Tumor-targeted RNA-interference: functional non-viral nanovectors

This is the published version, also available here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3092671/.While small interfering RNA (siRNA) and microRNA (miRNA) have attracted extensive attention and showed significant promise for the study, diagnosis and treatment of human cancers, delivering siRNA or miRNA specifically and efficiently into tumor cells in vivo remains a great challenge. Delivery barriers, which arise mainly from the routes of administration associated with complex physiochemical microenvironments of the human body and the unique properties of RNAs, hinder the development of RNA-interference (RNAi)-based therapeutics in clinical practice. However, in available delivery systems, non-viral nanoparticle-based gene/RNA-delivery vectors, or nanovectors, are showing powerful delivery capacities and huge potential for improvements in functional nanomaterials, including novel fabrication approaches which would greatly enhance delivery performance. In this review, we summarize the currently recognized RNAi delivery barriers and the anti-barrier requirements related to vectors' properties. Recent efforts and achievements in the development of novel nanomaterials, nanovectors fabrication methods, and delivery approaches are discussed. We also review the outstanding needs in the areas of material synthesis and assembly, multifunction combinations, proper delivery and assisting approaches that require more intensive investigation for the comprehensive and effective delivery of RNAi by non-viral nanovectors

Dilute Magnetic Semiconductor Cu2FeSnS4 Nanocrystals with a Novel Zincblende Structure

Diluted magnetic semiconductor Cu2FeSnS4 nanocrystals with a novel zincblende structure have been successfully synthesized by a hot-injection approach. Cu+, Fe2+, and Sn4+ ions occupy the same position in the zincblende unit cell, and their occupancy possibilities are 1/2, 1/4, and 1/4, respectively. The nanocrystals were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy-dispersive spectroscopy (EDS), and UV-vis-NIR absorption spectroscopy. The nanocrystals have an average size of 7.5 nm and a band gap of 1.1 eV and show a weak ferromagnetic behavior at low temperature

Fabrication of a Cu2MnSn(S,Se)(4) thin film based on a low-cost degradable solution process

Achieving micro-sized and closely packed grains is an essential requirement for high-performance chalcogenide thin film solar cells. Here, I-2-II-IV-VI4 (Cu2MnSn(S,Se)(4)) (CMTSSe) thin films were successfully deposited by carrying out a simple, degradable solution-based process. The structure, composition, and morphology were characterized by powder X-ray diffraction (XRD), energy dispersive spectrometry (EDS), and scanning electron microscopy (SEM), and the Hall effect was also measured. These characterizations indicated that CMTSSe thin films may find applications in photovoltaic absorbing materials. In addition, different substrates were found to affect the morphology and compactness of the grains of the thin film

Kesterite Cu2Zn(Sn,Ge)(S,Se)(4) thin film with controlled Ge-doping for photovoltaic application

Cu2ZnSn(S,Se)(4) (CZTSSe) semiconductors have been a focus of extensive research effort owing to low-toxicity, high abundance and low material cost. Yet, the CZTSSe thin film solar cell has a low open-circuit voltage value that presents challenges. Herein, using GeSe2 as a new Ge source material, we have achieved a wider band gap CZTSSe-based semiconductor absorber layer with its band-gap controlled by adjusting the ratio of SnS2 : GeSe2 used. In addition, the Cu2Zn(Sn,Ge)(S,Se)(4) thin films were prepared with optimal Ge doping (30%) and solar cells were fabricated to attain a respectable power conversion efficiency of 4.8% under 1.5 AM with an active area of 0.19 cm(2) without an anti-reflection layer

New Insight of Li-Doped Cu₂ZnSn(S,Se)₄ Thin Films: Li-Induced Na Diffusion from Soda Lime Glass by a Cation-Exchange Reaction

In our recent report (<i>ACS Appl. Mater. Interfaces</i> <b>2016</b>, <i>8</i>, 5308), Li⁺ ions had been successfully incorporated into the lattice of the selenized Cu₂ZnSn­(S,Se)₄ thin film on a quartz substrate by substituting equivalent Cu⁺ ions, and Li⁺ ions was also found to have the little effect on the crystal growth and defect passivation. To further improve the cell performance of Li-doped CZTSSe devices, we conducted the same experiments on the sodium-rich soda-lime glass (SLG) substrate in this study, instead of sodium-free quartz substrate. Surprisingly, only trace amounts of Li (Li/Cu molar ratio ∼1 × 10^–4) were detected in the final CZTSSe thin films; meanwhile, a large amount of sodium was present on the surface and at the grain boundaries of the selenized thin films. A Li/Na exchange mechanism is used to explain this phenomenon. Only on the sodium-free substrate can Li⁺ ions enter the CZTSSe host lattice, and doping Li⁺ ions on the SLG substrate are nearly identical to doping Na⁺ ions

Tumor-targeted RNA-interference: functional non-viral nanovectors

While small interfering RNA (siRNA) and microRNA (miRNA) have attracted extensive attention and showed significant promise for the study, diagnosis and treatment of human cancers, delivering siRNA or miRNA specifically and efficiently into tumor cells in vivo remains a great challenge. Delivery barriers, which arise mainly from the routes of administration associated with complex physiochemical microenvironments of the human body and the unique properties of RNAs, hinder the development of RNA-interference (RNAi)-based therapeutics in clinical practice. However, in available delivery systems, non-viral nanoparticle-based gene/RNA-delivery vectors, or nanovectors, are showing powerful delivery capacities and huge potential for improvements in functional nanomaterials, including novel fabrication approaches which would greatly enhance delivery performance. In this review, we summarize the currently recognized RNAi delivery barriers and the anti-barrier requirements related to vectors' properties. Recent efforts and achievements in the development of novel nanomaterials, nanovectors fabrication methods, and delivery approaches are discussed. We also review the outstanding needs in the areas of material synthesis and assembly, multifunction combinations, proper delivery and assisting approaches that require more intensive investigation for the comprehensive and effective delivery of RNAi by non-viral nanovectors

Gram-Scale Synthesis of Hydrophilic PEI-Coated AgInS₂ Quantum Dots and Its Application in Hydrogen Peroxide/Glucose Detection and Cell Imaging

Assisted with polyethylenimine, 4.0 L of water-soluble AgInS₂ quantum dots (AIS QDs) were successfully synthesized in an electric pressure cooker. As-prepared QDs exhibit yellow emission with a photoluminescence (PL) quantum yield up to 32%. The QDs also show excellent water/buffer stability. The highly luminescent AIS QDs are used to explore their dual-functional behavior: detection of hydrogen peroxide (H₂O₂)/glucose and cell imaging. The amino-functionalized AIS QDs show high sensitivity and specificity for H₂O₂ and glucose with detection limits of 0.42 and 0.90 μM, respectively. A linear correlation was established between PL intensity and concentration of H₂O₂ in the ranges of 0.5–10 μM and 10–300 μM, while the linear ranges were 1–10 μM and 10–1000 μM for detection of glucose. The AIS QDs reveal negligible cytotoxicity on HeLa cells. Furthermore, the luminescence of AIS QDs gives the function of optical imaging