Supramolecular Sequential Light-Harvesting Systems for Constructing White LED Device and Latent Fingerprint Imaging.

The fabrication of supramolecular light-harvesting systems (LHS) with sequential energy transfer is of significance in utilizing light energy. In this study, we report the non-covalent self-assembly of a sequential LHS by pillar[5]arene-based host-guest interaction in water and its applications in white light-emitting diode (LED) device and latent fingerprint imaging. The host-guest complex WP5 ⊃ ${ \supset }$ G self-assembles into nanoparticles in water and shows enhanced aggregation-induced emission (AIE) effect. The nanoparticles can be further used to construct sequential LHS with fluorescent dyes 4,7-di(2-thienyl)-benzo[2,1,3]thiadiazole (DBT) and sulforhodamine 101 (SR101). Impressively, the system shows white-light emission when the molar ratio of WP5 ⊃ ${ \supset }$ G/DBT/SR101 is 1100/2/16. The material can be coated on a LED bulb to achieve white-light emission. In addition, the sequential LHS exhibit multicolor fluorescence including red emission, which have been successfully applied to high-resolution imaging of latent fingerprints. Therefore, we demonstrated a general strategy for the construction of sequential LHS in water based on macrocyclic host-guest interaction and explored its multi-functional applications in white-light LED device and imaging of latent fingerprints, which will promote future development and application of supramolecular LHSs.

Host-Guest Complexes of Pillar[5]arene as Components for Supramolecular Light-Harvesting Systems with Tunable Fluorescence.

A guest molecule containing a short alkyl spacer between the tetraphenylethylene group and the methylpyridinium group was designed and synthesized. After complexation with a water-soluble pillar[5]arene, the resulting host-guest complex can further self-assemble into fluorescence-emitting nanoparticles in water. By loading a commercially available dye Rhodamine 6G into the nanoparticles, an efficient artificial light-harvesting system with high donor/acceptor ratios (>400/1) was successfully constructed. The obtained systems show considerable antenna effects with values of more than 10 times. The system also exhibits tunable fluorescence emission behavior and can be used as a fluorescent ink for information encryption.

Fluorescent Nanoassemblies in Water Exhibiting Tunable LCST Behavior and Responsive Light Harvesting Ability.

Responsive fluorescent nanomaterials have been received considerable attention in recent years. In this work, a bola-type amphiphilic molecule, CSO, was synthesized which contains a hydrophobic cyanostilbene core and hydrophilic oligo(ethylene glycol) (OEG) coils at both sides. The cyanostilbene group is aggregation-induced emission (AIE) active, while the OEG coils are thermo-responsive. As a result, the CSO molecules can self-assemble into blue-fluorescent nanoassemblies with lower critical solution temperature (LCST) behavior in aqueous media. It is noteworthy that the LCST behavior can be reversibly regulated with changes in concentration and the introduction of K+ . Intriguingly, fluorescence of CSO assembly shows a blue-shift upon heating. Finally, by employing CSO as a light capturing antenna and energy donor, an artificial light harvesting system with tunable emission and thermo-responsive characteristics was fabricated. This study not only demonstrates an integrated approach to create responsive fluorescent nanomaterials, but also shows great potential for producing luminescent materials and mimicking photosynthesis in nature.

Self-assembled Fluorescent Nanoparticles with Tunable LCST Behavior in Water.

The development of stimuli-responsive fluorescent materials in water based on organic molecule has drawn significant interest. Herein, we designed and synthesized an amphiphilic molecule M containing a fixed tetraphenylethylene moiety (FTPE) as hydrophobic part and tri(ethylene glycol) (TEG) chains as hydrophilic part. Notably, the FTPE moiety is aggregation-induced emission (AIE) active, while the TEG chains are thermo-responsive. M can self-assemble into fluorescent nanoparticles (NPs) in water, which showed lower critical solution temperature (LCST) behavior. Moreover, its clouding point can be reversibly tuned upon the concentration variation. Interestingly, the NPs can be acted as a fluorescence thermometer in aqueous media owing to their unique AIE and LCST behaviors. Our work herein not only provides an integration strategy to construct stimuli-responsive fluorescent materials but also shows great potential in biological applications including bioimaging and biosensors.

An ultralow-acceptor-content supramolecular light-harvesting system for white-light emission.

White-light emission in donor-acceptor systems usually requires relatively high acceptor content and/or multiple acceptors to "neutralize" the primary color of donors. Herein, a cyanostilbene-bridged ditopic ureidopyrimidinone donor (CSU) was designed and synthesized, which can self-assemble into dispersed nanoparticles in water. Fascinatingly, efficient white-light emission can be realized by co-assembling 0.1% DBT into the nanoparticles through a light-harvesting strategy. This new system is further demonstrated for use in white-light encryption materials.

Supramolecular polymer-directed light-harvesting system based on a stepwise energy transfer cascade.

The design and construction of an artificial light-harvesting system in water by mimicking the energy transfer cascade in natural photosynthesis are of significant importance. Herein, we report an efficient two-step sequential energy transfer system based on quadruple hydrogen-bonded supramolecular polymeric nanoparticles. By loading two types of hydrophobic dyes as energy acceptors, excitation energy from the supramolecular polymer could be funneled efficiently to the final acceptor through the relay acceptor. The system exhibits tunable multicolor emission from blue through yellow to red, as well as white light emission.

Evaluation of Silk Fibroin-RGD-Stem Cell Factor Scaffold Effect on Adhesion, Migration, and Proliferation of Stem Cells of Apical Papilla.

This study explored the effects of a silk fibroin-RGD-stem cell factor (SF-RGD-SCF) scaffold on the migration, proliferation, and attachment of stem cells of apical papilla (SCAPs). SF, SF-RGD, SF-SCF, and SF-RGD-SCF scaffolds were prepared, and laser confocal microscopy was used to observe the adhesion and growth status of SCAPs on the scaffolds. Furthermore, the numbers of SCAPs on the scaffolds were counted by a digestion counting method to evaluate their proliferation. Cells on the SF-RGD-SCF scaffold proliferated more than those on the other scaffolds and showed a more obvious tendency to migrate to the scaffold's deep porous structure after 7 d seeding. Live/dead cell staining results showed that almost all the adhered cells were alive after 7 d. Furthermore, cell counting showed that the number of cells on the SF-RGD-SCF scaffold was highest after both 1 and 7 d (P < 0.05). Thus, the SF-RGD-SCF composite is biocompatible and promotes the migration, adhesion, and proliferation of SCAPs, making it of potential use as a scaffold for cell-homing pulp regeneration.

Reversible hydrogen-bonded polymerization regulated by allosteric metal templation.

Allosteric effects are common in biology, but have not been fully explored in the control of supramolecular polymerization. Herein, ditopic UPy derivatives with acyclic crown ether-like spacers were designed and synthesized, which can undergo supramolecular polymerization through quadruple hydrogen bonding. Upon the addition of K+, drastic molecular conformational change to the U-shape is induced by metal-coordination, reconfiguring remote UPy sites towards the formation of discrete cyclic dimers. Interestingly, the supramolecular polymerization can be restored by simply removing K+ by water-extraction.

An efficient artificial light-harvesting system with tunable emission in water constructed from a H-bonded AIE supramolecular polymer and Nile Red.

With the aid of CTAB amphiphile, water-phase artificial light-harvesting systems were fabricated as nanoparticles by the self-assembly of two low-molecular-weight organic molecules: a UPy-functionalized TPE derivative 1 with both supramolecular polymerization and AIE capabilities as a donor and a fluorescent chromophore NiR as an acceptor. Owing to the flexibility of supramolecular self-assembly, tunable emissions including white-light emission could be easily realized with high energy transfer efficiency and the antenna effect.

Dynamic gene regulatory network reconstruction and analysis based on clinical transcriptomic data of colorectal cancer.

Inferring dynamic regulatory networks that rewire at different stages is a reasonable way to understand the mechanisms underlying cancer development. In this study, we reconstruct the stage-specific gene regulatory networks (GRNs) for colorectal cancer to understand dynamic changes of gene regulations along different disease stages. We combined multiple sets of clinical transcriptomic data of colorectal cancer patients and employed a supervised approach to select initial gene set for network construction. We then developed a dynamical system-based optimization method to infer dynamic GRNs by incorporating mutual information-based network sparsification and a dynamic cascade technique into an ordinary differential equations model. Dynamic GRNs at four different stages of colorectal cancer were reconstructed and analyzed. Several important genes were revealed based on the rewiring of the reconstructed GRNs. Our study demonstrated that reconstructing dynamic GRNs based on clinical transcriptomic profiling allows us to detect the dynamic trend of gene regulation as well as reveal critical genes for cancer development which may be important candidates of master regulators for further experimental test.

Low power consumption thermo-optic switch formed by an integrated processing method.

In this paper, an integrated processing method was demonstrated to fabricate the polymer-based thermo-optic (TO) switch with low power consumption. The characteristic parameters of the switch were carefully designed and simulated. The air trench structure was exploited to reduce the power consumption, which can be formed with the waveguide simultaneously by the integrated processing method. Moreover, the introduced polymer/silica hybrid waveguide structure can also improve the response time of the device. A typical fabricated switch presented a low switching power of 5.2 mW. The measured switching rise time and fall time are 192.2 and 201.1 µs, respectively.

Correlation between immune signature and high-density lipoprotein cholesterol level in stage II/III colorectal cancer.

An increasing amount of evidence suggests that high-density lipoprotein cholesterol (HDL-C) is related to a positive prognosis in various cancers. However, the correlation between HDL-C and the immune signature and the prognostic role of HDL-C in stage II/III colorectal cancer (CRC) has not been previously reported. A total of 667 CRC patients were enrolled and divided into two groups based on the lower limit of normal HDL-C values (0.78 mmol/L). We used Kaplan-Meier curves and the Cox regression model to analyze the prognostic role of HDL in both disease-free survival (DFS) and overall survival (OS). Fifty-five pairs of tumor tissues were selected according to the variation in HDL-C levels (high or low) and the matched characterizes (ages, T stage, and N stage). Using immunohistochemistry, tumor tissues were stained with antibodies against CD3, CD8, CD163, iNOS, Forkhead box P3 (FOXP3), and CD33. We calculated the density of positively-stained infiltrating cells in the tumor center (TC) and invasive margin (IM). We then used Spearman rank correlation to further investigate the relationship between HDL-C levels and the immune signatures. Our results revealed that compared to patients with high HDL-C levels, patients with low HDL-C levels had poor 3-year DFS (68.9% vs 83.1%, P = 0.032) and 5-year OS rates (66.6% vs 85.3%, P = 0.002). We also identified a positive correlation between HDL-C and CD3+ , CD8+ and iNOS+ cells and a negative correlation between HDL-C and CD163+ cells in both the TC and IM. This study reveals that a low HDL-C level in stage II/III CRC patients predicts poor prognosis. The correlation between the HDL-C level and immune signature in tissue specimens suggested that HDL-C is likely to play an inhibitory role in tumor development via affecting immune responses.

Supramolecular vesicles based on pillar[n]arenes: design, construction, and applications.

Supramolecular vesicles have attracted considerable attention due to their advantages of facile construction, high-cargo-loading capacity, and good biocompatibility. Pillar[n]arenes are a unique family of supramolecular macrocycles, exhibiting excellent features and broad applications due to their intrinsic topology and high functionality. In the past decade, the construction of pillar[n]arene-based supramolecular vesicles has been continuously attempted and developed rapidly. In this review, we mainly summarize the significant advancements of such supramolecular vesicles in the last three years. By showing some representative examples, the design strategies, construction methods, and potential applications of these dynamic nanocarriers are discussed in detail. In particular, the responsiveness of such vesicles to various external stimuli and their applications in drug delivery are highlighted. The outstanding performance of pillar[n]arene-based supramolecular vesicles would definitely enrich the family of supramolecular vesicles and promote the development of dynamic supramolecular materials.

Dynamic hydrogels mediated by macrocyclic host-guest interactions.

Hydrogels have attracted increasing research interest in recent years due to their dynamic properties and potential applications in biomaterials. Concurrently, macrocycle-based host-guest interactions have played an important role in the development of supramolecular chemistry. Recently, research towards dynamic hydrogels mediated by various macrocyclic host-guest interactions has been gradually disclosed. In this review, we will outline the burgeoning progress in the development of functional hydrogels mediated by various host molecules, such as cyclodextrins, cucurbit[n]urils, calix[n]arenes, pillar[n]arenes, and other macrocycles. Smart hydrogels with outstanding properties, like biocompatibility, toughness, and self-healing, are mainly focused. We believe that this review will highlight the potential of dynamic hydrogels mediated by macrocycle-based host-guest interactions.

Tunable Copper-Catalyzed Reaction of C60 with 2-Ethoxycarbonylacetamides and Subsequent BF3·Et2O-Mediated Isomerization of the Generated Dihydrofuran-Fused Fullerenes to Fulleropyrrolidinones.

A tunable copper-catalyzed reaction of C60 with 2-ethoxycarbonylacetamides using air as the oxidant has been explored, which selectively affords methanofullerenes (2) and dihydrofuran-fused fullerenes (3) under the CuI/DMAP and CuCl/NMI catalytic systems, respectively. Furthermore, the generated dihydrofuran-fused fullerenes could be transformed to fulleropyrrolidinones (4 and 5) upon treatment with BF3·Et2O.

Asymmetric Michael addition reactions catalyzed by calix[4]thiourea cyclohexanediamine derivatives.

A number of upper rim-functionalized calix[4]thiourea cyclohexanediamine derivatives have been designed, synthesized and used as catalysts for enantioselective Michael addition reactions between nitroolefins and acetylacetone. The optimal catalyst 2 with a mono-thiourea group exhibited good performance in the presence of water/toluene (v/v = 1:2). Under the optimal reaction conditions, high yields of up to 99% and moderate to good enantioselectivities up to 94% ee were achieved. Detailed experiments clearly showed that the upper rim-functionalized hydrophobic calixarene scaffold played an important role in cooperation with the catalytic center to the good reactivities and enantioselectivities.

Calix[4]arene containing thiourea and coumarin functionality as highly selective fluorescent and colorimetric chemosensor for fluoride ion.

A novel calix[4]arene based chemosensor L which contains coumarin and thiourea group has been synthesized and characterized. Interestingly, probe L exhibits both fluorescent and colorimetric response to fluoride anion with high selectivity and sensitivity. The addition of F- to a solution of probe L resulted in obvious naked-eye color change from colorless to orange under daylight and prominent fluorescence quenching. Further studies showed that the recognition process was less affected by other anions. The binding property of L with F- was studied by a combination of combination of various spectroscopic techniques, such as absorption spectra, fluorescence titration, Job's plot and 1H NMR titration. We are anticipating that this architecture with functional group attached to upper rim of calix[4]arene platform may provide a new approach for the development of F- chemosensor.

Copper-Catalyzed Functionalizations of C60 with Amino Alcohols.

CuI-catalyzed diverse functionalizations of C60 with amino alcohols with aerobic oxygen as the sole oxidant have been explored. For 2-/3-amino alcohols, an aminooxygenation reaction occurs to generate fulleromorpholine and fullerooxazepane derivatives. When a tethered furan ring exists, a further intramolecular [4 + 2] reaction with the neighboring double bond occurs to furnish the cis-1 products. In the case of 4-/5-amino alcohols, methanofullerenes linking with cyclic amides are obtained through cyclic enamine intermediates.

Chiral exploration of 6,12-diphenyldibenzo[b,f][1,5]diazocine with stable conformation.

A first optical resolution of 6,12-diphenyldibenzo[b,f][1,5]diazocine with stable boat conformation was achieved by chiral supercritical fluid chromatography (SFC). The absolute configurations of enantiomers were first assigned and determined by X-ray crystal structure based on CIP-rules. The high optical rotation and circular dichroism spectrum were well explained by electronic helix theory. Owing to the high stabilization of boat conformation, the chiral configuration could be maintained at very high temperature, more than 200 °C, which was proved by Density Functional Theory calculations.

The Cs2CO3-Catalyzed Reaction of 2-Oxindoles with Enones for the Preparation of Indolin-3-Ones and Their Further Transformation.

The Cs2CO3-catalyzed reaction of 2-oxindoles with enones affords 2,2-disubstituted indolin-3-ones through domino "Michael addition-oxidation-ring-cleavage-C-N coupling" process. O2 acts as the sole oxidant to accomplish the oxidative process. The indolin-3-ones can be further transformed to pyridazine, azirdine-fused 3-oxindoles, 4-quinolone derivatives easily.