Silicon (Si)-based anodes are promising for next-generation lithium (Li)-ion batteries due to their high theoretical capacity (∼3600 mAh/g). However, they suffer quantities of capacity loss in the first cycle from initial solid electrolyte interphase (SEI) formation. Here, we present an prelithiation method to directly integrate a Li metal mesh into the cell assembly.
View Article and Find Full Text PDFKey to the widespread and secure application of genome editing tools is the safe and effective delivery of multiple components of ribonucleoproteins (RNPs) into single cells, which remains a biological barrier to their clinical application. To overcome this issue, a robust RNP delivery platform based on a biocompatible sponge-like silica nanoconstruct (SN) for storing and directly delivering therapeutic RNPs, including Cas9 nuclease RNP (Cas9-RNP) and base editor RNP (BE-RNP) is designed. Compared with commercialized material such as lipid-based methods, up to 50-fold gene deletion and 10-fold base substitution efficiency is obtained with a low off-target efficiency by targeting various cells and genes.
View Article and Find Full Text PDFRibonucleoprotein (RNP) complex-mediated base editing is expected to be greatly beneficial because of its reduced off-target effects compared to plasmid- or viral vector-mediated gene editing, especially in therapeutic applications. However, production of recombinant cytosine base editors (CBEs) or adenine base editors (ABEs) with ample yield and high purity in bacterial systems is challenging. Here, we obtained highly purified CBE/ABE proteins from a human cell expression system and showed that CBE/ABE RNPs exhibited different editing patterns (i.
View Article and Find Full Text PDFAdenine base editors (ABEs) catalyze specific A-to-G conversions at genomic sites of interest. However, ABEs also induce cytosine deamination at the target site. To reduce the cytosine editing activity, we engineered a commonly used adenosine deaminase, TadA7.
View Article and Find Full Text PDFPrime editing technology is capable of generating targeted insertions, deletions, and base conversions. However, the process of designing prime editing guide RNAs (pegRNAs), which contain a primer binding site and a reverse-transcription template at the 3' end, is more complex than that for the single guide RNAs used with CRISPR nucleases or base editors. Furthermore, the assessment of high-throughput sequencing data after prime editors (PEs) have been employed should consider the unique feature of PEs; thus, pre-existing assessment tools cannot directly be adopted for PEs.
View Article and Find Full Text PDFCoproduction of multiple proteins at high levels in a single human cell line would be extremely useful for basic research and medical applications. Here, a novel strategy for the stable expression of multiple proteins by integrating the genes into defined transcriptional hotspots in the human genome is presented. As a proof-of-concept, it is shown that EYFP is expressed at similar levels from hotspots and that the EYFP expression increases proportionally with the copy number.
View Article and Find Full Text PDFCRISPR-mediated DNA base editors, which include cytosine base editors (CBEs) and adenine base editors (ABEs), are promising tools that can induce point mutations at desired sites in a targeted manner to correct or disrupt gene expression. Their high editing efficiency, coupled with their ability to generate a targeted mutation without generating a DNA double-strand break (DSB) or requiring a donor DNA template, suggests that DNA base editors will be useful for treating genetic diseases, among other applications. However, this hope has recently been challenged by the discovery of DNA base editor shortcomings, including off-target DNA editing, the generation of bystander mutations, and promiscuous deamination effects in both DNA and RNA, which arise from the main DNA base editor constituents, a Cas nuclease variant and a deaminase.
View Article and Find Full Text PDFThe overproduction and purification of human proteins is a requisite of both basic and medical research. Although many recombinant human proteins have been purified, current protein production methods have several limitations; recombinant proteins are frequently truncated, fail to fold properly, and/or lack appropriate post-translational modifications. In addition, such methods require subcloning of the target gene into relevant plasmids, which can be difficult for long proteins with repeated domains.
View Article and Find Full Text PDFAdenine base editors comprise an adenosine deaminase, evolved in vitro, and a Cas9 nickase. Here, we show that in addition to converting adenine to guanine, adenine base editors also convert cytosine to guanine or thymine in a narrow editing window (positions 5-7) and in a confined TC*N sequence context. Adenine base editor-induced cytosine substitutions occur independently of adenosine conversions with an efficiency of up to 11.
View Article and Find Full Text PDFPolymers with supramolecular functionality are receiving increasing attention for rechargeable battery binders as strong supramolecular interactions can facilitate self-healing effects bond recovery of the cleaved cross-links. Such self-healing capability is useful for emerging high-capacity battery materials that undergo large volume changes. Benchmarking mussel's sticky byssus cuticle, herein we report a copolymer binder with Fe-(tris)catechol coordination cross-links, which can induce a self-healing effect for silicon anodes.
View Article and Find Full Text PDFMolecular cloning is an essential technique in molecular biology and biochemistry, but it is frequently laborious when adequate restriction enzyme recognition sites are absent. Cas9 endonucleases can induce site-specific DNA double-strand breaks at sites homologous to their guide RNAs, rendering an alternative to restriction enzymes. Here, by combining DNA cleavage via a Cas9 endonuclease and DNA ligation via Gibson assembly, we demonstrate a precise and practical DNA cloning method for replacing part of a backbone plasmid.
View Article and Find Full Text PDFCas12a (also called Cpf1) is a representative type V-A CRISPR effector RNA-guided DNA endonuclease, which provides an alternative to type II CRISPR-Cas9 for genome editing. Previous studies have revealed that Cas12a has unique features distinct from Cas9, but the detailed mechanisms of target searching and DNA cleavage by Cas12a are still unclear. Here, we directly observe this entire process by using single-molecule fluorescence assays to study Cas12a from Acidaminococcus sp.
View Article and Find Full Text PDFNew binder concepts have lately demonstrated improvements in the cycle life of high-capacity silicon anodes. Those binder designs adopt adhesive functional groups to enhance affinity with silicon particles and 3D network conformation to secure electrode integrity. However, homogeneous distribution of silicon particles in the presence of a substantial volumetric content of carbonaceous components (i.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2018
A significant effort is currently being invested to improve the electrochemical performance of classical lithium-ion batteries (LIBs) or to accelerate the advent of new chemistry-based post-LIBs. Regardless of the governing chemistry associated with charge storage, stable electrode-electrolyte interface and wet-adhesion among the electrode particles are universally desired for rechargeable batteries adopting liquid electrolytes. In this regard, recent studies have witnessed the usefulness of mussel-inspired polydopamine or catechol functional group in modifying the key battery components, such as active material, separator, and binder.
View Article and Find Full Text PDFDespite two decades of commercial history, it remains very difficult to simultaneously achieve both high rate capability and thermal stability in the graphite anodes of Li-ion batteries because the stable solid electrolyte interphase (SEI) layer, which is essential for thermal stability, impedes facile Li(+) ion transport at the interface. Here, we resolve this longstanding challenge using a mussel-inspired polydopamine (PD) coating via a simple immersion process. The nanometer-thick PD coating layer allows the formation of an SEI layer on the coating surface without perturbing the intrinsic properties of the SEI layer of the graphite anodes.
View Article and Find Full Text PDFWe report supramolecular cross-linking of polymer binders via dynamic host-guest interactions between hyperbranched β-cyclodextrin polymer and a dendritic gallic acid cross-linker incorporating six adamantane units for high-capacity silicon anodes. Calorimetric analysis in the solution phase indicates that the given host-guest complexation is a highly spontaneous and enthalpically driven process. These findings are further verified by carrying out gelation experiments in both aqueous and organic media.
View Article and Find Full Text PDFCovalent or Noncovalent? Systematic investigation of polymeric binders incorporating Meldrum's acid reveals most critical binder properties for silicon -anodes in lithium ion batteries, that is self-healing effect facilitated by a series of noncovalent interactions.
View Article and Find Full Text PDFPolymeric binders play an important role in electrochemical performance of high-capacity silicon (Si) anodes that usually suffer from severe capacity fading due to unparalleled volume change of Si during cycling. In an effort to find efficient polymeric binders that could mitigate such capacity fading, herein, we introduce polymerized β-cyclodextrin (β-CDp) binder for Si nanoparticle anodes. Unlike one-dimensional binders, hyperbranched network structure of β-CDp presents multidimensional hydrogen-bonding interactions with Si particles and therefore offers robust contacts between both components.
View Article and Find Full Text PDFConjugation of mussel-inspired catechol groups to various polymer backbones results in materials suitable as silicon anode binders. The unique wetness-resistant adhesion provided by the catechol groups allows the silicon nanoparticle electrodes to maintain their structure throughout the repeated volume expansion and shrinkage during lithiation cycling, thus facilitating substantially improved specific capacities and cycle lives of lithium-ion batteries.
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