Highly specific characterization and discrimination of monosodium urate crystals in gouty arthritis based on aggregation-induced emission luminogens

Existing technologies used to detect monosodium urate(MSU)crystals for gout diagnosis are not ideal due to their low sensitivity and complexity of operation.The purpose of this study was to explore whether aggregation-induced emission luminogens(AIEgens)can be used for highly specific imaging of MSU crystals to assist in the diagnosis of gout.First,we developed a series of luminogens(i.e.,tetraphenyl ethylene(TPE)-NH_(2),TPE-2NH_(2),TPE-4NH_(2),TPE-COOH,TPE-2COOH,TPE-4COOH,and TPE-Ketoalkyne),each of which was then evenly mixed with MSU crystals.Next,optimal fluorescence imaging of each of the luminogens was characterized by a confocal laser scanning microscope(CLSM).This approach was used for imaging standard samples of MSU,hydroxyapatite(HAP)crystals,and mixed samples with 1:1 mass ratio of MSU/HAP.We also imaged samples from mouse models of acute gouty arthritis,HAP deposition disease,and comorbidities of interest.Subsequently,CLSM imaging results were compared with those of compensated polarized light microscopy,and we assessed the biosafety of TPE-Ketoalkyne in the RAW264.7 cell line.Finally,CLSM time series and three-dimensional imaging were performed on MSU crystal samples from human gouty synovial fluid and tophi.As a promising candidate for MSU crystal labeling,TPE-Ketoalkyne was found to detect MSU crystals accurately and rapidly in standard samples,animal samples,and human samples,and could precisely distinguish gout from HAP deposition disease.This work demonstrates that TPE-Ketoalkyne is suitable for highly specific and timely imaging of MSU crystals in gouty arthritis and may facilitate future research on MSU crystal-related diseases.

异腈单体的聚合及在功能高分子材料制备中的应用

作为一类重要的三键单体,异腈单体的聚合可产生含氮原子的新型聚合物,并赋予其特殊的功能和应用,因而这一领域的研究引起了越来越多的关注并已经取得了长足的进展。但是,目前鲜有文献对该领域进行较全面的综述。本专论较系统地总结了近年来基于异腈单体的单组分、双组分以及多组分聚合反应,并较详细介绍了其在制备光电和生物等功能高分子材料方面的应用,最后对其未来可能的发展方向进行了展望。

New sustainable polymers with on-demand depolymerization property

To combat the crisis of today's synthetic polymers arising from unsustainable production and disposal,it is essential for the synthetic polymer community to reshape the current polymer industry with sustainable polymers.As an emerging class of sustainable polymers,the development of chemically depolymerizable polymers(CDPs),which can undergo closed-loop depolymerization/repolymerization cycles to reproduce virgin polymers without the loss of properties from recovered monomers,offers an ideal solution to preserve finite natural resources,provides a feasible solution to the end-of-life issue of polymer waste,and thereby establishes a circular materials economy.However,two grand key challenges have been encountered in the establishment of practically useful CDPs:how to balance polymerization and depolymerization ability and how to unify conflicted depolymerizability and physical properties.Accordingly,this critical review article presents our vision for summarizing feasible strategies to overcome the above two significant challenges and the design principles for constructing an ideal CDP by highlighting selected major progress made in this rapidly expanding field.

AIEgen configuration transition and aggregation enable dual prompt emission for single-component nondoped white OLEDs

The dual emission(DE)feature in materials holds great potential to revolutionize the development of one-component system white organic lightemitting diodes(WOLEDs).However,the reported DE materials remain scarce owing to the formidable challenge of breaking Kasha’s rule and managing the intricate energy/charge transfer processes.Herein,we have introduced a groundbreaking DE AIEgen,2CzAn-TPE,which possesses a simple structure and undergoes Z-to-E isomerization and exhibits yellow and red fluorescence powders for pre-and post-sublimation,respectively.With relatively lower potential energy,Z-conformation((Z)-1,2-diphenyl-1,2-bis(4-(10-(9-phenyl-9H-carbazol-3-yl)anthracen-9-yl)phenyl)ethene)of 2CzAn-TPE can be readily transformed into E-conformation((E)-1,2-diphenyl-1,2-bis(4-(10-(9-phenyl-9Hcarbazol-3-yl)anthracen-9-yl)phenyl)ethene)via vacuum sublimation.The utilization of X-ray diffraction and grazing-incidence-wide-angle X-ray scattering techniques confirms the structural transformation,while the crystallographic analysis reveals the establishment of numerous intermolecular CH⋅⋅⋅πinteractions between the tetraphenylethene(TPE)moiety and both the anthracene and carbazole units.This allows a densely packed molecular arrangement,thereby offering propitious conditions for excimer generation in the E-conformation aggregated state.By utilizing the sublimated 2CzAn-TPE as an emitter,a nondoped one-component WOLED was prepared,exhibiting an exceptionally high external quantum efficiency(EQE)of 5.0%,which represents one of the highest performances among all one-componentWOLEDs.This research introduces a novel,simple,and efficient approach to realize highly efficient one-molecule WOLEDs.

The commercial antibiotics with inherent AIE feature: In situ visualization of antibiotic metabolism and specifically differentiation of bacterial species and broad-spectrum therapy

The research on pharmacology usually focuses on the structure-activity relationships of drugs,such as antibiotics,to enhance their activity,but often ignores their optical properties.However,investigating the photophysical properties of drugs is of great significance because they could be used to in situ visualize their positions and help us to understand their working metabolism.In this work,we identified a class of commercialized antibiotics,such as levofloxacin,norfloxacin,and moxifloxacin(MXF)hydrochloride,featuring the unique aggregation-induced emission(AIE)characteristics.By taking advantage of their AIE feature,antibiotic metabolism in cells could be in situ visualized,which clearly shows that the luminescent aggregates accumulate in the lysosomes.Moreover,after a structure-activity relationship study,we found an ideal site of MXF to be modified with a triphenylphosphonium and an antibiotic derivative MXF-P was prepared,which is able to specifically differentiate bacterial species after only 10 min of treatment.Moreover,MXF-P shows highly effective broad-spectrum antibacterial activity,excellent therapeutic effects and biosafety for S.aureus-infected wound recovery.Thus,this work not only discovers the multifunctionalities of the antibiotics but also provides a feasible strategy to make the commercialized drugs more powerful.

X-yne click polymerization

Alkyne-based click polymerizations have been nurtured into a powerful synthetic technique for the preparation of new polymers with advanced structures and versatile properties.Among them,the emerging thiol-yne,hydroxyl-yne,and amino-yne click polymerizations have made remarkable progress from reactions to applications.These polymerizations avoid the usage of inherently dangerous monomers and are safer to operate than the classical azide-alkyne click polymerization(AACP),making them more prospective for diverse applications.To greatly promote the new alkyne-based click polymerizations beyond AACP,a new concept of“X-yne click polymerization”is proposed to unify them,where“X”denotes the monomers that can react with alkynes under mild reaction conditions,including thiols,alcohols,amines,and other promising ones.In this review,we mainly present a brief account of the progress of X-yne click polymerization and discuss in detail the challenges and opportunities in this field.

Highly Emissive Luminogens in Both Solution and Aggregate States

Organic light-emitting materials have attracted considerable attention because of their promising applications in diverse areas.Most fluorophores emit brightly in either dilute solutions or aggregate states;the former generally suffer from aggregation-caused quenching problem,and the latter encounter intensity loss at low concentrations.Herein,we propose a new strategy to overcome these dilemmas by balancing the planar and distorted structures of terphenyl-based luminogens and obtain three luminogens,2PB-AC,2Me2PB-AC,and 2T2PB-AC,with bright emission in both solution and aggregate states.Among them,2PB-AC shows absolute photoluminescence quantum yields(ФPL)higher than 90%in both tetrahydrofuran solution(90.2%)and aggregate states(92.7%for powder and 95.3%for crystal).Thus,2PB-AC could be an efficient probe to realize dual-channel explosive detection in both solution and aggregate states.Moreover,it could be used to image live-cell lipid droplets at a wide range of concentrations.In addition,benefiting from its thermodynamically favorable intersystem crossing process,2Me2PB-AC could be doped in polymethyl methacrylate matrix to provide efficient room-temperature phosphorescence.Thus,this work provides a feasible strategy for the design of luminogens with highly efficient emission in both solution and aggregate states,greatly facilitating and broadening their practical applications.

聚集诱导发光

聚集诱导发光(AIE)是唐本忠院士于2001年提出的一个科学概念,是指一类在溶液中不发光或者发光微弱的分子聚集后发光显著增强的现象。高效固态发光的AIE材料有望从根本上解决有机发光材料面临的聚集导致发光猝灭难题,具有重大的实际应用价值。从分子内旋转受限到分子内运动受限,从聚集诱导发光到聚集体科学,AIE领域已经取得了许多原创性的成果。在本综述中,我们从AIE材料的分类、机理、概念衍生、性能、应用和挑战等方面讨论了AIE领域最近取得的显著进展。希望本综述能激发更多关于分子聚集体的研究,并推动材料、化学和生物医学等学科的进一步交叉融合和更大发展。

聚集诱导发光探针分子在荧光传感中的应用

荧光传感作为化学传感领域中的一项重大技术,具有灵敏度高、选择性好和响应快等优点,但是传统有机发光分子在高浓度或者聚集状态下,容易发生荧光强度的降低或是完全消失,这在一定程度上不利于其在应用中发挥最佳效果.聚集诱导发光(AIE)概念的提出为解决聚集导致发光猝灭(ACQ)的难题提供了方案,实现了发光分子在聚集态下的高荧光量子产率.具有AIE特性的发光分子被用作荧光传感器不仅具有高亮度的荧光信号,而且不必担心由于分子聚集导致的荧光信号的降低或猝灭.同时,由于某些分子聚集程度的增强导致的荧光颜色和强度的变化,可以被用来实现对靶标物的定性和定量分析.本文简述了近几年来AIE分子在荧光传感方面的应用,如离子检测、气体、有机小分子、爆炸物、蛋白质及酶等化学/生物传感器,同时对基于AIE分子的荧光传感器在设计和应用前景做了展望.

A Simple Approach to Bioconjugation at Diverse Levels: Metal-Free Click Reactions of Activated Alkynes with Native Groups of Biotargets without Prefunctionalization

Te efcient bioconjugation of functional groups/molecules to targeted matrix and bio-related species drives the great development of material science and biomedicine,while the dilemma of metal catalysis,uneasy premodifcation,and limited reaction efciency in traditional bioconjugation has restricted the booming development to some extent.Here,we provide a strategy for metal-free click bioconjugation at diverse levels based on activated alkynes.As a proof-of-concept,the abundant native groups including amine,thiol,and hydroxyl groups can directly react with activated alkynes without any modifcation in the absence of metal catalysis.Trough this strategy,high-efcient modifcation and potential functionalization can be achieved for natural polysaccharide,biocompatible polyethylene glycol(PEG),synthetic polymers,cell penetrating peptide,protein,fast whole-cell mapping,and even quick diferentiation and staining of Gram-positive bacteria,etc.Terefore,current metal-free click bioconjugation strategy based on activated alkynes is promising for the development of quick fuorescence labeling and functional modifcation of many targets and can be widely applied towards the fabrication of complex biomaterials and future in vivo labeling and detection.

Electronic effect on the optical properties and sensing ability of AIEgens with ESIPT process based on salicylaldehyde azine

Two novel AIE-active salicylaldehyde azine(SAA) derivatives with a typical excited-state intramolecular proton transfer(ESIPT) process are prepared by introducing electron-withdrawing and donating groups at para-position of phenolic hydroxyl group(CN-SAA and TPA-SAA). The effect of the proton activity in SAA framework on their optical behaviors is investigated spectroscopically. The results from NMR and solvation measurements show that the proton of phenolic hydroxyl group has higher activity when there are electron-withdrawing groups, and the absorption and fluorescence spectra in buffers with different pH also provide the same results. After inviting F. as a nucleophilic probe, this proton activity difference in CN-SAA and TPA-SAA becomes more obvious. The potential application of both molecules is investigated. TPA-SAA exhibits good quantitative sensing ability towards F. with a fluorescence "turn-on" mode, whereas the aggregates of TPA-SAA can selectively and sensitively detect Cu2+ in aqueous solution. From these results, a structure-property relationship is established: the occurrence of ESIPT process will become much easier when linking electron-withdrawing groups at the para-position of phenolic hydroxyl group(e.g., CN-SAA),and it is better to introduce electron-donating groups to enhance the sensing ability towards ions(e.g., TPA-SAA). This work will provide guidance for further design and preparation of AIE-active luminogens with ESIPT process for sensing applications.

Lab-in-cell based on spontaneous amino-yne click polymerization

Unnatural reaction in the living cells is a powerful tool for biological research. However, the polymerization inside cells is rarely reported. In this work, a lab-in-cell is illustrated based on our developed spontaneous amino-yne click polymerization. Carbonyl group activated terminal diyne can spontaneously polymerize with tetraphenylethene(TPE)-containing primary diamine inside cells, and polymer with weight-average molecular weight of 7,300 was yielded. By utilizing this in vivo amino-yne click polymerization and taking advantage of the aggregation-induced emission feature of TPE, a "turn-on" cell imaging was realized,and in-situ killing of cells was also acquired by destroying the structures of actin and tubulin, which cannot be realized by preprepared polymer. This strategy provides a useful platform and holds great promise in biochemistry and therapy applications.

A specific aggregation-induced emission-conjugated polymer enables visual monitoring of osteogenic differentiation

Osteogenic differentiation is the basis of bone growth and repair related to many diseases,in which evaluating the degree and ability of osteogenic transformation is quite important and highly desirable.However,fixing or stopping the growth of cells is required for conventional methods to monitor osteogenic differentiation,which cannot realize the full investigation of the dynamic process.Herein,a new anion conjugated polymer featuring aggregation-induced emission(AIE)characteristics is developed with excellent solubility for in-situ monitoring the process of osteogenic differentiation.This novel polymer can bind with osteogenic differentiated cells,and the intracellular fluorescence increases gradually with the enhancement of osteogenic differentiation.Moreover,it possesses good biosafety with negligible effect on cell activity and osteogenic differentiation,which cannot be realized by the typical method of Alizarin Red S staining.Further study shows that the polymer crosses the cell membrane through endocytosis and enriches in lysosomes,whereas no obvious fluorescence is detected with other cells,including non-differentiated osteoblast cells,under the same conditions,demonstrating the high selectivity.This is the first fluorescent probe with excellent specificity to realize real-time observation of the process of osteogenic differentiation.Therefore,PTB-EDTA shows great promise in the study of osteogenic differentiation and related applications.

Ultralong organic room-temperature phosphorescence of electrondonating and commercially available host and guest molecules through efficient Förster resonance energy transfer

Ultralong organic room-temperature phosphorescence(RTP)materials have attracted tremendous attention recently due to their diverse applications.Several ultralong organic RTP materials mimicking the host-guest architecture of inorganic systems have been exploited successfully.However,complicated synthesis and high expenditure are still inevitable in these studies.Herein,we develop a series of novel host-guest organic phosphorescence systems,in which all luminophores are electron-rich,commercially available and halogen-atom-free.The maximum phosphorescence efficiency and the longest lifetime could reach 23.6%and 362 ms,respectively.Experimental results and theoretical calculation indicate that the host molecules not only play a vital role in providing a rigid environment to suppress non-radiative decay of the guest,but also show a synergistic effect to the guest through Förster resonance energy transfer(FRET).The commercial availability,facile preparation and unique properties also make these new host-guest materials an excellent candidate for the anti-counterfeiting application.This work will inspire researchers to develop new RTP systems with different wavelengths from commercially available luminophores.

Effective enhancement of the emission efficiency of tetraphenylporphyrin in solid state by tetraphenylethene modification

Tetraphenylporphyrin(TPP) is a typical red-emitting luminogen showing evident aggregation caused quenching(ACQ) effect. To enhance its emission efficiency in solid state, four tetraphenylethene(TPE)units were attached to the four meso-positions of TPP core via ester group through a facile and efficient route. The derived compound(4(TPE-COO)-TPP) emits red fluorescence(peak at 655 nm) with a good quantum efficiency(F) of 7.5%, which is much higher than that of TPP(Φ～ 0.1%). In molecular aggregate formed in tetrahydrofuran(THF) and water mixtures, 4(TPE-COO)-TPP has a relative high F of 12%. The evidently subdued ACQ behavior can be ascribed to the propeller shape and bulky size of the TPE units,which prevent the close packing and strong p-p interaction of TPP cores. The loose molecular packing and weak interchromophore interactions were validated by different characterization methods including UV-visible absorption, steady state and transient fluorescence spectroscope, X-ray diffraction and scanning electronic microscope observations. It is noted that 4(TPE-COO)-TPP has an emission efficiency of 14.4% in dilute THF solution. This is due to the conjugation break between the TPP and TPE moieties, the rotational and vibrational motions of the phenyl groups cannot quench the fluorescence of 4(TPE-COO)-TPP.

A Silole-Based Efficient Electroluminescent Material with Good Electron-Transporting Potential

A new silole derivative, 2,5-bis（7-（dimesitylboranyl）-9,9-dimethylfluoren-2-yl）- 1 -methyl- 1,3,4-triphenylsilole （（MesBF）2MTPS）, is synthesized and characterized. （MesBF）2MTPS shows a good fluorescence efficiency of 15% in THF solution and a higher efficiency of 86% in solid film, presenting an aggregation-enhanced emission charac- teristic. It is thermally and morphologically stable, with high decomposition and glass-transition temperatures of 257 and 171 ℃, respectively. The LUMO energy level （-2.96 eV） of （MesBF）zMTPS is lower than that of TPBi, revealing its electron-transporting potential. Efficient organic light-emitting diodes （OLEDs） are fabricated using （MesBF）2MTPS as emitter, which radiates yellow light at 554 nm, and affords high maximum luminance, current efficiency, and external quantum efficiency of 48348 cd·m^-2, 12.3 cd·A^-1, and 4.1%, respectively.

Self-healing hyperbranched polytriazoles prepared by metal-free click polymerization of propiolate and azide monomers

The last decade has witnessed the quick develop of self-healing materials. As a newborn strategy, the alternative of irreversible covalent bond formation is, however, to be further developed. In this paper, self-healing hyperbranched poly(aroxycarbonyltriazole)based on such mechanism were prepared by our developed metal-free click polymerization of simplified dipropiolate and triazide. Thanks to their excellent processability and film-forming ability, high quality homogeneous films free from defects were obtained by casting. The cut films could be healed by stacking or pressing the halves together at room temperature and elevated temperature. Thus, this design concept for self-healing materials should be generally applicable to other hyperbranched polymers with reactive groups on their peripheries.

Theranostic hyaluronic acid prodrug micelles with aggregation- induced emission characteristics for targeted drug delivery

Theranostic hyaluronic acid(HA) prodrug micelles with pH-responsive drug release and aggregation-induced emission(AIE)properties were prepared by chemical graft of biomimetic phosphorylcholine(PC), anticancer drug doxorubicin(DOX) and AIE fluorogen tetraphenylene(TPE) to the HA backbone. DOX was conjugated to the HA backbone by a hydrazone bond which can be hydrolyzed under acidic environment and result in pH-triggered smart release of DOX. The TPE units with typical AIE characteristics were applied for real time drug tracking in cancer cells. The HA-based prodrugs could self-assemble into micelles in aqueous solution as confirmed by the dynamic light scattering(DLS) and transmission electron microscopy(TEM). The intracellular distribution of HA prodrug micelles could be clearly observed by fluorescence microscopy based on the strong fluorescence of TPE. Moreover, after treated with the micelles, stronger fluorescence of TPE in CD44 overexpressed MDA-MB-231 cancer cells was observed, compared to the CD44 negative cell line, NIH3T3 cells, suggesting efficient cell uptake of HA prodrug micelles by receptor-mediated endocytosis. The cell viability results indicated that the prodrug micelles could inhibit the proliferation of the cancer cells effectively. Such pH-triggered theranostic drug delivery system with AIE features can provide a new platform for targeted and image-guided cancer therapy.

Responsive hyperbranched poly(formyl-1,2,3-triazole)s toward quadruple-modal information security protection

Secrecy has received tremendous attention in modern information society. Innovative polymer-based fluorescent materials with multiple mode emission are quite desirable to achieve multistage data security. Herein, a series of soluble and thermally stable hyperbranched poly(formyl-1,2,3-triazole)s(hb-PFTAs) with high molecular weights were facilely prepared by catalyst-free polycycloaddition of aldehyde-activated internal triyne and diazides. Functional moieties of triphenylamine and binaphthyl could be incorporated into the polymers to offer them with unique fluorescence and circular dichroism properties, respectively.By taking advantage of activated ethynyl and aldehyde groups on their peripheries and in the internal branch chains, the hbPFTAs can undergo efficient single-and double-stage post-functionalization. More importantly, based on the remarkable fluorescence responses to hydrazine and hydrochloric acid, the hyperbranched polymers are featured with triple-mode fluorescent patterns and have been applied in quadruple-modal information encryption and storage with enhanced security and density. Collectively, this work not only enriches the structural diversity of the existing triazole-based material library, but also provides new polymeric materials for data and information security application.

3,4,5-Triphenyl-1,2,4-triazole-based multifunctional n-type AIEgen

The luminogens with aggregation-induced emission(AIEgens) characteristics have been widely applied in diverse areas. However,the n-type AIEgens are to be further developed. In this paper, we designed and synthesized an n-type multifunctional AIEgen of tetraphenylethene-substituted 3,4,5-triphenyl-4H-1,2,4-triazole(BTPE-TAZ). This AIEgen can serve as both light-emitting and electron-transporting layers in organic light-emitting devices. Moreover, it also exhibits the interesting optical waveguide and reversible mechanochromic luminescence properties, which are of great potential for practical applications.