In article number 2000020, Won Jong Kim and co-workers describe a reinforced natural killer (ReNK) system, adopting the formation of NK–tumor cell immunological synapses (IS) as a trigger for delivery of tumor-specific chemotherapeutics. NK cells are decorated with the IS environment-responsive micellar system to ensure the release of drug when they attack cancer cells. The strategy enables the NK cells to inhibit the growth of solid tumors by efficient penetration of the delivered drug into the tumor tissue; otherwise, its penetration is hindered by the dense extracellular matrix of the tumor tissue.

Patterned magnetic nanostructures are foundational to magnetic memory and logic devices. In article number 2001080, Antonio B. Mei, Gregory D. Fuchs, and co-workers design a platform for reconfigurable magnetic nanostructures in FeRh by tuning the transition temperature from antiferromagnetic to ferromagnetic such that both phases are stable at room temperature. Focused laser heating is used to write ferromagnetic patterns of arbitrary shape at ultrafast speeds, which can be erased by cooling below room temperature.

In article number 1908127, Cheng Zhong and co-workers report the development of an alkaline gel polymer electrolyte (GPE), which is fabricated through multiple crosslinking reactions among poly(vinyl alcohol), poly(acrylic acid), and graphene oxide followed by intense uptake of an alkali and a KI reaction modifier. This electrolyte enables the construction of zinc–air batteries that exhibit low charge potential, long working life, high energy efficiency, and excellent practicability for flexible power sources.

Optical activity of surface lattice resonances is demonstrated by Nicolas Vogel and co-workers in article number 2001330. The controlled arrangement of chiral crescent-shaped nanoantennae allows a selective response of the surface lattice resonances to the handedness of incident circularly polarized light. Modified colloidal lithtography enables the fabrication of cm²-scale substrates using a self-assembled poly(N-isopropylacrylamide)–silica core–shell system as particle masks.

An overview of the design of stimuli-responsive upconversion nanoparticles that can precisely target and respond to tumors via targeting the tumor microenvironment and intracellular signals is presented. Personalized design of upconversion nanoparticles and detailed understanding of the tumor microenvironment will result in more effective clinical translation.

Different types of biomineralization, including calcification, silicification, iron, carbon, nitrogen, and phosphorus mineralization, which are mediated by algae, bacteria, fungi, and viruses, are summarized. The mechanisms of extracellular and intracellular microbe-mediated mineralization, as well as their environmental, industrial, and biotechnological applications are discussed in depth.

An overview of cation–π interactions and their roles in graphene-containing material systems is presented, with a focus on water treatment applications. Relevant theoretical modeling and calculations are summarized to offer an in-depth understanding of the underlying mechanisms. Perspectives on the potential directions that are worth effort are presented.

A reinforced natural killer (ReNK) cell system is designed to release drugs upon the formation of an NK–tumor cell immunological synapse. Degranulation and acidification at the synapse cleft trigger the disassembly of pH-sensitive polymeric micelles on the surface of the NK cells. Doxorubicin released from ReNK diffuses into the tumor tissue, overcoming the insufficient therapeutic effect due to restricted infiltration of NK cells.

By controlling the stoichiometry in epitaxial FeRh/MgO, the transition temperature from antiferromagnet to ferromagnet is tuned such that both phases are stable at room temperature. Focused pulsed laser heating is used to write and image arbitrarily shaped ferromagnetic patterns at ultrafast speeds, which can be erased by cooling the film below room temperature.

Electrolytes play a significant role in the development of high-energy-density and long-life rechargeable zinc–air batteries. A developed KI–PVAA–GO hydrogel electrolyte enables zinc–air batteries that exhibit low charge potential of 1.69 V, long working life of 200 h, high energy efficiency of 73%, and excellent practicability for flexible power sources.

Surface lattice resonances result from coupling of localized surface plasmon resonances to grazing diffraction orders. By arranging chiral nanocrescents into periodic arrays with controlled interparticle distances, chiral lattice resonances become accessible. These resonances show a selective response to the handedness of incident circularly polarized light. Such arrays are fabricated over large areas (>cm²) by self-assembly of core–shell masking particles and modified colloidal lithography.

The quasi-2D heterostructure of atomically thin ZnO monocrystalline nanosheet/amorphous Al₂O₃ enables exotic memristive behavior, which is attributed to the generation of concentrated oxygen vacancies with a high mobility in the low-resistance state. This discovery reveals a new route for tuning the electronic transport property by 2D heterostructuring.

Novel pressure-driven thin-film composite membranes containing entrapped structural submicroporosity (pore size < 4 Å) exhibit superb performance for removal of small solutes from aqueous or organic solutions. The membranes potentially lower the energy burden and improve the environmental sustainability of chemical separations that are currently based on thermal principles and account for ≈10–15% of the world's total energy consumption.

Novel thin-film composite membranes containing entrapped structural submicroporosity (pore size of <4 Å) exhibit superb performance for removal of small solutes from aqueous or organic solutions, as discussed by Ingo Pinnau and co-workers in article number 2001132. The membranes potentially lower the energy burden and improve the environmental sustainability of chemical separations, which are currently based on thermal principles and account for approximately 10–15% of the world's total energy consumption.

A ternary hybrid-cation room-temperature liquid metal battery is developed to explore lithium ions as the cathodic charge carrier and potassium ions as the anodic charge carrier. Stable cycling and high voltage are achieved, and the interfacial chemistry that controls cation selective transportation is also modeled and characterized.

A highly stretchable cross-reactive sensor matrix for electronic-skin applications is demonstrated, which can detect, classify, and discriminate various intermixed tactile and thermal stimuli based on machine learning. By adopting a learning algorithm based on the bag-of-words model, highly accurate classification of intermixed stimuli is achieved.

Micrometer-sized single crystal H-Nb₂O₅ with an amorphous N-doped carbon shell (N-C@MSC-Nb₂O₅) is designed to optimize the homogeneity of electron and ion transport, which dramatically improves its electrochemical reaction kinetics and synchronism of phase change during (de)intercalation. Therefore, N-C@MSC-Nb₂O₅ shows a better high-rate performance than most Li₄Ti₅O₁₂-based and T-Nb₂O₅-based anode materials for lithium-ion batteries.

An electro-photoluminescence (EPL) color-change system is presented. The chromaticity of EPL can be controlled systematically in a wide range of color variation while maintaining high luminance. The EPL color-changing device can be used in a deformable visual encryption and as a soft skin for a soft robotic rover.

CsBr/KBr-additive-assisted all-inorganic perovskite quantum dots demonstrate reduced nonradiative recombination paths and improved carrier transport. The as-fabricated self-powered flexible photodetector arrays exhibit superior photoresponse and electrical stability under different bending conditions (60° and 1600 cycles) with marginal degradation. Moreover, uniform photoresponse is achieved in photodetector arrays, promising for photosensing and imaging systems.

Multistable morphing configurations are obtained in one composite hydrogel with kirigami design by controlling the buckling direction of high-swelling gel strips constrained by a stiff frame. In the kirigami structure, the introduction of cutouts destroys the geometric continuity, increasing the deformation freedom of the discrete strips. A multistate switch is designed by harnessing the hydrogel multimorphs to control a set of light-emitting diodes.

Activated Bi₂Te₃ nanoplates are demonstrated as highly universal and robust electrocatalysts for reduction of small molecules, where they exhibit nearly 100% H₂O₂ selectivity for the oxygen reduction reaction, 89.6% Faradaic efficiency (FE) of HCOOH for the CO₂ reduction reaction, and 7.9% FE of NH₃ for the nitrogen reduction reaction, showing a new class of electrocatalysts for conversion of small molecules with potential practical applications.

Converting biomass-derived substances into value-added chemicals such as single-antipode compounds is an effective strategy to reduce the rapid consumption of fossil resources. Porous organic frameworks with conjugated inner surfaces provide strong π–π interaction for steric hindrance of substrate molecules around the metal active site to achieve stronger asymmetric induction.

A directed-assembly-based printing technique, interfacial convective assembly, is developed to print micro/nanoscale patterns at desired areas of substrates. Various nanoparticles are printed in patterns of different shapes with a high resolution down to 25 nm. Assembly only takes a few minutes, which is two orders of magnitude faster than the conventional convective assembly.

Mechanical tolerance of bioreactions is crucial for obtaining high biosensing fidelity. By combining simulations and experiments, it is found that strain-induced change in reactant flux accounts for the performance drop in flat bioelectrodes. Wavy bioelectrodes capable of curvature adaptation maintain the reactant flux and preserve biosensing performance under static strain and dynamic stretching, which are demonstrated in gesture-insensitive epidermal metabolite biosensors.

A novel approach to achieve a pure organic long-persistent luminescent material using a phosphonium salt doped with dimethylaniline is reported. The doped crystals can exhibit a green afterglow emission lasting up to 7 h after the cessation of UV excitation. The positive phosphonium salt holds and protects the separated charge to produce unprecedented afterglow duration.

Ultrathin unobstructed gas transport channels through the membrane selective layer are constructed in mixed matrix membranes (MMMs) by using gravity-induced interface self-assembly of poly(vinylamine) and polymer-modified MIL-101(Cr). For CO₂/N₂ (15/85 by volume) mixed gas, the MMMs achieved a high CO₂ permeance of 823 gas permeation units and CO₂/N₂ selectivity of 242 at 0.5 MPa.

3D porous LiFeO_2−x rich with Fe(II) is prepared by reacting Fe₂O₃ with LiH at 550 °C. With a unique staghorn-coral-like skeleton measuring ≈100 nm in diameter, the Fe(II)-rich LiFeO_2−x delivers the presently known highest initial coulombic efficiency (ICE) value of 90.2% with 1170 mAh g⁻¹ of discharge capacity favored by a fast conversion reaction of LiFeO_2−x upon lithiation/delithiation.

Two stacking orders of ReS₂ are identified. Stacking AA has negligible displacement across layers and stacking AB has a one-unit cell displacement along the a-axis. AB stacking has stronger interlayer coupling than AA. The cross-layer displacement in AB stacking disrupts excited-state excitons. Vibrational, optical properties and carrier dynamics in two stacking orders are drastically different.

Boosting charge transfer in materials is critical for applications involving charge carriers. Engineering ionic channels in electrode materials can create a skeleton to manipulate their ion/electron behaviors with favorable parameters to promote their performance. Tailoring of the atomic structure in layered potassium niobate and facilitating its application in Li/K storage by dehydration-triggered lattice rearrangement is reported.

Heterostructures of 2D molybdenum dichalcogenide on 2D nitrogen-doped carbon (MoS₂-on-NC and MoSe₂-on-NC) are designed for potassium-ion batteries with superior electrochemical performance and outstanding cycle life. The insertion–conversion mechanism of MoSe₂ is revealed during the process of potassiation and depotassiation by in situ Raman spectra and ex situ high-resolution transmission electron microscopy (HRTEM).

End-group π−π stacking is proved to be able to effectively reduce the singlet−triplet energy difference in narrow-bandgap A−D−A acceptors, which is beneficial in simultaneously decreasing the voltage loss in exciton dissociation and suppressing triplet recombination. Furthermore, the absorption spectra can be broadened or redshifted, thus improving the light-harvesting efficiencies. These results pave the way toward high-efficiency organic photovoltaics.

In treatment of hypoxic tumors, oxygen-dependent photodynamic therapy (PDT) is considerably limited. In this work, a new bimetallic and biphasic Rh-based core–shell nanosystem (Au@Rh-indocyanine green-cell membrane) is developed. Such porous Au@Rh core–shell nanostructures exhibit catalase-like activity to efficiently catalyze oxygen generation from endogenous hydrogen peroxide to address tumor hypoxia while achieving high PDT efficacy.