Aggregation‐induced emission (AIE), as an exciting photophysical phenomenon, has been regarded as one frontier research topic within both ranges of molecular luminescence and materials science over the last two decades. Since controllable molecular ensembles with particular morphologies and tunable functions can be elegantly constructed in the realm of supramolecular chemistry, the integration of supramolecular assembly and AIE systems can expectedly bring about luminescent materials with tunable emission and tailorable well‐ordered architectures. In this review, we will provide a summary of the creation and working mechanisms of AIE systems involving supramolecular systems that are driven by different supramolecular driving forces including hydrogen bonding, host−guest interactions, metal coordination, and π–π interactions. The morphological and photoluminescent features of these AIE‐active supramolecular assemblies will be elucidated, and the regulated fluorescence properties of the AIEgens induced by the assembling–disassembling processes will be discussed in detail.

host and guest bears excellent selectivity. [5] On the other hand, the noncovalent interactions are sensitive to various influential elements in the surrounding environment, including light irradiation, [6] redox reactions, [7] pH variations, [8] competitive factors, [9] and chemical or biological interfering. [10,11] Owing to the highly desired characteristics of host-guest systems comprising of supramolecular macrocycles and their guests, the dynamic nature of their molecular activities, the reversibility between assembly and disassembly, the particular intermolecular recognition and the responsiveness toward external stimuli, supramolecular host-guest systems become outstanding candidates as building blocks in the construction of nanoscaled smart materials with controllable properties, which are substantial in the research ranges of nanotechnology and materials science. Up till today, a number of host compounds, such as crown ethers, [12,13] cyclodextrins (CDs), [14] calixarenes, [15] cucurbit[n]urils (CB[n]s), [16][17][18] and pillararenes, [19,20] on account of their developed synthetic procedures, relatively high yieldings, numerous modification possibilities and tunability, [21,22] along with their well-explored host-guest properties, [5] have been utilized to construct stimuliresponsive smart materials to serve as either supramolecular recognizing agents or the major building blocks for reversible artificial complexes. [1,23,24] An important use of macrocyclic compounds to create functional smart materials lies in the construction of controllable fluorescent systems. [25] In the literature, one can find considerable examples of fluorescent systems manipulated by supramolecular macrocycles through their distinctive inclusion complexation activities. [26][27][28][29] The concept of aggregation-induced emission (AIE) was first proposed by Tang and co-workers in 2001, [30] demonstrating an unprecedented fluorescent phenomenon, which bears luminescent features in sharp contrast to the traditional aggregation-caused quenching (ACQ) that is typical for conventional organic fluorophores. While the ACQ effect stands as a major hindrance for the solidation of luminescent materials since luminophores with planar molecular structures undergo fluorescence quenching in aggregated state, dye molecules possessing unplanar conformations, on the contrary, are able to exhibit stronger emission upon aggregation according to the restriction of intramolecular motions (RIM) or rotations (RIR), which suppresses nonradiative relaxation and actuates the energy release through radiative pathway. [31,32] Two essential elements of smart materials are their capabilities of responding to external stimuli and the specific recognition toward different targets, which renders supramolecular macrocycles an ideal type of building blocks for materials construction. Aggregation-induced emission (AIE) has been intensively investigated for two decades not only for the realization of solid-state fluorescent materials, but also for the fabrication...

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response to specific physical or chemical stimuli including, but not limited to, pH, light, redox, competitive agents, and tem perature. In particular, pseudorotaxanes, comprising of a rod component without bulky end groups encircled by a wheel entity via noncovalent bonds, can be employed as a superior class of candidates for supramolecular switches. [3] There fore, the study of macrocyclic receptors as the wheel entity of pseudorotaxanes has become one of the research hotspots in the field and received great attention. [4] Following the advance of macrocyclic chemistry based on crown ethers, cyclo dextrins, calixarenes, and cucurbit[n]urils, pillar[n]arenes (n = 5-15), first reported by Ogoshi et al. in 2008, have emerged as a rising star among synthesized macro cycles. [5] Pillar[n]arenes, composed of n hydroquinone units linked by methylene bridges at the 2 and 5positions, pos sess rigid pillarlike molecular structures and πelectron rich hydrophobic cavities that are favorable for the binding of electrondeficient guests. [6] Owing to the highly modi fiable rims of pillar[n]arenes, numerous pillar[n]arene derivatives with diverse functionalities can be facilely obtained either via the cyclization of pretailored 1,4dialkoxybenzene monomers or by postsynthetic modification. [7] The versatile functionalization of pillar[n]arenes beneficially affords their pos sible usages in both organic and aqueous phases, making the host−guest interactions with a large variety of ionic or neutral guests possible. [8] Thus far, pillar[n]arenes and their deriva tives have served as a prominent family of building blocks for the rational creation of supramolecular switches on the basis of the formation of various pseudorotaxanes upon their respon sive complexation with guest entities. [3] Although the dynamic activities of supramolecular switches are generally and fundamentally investigated in solution, growing interest has been focused on the transfer of supra molecular switches from solution phase to more condensed phases, that is, solid surfaces and interfaces. Through the incor poration on rigid solid supports of metal or other inorganic surfaces, the installed switches are able to produce amplified collective switching motions, concurrently modulating the sur face properties and endowing the inherent substrates with valid responses to specific triggers. [2a,9] Hence, the shifting of supra molecular switches from solution to solid surfaces denotes a significant step toward the realization of artificial nanosystems with operationally controllable properties, stimuliresponsive features, and multifunctionalities. The design and synthesis of new synthetic macrocycles has driven the rapid development of supramolecular chemistry and materials. Pillar[n]arenes, 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...

With the rapid development of supramolecular chemistry and nanomaterials, supramolecular nanotheranostics has attracted remarkable attention owing to the advantages compared with conventional medicine. Supramolecular architectures relying on non-covalent interactions possess reversible and stimuli-responsive features; endowing supramolecular nanotheranostics based on supramolecular assemblies great potentials for the fabrication of integrated novel nanomedicines and controlled drug delivery systems. In particular, pillarenes, as a relatively new class of synthetic macrocycles, are important candidates in the construction of supramolecular therapeutic systems due to their excellent features such as rigid and symmetric structures, facile substitution, and unique host-guest properties. This review summarizes the development of pillarene-based supramolecular nanotheranostics for applications in biological mimicking, virus inhibition, cancer therapy, and diagnosis, which contains the following two major parts: (a) pillarene-based hybrid supramolecular nanotheranostics upon hybridizing with porous materials such as mesoporous silica nanoparticles, metal-organic frameworks, metal nanoparticles, and other inorganic materials; (b) pillarene-based organic supramolecular therapeutic systems that include supramolecular amphiphilic systems, artificial channels, and prodrugs based on host-guest complexes. Finally, perspectives on how pillarene-based supramolecular nanotheranostics will advance the field of pharmaceuticals and therapeutics are given.

Supramolecular nanovalves are an emerging class of important elements that are functionalized on the surfaces of inorganic or hybrid nanocarriers in the constructions of smart cargo delivery systems. Taking advantage of the pseudorotaxane structure via host‐guest complexation and the dynamic nature of supramolecular interactions, macrocyclic arene‐based supramolecular nanovalves have shown great promise in the applications of drug delivery and controlled release. Careful selection of diverse external stimuli, such as pH variations, temperature changes, redox, enzymes, light irradiation, and competitive binding, can activate the opening and closing of the nanovalves by altering the supramolecular structure or binding affinities. Meanwhile, the porous solid supports in controlled release systems also play an important role in the functionalities of the nanocarriers, which include, but not limited to, mesoporous silica nanoparticles (MSNs), metal‐organic frameworks (MOFs), core‐shell nanomaterials, and rare‐earth porous nanomaterials. The elaborate decoration by macrocyclic arenes‐based supramolecular nanovalves on porous nanomaterials has provided intelligent controlled release platforms. In this review, we will focus on the overview of supramolecular nanovalves based on two typical macrocyclic arenes, that is, calixarenes and pillarenes, and their operation manners in the controlled release processes.

A luminescent molecular crystal (P5bipy) and a Cu(I)-coordinated luminescent nanocrystal (Cu(I)-P5bipy) have been prepared concurrently using one conjugated pillar[5]arene macrocycle via a facile supramolecular self-assembling strategy. The molecular crystal shows enhanced luminescence compared with unmodified pillar[5]arene, attributed to its conjugated structure and staggered packing mode, while the coordination nanocrystal exhibits well-defined crystalline structures and long-lifetime triplet state emission along with pronounced solvochromic features.

Multifunctional supramolecular nanoplatforms that integrate the advantages of different therapeutic techniques can trigger multimodal synergistic treatment of tumors, thus representing an emerging powerful tool for cancer therapeutics.Methods: In this work, we design and fabricate a multifunctional supramolecular drug delivery platform, namely Fa-mPEG@CP5-CuS@HMSN-Py nanoparticles (FaPCH NPs), consisting of a pyridinium (Py)-modified hollow mesoporous silica nanoparticles-based drug reservoir (HMSN-Py) with high loading capacity, a layer of NIR-operable carboxylatopillar[5]arene (CP5)-functionalized CuS nanoparticles (CP5-CuS) on the surface of HMSN-Py connected through supramolecular host-guest interactions between CP5 rings and Py stalks, and another layer of folic acid (Fa)-conjugated polyethylene glycol (Fa-PEG) antennas by electrostatic interactions capable of active targeting at tumor lesions, in a controlled, highly integrated fashion for synergistic chemo-photothermal therapy.Results: Fa-mPEG antennas endowed the enhanced active targeting effect toward cancer cells, and CP5-CuS served as not only a quadruple-stimuli responsive nanogate for controllable drug release but also a special agent for NIR-guided photothermal therapy. Meanwhile, anticancer drug doxorubicin (DOX) could be released from the HMSN-Py reservoirs under tumor microenvironments for chemotherapy, thus realizing multimodal synergistic therapeutics. Such a supramolecular drug delivery platform showed effective synergistic chemo-photothermal therapy both in vitro and in vivo.Conclusion: This novel supramolecular nanoplatform possesses great potential in controlled drug delivery and tumor cellular internalization for synergistic chemo-photothermal therapy, providing a promising approach for multimodal synergistic cancer treatment.