Nature nanotechnology最新文献

Nucleic acid therapeutics are used for silencing, expressing or editing genes in vivo. However, their systemic stability and targeted delivery to bone marrow resident cells remains a challenge. In this study we present a nanotechnology platform based on natural lipoproteins, designed for delivering small interfering RNA (siRNA), antisense oligonucleotides and messenger RNA to myeloid cells and haematopoietic stem and progenitor cells in the bone marrow. We developed a prototype apolipoprotein nanoparticle (aNP) that stably incorporates siRNA into its core. We then created a comprehensive library of aNP formulations and extensively characterized their physicochemical properties and in vitro performance. From this library, we selected eight representative aNP-siRNA formulations and evaluated their ability to silence lysosomal-associated membrane protein 1 (Lamp1) expression in immune cell subsets in mice after intravenous administration. Using the most effective aNP identified from the screening process, we tested the platform’s potential for therapeutic gene silencing in a syngeneic murine tumour model. We also demonstrated the aNP platform’s suitability for splice-switching with antisense oligonucleotides and for protein production with messenger RNA by myeloid progenitor cells in the bone marrow. Our data indicate that the aNP platform holds translational potential for delivering various types of nucleic acid therapeutics to myeloid cells and their progenitors.

Despite substantial advances in green and red metal halide perovskite light-emitting diodes (PeLEDs), blue PeLEDs, particularly deep-blue ones (defined as Commission International de l’Eclairage y coordinate (CIE_y) less than 0.06) that meet the latest Rec. 2020 colour gamut standard, lag dramatically behind owing to a severe phase segregation-induced electroluminescent spectral shift and low exciton utilization in broadened bandgap perovskite emitters. Here we propose a multivalent immobilization strategy to realize high-efficiency and spectrally stable deep-blue PeLEDs by introducing a polyfluorinated oxygen-containing molecule. Systematic experiments and extensive 5,000 fs ab initio molecular dynamics simulations reveal that a crucial role of the multivalent effect stemming from three kinds of interaction of hydrogen bond (F···H–N), ionic bond (F–Pb) and coordination bond (C=O:Pb) with perovskite is to synergistically stabilize the perovskite phase and enhance exciton radiative recombination. The resultant exciton concentration and exciton recombination rate of the deep-blue perovskite emitter are increased by factors of 1.66 and 1.64, respectively. In this context, our target PeLEDs demonstrate a peak external quantum efficiency of up to 15.36% at a deep-blue emission wavelength of 459 nm and a half-lifetime of 144 min at a constant current density of 0.45 mA cm⁻². Moreover, the deep-blue PeLEDs maintain a constant spectrum peak with CIE chromaticity coordinates of (0.136, 0.051) under a steady driving current for 60 min.

Non-collinear antiferromagnets, such as Mn₃Sn, stand out for their topological properties and potential in antiferromagnetic spintronics. This emerging field aims at harnessing ultrafast magnetization dynamics of antiferromagnets through spin torques. Here we report the time-resolved dynamics of Mn₃Sn on a picosecond timescale, driven by an optically induced spin current pulse. Our results reveal that the magnetization of Mn₃Sn tilts immediately after the spin current pulse and subsequently undergoes 70 GHz precession. This immediate tilting underscores the predominant role of damping-like torque stemming from spin current absorption by Mn₃Sn. We also determine the spin coherence length of Mn₃Sn to be approximately 15 nm. This value substantially exceeds that of ferromagnets, highlighting a distinct spin-dephasing process in non-collinear antiferromagnets. Our results hold promise for ultrafast applications of non-collinear antiferromagnets and enrich our understanding of their spin-transfer physics.

Sliding ferroelectricity, an emerging type of hysteretic behaviour with strong potential for memory-related applications, involves dynamically switching the polarization associated with the stacking arrangement in two-dimensional van der Waals materials. Because different stacking configurations can share a degenerate net polarization, it has remained a challenge to resolve the intermediate stacking configuration and the polarization switching pathway in multi-interface devices. In this work, we present an optical approach to resolve the polarization degeneracy in a trilayer 3R-MoS₂ over different switching cycles. By performing reflection contrast spectroscopy in dual-gated devices, we identify distinct responses of inter- and intralayer excitons in all four possible stacking configurations (ABC, ABA, BAB and CBA). Diffraction-limited spatial resolution makes it possible to image the switching of the stacking configurations. We find that the switching pathway is influenced not only by the competition among pinning centres—which localize domain walls at different interfaces—but also by a free-carrier screening effect linked to chemical doping. These findings highlight the importance of managing domain walls, pinning centres and doping levels in sliding ferroelectric devices, offering insights for further development in sensing and computing applications.