Jiong Zhou

Nanoparticles with Near-Infrared Emission Enhanced by Pillararene-Based Molecular Recognition in Water

Here we report the unprecedented preparation of nanoparticles with near-infrared (NIR) emission enhanced by host-guest complexation between a water-soluble pillar[5]arene (WP5) and a cyanostilbene derivative (1) in water. Amphiphilic 1 self-assembles in water to form nanoribbons with relatively weak NIR emission at low concentrations. However, after addition of equimolar WP5, these nanoribbons transform into nanoparticles with stronger NIR emission due to the formation of a supramolecular amphiphile and host-guest complexation-enhanced aggregation. These nanoparticles show pH responsiveness, and collapse after treatment with acid. More importantly, these nanoparticles can be used in living cell imaging.

Pillar[10]arene‐Based Size‐Selective Host–Guest Complexation and Its Application in Tuning the LCST Behavior of a Thermoresponsive Polymer

A new molecular recognition motif between a water soluble pillar[10]arene (WP10) and 1,10-phenanthrolinium guest (G) in water is established. Mainly driven by the cooperativity of multiple electrostatic interactions, hydrophobic interactions, and π-π stacking interactions between WP10 and G, this host-guest complex exhibits a high association constant in water, which is about 17 times higher than that between WP10 and paraquat (PQ). Furthermore, this size selective host-guest complexation is employed to tune the lower critical solution temperature behavior of a random copolymer with PQ derivative pendants.

Supramolecular Polymer-Based Nanomedicine: High Therapeutic Performance and Negligible Long-Term Immunotoxicity

Nanomedicines have achieved several breakthroughs in cancer treatment over the past decades; however, their potential immunotoxicities are ignored, which results in serious adverse effects and greatly reduces the potential in clinical translation. Herein, we innovatively develop a theranostic supramolecular polymer using β-cyclodextrin as the host and camptothecin (CPT) as the guest linked by a glutathione-cleavable disulfide bond. The supramolecular polymerization remarkably increases the solubility of CPT by a factor of 232 and effectively inhibits its lactone ring opening in physiological environment, which is favorable for intravenous formulation and maintenance of the therapeutic efficacy. Supramolecular nanoparticles can be prepared through orthogonal self-assembly driven by π-π stacking interaction, host-guest complexation, and hydrogen bonds. The sophisticated nanomedicine constructed from the obtained supramolecular polymer can be specifically delivered to tumor sites and rapidly excreted from body after drug release, thus effectively avoiding systemic toxicity, especially long-term immunotoxicity. In vivo investigations demonstrate this supramolecular nanomedicine possesses superior antitumor performance and antimetastasis capability. This pioneering example integrating the advantages of the dynamic nature of supramolecular chemistry and nanotechnology provides a promising platform for cancer theranostics.

AIE opens new applications in super-resolution imaging

With the rapid development of image processing for scene recognition and visual communication, there is an intense demand to provide the observer with a high-resolution image not only for offering better visualization but also for extracting additional details. In recent years, the invention of super-resolution imaging techniques has overcome the diffraction barrier and has provided clear insights into biological processes at the cellular and molecular scale. In general, the commonly used probes for super-resolution imaging are focused on fluorescent proteins, quantum dots and organic small-molecule fluorophores. Their photostability, biocompatibility and specificity, however, leave much to be desired. Aggregation-induced emission (AIE), a fascinating photoluminescence phenomenon, has found a wide range of applications in fluorescent sensors, biological probes and smart nanomaterials. Herein, we introduce a new class of AIE-based bioprobes for super-resolution imaging, which has recently been reported by Tang and co-workers. The results will inspire the design of AIE luminogens for specific super-resolution imaging in more fields.

A cationic water-soluble biphen[3]arene: synthesis, host–guest complexation and fabrication of a supra-amphiphile

The first cationic water-soluble biphen[3]arene was synthesized and its host–guest complexation with sodium 1-hexanesulfonate was investigated, which was further used to change the aggregation of the amphiphilic guest in water.

A diols-responsive triple-component supra-amphiphile constructed from pillar[5]arene-based recognition

A triple-component supra-amphiphile WSP5⊃G1@A is constructed based on phenylboronic acid/diols dynamic covalent chemistry and water-soluble pillararenes/trimethylamine host–guest recognition. Diols-responsive self-assembly of this ternary supra-amphiphile is fully investigated in aqueous solution.

Barium cation-responsive supra-amphiphile constructed by a new twisted cucurbit[15]uril/paraquat recognition motif in water

A barium cation-responsive supra-amphiphile was constructed by a new twisted cucurbit[15]uril/paraquat host–guest recognition motif in water.

Highly Emissive Self-Assembled BODIPY-Platinum Supramolecular Triangles

Light-emitting supramolecular coordination complexes (SCCs) have been widely studied for applications in the chemical and biological sciences. Herein, we report the coordination-driven self-assembly of two highly emissive platinum(II) supramolecular triangles (1 and 2) containing BODIPY-based bridging ligands. The metallacycles exhibit favorable anticancer activities against HeLa cells (IC50 of 6.41 and 2.11 μM). The characteristic ∼570 nm fluorescence of the boron dipyrromethene (BODIPY) moieties in the metallacycles permits their intracellular visualization using confocal microscopy. Additionally, the BODIPY fluorophore is an excellent photodynamic agent, making the metallacycles as ideal therapeutics for photodynamic therapy (PDT) and chemotherapy. In vitro studies demonstrate that the combination indexes against HeLa cells are 0.56 and 0.48 for 1 and 2, respectively, confirming their synergistic anticancer effect. More importantly, these SCCs also exhibit superior anticancer efficacy toward cisplatin-resistant A2780cis cell line by combining PDT and chemotherapy, showing promise in overcoming drug resistance. This study exploits a multicomponent approach to self-assembled metallacages that enables design of effective theranostic agents wherein the platinum acceptors are toxic chemotherapeutics and the BODIPY donors are imaging probes and photosensitizers. Since each piece may be independently tuned, i.e., Pt(II) polypyridyl fragment swapped for Pt(II) phosphine, the activity may be optimized without a total redesign of the system.

A water-soluble hybrid[4]arene: synthesis, host–guest complexation and application in the construction of a supra-amphiphile

A water-soluble hybrid[4]arene was synthesized for the first time and its pH-responsive host–guest complexation with paraquat in water was investigated. This new host–guest recognition motif was further applied in the construction of a supra-amphiphile.

A discrete organoplatinum(II) metallacage as a multimodality theranostic platform for cancer photochemotherapy

Photodynamic therapy is an effective alternative to traditional treatments due to its minimally invasive nature, negligible systemic toxicity, fewer side effects, and avoidance of drug resistance. However, it is still challenging to design photosensitizers with high singlet oxygen (1O2) quantum yields (QY) due to severe aggregation of the hydrophobic photosensitizers. Herein, we developed a discrete organoplatinum(II) metallacage using therapeutic cis-(PEt3)2Pt(OTf)2 as the building block to improve the 1O2 QY, thus achieving synergistic anticancer efficacy. The metallacage-loaded nanoparticles (MNPs) with tri-modality imaging capability allow precise diagnosis of tumor and real-time monitoring the delivery, biodistribution, and excretion of the MNPs. MNPs exhibited excellent anti-metastatic effect and superior anti-tumor performance against U87MG, drug resistant A2780CIS, and orthotopic tumor models, ablating the tumors without recurrence after a single treatment. Gene chip analyses confirmed the contribution of different therapeutic modalities to the tumor abrogation. This supramolecular platform holds potential in precise cancer theranostics.It is challenging to design photosensitizers (PS) with high quantum yields generating singlet oxygen due to severe aggregation between the hydrophobic PSs. Here they develop organoplatinum(II) metallatocage-based PS to overcome these challenges and show excellent antitumor effect.