Most of the recent reports focused on using cyclodextrin/azobenzene/polymer for reversible immobilization of biomolecules, the reversible photoswitching of biofunctions via universal and low-cost strategy, were barely investigated. Herein, we report light-triggered switching of reversible and alterable biofunctionality on silicon interface via β-cyclodextrin/azobenzene based host−guest interaction. Biofunctional azobenzene-grafted polymers were synthesized and assembled onto β-cyclodextrin anchored interfaces to form "smart" monolayers of light-triggered switchable brushes. The photoresponsive interfaces exhibit reversible and alterable biofunctionality switching from antibacterial/hemostatic to bioadhesion/anticoagulant upon ultraviolet and visible (UV−vis) light cycles.

Adaptive molecular self-assemblies provide possibility of constructing smart and functional materials in a non-covalent bottom-up manner. Exploiting the intrinsic properties of responsiveness of non-covalent interactions, a great number of fancy self-assemblies have been achieved. In this review, we try to highlight the recent advances in this field. The following contents are focused: (1) environmental adaptiveness, including smart self-assemblies adaptive to pH, temperature, pressure, and moisture; (2) special chemical adaptiveness, including nanostructures adaptive to important chemicals, such as enzymes, CO2, metal ions, redox agents, explosives, biomolecules; (3) field adaptiveness, including self-assembled materials that are capable of adapting to external fields such as magnetic field, electric field, light irradiation, and shear forces.

Multifunctional hydrogels acting as wound dressing have received extensive attention in soft tissue repair; however, it is still a challenge to develop a non-antibiotic-dependent antibacterial hydrogel that has tunable adhesion and deformation to achieve on-demand removal. Herein, an asymmetric adhesive hydrogel with near-infrared (NIR)-triggered tunable adhesion, self-deformation, and bacterial eradication is designed. The hydrogel is prepared by the crosslinking polymerization of N-isopropylacrylamide and acrylic acid, during the sedimentation of conductive PPy-PDA nanoparticles based on the polymerization of pyrrole (Py) and dopamine (DA). Due to the conversion capacity from NIR light into heat for PPy-PDA NPs, the formed temperature-sensitive hydrogel exhibits tissue adhesive as well as NIR-triggered tunable adhesion and self-deformation property, which can achieve an on-demand dressing refreshing. Systematically in vitro/in vivo antibacterial experiments indicate that the hydrogel shows excellent disinfection capability to both Gram-negative and Gram-positive bacteria. The in vivo experiments in a full-layer cutaneous wound model demonstrate that the hydrogel has a good treatment effect to promote wound healing. Overall, the asymmetric hydrogel with tunable adhesion, self-deformation, conductive, and photothermal antibacterial activity may be a promising candidate to fulfill the functions of adhesion on skin tissue, easy removing on-demand, and accelerating the wound healing process.

In this study, multifunctional and heparin-mimicking star-shaped supramolecules-deposited 3D porous multilayer films with improved biocompatibility were fabricated via a layer-by-layer (LbL) self-assembly method on polymeric membrane substrates. Star-shaped heparin-mimicking polyanions (including poly(styrenesulfonate-co-sodium acrylate; Star-PSS-AANa) and poly(styrenesulfonate-co-poly(ethylene glycol)methyl ether methacrylate; Star-PSS-EGMA)) and polycations (poly(methyl chloride-quaternized 2-(dimethylamino)ethyl methacrylate; Star-PMeDMA) were first synthesized by atom transfer radical polymerization (ATRP) from β-cyclodextrin (β-CD) based cores. Then assembly of 3D porous multilayers onto polymeric membrane surfaces was carried out by alternating deposition of the polyanions and polycations via electrostatic interaction. The surface morphology and composition, water contact angle, blood activation, and thrombotic potential as well as cell viability for the coated heparin-mimicking films were systematically investigated. The results of surface ATR-FTIR spectra and XPS spectra verified successful deposition of the star-shaped supramolecules onto the biomedical membrane surfaces; scanning electron microscopy (SEM) and atomic force microscopy (AFM) observations revealed that the modified substrate had 3D porous surface morphology, which might have a great biological influence on the biointerface. Furthermore, systematic in vitro investigation of protein adsorption, platelet adhesion, human platelet factor 4 (PF4, indicates platelet activation), activate partial thromboplastin time (APTT), thrombin time (TT), coagulation activation (thrombin-antithrombin III complex (TAT, indicates blood coagulant)), and blood-related complement activation (C3a and C5a, indicates inflammation potential) confirmed that the heparin-mimicking multilayer coated membranes exhibited ultralow blood component activations and excellent hemocompatibility. Meanwhile, after surface coating, endothelial cell viability was also promoted, which indicated that the heparin-mimicking multilayer coating might extend the application fields of polymeric membranes in biomedical fields.

High-performance lithium-ion batteries (LIBs) demand efficient and selective transport of lithium ions. Inspired by ion channels in biology systems, lithium-ion channels are constructed by chemically modifying the nanoporous channels of metal–organic frameworks (MOFs) with negatively charged sulfonate groups. Analogous to the biological ion channels, such pendant anionic moieties repel free anions while allowing efficient transport of cations through the pore channels. Implementing such MOFs as an electrolyte membrane doubly enhances the lithium-ion transference number, alleviates concentration polarization, and affords striking durability of high-rate LIBs. This work demonstrates an ion-selective material design that effectively tunes the ion-transport behavior and could assist with more efficient operation of LIBs.

The existing defects on the surface of CsPbX3 nanocrystals (NCs) resulted in the decrease of the photoluminescence quantum yields (PLQYs) of NCs. In this study, we developed a simple strategy, which can make the treated CsPbX3 NCs exhibit high PLQYs and better stability by CdX2 post-treatment at room temperature. The treated CsPbX3 NCs were characterized by X-ray diffraction (XRD) patterns and PL spectra. The shape, size, and crystal structure of the NCs remained unchanged after Cd ion treatment. The PLQYs of CsPbCl3 increased from 24 to 73% and the PLQYs of CsPbBr3 NCs increased from 85 to 92% after treatment. The significant enhancement of PLQYs is ascribed to the effective passivation of surface defects, in which Cd2+ and X– ions occupied the Pb–X vacancies existing on the surface of the NCs. In addition, this strategy was also applied to a mixed halide perovskite. The practical application of CsPbX3 NCs will be extended by this method.

A new family of solid-like electrolytes was developed by infiltrating MIL-100(Al), an electrochemically stable metal−organic-framework (MOF) material, with liquid electrolytes that contain cations from the 3rd period (Na + , Mg 2+ , and Al 3+ ) and the 1st group (Li + , Na + , K + , and Cs + ). The anions were immobilized within the MOF scaffolds upon complexing with the open metal sites, allowing effective transport of the cations in the nanoporous channels with high conductivity (up to 1 mS cm −1 ) and low activation energy (down to 0.2 eV). This general approach enables the fabrication of superior conductive solid-like electrolytes beyond lithium ions.

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