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Promoter editing represents an innovative approach to introduce quantitative trait variation (QTV) in crops. However, an efficient promoter editing system for QTV needs to be established. Here we develop a CRISPR–Cas12a promoter editing (CAPE) system that combines a promoter key-region estimating model and an efficient CRISPR–Cas12a-based multiplexed or singular editing system. CAPE is benchmarked in rice to produce QTV continuums for grain starch content and size by targeting OsGBSS1and OsGS3, respectively. We then apply CAPE for promoter editing of OsD18, a gene encoding GA3ox in the gibberellin biosynthesis pathway. The resulting lines carry a QTV continuum of semidwarfism without significantly compromising grain measures. Field trials demonstrated that the OsD18promoter editing lines have the same yield performance and antilodging phenotype as the Green Revolution OsSD1mutants in different genetic backgrounds. Hence, promoter editing of OsD18generates a quantitative Green Revolution trait. Together, we demonstrate a CAPE-based promoter editing and tuning pipeline for efficient production of useful QTV continuum in crops.

Interaction of single-chain nanoparticles (SCNPs) with lipid membranes is studied theoretically based on Monte Carlo simulations using the bond fluctuation model. SCNPs with a tunable elasticity represent an intermediate between rigid nanoparticles and flexible polymers. The degree of cross-linking between monomers of the precursor polymer is the key parameter that allows gradually tuning the properties of SCNPs. Both the alternation of lipid bilayers by SCNPs with different degrees of hydrophobicity and cross-linking and the effect of a lipid bilayer on the shape of the SCNPs are studied. Simulation results for SCNPs indicate an adsorption transition on the bilayer which is sharply peaked around a critical degree of hydrophobicity. At this specific value of hydrophobicity SCNPs can destabilize the structure of the bilayer inducing enhanced permeability for water and small solutes. With increasing degrees of cross-linking, however, membrane penetration and induced permeability get suppressed as the object’s shape gets more conserved. Hydrophobic SCNPs can be fully embedded into the membrane, and the induced permeability increases with the degree of cross-linking. Soft hydrophobic SCNPs adapt their shape changing from spherical to disklike upon membrane insertion, which allows them to minimize the lipid bilayer disturbance, while at high degrees of cross-linking SCNPs keep a spherical shape and disrupt the bilayer at the rim.

Increasing awareness of bioeffects and toxicity of nanomaterials interacting with cells puts in focus the mechanisms by which nanomaterials can cross lipid membranes. Apart from well-discussed energy-dependent endocytosis for large objects and passive diffusion through membranes by solute molecules, other translocation mechanisms based on physical principles can exist. We show the importance of membrane tension on the translocation through lipid bilayers of ultrashort carbon nanotubes (USCNTs). By using a combination of a microfluidic setup and single chain mean field (SCMF) theory, we observed that, under membrane tension, USCNT inserted into a lipid bilayer may spontaneously nucleate an unstable local pore, allowing it to escape from the bilayer. We demonstrated that stretching of the membrane is essential for triggering this mechanism of translocation, and no translocation is observed at low membrane tension. For this purpose, a quantitative analysis of the kinetic pathway associated with USCNT translocation induced by tension was performed in a specially designed microfluidic device, simultaneously combining optical fluorescence microscopy and electrophysiological measurements. An important outcome of these findings is the identification of the way to control the nanomaterial translocation through the lipid bilayer by membrane tension that can be useful in many practical applications.

Pristine graphene, its derivatives, and composites have been widely reported to possess antibacterial properties. Most of the studies simulating the interaction between bacterial cell membranes and the surface of graphene have proposed that the graphene-induced bacterial cell death is caused either by (1) the insertion of blade-like graphene-based nanosheets or (2) the destructive extraction of lipid molecules by the presence of the lipophilic graphene. These simulation studies have, however, only take into account graphene–cell membrane interactions where the graphene is in a dispersed form. In this paper, we report the antimicrobial behavior of graphene sheet surfaces in an attempt to further advance the current knowledge pertaining to graphene cytotoxicity using both experimental and computer simulation approaches. Graphene nanofilms were fabricated to exhibit different edge lengths and different angles of orientation in the graphene sheets. These substrates were placed in contact with Pseudomonas aeruginosaand Staphylococcus aureusbacteria, where it was seen that these substrates exhibited variable bactericidal efficiency toward these two pathogenic bacteria. It was demonstrated that the density of the edges of the graphene was one of the principal parameters that contributed to the antibacterial behavior of the graphene nanosheet films. The study provides both experimental and theoretical evidence that the antibacterial behavior of graphene nanosheets arises from the formation of pores in the bacterial cell wall, causing a subsequent osmotic imbalance and cell death.

Periodontal defect regeneration in severe periodontitis relies on the differentiation and proliferation of periodontal ligament cells (PDLCs). Recently, an emerging 2D nanomaterial, MXene (Ti3C2Tx), has gained more and more attention due to the extensive antibacterial and anticancer activity, while its potential biomedical application on tissue regeneration remains unclear. Through a combination of experimental and multiscale simulation schemes, Ti3C2Txhas exhibited satisfactory biocompatibility and induced distinguish osteogenic differentiation of human PDLCs (hPDLCs), with upregulated osteogenesis‐related genes. Ti3C2Txmanages to activate the Wnt/β‐catenin signaling pathway by enhancing the Wnt‐Frizzled complex binding, thus stabilizing HIF‐1αand altering metabolic reprogramming into glycolysis. In vivo, hPDLCs pretreated by Ti3C2Txdisplay excellent performance in new bone formation and osteoclast inhibition with enhanced RUNX2, HIF‐1α, and β‐catenin in an experimental rat model of periodontal fenestration defects, indicating that this material has high efficiency of periodontal regeneration promotion. It is demonstrated in this work that Ti3C2Txhas highly efficient therapeutic effects in osteogenic differentiation and periodontal defect repairment. MXene (Ti3C2Tx) enhances human periodontal ligament cells' osteogenetic differentiation in vitro and periodontal regeneration in a rat periodontal defect model by activating WNT/hypoxia‐inducible factors‐1α(HIF‐1α)‐mediated metabolism reprogramming, marked by increasing β‐catenin, HIF‐1α, and succinic acid.

Periodontal Tissue Engineering In article number 2101215by Yachong Guo, Wenrong Yang, Fuhua Yan, and co‐workers, 2D nanoflakes of MXene (Ti3C2Tx) enhance hPDLCs osteogenetic differentiation in vitro and periodontal regeneration in a rat periodontal defect mode by activating WNT/HIF‐1α‐mediated metabolism reprogramming. The results imply that Ti3C2Txmight be a potential therapeutic option in periodontal tissue engineering and treatment of periodontitis.