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Nanodiamonds (NDs) are considered to be relatively safe carbon nanomaterials used for the transmission of DNA, proteins and drugs. The feasibility of utilizing the NDs to deliver CRISPR-Cas9 system for gene editing has not been clearly studied. Therefore, in this study, we aimed to use NDs as the carriers of CRISPR-Cas9 components designed to introduce the mutation in RS1 gene associated with X-linked retinoschisis (XLRS). ND particles with a diameter of 3 nm were functionalized by carboxylation of the surface and covalently conjugated with fluorescent mCherry protein. Two linear DNA constructs were attached to the conjugated mCherry: one encoded Cas9 endonuclease and GFP reporter, another encoded sgRNA and contained insert of HDR template designed to introduce RS1 c.625C>T mutation. Such nanoparticles were successfully delivered and internalized by human iPSCs and mouse retinas, the efficiency of internalization was significantly improved by mixing with BSA. The delivery of ND particles led to introduction of RS1 c.625C>T mutation in both human iPSCs and mouse retinas. Rs1 gene editing in mouse retinas resulted in several pathological features typical for XLRS, such as aberrant photoreceptor structure. To conclude, our ND-based CRISPR-Cas9 delivery system can be utilized as a tool for creating in vitro and in vivo disease models of XLRS. STATEMENT OF SIGNIFICANCE: X-linked retinoschisis (XLRS) is a prevalent hereditary retinal disease, which is caused by mutations in RS1 gene, whose product is important for structural organization of the retina. The recent development of genome editing techniques such as CRISPR-Cas9 significantly improved the prospects for better understanding the pathology and development of treatment for this disease. Firstly, gene editing can allow development of appropriate in vitro and in vivo disease models; secondly, CRISPR-Cas9 can be applied for gene therapy by removing the disease-causative mutation in vivo. The major prerequisite for these approaches is to develop safe and efficient CRISPR-Cas9 delivery system. In this study, we tested specifically modified nanodiamonds for such a delivery system. We were able to introduce Rs1 mutation into the mouse retina and, importantly, observed several XLRS-specific effects., (Copyright © 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Maintaining the physical integrity of a silicon-based anode, which suffers from damage caused by severe volume changes during cycling, is a top priority in its practical applications. The performance of silicon-flake-based anodes has been significantly improved by mixing nanodiamond powders with silicon flakes for the fabrication of anodes for lithium-ion batteries (LIBs). Nanodiamonds adhere to the surfaces of silicon flakes and are distributed in the binder between flakes. A consistent and robust solid electrolyte interphase (SEI) is promoted by the aid of abundant reactive surface-linked functional groups and exposed dangling bonds of nanodiamonds, leading to enhanced physical integrity of the silicon flakes and the anode. The battery's high-rate discharge capabilities and cycle life are thus improved. SEM, Raman spectroscopy, and XRD were applied to examine the structure and morphology of the anode. Electrochemical performance was evaluated to demonstrate a capacity retention of nearly 75% after 200 cycles, with the final specific capacity exceeding 1000 mAh/g at a test current of 4 mA/cm2. This is attributed to the improved stability of the solid electrolyte interphase (SEI) structure that was achieved by integrating nanodiamonds with silicon flakes in the anode, leading to enhanced cycling stability and rapid charge-discharge performance. The results from this study present an effective strategy of achieving high-cycling-performance by adding nanodiamonds to silicon-flake-based anodes. [ABSTRACT FROM AUTHOR]

Abstract: RF MEMS capacitive switches using leaky nanodiamond as a dielectric film are studied and compared with those using Si3N4. Characteristics of dielectric charging and discharging are analyzed at temperature ranging from −196°C to 150°C. Electrical resistivity of leaky nanodiamond is measured to be lower than that of Si3N4 by 3 to 6 orders of magnitude at room temperature. Trapped charges in leaky nanodiamond dielectric discharge much more quickly than those in Si3N4 while the power dissipation of nanodiamond based switches remains low. As a result, charge trapping induced shift in electrostatic actuation voltage is greatly reduced compared to that with Si3N4 and becomes non-detectable under the reported conditions. RF MEMS capacitive switches based on leaky nanodiamond dielectric are, therefore, more reliable than those with Si3N4. [Copyright &y& Elsevier]

Abstract: Composite thin films of nanodiamond and silica nanotubes were synthesized by means of microwave plasma assisted chemical vapor deposition (MPCVD) on silica nanotube matrix that was seeded with nanodiamond particles. SEM, Raman spectroscopy, and EDX were used to analyze the composite. Wet chemical etching was applied to selectively remove exposed silica from the composites for further revealing the nanostructure of the composites. Nanodiamond grew around silica nanotubes and filled the space left between silica nanotubes to form a continuous film. When appropriately selected sizes of nanodiamond particles were used as diamond seeds, silica nanotubes capped with CVD-grown diamond crystals were also obtained. Potential applications and implication of composites of nanodiamond and 1-D nanostructures will be discussed. [Copyright &y& Elsevier]

Abstract: Fabrication of patterned diamond structures in an inexpensive way is desirable for a variety of practical applications. Inkjet printing is a well-developed and inexpensive process by which liquid ink, as well as solid suspensions in a properly formulated solution, can be applied in a precise quantity and at selected locations on a rigid or flexible substrate. In this work, nanodiamond suspensions in ethylene glycol were used as inks for the printing of patterned nanodiamond particles on substrates. By utilizing inks with optimized nanodiamond suspensions, high number density of diamond nanoparticles were laid down directly by inkjet printing to form almost continuous nanodiamond films of designed patterns on a substrate. A brief chemical vapor deposition process that lasted for 15 to 20 min or so was adequate for the further growth of nanodiamond seeds to form a continuous nanocrystalline diamond film. This process allows inexpensive seeding of diamond in selected areas as well as possible formation of 1-D, 2-D, and 3-D nanodiamond structures. Details of the inkjet printing process and its potential applications will be reported. [Copyright &y& Elsevier]