinal modes with the dipole moments, and the nonlocal nanocylinder can be designed to yield an abrupt transition between full transparency and strong scattering. Interestingly, both the frequencies at which the transparency and strong scattering occur can be described well by the equivalent permittivity. Our study may be helpful in the design of optical nanoswitches and nanomemories.

Apoptosis is a tightly regulated cellular process that plays an essential role in the development, aging, cancer biology, immune response, and pathogenesis of various diseases. Herein, we report a new SERS sensing strategy for in vitro sensitive detection of early apoptotic cells. The principle of this method is to in situ synthesize silver nanoparticles (AgNPs) on the phosphatidylserine (PS) of the apoptotic cell membrane during the early apoptosis, which enables distinguishing normal and apoptotic cells. The total assay time of the presented method is only 10 min, thus being faster, cheaper and simpler than current techniques for the detection of apoptosis. The intrinsic mechanism was verified by different approaches based on externalized phosphatidylserine. In addition, the detection process is real-time and label-free; i.e., the intrinsic SERS spectra from the cellular membrane are directly employed for apoptosis real-time detection, which avoids using additional chemical or biological reagents as external signal indicators. Therefore, our SERS approach may serve as a potentially practical tool for sensitive and real-time detection of early cell apoptosis, complementing the state-of-the-art strategies, e.g. flow cytometry. While further investigation is required to better understand the intrinsic mechanism of the in situ coating method, the current results may provide another choice for real-time detection of early apoptosis.