Suprasomes Based on Host-Guest Molecular Recognition: An Excellent Alternative to Liposomes in Cancer Theranostics

A chiral supramolecular liquid crystal based on pillararene and its application in information encryption

A chiral supramolecular liquid crystal based on a pillararene mesogen was constructed. The regulation of liquid crystal behavior was achieved through the host-guest interactions between the pillararene-based mesogen and a tetraphenylethylene-containing guest. In addition, this supramolecular liquid crystal system, showing pH-responsive fluorescence emission character, was applied as an information encryption material capable of storing multiple levels of distinct information, thereby enriching the application of liquid crystal materials in the field of information security.

A Cascade-Amplified Pyroptosis Inducer: Optimizing Oxidative Stress Microenvironment by Self-Supplying Reactive Nitrogen Species Enables Potent Cancer Immunotherapy

Selective generation of sufficient pyroptosis inducers at the tumor site without external stimulation holds immense significance for a longer duration of immunotherapy. Here, we report a cascade-amplified pyroptosis inducer CSCCPT/SNAP that utilizes reactive nitrogen species (RNS), self-supplied from the diffusion-controlled reaction between reactive oxygen species (ROS) and nitric oxide (NO) to potentiate pyroptosis and immunotherapy, while both endogenous mitochondrial ROS stimulated by released camptothecin and released NO initiate pyroptosis. Mechanistically, cascade amplification of the antitumor immune response is prompted by the cooperation of ROS and NO and enhanced by RNS with a long lifetime, which could be used as a pyroptosis trigger to effectively compensate for the inherent drawbacks of ROS, resulting in long-lasting pyroptosis for favoring immunotherapy. Tumor growth is efficiently inhibited in mouse melanoma tumors through the facilitation of reactive oxygen/nitrogen species (RONS)-NO synergy. In summary, our therapeutic approach utilizes supramolecular engineering and nanotechnology to integrate ROS producers and NO donors of tumor-specific stimulus responses into a system that guarantees synchronous generation of these two reactive species to elicit pyroptosis-evoked immune response, while using self-supplied RNS as a pyroptosis amplifier. RONS-NO synergy achieves enhanced and sustained pyroptosis and antitumor immune responses for robust cancer immunotherapy.

Enhancing the Photosensitivity of Hypocrellin A by Perylene Diimide Metallacage-Based Host-Guest Complexation for Photodynamic Therapy

The development of supramolecular hosts which can efficiently encapsulate photosensitizers to improve the photodynamic efficacy holds great promise for cancer therapy. Here, we report two perylene diimide-based metallacages that can form stable host-guest complexes with planar conjugated molecules including polycyclic aromatic hydrocarbons and photosensitizers (hypocrellin A). Such host-guest complexation not only prevents the aggregation of photosensitizers in aqueous environments, but also offers fluorescence resonance energy transfer (FRET) from the metallacage to the photosensitizers to further improve the singlet oxygen generation (ΦΔ = 0.66). The complexes are further assembled with amphiphilic polymers, forming nanoparticles with improved stability for anticancer study. Both in vitro and in vivo studies indicate that the nanoparticles display excellent anticancer activities upon light irradiation, showing great potential for cancer photodynamic therapy. This study provides a straightforward and effective approach for enhancing the photosensitivity of conventional photosensitizers via host-guest complexation-based FRET, which will open a new avenue for host-guest chemistry-based supramolecular theranostics.

Alleviating Recombinant Tissue Plasminogen Activator-induced Hemorrhagic Transformation in Ischemic Stroke via Targeted Delivery of a Ferroptosis Inhibitor

Intravenous thrombolysis with recombinant tissue plasminogen activator (rtPA) is the primary treatment for ischemic stroke. However, rtPA treatment can substantially increase blood-brain barrier (BBB) permeability and susceptibility to hemorrhagic transformation. Herein, the mechanism underlying the side effects of rtPA treatment is investigated and demonstrated that ferroptosis plays an important role. The ferroptosis inhibitor, liproxstatin-1 (Lip) is proposed to alleviate the side effects. A well-designed macrocyclic carrier, glucose-modified azocalix[4]arene (GluAC4A), is prepared to deliver Lip to the ischemic site. GluAC4A bound tightly to Lip and markedly improved its solubility. Glucose, modified at the upper rim of GluAC4A, imparts BBB targeting to the drug delivery system owing to the presence of glucose transporter 1 on the BBB surface. The responsiveness of GluAC4A to hypoxia due to the presence of azo groups enabled the targeted release of Lip at the ischemic site. GluAC4A successfully improved drug accumulation in the brain, and Lip@GluAC4A significantly reduced ferroptosis, BBB leakage, and neurological deficits induced by rtPA in vivo. These findings deepen the understanding of the side effects of rtPA treatment and provide a novel strategy for their effective mitigation, which is of great significance for the treatment and prognosis of patients with ischemic stroke.

Recent Progress of Supramolecular Chemotherapy Based on Host-Guest Interactions

Chemotherapy is widely recognized as an effective approach for treating cancer due to its ability to eliminate cancer cells using chemotherapeutic drugs. However, traditional chemotherapy suffers from various drawbacks, including limited solubility and stability of drugs, severe side effects, low bioavailability, drug resistance, and challenges in tracking treatment efficacy. These limitations greatly hinder its widespread clinical application. In contrast, supramolecular chemotherapy, which relies on host-guest interactions, presents a promising alternative by offering highly efficient and minimally toxic anticancer drug delivery. In this review, an overview of recent advancements in supramolecular chemotherapy based on host-guest interactions is provided. The significant role it plays in guiding cancer therapy is emphasized. Drawing on a wealth of cutting-edge research, herein, a timely and valuable resource for individuals interested in the field of supramolecular chemotherapy or cancer therapy, is presented. Furthermore, this review contributes to the progression of the field of supramolecular chemotherapy toward clinical application.

Dual-Responsive Supramolecular Polymeric Nanomedicine for Self-Cascade Amplified Cancer Immunotherapy

Insufficient tumor immunogenicity and immune escape from tumors remain common problems in all tumor immunotherapies. Recent studies have shown that pyroptosis, a form of programmed cell death that is accompanied by immune checkpoint inhibitors, can induce effective immunogenic cell death and long-term immune activation. Therapeutic strategies to jointly induce pyroptosis and reverse immunosuppressive tumor microenvironments are promising for cancer immunotherapy. In this regard, a dual-responsive supramolecular polymeric nanomedicine (NCSNPs) to self-cascade amplify the benefits of cancer immunotherapy is designed. The NCSNPs are formulated by β-cyclodextrin coupling nitric oxide (NO) donor, a pyroptosis activator, and NLG919, an indoleamine 2,3-dioxygenase (IDO) inhibitor, and self-assembled through host-guest molecular recognition and hydrophobic interaction to obtain nanoparticles. NCSNPs possess excellent tumor accumulation and bioavailability attributed to ingenious supramolecular engineering. The study not only confirms the occurrence of NO-triggered pyroptosis in tumors for the first time but also reverses the immunosuppressive microenvironment in tumor sites via an IDO inhibitor by enhancing the infiltration of cytotoxic T lymphocytes, to achieve remarkable inhibition of tumor proliferation. Thus, this study provides a novel strategy for cancer immunotherapy.

Regulation of Fluorescence and Self-assembly of a Salicylaldehyde Azine-Containing Amphiphile by Pillararene

Regulation of fluorescence and self-assembly of a salicylaldehyde azine-containing amphiphile by a water-soluble pillar[5]arene via host-guest recognition in water was realized. The fluorescence and the self-assembled aggregates of the bola-type amphiphile G can be tailored by adding different amounts of water-soluble pillar[5]arene (WP5). In addition, the emission property and self-assembly behavior of G and WP5 are responsive to pH conditions. Furthermore, the fluorescence emission property of G and the regulation by WP5 or pH conditions was applied as information encryption material, rewritable paper, and erasable ink. We believe that this fluorescence regulation strategy is promising for the construction of advanced fluorescent organic materials.

Pillararene-Based Stimuli-Responsive Supramolecular Delivery Systems for Cancer Therapy

Cancer poses a significant challenge to global public health, seriously threatening human health and life. Although various therapeutic strategies, such as chemotherapy (CT), radiotherapy, phototherapy, and starvation therapy, are applied to cancer treatment, their limited therapeutic effect, severe side effects, and unsatisfactory drug release behavior need to be carefully considered. Thus, there is an urgent need to develop efficient drug delivery strategies for improving cancer treatment efficacy and realizing on-demand drug delivery. Notably, pillararenes, as an emerging class of supramolecular macrocycles, possess unique properties of highly tunable structures, superior host-guest chemistry, facile modification, and good biocompatibility, which are widely used in cancer therapy to achieve controllable drug release and reduce the toxic side effects on normal tissues under various internal/external stimuli conditions. This review summarizes the recent advance of stimuli-responsive supramolecular delivery systems (SDSs) based on pillararenes for tumor therapy from the perspectives of different assembly methods and hybrid materials, including molecular-scale SDSs, supramolecular nano self-assembly delivery systems, and nanohybrid SDSs. Moreover, the prospects and critical challenges of stimuli-responsive SDSs based on pillararenes for cancer therapy are also discussed.

Bifunctional drug delivery system with carbonic anhydrase IX targeting and glutathione-responsivity driven by host-guest amphiphiles for effective tumor therapy

It remains a critical issue to deliver anticancer drugs to tumor tissues and reducing the toxic effects on normal tissues. The drug delivery system (DDS) based on self-assembly provides a multi-functional way for drug delivery. In this work, a supramolecular host (L-CD) with targeting function based on a β-cyclodextrin (β-CD) backbone was synthesized with carbonic anhydrase IX (CAIX) overexpressed on tumor cells as a target, and the methotrexate prodrug (MTX-SS-Ad) modified by adamantane and disulfide bond was prepared to be used as the guest. The amphiphilic complex was prepared between L-CD and MTX-SS-Ad through host-guest interactions and could further self-assemble into supramolecular nanoparticles (SNPs) with active targeting and stimulus release functions. The interaction between host and guest was investigated by UV, NMR, IR, XRD and TGA. The characteristic of SNPs was observed by DLS and TEM. Throng the study of molecular docking, in vitro inhibition, cell uptake experiments, and western blotting, SNPs have showed CAIX inhibitory effects both inside and outside the cells. The in vitro release experiments indicated that SNPs can undergo disintegration and release drugs under acidic and GSH conditions. Moreover, SNP can effectively inhibit the proliferation of cancer cells without generating additional toxic side effects on normal cells. So, we provide a strategy of bifunctional drug delivery system with targeting and glutathione-responsivity for effective tumor therapy.

Applications of supramolecular assemblies in drug delivery and photodynamic therapy

One of the world's serious health challenges is cancer. Anti-cancer agents delivered to normal cells and tissues pose several problems and challenges. In this connection, photodynamic therapy (PDT) is a minimally invasive therapeutic technique used for selectively destroying malignant cells while sparing the normal tissues. Development in photosensitisers (PSs) and light sources have to be made for PDT as a first option treatment for patients. In the pursuit of developing new attractive molecules and their formulations for PDT, researchers are working on developing such type of PSs that perform better than those being currently used. For the widespread clinical utilization of PDT, effective PSs are of particular importance. Host-guest interactions based on nanographene assemblies such as functionalized hexa-cata-hexabenzocoronenes, hexa-peri-hexabenzocoronenes and coronene have attracted increasing attention owing to less complicated synthetic steps and purification processes (gel permeation chromatography) during fabrication. Noncovalent interactions provide easy and facile approaches for building supramolecular PSs and enable them to have sensitive and controllable photoactivities, which are important for maximizing photodynamic effects and minimizing side effects. Various versatile supramolecular assemblies based on cyclodextrins, cucurbiturils, calixarenes, porphyrins and pillararenes have been designed in order to make PDT an effective therapeutic technique for curing cancer and tumours. The supramolecular assemblies of porphyrins display efficient electron transfer and fluorescence for use in bioimaging and PDT. The multifunctionalization of supramolecular assemblies is used for designing biomedically active PSs, which are helpful in PDT. It is anticipated that the development of these functionalized supramolecular assemblies will provide more fascinating advances in PDT and will dramatically expand the potential and possibilities in cancer treatments.

Engineered Nanovesicles Expressing Bispecific Single Chain Variable Fragments to Protect against SARS-CoV-2 Infection

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in high morbidity and mortality rates worldwide. Although the epidemic has been controlled in many areas and numerous patients have been successfully treated, the risk of reinfection persists due to the low neutralizing antibody titers and weak immune response. To provide long-term immune protection for infected patients, novel bispecific CB6/dendritic cell (DC)-specific intercellular adhesion molecule 3-grabbing nonintegrin (SIGN) nanovesicles (NVs) were constructed to target both the SARS-CoV-2 spike protein (S) and the DC receptors for virus neutralization and immune activation. Herein, we designed NVs expressing both CB6 and DC-SIGN single chain variable fragments (scFvs) on the surface to block SARS-CoV-2 invasion and activate DC function. Monophosphoryl lipid A (MPLA) was loaded into the CB6/DC-SIGN NVs as an adjuvant to promote this process. The CB6/DC-SIGN NVs prevented a pseudovirus expressing the S protein from infecting the target cells expressing high levels of angiotensin-converting enzyme 2 in vitro. Additionally, CB6/DC-SIGN NVs admixed with S-expressing pseudoviruses activated the DCs, which was promoted by the adjuvant MPLA loaded in the NVs. Using a mouse model, we also confirmed that the CB6/DC-SIGN NVs effectively improved the neutralizing antibody titer and inhibited the growth of tumors expressing the S protein after 3 weeks of treatment. This potential NV-based treatment not only exerts a blocking effect by binding the S protein in the short term but may also provide patients with long-term protection against secondary infections.

Surface modification strategies in translocating nano-vesicles across different barriers and the role of bio-vesicles in improving anticancer therapy

Nanovesicles and bio-vesicles (BVs) have emerged as promising tools to achieve targeted cancer therapy due to their ability to overcome many of the key challenges currently being faced with conventional chemotherapy. These challenges include the diverse and often complex pathophysiology involving the progression of cancer, as well as the various biological barriers that circumvent therapeutic molecules reaching their target site in optimum concentration. The scientific evidence suggests that surface-functionalized nanovesicles and BVs camouflaged nano-carriers (NCs) both can bypass the established biological barriers and facilitate fourth-generation targeting for the improved regimen of treatment. In this review, we intend to emphasize the role of surface-functionalized nanovesicles and BVs camouflaged NCs through various approaches that lead to an improved internalization to achieve improved and targeted oncotherapy. We have explored various strategies that have been employed to surface-functionalize and biologically modify these vesicles, including the use of biomolecule functionalized target ligands such as peptides, antibodies, and aptamers, as well as the targeting of specific receptors on cancer cells. Further, the utility of BVs, which are made from the membranes of cells such as mesenchymal stem cells (MSCs), white blood cells (WBCs), red blood cells (RBCs), platelets (PLTs) as well as cancer cells also been investigated. Lastly, we have discussed the translational challenges and limitations that these NCs can encounter and still need to be overcome in order to fully realize the potential of nanovesicles and BVs for targeted cancer therapy. The fundamental challenges that currently prevent successful cancer therapy and the necessity of novel delivery systems are in the offing.

Self-Luminescent Drug Delivery Vehicle: Synthesis, Self-Assembly Behavior, Cysteine-Responsive Property, and Application in the Visualization of Drug Release

Targeted drug delivery systems have gained great attention from the chemistry and biomedical fields in recent years due to the minimized harm to normal cells. When designing targeted drug delivery systems, the property of harmlessness to normal cells and the tracking ability of the whole process are quite crucial. These two characters can be brought into the related systems by applying a drug carrier that is self-luminescent and its drug release can be induced by the microenvironment of cancer cells. Therefore, the design and synthesis of drug delivery vehicles are significant for the fabrication of target drug delivery systems. Herein, we have synthesized a cysteine-responsive and fluorescent molecule, maleic acid-modified tetraphenylethylene derivative (MATPE), by a facile method. In addition, a drug delivery system with self-luminescence and cysteine-responsiveness based on the self-assembly of MATPE was fabricated. In this system, MATPE and cysteine both played dual roles as cysteine probe/drug carrier and emission-enhanced inducement/drug-release stimulus. The drug-release process was successfully realized in cancer cells and can be visualized, exhibiting great potential in the field of theranostics.

Smart organic materials based on macrocycle hosts

Innovative design of smart organic materials is of great importance for the advancement of modern technology. Macrocycle hosts, possessing cyclic skeletons, intrinsic cavities, and specific guest binding properties, have demonstrated pronounced potential for the elaborate fabrication of a variety of functional organic materials with smart stimuli-responsive characteristics. In this tutorial review, we outline the current development of smart organic materials based on macrocycle hosts as key building blocks, focusing on the design principles and functional mechanisms of the tailored systems. Three main types of macrocycle-based smart organic materials are exemplified as follows according to the distinct forms of construction patterns: (1) supramolecular polymeric materials and nanoassemblies; (2) adaptive molecular crystals; (3) smart porous organic materials. The responsive performances of macrocycle-containing smart materials in versatile aspects, including mechanically adaptive polymers, soft optoelectronic devices, data encryption, drug delivery systems, artificial transmembrane channels, crystalline-state gas adsorption/separation, and fluorescence sensing, are illustrated by discussing the representative studies as paradigms, where the roles of macrocycles in these systems are highlighted. We also provide in the conclusion part the perspectives and remaining challenges in this burgeoning field.

Photothermal Nanomaterials: A Powerful Light-to-Heat Converter

All forms of energy follow the law of conservation of energy, by which they can be neither created nor destroyed. Light-to-heat conversion as a traditional yet constantly evolving means of converting light into thermal energy has been of enduring appeal to researchers and the public. With the continuous development of advanced nanotechnologies, a variety of photothermal nanomaterials have been endowed with excellent light harvesting and photothermal conversion capabilities for exploring fascinating and prospective applications. Herein we review the latest progresses on photothermal nanomaterials, with a focus on their underlying mechanisms as powerful light-to-heat converters. We present an extensive catalogue of nanostructured photothermal materials, including metallic/semiconductor structures, carbon materials, organic polymers, and two-dimensional materials. The proper material selection and rational structural design for improving the photothermal performance are then discussed. We also provide a representative overview of the latest techniques for probing photothermally generated heat at the nanoscale. We finally review the recent significant developments of photothermal applications and give a brief outlook on the current challenges and future directions of photothermal nanomaterials.

Designing supramolecular self-assembly nanomaterials as stimuli-responsive drug delivery platforms for cancer therapy

Stimuli-responsive nanomaterials have attracted substantial interest in cancer therapy, as they hold promise to deliver anticancer agents to tumor sites in a precise and on-demand manner. Interestingly, supramolecular chemistry is a burgeoning discipline that entails the reversible bonding between components at the molecular and nanoscale levels, and the recent advances in this area offer the possibility to design nanotherapeutics with improved controllability and functionality for cancer therapy. Herein, we provide a comprehensive summary of typical non-covalent interaction modes, which primarily include hydrophobic interaction, hydrogel bonding, host-guest interaction, π-π stacking, and electrostatic interaction. Special emphasis is placed on the implications of these interaction modes to design novel stimuli-responsive drug delivery principles and concepts, aiming to enhance the spatial, temporal, and dosage precision of drug delivery to cancer cells. Finally, future perspectives are discussed to highlight current challenges and future opportunities in self-assembly-based stimuli-responsive drug delivery nanotechnologies for cancer therapy.

An Engineered Design of Self-Assembly Nanomedicine Guided by Molecular Dynamic Simulation for Photodynamic and Hypoxia-Directed Therapy

To overcome the hypoxia barrier in tumor therapy, a hypoxia-activated prodrug of docetaxel (DTX-PNB) was synthesized and self-assembled with indocyanine green (ICG), forming a combination nanomedicine ISDNN. With the guidance of molecular dynamic simulation, the ISDNN construction could be accurately controlled, achieving uniform size distribution and high drug loading up to 90%. Within the hypoxic tumor environment, ISDNN exerted ICG-mediated photodynamic therapy and aggravated hypoxia to boost DTX-PNB activation for chemotherapy, enabling enhanced antitumor efficacy.

Pillararene-Based Supramolecular Polymers for Cancer Therapy

Supramolecular polymers have attracted considerable interest due to their intriguing features and functions. The dynamic reversibility of noncovalent interactions endows supramolecular polymers with tunable physicochemical properties, self-healing, and externally stimulated responses. Among them, pillararene-based supramolecular polymers show great potential for biomedical applications due to their fascinating host-guest interactions and easy modification. Herein, we summarize the state of the art of pillararene-based supramolecular polymers for cancer therapy and illustrate its developmental trend and future perspective.