Enhanced drug delivery can improve the therapeutic efficacy of drugs and help overcome side effects. However, many reported drug‐delivery systems are too complex and irreproducible for practical use. ...In this work, the design of a hypoxia‐responsive molecular container based on calixarene, called CAC4A, which presents a significant advance in practical, hypoxia‐targeted drug‐delivery, is reported. CAC4A enables a wide variety of clinical drugs to be quantitatively loaded to improve their solubility and stability, as well as enable the administration of reduced doses. Furthermore, as a result of its azo functional groups, which are sensitive to reduction within a hypoxic environment, it is possible to achieve tumor‐targeted drug‐release with reduced side effects. CAC4A fulfils all essential requirements for a drug‐delivery system in addition to multiple advantages, including facile preparation, well‐defined molecular weight, and structure, and universal applicability. Such features collectively enable supramolecular prodrugs to be formulated simply and reproducibly, with potential for bench‐to‐bedside translation. Moreover, CAC4A is amenable to other therapy modalities and can be facilely decorated with functional groups and hybridized with nanomaterials, providing ample possibilities for its role in future drug‐delivery systems.
Carboxylated azocalix4arene is designed as a hypoxia‐responsive molecular container, which affords strong binding toward a series of chemotherapeutic drugs, and improves the drugs’ solubility and stability, demonstrating its universality as a supramolecular drug carrier. Taking one supramolecular prodrug as an example, the efficacy of this hypoxia‐targeted therapy is validated in vitro and in vivo.
Poisoning is a leading cause of admission to medical emergency departments and intensive care units. Supramolecular detoxification, which involves injecting supramolecular receptors that bind with ...toxins to suppress their biological activity, is an emerging strategy for poisoning treatment; it has few requirements and a broad application scope. However, it is still a formidable challenge to design supramolecular therapeutic materials as an antidote to macromolecular toxins, because the large size, flexible conformation, and presence of multiple and diverse binding sites of biomacromolecules hinder their recognition. Herein, a supramolecular antidote to macromolecular toxins is developed through the coassembly of macrocyclic amphiphiles, relying on heteromultivalent recognition between the coassembled components and toxic macromolecules. The coassembly of amphiphilic cyclodextrin and calixarene strongly and selectively captures melittin, a toxin studied herein; this imparts various therapeutic effects such as inhibiting the interactions of melittin with cell membranes, alleviating melittin cytotoxicity and hemolytic toxicity, reducing the mortality rate of melittin‐poisoned mice, and mitigating damage to major organs. The use of the proposed antidote overcomes the limitation of supramolecular detoxification applicability to only small‐molecular toxins. The antidote can also detoxify other macromolecular toxins as long as selective and strong binding is achieved because of the coassembling tunability.
Supramolecular detoxification is an emerging strategy for treating poisoning; however, developing supramolecular therapeutic materials as an antidote to macromolecular toxins is challenging. To overcome this challenge, a heteromultivalent coassembling material (CCA‐CD) comprising macrocyclic amphiphiles is developed. The CCA‐CD binds with melittin strongly and selectively, and significantly alleviates its toxicity, serving as a novel supramolecular antidote used for melittin poisoning treatment.
Calixarenes (CAs), representing the third generation of supramolecular hosts and one of the most widely studied macrocyclic scaffolds, offer (almost) unlimited structure and application possibilities ...due to their ease of modification, which allows one to establish a large molecular library as a material basis for diverse biomedical applications. Moreover, CAs and their derivatives engage in various noncovalent interactions for the facile recognition of guests including bioactive molecules and are also important building blocks for the fabrication of supramolecular architectures. In view of their molecular recognition and self‐assembly properties, CAs are extensively applied in biosensing, bioimaging, and drug/gene delivery. Additionally, some CA derivatives exhibit biological activities and can therefore be used as new therapeutic agents. Herein, we summarize the diverse biomedical applications of CAs including in vitro diagnosis (biosensing), in vivo diagnosis (bioimaging), and therapy.
Calixarenes (CAs) represent the third generation of supramolecular hosts and one of the most widely studied macrocyclic scaffolds. They offer almost unlimited structural possibilities due to their ease of modification, providing a tremendous molecular library as a material basis for diverse biomedical applications.
The design and synthesis of new synthetic macrocycles has driven the rapid development of supramolecular chemistry and materials. Pillarnarenes, as a new type of macrocyclic compounds, are used as a ...promising type of building blocks for switchable supramolecular systems due to their versatile functionalization and the ability of binding toward various guest molecules. A number of guests can form inclusion complexes with pillarnarenes and their derivatives in solution, which are sensitive to different external triggers. Interestingly, the pursuit of complex stimuli‐responsive functional materials and devices has largely motivated the shift of pillarnarene‐based switches from solution media to surfaces for controllable macroscopic motions on solid platforms. Facilitated by the facile modification of pillarnarenes on various solid supports and the dynamic binding of host–guest complexes, numerous functional hybrid materials with adjustable physical or chemical properties and integrated functionalities have been reported in the last decade. Here, the advance of supramolecular switches in solution and on surfaces based on pillarnarenes and derivatives with an emphasis on the efforts and the latest contributions from the field is discussed.
The supramolecular switches based on pillarnarene derivatives that have been investigated in solution and further shifted to the solid surfaces of materials for collective amplified motions controlled by actuations are reviewed. The afforded materials present combined features of stimuli‐responsiveness of pillarnarene‐based switches and intrinsic properties of solid supports and show applications in various aspects.
Hypoxia is a major contributor to global kidney diseases. Targeting hypoxia is a promising therapeutic option against both acute kidney injury and chronic kidney disease; however, an effective ...strategy that can achieve simultaneous targeted kidney hypoxia imaging and therapy has yet to be established. Herein, we fabricated a unique nano-sized hypoxia-sensitive coassembly (Pc/C5A@EVs) via molecular recognition and self-assembly, which is composed of the macrocyclic amphiphile C5A, the commercial dye sulfonated aluminum phthalocyanine (Pc) and mesenchymal stem cell-excreted extracellular vesicles (MSC-EVs).
In murine models of unilateral or bilateral ischemia/reperfusion injury, MSC-EVs protected the Pc/C5A complex from immune metabolism, prolonged the circulation time of the complex, and specifically led Pc/C5A to hypoxic kidneys via surface integrin receptor α
β
and α
β
, where Pc/C5A released the near-infrared fluorescence of Pc and achieved enhanced hypoxia-sensitive imaging. Meanwhile, the coassembly significantly recovered kidney function by attenuating cell apoptosis, inhibiting the progression of renal fibrosis and reducing tubulointerstitial inflammation. Mechanistically, the Pc/C5A coassembly induced M1-to-M2 macrophage transition by inhibiting the HIF-1α expression in hypoxic renal tubular epithelial cells (TECs) and downstream NF-κB signaling pathway to exert their regenerative effects.
This synergetic nanoscale coassembly with great translational potential provides a novel strategy for precise kidney hypoxia diagnosis and efficient kidney injury treatment. Furthermore, our strategy of coassembling exogenous macrocyclic receptors with endogenous cell-derived membranous structures may offer a functional platform to address multiple clinical needs.
Perfluorinated alkyl substances, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are toxic materials that are known to globally contaminate water, air, and soil resources. ...Strategies for the simultaneous detection and removal of these compounds are desired to address this emerging health and environmental issue. Herein, we develop a type of guanidinocalix5arene that can selectively and strongly bind to PFOS and PFOA, which we use to demonstrate the sensitive and quantitative detection of these compounds in contaminated water through a fluorescent indicator displacement assay. Moreover, by co-assembling iron oxide nanoparticle with the amphiphilic guanidinocalix5arene, we are able to use simple magnetic absorption and filtration to efficiently remove PFOS and PFOA from contaminated water. This supramolecular approach that uses both molecular recognition and self-assembly of macrocyclic amphiphiles is promising for the detection and remediation of water pollution.
Sub‐freezing temperature presents a significant challenge to the survival of current Li‐ion batteries (LIBs) as it leads to low capacity retention and poor cell rechargeability. The electrolyte in ...commercial LIBs relies too heavily on ethylene carbonate (EC) to produce a stable solid electrolyte interphase (SEI) on graphite (Gr) anodes, but its high melting point (36.4 °C) severely restricts ion transport below 0 °C, causing energy loss and Li plating. Here, a class of EC‐free electrolytes that exhibits remarkable low‐temperature performance without compromising cell lifespan is reported. It is found that at sub‐zero temperatures, EC forms highly resistive SEI that seriously impedes electrode kinetics, whereas EC‐free electrolytes create a highly stable, low‐impedance SEI through anion decomposition, which boosts capacity retention and eliminates Li plating during charging. Pouch‐type LiCoO2 (LCO)|Gr cells with EC‐free electrolytes sustain 900 cycles at 25 °C with 1 C charge/discharge, and LiNi0.85Co0.10Al0.05O2 (NCA)|Gr cells last 300 cycles at −15 °C with 0.3 C charge, both among the best‐performing in the literature under comparable conditions. Even at −50 °C, the NCA|Gr cell with EC‐free electrolytes still delivers 76% of its room‐temperature capacity, outperforming EC‐based electrolytes.
A new class of ethylene carbonate (EC)‐free electrolytes, based on methyl acetate and fluorinated ethers, is proposed for Li‐ion batteries operating at sub‐freezing temperatures. The EC‐free electrolyte demonstrates all‐round performance advantages over the traditional EC‐based electrolyte and presents a viable solution to improve the capacity retention and rechargeability of metal‐ion batteries in cold climates.
Boosting charge separation and transfer of photoanodes is crucial for providing high viability of photoelectrochemical hydrogen (H2) generation. Here, a structural engineering strategy is designed ...and synthesized for uniformly coating an ultrathin CoFe bimetal‐organic framework (CoFe MOF) layer over a BiVO4 photoanode for boosted charge separation and transfer. The photocurrent density of the optimized BiVO4/CoFe MOF(NA) photoanode reaches a value of 3.92 mA cm−2 at 1.23 V versus reversible hydrogen electrode (RHE), up to 6.03 times that of pristine BiVO4, due to the greatly increased efficiency of charge transfer and separation. In addition, this photoanode records one onset potential that is considerably shifted negatively when compared to BiVO4. Transient absorption spectroscopy reveals that the CoFe MOF(NA) prolongs charge recombination lifetime by blocking the hole‐transfer pathway from the BiVO4 to its surface trap states. This work sheds light on boosting charge separation and transfer through structural engineering to enhance the photocurrent of photoanodes for solar H2 production.
Here a structural engineering design to coat an ultrathin bimetal‐organic framework (MOF) layer on the BiVO4 photoanode is demonstrated. This MOF layer can shut down the hole‐transfer channels from the BiVO4 to its surface trap states, build heterojunction with BiVO4 to provide strong carrier drive force and accelerate surface reaction kinetics as a cocatalyst, achieving highly efficient water oxidation performance.
Surface-functionalized gold and silver nanoparticles are promising nanosensors for applications in the environmental and biological fields. In this review, various organic chelating ...receptors-functionalized gold and silver nanoparticles as sensing materials are systematically summarized and discussed from their attached receptor structures to their applications in metal ions and biomolecules sensing.
Display omitted
•Surface functionalized AuNPs and AgNPs-based colorimetric and fluorometric sensors are reviewed.•AuNPs and AgNPs-based colorimetric and fluorometric sensors for metal ions and biomolecules sensing applications are discussed.•This review analyzes and summarizes the structure of various organic chelating motifs.•Conclusion and Future Perspective on using surface-functionalized AuNPs and AgNPs in visual sensing applications.
Surface-functionalized gold and silver nanoparticles, AuNPs and AgNPs for short, prepared via the modification of organic chelating motifs by covalent or non-covalent bonds, represent an ideal type of hybrid nanomaterials that attract widespread attention because of their outstanding advantages, including exceptional optical, electrical, and photothermal properties, and more importantly, specific surface plasmon resonance (SPR) property in well-dispersed solutions. In recent years, AuNPs and AgNPs modified with functional organic chelating receptors have been extensively studied as robust colorimetric and fluorescent sensors, showing broad application prospects in pollutant detection, trace analysis, and other related research fields. Therefore, this review article outlines various AuNPs and AgNPs equipped with thiol-based organic molecules, amino acids, biomolecules, and fluorophores for colorimetric and fluorescent sensing towards toxic metal ions and essential biomolecules. Certain other types of gold and silver nanomaterials are also covered, such as gold nanoclusters (AuNCs), silver nanoclusters (AgNCs), and silver quantum clusters (AgQCs).
The synthesis strategy, structural characteristics and stability, proton conducting features and mechanism of COFs in the past five years were fully reviewed. Future design ideas, research priorities ...and application prospects for such promising COFs are highlighted.
Display omitted
•Proton conductive covalent organic frameworks were reviewed.•COFs are classified and described according to the type of linkages.•Proton conductivity and conducting mechanism were discussed.•The future development trend of such COFs is prospected.
As a new class of promising crystalline solid materials, the preparation and application of covalent organic frameworks (COFs) have aroused great interest in recent years. In this review, we will focus on the recent research achievements of COFs in the field of proton conductivity from the aspects of design strategies, structural characteristics, proton conducting features and mechanism, application research, etc. Finally, we will present a forward-looking view on the future development and challenges of such functional materials as well as preparation techniques and strategies.
PDF
![Guanidinocalix[5]arene for ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/2041-1723/small "Guanidinocalix[5]arene for sensitive fluorescence detection and magnetic removal of perfluorinated pollutants")
