Nature nanotechnology最新文献

Strategies that selectively bind proteins of interest and target them to the intracellular protein recycling machinery for targeted protein degradation have recently emerged as powerful tools for undruggable targets in biomedical research and the pharmaceutical industry. However, targeting any new protein of interest with current degradation tools requires a laborious case-by-case design for different diseases and cell types, especially for extracellular targets. Here we observe that nanoparticles can mediate specific receptor-independent internalization of a bound protein and further develop a general strategy for degradation of extracellular proteins of interest by making full use of clinically approved components. This extremely flexible strategy aids in targeted protein degradation tool development and provides knowledge for targeted drug therapies and nanomedicine design.

Programmed cell death-ligand 1 (PD-L1) blockers have advanced immunotherapy, but their lack of tumour homing capability represents a substantial challenge. Here we show that genetically engineered filamentous phages can be used as tumour-targeting immunotherapeutic agents that reduce the side effects caused by untargeted delivery of PD-L1 blockers. Specifically, we improved biopanning to discover a peptide binding the extracellular domain of PD-L1 and another targeting both melanoma tissues and cancer cells. The two peptides were genetically fused to the sidewall protein and tip protein of fd phages, respectively. The intravenously injected phages homed to tumours and bound PD-L1 on cancer cells, effectively blocking PD-1/PD-L1 recognition to trigger targeted immunotherapy without body weight loss, organ abnormalities and haematological aberrations. The phages, cost-effectively replicated by bacteria, are cancer-targeting immunotherapeutic nanofibres that can be flexibly designed to target different cancer types and immune checkpoints.

Alkaline-earth metal peroxides (MO₂, M = Ca, Sr, Ba) represent a category of versatile and clean solid oxidizers, while the synthesis process usually consumes excessive hydrogen peroxide (H₂O₂). Here we discover that H₂O₂ synthesized via two-electron electrochemical oxygen reduction (2e⁻ ORR) on the electrode surface can be efficiently and durably consumed to produce high-purity MO₂ in an alkaline environment. The crucial factor lies in the in-time detachment of in situ-generated MO₂ from the self-cleaning electrode, where the solid products spontaneously detach from the electrode to solve the block issue. The self-cleaning electrode is achieved by constructing micro-/nanostructure of a highly active catalyst with appropriate surface modification. In experiments, an unprecedented accumulated selectivity (~99%) and durability (>1,000 h, 50 mA cm⁻²) are achieved for electrochemical synthesis of MO₂. Moreover, the comparability of CaO₂ and H₂O₂ for tetracycline degradation with hydrodynamic cavitation is validated in terms of their close efficacies (degradation efficiency of 87.9% and 93.6% for H₂O₂ and CaO₂, respectively).

Advancements in single-atom-based catalysts are crucial for enhancing oxygen evolution reaction (OER) performance while reducing precious metal usage. A comprehensive understanding of underlying mechanisms will expedite this progress further. Here we report Ir single atoms coordinated out-of-plane with dimethylimidazole (MI) on CoFe hydroxide (Ir₁/(Co,Fe)-OH/MI). This Ir₁/(Co,Fe)-OH/MI catalyst, which was prepared using a simple immersion method, delivers ultralow overpotentials of 179 mV at a current density of 10 mA cm⁻² and 257 mV at 600 mA cm⁻² as well as an ultra-small Tafel slope of 24 mV dec⁻¹. Furthermore, Ir₁/(Co,Fe)-OH/MI has a total mass activity exceeding that of commercial IrO₂ by a factor of 58.4. Ab initio simulations indicate that the coordination of MI leads to electron redistribution around the Ir sites. This causes a positive shift in the d-band centre at adjacent Ir and Co sites, facilitating an optimal energy pathway for OER.

Living systems depend on continuous energy input for growth, replication and information processing. Cells use membrane proteins as nanomachines to convert light or chemical energy of nutrients into other forms of energy, such as ion gradients or adenosine triphosphate (ATP). However, engineering sustained fuel supply and metabolic energy conversion in synthetic systems is challenging. Here, inspired by endosymbionts that rely on the host cell for their nutrients, we introduce the concept of cross-feeding to exchange ATP and ADP between lipid-based compartments hundreds of nanometres in size. One population of vesicles enzymatically produces ATP in the mM concentration range and exports it. A second population of vesicles takes up this ATP to fuel internal reactions. The produced ADP feeds back to the first vesicles, and ATP-dependent reactions can be fuelled sustainably for up to at least 24 h. The vesicles are a platform technology to fuel ATP-dependent processes in a sustained fashion, with potential applications in synthetic cells and nanoreactors. Fundamentally, the vesicles enable studying non-equilibrium processes in an energy-controlled environment and promote the development and understanding of constructing life-like metabolic systems on the nanoscale.

The exotic properties of three-dimensional halide perovskites, such as mixed ionic–electronic conductivity and feasible ion migration, have enabled them to challenge traditional memristive materials. However, the poor moisture stability and difficulty in controlling ion transport due to their polycrystalline nature have hindered their use as a neuromorphic hardware. Recently, two-dimensional (2D) halide perovskites have emerged as promising artificial synapses owing to their phase versatility, microstructural anisotropy in electrical and optoelectronic properties, and excellent moisture resistance. However, their asymmetrical and nonlinear conductance changes still limit the efficiency of training and accuracy of inference. Here we achieve highly linear and symmetrical conductance changes in Dion–Jacobson 2D perovskites. We further build a 7 × 7 crossbar array based on analogue perovskite synapses, achieving a high device yield, low variation with synaptic weight storing capability, multi-level analogue states with long retention, and moisture stability over 7 months. We explore the potential of such devices in large-scale image inference via simulations and show an accuracy within 0.08% of the theoretical limit. The excellent device performance is attributed to the elimination of gaps between inorganic layers, allowing the halide vacancies to migrate homogeneously regardless of grain boundaries. This was confirmed by first-principles calculations and experimental analysis.