Hang Qian

Study on SnO2/graphene composites with superior electrochemical performance for lithium-ion batteries

In this study, the in situ growth of tin dioxide (SnO2) nanoparticles on reduced graphene oxide (rGO) has been realized using a hydrothermal method. The size of the SnO2 nanoparticles in the SnO2/rGO composites prepared by three different procedures is about 5 nm, and they are well dispersed on rGO. When applied as anode materials for lithium-ion batteries, we found that the composites synthesized from the stannous oxalate precursor showed the best rate performance and highest cyclic stability. The surface status of the composites, including interactions between SnO2 and rGO and surface chemical components, was investigated in detail in order to understand why the composites prepared using different procedures displayed vastly different electrochemical performances. The results presented here describe a new approach for the synthesis of uniform and nanosized metal-oxide/rGO composites with excellent electrochemical performance.

Reversibly Switching the Surface Porosity of a DNA Tetrahedron

The ability to reversibly switch the surface porosity of nanocages would allow controllable matter transport in and out of the nanocages. This would be a desirable property for many technological applications, such as drug delivery. To achieve such capability, however, is challenging. Herein we report a strategy for reversibly changing the surface porosity of a self-assembled DNA nanocage (a DNA tetrahedron) that is based on DNA hydridization and strand displacement. The involved DNA nanostructures were thoroughly characterized by multiple techniques, including polyacrylamide gel electrophoresis, dynamic light scattering, atomic force microscopy, and cryogenic electron microscopy. This work may lead to the design and construction of stimuli-responsive nanocages that might find applications as smart materials.

Polyvinyl pyrrolidone-assisted synthesis of a Fe3O4/graphene composite with excellent lithium storage properties

This paper reports a weak interaction between metal oxide and graphene in the Fe3O4/graphene composite, which results in the superior electrochemical performance.

Controlling the chirality of DNA nanocages.

We report a rational approach for controlling the chirality of self-assembled DNA nanocages at the nanoscale. Chirality on the nanoscale originates from the asymmetric characteristics of the component DNA building block (DNA nanomotif), but is distinct from the intrinsic, molecular-level chirality of the DNA duplex. By purposely removing two-dimensional (2D) rotation symmetry from the DNA nanomotif, we can control the three-dimensional (3D) chirality of the DNA nanocages. Such chiral control would be useful for tuning the photonic/ optical properties of nanophotonic devices when DNA nanostructures are used as structural scaffolds. [1–3] Chirality is an important structural feature across all size scales, from molecules to galaxies. Nanoscaled (1–100 nm) chirality bridges between the intrinsic chirality of molecules and the macroscale chirality of materials. Chemical synthesis and stereo-selective separation readily allow preparation of chiral molecules, and advanced fabrication methods can be used to fabricate chiral structures at the micrometer scale. However, there is a gap between these two approaches, how to rationally design and prepare chiral objects at the nanometer scale (1–100 nm). Such nanoscaled chiral structures have many technological applications, for example, chiral plasmonic devices. [4–6] Biomimetic, supramolecular DNA selfassembly is a powerful technique for building nanostructures because of its programmability and well-established secondary structure. [7–9] DNA nanocages [10–22] are intrinsically chiral at the molecular level, because DNA duplexes are chiral. In addition, the geometric folding, twisting, bending, and association of the component DNA duplexes in DNA nanostructures could also lead to nanoscaled chiral features. [14] Turberfield and co

Regulation of vascular smooth muscle cell autophagy by DNA nanotube-conjugated mTOR siRNA

The efficient delivery of short interfering RNA (siRNA) is an enormous challenge in the field of gene therapy. Herein, we report a delivery nanosystem based on programmed DNA self-assembly mammalian target of rapamycin (mTOR) siRNA-loaded DNA nanotubes (DNA-NTs). We demonstrate that these siRNA-DNA-NTs can be effectively transfected into pulmonary arterial smooth muscle cells (PASMCs) via endocytosis; and that the loaded mTOR siRNA can induce obvious autophagy and inhibit cell growth under both normal and hypoxic conditions. Moreover, we found that mTOR siRNA can control the autophagy and proliferation of PASMCs under hypoxic condition, suggesting a potential therapeutic application for mTOR siRNA in diseases involving abnormal autophagy in PASMCs.

Inhibition of DNA nanotube-conjugated mTOR siRNA on the growth of pulmonary arterial smooth muscle cells.

Here we provide raw and processed data and methods behind mTOR siRNA loaded DNA nanotubes (siRNA-DNA-NTs) in the growth of pulmonary arterial smooth muscle cells (PASMCs) under both normoxic and hypoxic condition, and also related to (You et al., Biomaterials, 2015, 67:137–150, [1]). The MTT analysis, Semi-quantitative RT-PCR data presented here were used to probe cytotoxicity of mTOR siRNA-DNA-NT complex in its TAE-Mg2+ buffer. siRNA-DNA-NTs have a lower cytotoxicity and higher transfection efficiency and can, based on inhibition of mTOR expression, decrease PASMCs growth both hypoxic and normal condition.

Regulation on Toll-like Receptor 4 and Cell Barrier Function by Rab26 siRNA-loaded DNA Nanovector in Pulmonary Microvascular Endothelial Cells

The small GTPase Rab26 is involved in multiple processes, such as vesicle-mediated secretion and autophagy. However, the mechanisms and functions of Rab26 in the human pulmonary microvascular endothelial cells (HPMVECs) are not clear. In this study, we thoroughly investigated the role and novel mechanism of Rab26 in permeability and apoptosis of HPMVECs using a self-assembled Rab26 siRNA loaded DNA Y-motif nanoparticle (siRab26-DYM) and Rab26 adenovirus. We found that siRab26-DYM could be efficiently transfected into HPMVECs in a time- and dose-dependent manner. Importantly, the siRab26-DYM nanovector markedly aggravated the LPS-induced apoptosis and hyper-permeability of HPMVECs by promoting the nuclear translocation of Foxo1, and subsequent activation of Toll-like receptor 4 (TLR4) signal pathway. Overexpression of Rab26 by Rab26 adenoviruses partially inactivated LPS-induced TLR4 signaling pathway, suppressed the cell apoptosis and attenuated the hyperpermeability of HPMVECs. These results suggest that the permeability and apoptosis of HPMVECs can be modulated by manipulating Rab26 derived TLR4 signaling pathway, and that Rab26 can be potential therapeutic target for the treatment of vascular diseases related to endothelial barrier functions.