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Myocardial ischemia/reperfusion injury (MIRI) is the leading cause of irreversible myocardial damage. A pivotal pathogenic factor is ischemia/reperfusion (I/R)‐induced cardiomyocyte ferroptosis, marked by iron overload and lipid peroxidation. However, the impact of lipid droplet (LD) changes on I/R‐induced cardiomyocyte ferroptosis is unclear. In this study, an aggregation‐induced emission probe, TPABTBP is developed that is used for imaging dynamic changes in LD during myocardial I/R‐induced ferroptosis. TPABTBP exhibits excellent LD‐specificity, superior capability for monitoring lipophagy, and remarkable photostability. Molecular dynamics (MD) simulation and super‐resolution fluorescence imaging demonstrate that the TPABTBP is specifically localized to the phospholipid monolayer membrane of LDs. Imaging LDs in cardiomyocytes and myocardial tissue in model mice with MIRI reveals that the LD accumulation level increase in the early reperfusion stage (0–9 h) but decrease in the late reperfusion stage (>24 h) via lipophagy. The inhibition of LD breakdown significantly reduces the lipid peroxidation level in cardiomyocytes. Furthermore, it is demonstrated that chloroquine (CQ), an FDA‐approved autophagy modulator, can inhibit ferroptosis, thereby attenuating MIRI in mice. This study describes the dynamic changes in LD during myocardial ischemia injury and suggests a potential therapeutic target for early MIRI intervention. [ABSTRACT FROM AUTHOR]

Recently, extensive works have focused on increasing the dissymmetry factors (glum) of various circularly polarized luminescence (CPL) materials, which is one of the most important factors for future applications of CPL. Herein, we designed a chiral co‐assembled liquid crystal polymer (LCP) PTZ@R/S‐PB2, which was prepared by chiral binary co‐polymer (R/S‐PB2) doped with achiral phenothiazine derivation dye (PTZ). For comparison, ternary co‐polymerized LCP (R/S‐PT) was synthesized by co‐polymerizing with mesogenic monomer, chiral monomer and emissive monomer. Both PTZ@R/S‐PB2 and R/S‐PT showed aggregation‐induced emission (AIE) properties. Interestingly, the CPL signals of both PTZ@R/S‐PB2 and R/S‐PT were reversed and amplified after thermal annealing treatment. The |glum| values of the co‐assembled PTZ@R/S‐PB2 were up to 0.13 at a 32 nm thickness, which was 5.4 times that of R/S‐PT (|glum|=0.024). This is due to PTZ@R/S‐PB2 could form more orderly chiral co‐assembly structures. Noticeably, increasing the LCP film thickness could further improve the glum value, and the maximum glum of PTZ@R/S‐PB2 could be enhanced to +0.91/−0.82 at a 220 nm thickness. [ABSTRACT FROM AUTHOR]

Abstract Myocardial ischemia/reperfusion injury (MIRI) is the leading cause of irreversible myocardial damage. A pivotal pathogenic factor is ischemia/reperfusion (I/R)‐induced cardiomyocyte ferroptosis, marked by iron overload and lipid peroxidation. However, the impact of lipid droplet (LD) changes on I/R‐induced cardiomyocyte ferroptosis is unclear. In this study, an aggregation‐induced emission probe, TPABTBP is developed that is used for imaging dynamic changes in LD during myocardial I/R‐induced ferroptosis. TPABTBP exhibits excellent LD‐specificity, superior capability for monitoring lipophagy, and remarkable photostability. Molecular dynamics (MD) simulation and super‐resolution fluorescence imaging demonstrate that the TPABTBP is specifically localized to the phospholipid monolayer membrane of LDs. Imaging LDs in cardiomyocytes and myocardial tissue in model mice with MIRI reveals that the LD accumulation level increase in the early reperfusion stage (0–9 h) but decrease in the late reperfusion stage (>24 h) via lipophagy. The inhibition of LD breakdown significantly reduces the lipid peroxidation level in cardiomyocytes. Furthermore, it is demonstrated that chloroquine (CQ), an FDA‐approved autophagy modulator, can inhibit ferroptosis, thereby attenuating MIRI in mice. This study describes the dynamic changes in LD during myocardial ischemia injury and suggests a potential therapeutic target for early MIRI intervention.

Luminogens with aggregation‐induced emission properties (AIEgens), as a novel and attractive fluorescent molecule, have been used in various fields, such as detection, imaging, and disease treatment, which can overcome the traditional aggregation‐caused quenching of organic fluorescent molecules. Nevertheless, AIEgens still have the problems of water solubility and fluorescence stability in practical applications. Aiming for improving the AIEgens' performance and promoting the development of diverse applications of AIEgens, it is an available strategy to bind AIEgens to those inorganic materials with abundant variety, easy synthesis, and a unique rigid pore structure. The constructed inorganic‐based AIE materials not only inherit the unique luminescence characteristics of AIEgens, but also retain the biocompatibility and degradability of inorganic materials, endowing AIEgens with more attractive versatility. Herein, the up‐to‐date researches of several representative inorganic‐based AIE materials are introduced, with emphasis on their structure design, synthesis strategy, regulation of fluorescence properties of AIE, and their application in the biological field. Finally, the current situation, challenges, and future development potential of inorganic‐based AIE materials are discussed and prospected. [ABSTRACT FROM AUTHOR]

Luminogens with aggregation‐induced emission properties (AIEgens), as a novel and attractive fluorescent molecule, have been used in various fields, such as detection, imaging, and disease treatment, which can overcome the traditional aggregation‐caused quenching of organic fluorescent molecules. Nevertheless, AIEgens still have the problems of water solubility and fluorescence stability in practical applications. Aiming for improving the AIEgens’ performance and promoting the development of diverse applications of AIEgens, it is an available strategy to bind AIEgens to those inorganic materials with abundant variety, easy synthesis, and a unique rigid pore structure. The constructed inorganic‐based AIE materials not only inherit the unique luminescence characteristics of AIEgens, but also retain the biocompatibility and degradability of inorganic materials, endowing AIEgens with more attractive versatility. Herein, the up‐to‐date researches of several representative inorganic‐based AIE materials are introduced, with emphasis on their structure design, synthesis strategy, regulation of fluorescence properties of AIE, and their application in the biological field. Finally, the current situation, challenges, and future development potential of inorganic‐based AIE materials are discussed and prospected.

Three‐photon fluorescence (3PF) imaging excited at 1700 nm window is an enabling technology for visualizing deep brain structures and dynamics. Recently, the 2200 nm window has emerged as the longest excitation window suitable for deep‐brain 3PF imaging. Bright fluorescent probes lay the material basis for deep‐brain 3PF imaging. Among various fluorescent probes, aggregation‐induced emission luminogens (AIEgens) have great potential in 3PF imaging excited at the 1700 nm window in vivo. However, to the best of knowledge, there is no AIEgens applicable to 3PF imaging excited at both the 1700 and 2200 nm windows. To readily fill this gap, here this study designs and synthesizes a novel AIEgen, namely TPE‐DPTT‐ICP, which generates bright 3PF signals excited at both 1700 and 2200 nm. The accordingly fabricated TPE‐DPTT‐ICP nanoparticles (NPs) possess excellent water dispersibility, colloidal stability, biocompatibility, photostability and large 3P action cross section, key to in vivo imaging. In mouse brain in vivo, TPE‐DPTT‐ICP NPs enable deep‐brain 3PF imaging of subcortical structures excited at both the two windows, reaching depths of 1640 and 880 µm below the brain surface, respectively. TPE‐DPTT‐ICP NPs are thus a versatile material simultaneously catering to the need at two infrared optical windows with deep tissue penetration. [ABSTRACT FROM AUTHOR]

Spiropolymers have gained a great deal of interest from both academic and industrial fields by virtue of their unique geometric structures and physical properties. Herein, we prepared a series of spirocopolymers through the catalyst-free four-component spiropolymerization of diisocyanides, activated alkynes, and two different kinds of monomers with reactive carbonyl groups. It is found that the polymerization reactivity of monomers, feeding modes, and feed ratios play significant roles in spirocopolymerization. Monomers with high reactivity and feeding reactive monomers first contribute to improving the molecular weights and yields of the polymers. The constructed copolymers have two different kinds of spiro structures, which is confirmed by the nuclear magnetic resonance. In addition, the spirocopolymers display the unique cluster-triggered emission and aggregation-induced emission properties, and their emission properties can be well-modulated by altering the ratio of comonomers. It is highly anticipated that this line of research will enrich the methodology of multi-component spiropolymerization, and provide a new insight into developing spiropolymers with various spiro structures and tunable properties. [ABSTRACT FROM AUTHOR]

The polarity of lipid droplets (LDs) plays an important role in pathological processes associated with abnormal lipid metabolism. Monitoring the variation of LDs polarity in cells and tissues is of great importance in biomedical research and clinical diagnosis. However, developing fluorescent LDs‐specific probes with high polarity sensitivity, brightness, and permeability for deep tissue imaging is still challenging. Herein, a push–pull fluorescent luminogen (DPBT) with aggregation‐induced emission, strong solvatochromism, large Stokes shift, high solid‐state fluorescence efficiency and superior two‐photon absorption is facilely developed. The lipophilic DPBT can specifically stain LDs with high biocompatibility and good photostability. The viscosity‐enhanced solvatochromic emission property enables DPBT to visualize LDs polarity with high brightness and imaging contrast, and deep penetration depth under two‐photon microscopy. DPBT can specifically stain lipids in various mouse tissues (atherosclerotic plaque, liver, and mesenteric adipose tissues) and map their polarity distribution to reflect lipid metabolic states within those tissues. It is found that the lipids deposition as well as their polarity distribution in tissues of hyperlipoidemia mouse are clearly different from the tissues of the normal mouse. Its excellent properties make DPBT a promising candidate for investigating LDs‐associated physiological and pathological processes in live biological samples. [ABSTRACT FROM AUTHOR]

Strong intermolecular interactions usually facilitate charge transport, but impede photoluminescence, therefore, the development of organic π‐conjugated materials that exhibit both semiconducting and light‐emissive properties remains challenging. Herein, a series of perylene diimide (PDI)‐based carbolong complexes with dπ‐pπ conjugation is synthesized. The resulting alcohol‐soluble products exhibit broad and strong absorption combined with outstanding electronic and optical properties, and are applied as electron transport layer materials in organic solar cells, achieving power conversion efficiencies up to 17.36%. In addition, these complexes exhibit an uncommon aggregation‐induced emission phenomenon. These results will aid in future design of π‐conjugated materials with increased functionality. [ABSTRACT FROM AUTHOR]

Development of the powerful building block is of great significance to construct materials with advanced properties. Herein, for the first time, a triazole‐based luminescent core with balanced twist and conjugation is reported, which is explored to construct a D‐A near‐infrared (NIR) aggregation‐induced emission luminogens (TPT‐DCM) with high molar extinction coefficient, good brightness and excellent reactive oxygen species generation rate. These features enable it to function as a nanoprobe with ultralong NIR afterglow luminescence (up to 20 days) and ultrahigh tumor‐to‐liver signal ratio (up to 187) for in vivo deep‐tissue afterglow imaging (with depth reaching 1.6 cm), in combination with chemiluminescence resonance energy transfer aided by active Schaap's dioxetane. Moreover, thanks to the excellent properties of the nanoprobe, the afterglow imaging‐guided surgery navigation can be successfully conduced to remove the tumors especially with tiny size of < 1 mm. This is particularly useful to eliminate tumor residuals and prevent the cancer recurrence after surgery. [ABSTRACT FROM AUTHOR]

Photoswitches with multiple fluorescence states known as photofluoro-chromism upon photo-induced isomerization show practical applications in information storage, anticounterfeiting, and sensors. However, it is still challenging to realize rapid isomerization, efficient fluorescence, and gradient signal output simultaneously. Herein, by incorporating luminogenic units with aggregation-induced emission (AIE) features into photo-responsive hydrazone, a series of novel photofluorochromic AIE compounds are developed. These newly designed compounds exhibit quantum yields of up to 38.4% and could undergo reversible and swift photo-isomerization upon 450/365 nm irradiation. Accordingly, the fabricated photopatterns based on them are utilized as quantitatively described images for information storage, which show excellent rewritability and intensity-variable fluorescence with a high resolution of 10 |m. This work provides a new strategy to develop intelligent photopattern systems with continuous gradient fluorescence for information storage and cybernetics. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) have excellent properties and have made great progress in synthesis and applications. However, it is still a challenge to realize convenient preparation and highly emissive solid‐state luminescence without the assistance of matrix. In this study, high‐efficiency hydrophilic yellow emissive CDs (Y‐CDs) with aggregation‐induced emission (AIE) characteristics are synthesized by a one‐pot microwave method. Y‐CDs show weak yellow emission with a photoluminescence quantum yield (PLQY) of 6.14% in aqueous solutions, but exhibit a significantly enhanced PLQY of 58.35% in the solid state. The AIE characteristic is confirmed by the phenomenon that the fluorescence emission intensity of Y‐CDs continues to increase with the gradual increase of the poor solvent fraction. The AIE phenomenon of Y‐CDs is derived from the suppression of surface piperazine groups motions and decrease of the non‐radiative rate, as is verified by a series of experiments. Finally, based on the high PLQY and AIE property, Y‐CDs are applied as a color‐converting layer on blue‐light‐emitting chips to fabricate white‐light‐emitting diodes with color coordinates of (0.31, 0.35), while Y‐CDs are also explored for their potential applications in anti‐counterfeiting, encryption and bioimaging. [ABSTRACT FROM AUTHOR]

Threats posed by recalcitrant bacterial biofilms have been continuously challenging the public health due to the dramatically magnified antibiotic resistance resulted from the complicated biofilm microenvironment. Urgent demands on effective biofilm combating have propelled the rapid exploration of high‐performance antibiofilm systems. Thanks to the distinguished features of aggregation‐intensified fluorescence and aggregation‐enhanced generation of reactive oxygen species, aggregation‐induced emission luminogens (AIEgens) are becoming increasingly eye‐catching in the field of biofilm combating by serving as excellent fluorescence imaging probes or theranostic agents. This review aims to, for the first time, outline the current progress of AIEgens in bacterial biofilm imaging and antibiofilm theranostics. The up‐to‐date advancements of AIEgens in enzyme‐responsive biofilm imaging, discriminative imaging of Gram‐positive bacterial biofilm, as well as biofilm viability monitoring are summarized at first. Subsequently, the antiadhesion intervention‐mediated prevention of biofilm formation and photodynamic therapy‐involved eradication of preexisting biofilms are detailedly elucidated. Finally, a brief conclusion as well as a discussion on the current challenges and future expectations is presented.

Photoactivatable agent is a powerful tool in biomedicine studies due to high‐precision spatiotemporal control of light. However, those previously reported agents generally suffer from short wavelength, fluorescence self‐quenching effect, and the lack of photosensitizing property, which severely restrict their practical applications. To address these issues, molecular engineering of 1,4‐dihydropyridine derivatives is conducted to obtain an optimized agent, namely TPA‐DHPy‐Py, which exhibits low oxidation potential, high photoactivation efficiency, and excellent type I/II combined photodynamic activity. Concurrently, its photoactivated counterpart is featured by aggregation‐induced near‐infrared emission and remarkable reactive oxygen species (ROS) production efficiency. Upon photoactivation, TPA‐DHPy‐Py is capable of precisely identifying cancer cells from co‐culturing cancer cells and normal cells without the assistance of any extra targeting units, and in situ monitoring lipid droplets and endoplasmic reticulum alteration under ROS stress, as well as achieving fluorescent visualization of tumor in vivo with supremely high imaging contrast. Furthermore, the unprecedented performance on photodynamic cancer therapy is demonstrated by the significant inhibition of tumor growth. Therefore, the photoactivatable TPA‐DHPy‐Py with dual‐organelle‐targeted and excellent photodynamic activity associated with self‐monitoring ability is highly promising for cancer theranostics in clinical trials. [ABSTRACT FROM AUTHOR]

The novel pyrene-appended Schiff base probe L with aggregation-induced emissions (AIE) relevant to an increase in water fractions (0–90%) is synthesized and applied in sequentially detecting Cu2+ and CN−. The pyrene-based probe L firstly induces the excimer formation in the presence of Cu2+. However, the process can be reversed by sequentially adding CN−, which is demonstrated using the fluorescence "Off-On-Off" response in semi-aqueous media ethanol water (v/v = 7/3) under physiological pH (5 mM HEPES, pH 7.0). The Job's plot, mass analysis, 1H NMR titrations, and density functional theory (DFT) interrogations confirm the 2:1 stoichiometry of excimer complex L–Cu2+-L*, preferential binding atoms, and CN− tuned complex reversibility. Based on the photoluminescence (PL) titration, the association constant of L to Cu2+ is determined as 4.95 × 106 M−1. From standard deviation and linear fittings, the detection limits (LODs) of Cu2+ and CN− are estimated as 219 nM and 580 nM, respectively. The practicality of Cu2+ and CN− detection is demonstrated using a TLC plate and a blended polymer membrane through which significant color changes under a UV lamp can be monitored. Moreover, utility of the designed probe L towards biological application with low toxicity is demonstrated by detecting Cu2+ and CN− inside HeLa cells. The responses of the probe to Cu(II) ions were also verified using living HeLa cells imaging. [ABSTRACT FROM AUTHOR]

Synergistically enhancing luminescent and ferroelectric (SELF) properties are observed from a tetraphenylethene (TP) substituted with clipping groups (C), where the C is consisting of a 4‐[3,5‐bis‐(3‐decyloxy‐styryl)‐styryl]‐phenyl (DOS) unit. The DOS units of TPCn are self‐assembled via intermolecular interaction to clip themselves and induce TP aggregation, as evidenced by clip‐induced quenching of emission at DOS units (Eclip) accompanied by aggregation‐induced emission enhancement of TPs (EAIE). TPC4 demonstrates strong photoluminescence in a dilute chloroform solution and large EAIE in aqueous (>50%) THF solution. TPCn demonstrates SELF properties in film state, with high quantum yields of photoluminescence (>80%) and ferroelectric switching. Due to the introduction of four clips, TPC4 has a higher remnant polarization (Pr = 2.27 µC cm−2) at room temperature than TPC1. TPC4 is successfully employed in a light‐emitting electrochemical cell to achieve over 1290 cd m−2 under pulsed current conditions. The TPC4 film on a flexible substrate produced a piezoelectric output voltage of up to 0.13 V and a current density of 1.14 nA cm−2 upon bending. These results indicate that the side chain clipping and TP aggregation resulted in unprecedented flexible SELF properties in a single compound, offering simultaneous enhancement of electroluminescence, mechanical sensitivity, and energy harvesting capacity. [ABSTRACT FROM AUTHOR]

A nanomaterial with a high payload of nucleic acid drugs and low cytotoxicity is desirable for gene therapy. Herein, a new DNA assembly method triggered by hydrophobic interaction and strengthened by Mg2+ electrostatic interaction for carrier‐free gene transfection is reported. It is discovered that a hydrophobic aggregation‐induced emission dye with a low molecular weight that is modified to an oligonucleotide will greatly change the condensation properties of DNA. The conditions and the possible mechanism of such an aggregation process are carefully investigated. Further, it is revealed that the resultant aggregate is suitable for gene delivery, as in which the oligonucleotides are protected from degradation, and the intracellular permeability is enhanced. For the delivery of Bcl‐2 antisense oligonucleotide, such a system exhibits a high gene transfection efficiency both in vitro and in vivo. Accordingly, an interesting observation is reported in this study that an aggregation‐induced emission dye with a molecular weight much lower than the nucleic acid drugs can cause oligonucleotide aggregation and facilitate gene transfection. Such a delivery system provides a practical and inspiring example for the development of gene therapy in the future. [ABSTRACT FROM AUTHOR]

Photothermal therapy (PTT) holds potential as an alternative approach for effective cancer treatment since it exerts minimal side effects on normal tissues. However, the photothermal stimulation increases the expression of heat shock protein (HSP) in tumor cells, rendering the tumor cells insensitive to heat and thus constraining the effects of PTT. In this study, biomimetic aggregation‐induced emission (AIE) photothermal agents with hitchhiking ability (DC@BPBBT dots) are developed by coating the nanoaggregates of the NIR AIE polymeric photothermal agents with dendritic cell (DC) membranes. Notably, the inner nanoaggregate (BPBBT dots) holds bright second‐window near infrared (NIR‐II) fluorescence (quantum yield of up to 3.47%) and a high photothermal conversion performance (photothermal conversion efficiency of up to 30.5%), and the outer cell membrane can facilitate the hitchhiking of DC@BPBBT dots on endogenous T cells and enhance the tumor delivery efficiency by about 1.2 times. Furthermore, DC@BPBBT dots can activate and stimulate T cells in vivo to secrete cytokine tumor necrosis factor α (TNF‐α), which can reduce the expression of heat shock protein 70 (HSP70) to render tumor cells more sensitive to heat. This study not only provides an alternative heat shock protein inhibition strategy based on immune cell interactions but also provides a hitchhike approach for drug delivery in cancer photothermal immunotherapy. [ABSTRACT FROM AUTHOR]

To address urgent tasks in the treatment of advanced deep‐seated tumors, a 980 nm absorbing agent with aggregation‐induced emission tendency, namely TPE‐BT‐BBTD, which simultaneously possesses the longest absorption wavelength among all the reported AIE molecules is developed. The functionality of deep near‐infrared‐II fluorescence imaging (NIR‐II FLI) and outstanding photothermal performance is well‐tailored for advanced pancreatic cancer treatment. With the covalent attachment of the programmed death‐ligand 1 (αPD‐L1) antibody, αPD‐L1@TPE‐BT‐BBTD nanoparticles show precise tumor targeting and excellent immunosuppression reversal ability. Following local photothermal therapy, immunogenic tumor vaccination is induced to trigger the infiltration of cytotoxic T lymphocytes (CTLs) in tumors. With the decreased FoxP3+ Treg cells and M2‐like macrophages that are reversed by αPD‐L1, CTLs activity is further enhanced with more production of granzyme B (GrB), which much accurately leads to tumor apoptosis and effectively suppressed spontaneous metastases. Overall, αPD‐L1@TPE‐BT‐BBTD nanoparticles based NIR‐II FLI‐mediated photo‐immunotherapy is able to significantly improve the control of primary tumor and metastasis in the treatment of advanced deep‐seated tumors. [ABSTRACT FROM AUTHOR]

Lung cancer, a highly prevalent and lethal form of cancer, is often associated with oxidative stress. Photodynamic therapy (PDT) has emerged as a promising alternative therapeutic tool in cancer treatments, but its efficacy is closely correlated to the photosensitizers generating reactive oxygen species (ROS) and the antioxidant capacity of tumor cells. In particular, glutathione (GSH) can reduce the ROS and thus compromise PDT efficacy. In this study, a GSH-responsive near-infrared photosensitizer (TBPPN) based on aggregation-induced emission for real-time monitoring of GSH levels and enhanced PDT for lung cancer treatment is developed. The strategic design of TBPPN, consisting of a donor-acceptor structure and incorporation of dinitrobenzene, enables dual functionality by not only the fluorescence being activated by GSH but also depleting GSH to enhance the cytotoxic effect of PDT. TBPPN demonstrates synergistic PDT efficacy in vitro against A549 lung cancer cells by specifically targeting different cellular compartments and depleting intracellular GSH. In vivo studies further confirm that TBPPN can effectively inhibit tumor growth in a mouse model with lung cancer, highlighting its potential as an integrated agent for the diagnosis and treatment of lung cancer. This approach enhances the effectiveness of PDT for lung cancer and deserves further exploration of its potential for clinical application., (© 2024 Wiley‐VCH GmbH.)

The past one hundred years have witnessed the great development of polymer science. The advancement of polymer science is closely related with the development of characterization techniques and methods, from viscometry in molecular weight determination to advanced techniques including differential scanning calorimetry, nuclear magnetic resonance, and scanning electron microscopy. However, these techniques are normally constrained to tedious sample preparation, high costs, harsh experimental conditions, or ex situ characterization. Fluorescence technology has the merits of high sensitivity and direct visualization. Contrary to conventional aggregation‐causing quenching fluorophores, those dyes with aggregation‐induced emission (AIE) characteristics show high emission efficiency in aggregate states. Based on the restriction of intramolecular motions for AIE properties, the AIE materials are very sensitive to the surrounding microenvironments owing to the twisted propeller‐like structures and therefore offer great potential in the study of polymers. The AIE concept has been successfully used in polymer science and provides a deeper understanding on polymer structure and properties. In this review, the applications of AIEgens in polymer science for visualizing polymerization, glass transition, dissolution, crystallization, gelation, self‐assembly, phase separation, cracking, and self‐healing are exemplified and summarized. Lastly, the challenges and perspectives in the study of polymer science using AIEgens are addressed. [ABSTRACT FROM AUTHOR]

Nontraditional intrinsic luminescence (NTIL) which always accompanied with aggregation‐induced emission (AIE) features has received considerable attention due to their importance in the understanding of basic luminescence principle and potential practical applications. However, the rational modulation of the NTIL of nonconventional luminophores remains difficult, on account of the limited understanding of emission mechanisms. Herein, the emission color of nonconjugated poly(methyl vinyl ether‐alt‐maleic anhydride) (PMVEMA) can be readily regulated from blue to red by controlling the alkalinity during the hydrolysis process. The nontraditional photoluminescence with AIE property is from the new formed p‐band state, resulting from the strong overlapping of p orbitals of the clustered O atoms through space interactions. Hydrated hydroxide complexes embedded in the entangled polymer chain make big difference on the clustering of O atoms which dominates the AIE property of nonconjugated PMVEMA. These new insights into the photoluminescence mechanism of NTIL should stimulate additional experimental and theoretical studies and can benefit the molecular‐level design of nontraditional chromophores for optoelectronics and other applications. [ABSTRACT FROM AUTHOR]

In the synthesis of traditional AIE‐active polymers with conjugate or multi‐benzene system, the troublesome process is still faced such as consuming time, high temperature, catalysis, no water or vacuum, and so on. In this study, the polydihydropyrimidone derivatives (PDPMDs) with AIE properties are facilely synthesized by the introduction of 4‐dihydropyrimidone rings onto non‐AIE‐active intermediate polyureas (PUs) in Biginelli reaction. It is found that the unsymmetrical L‐lysine ethyl diisocyanate and butylenediamine played a very important role in the smooth preparation and fluorescence enhancement of PDPMDs. Compared with the intermediate PUs, the fluorescence of PDPMDs is significantly enhanced (35‐fold increase), which is mainly due to the intramolecular aggregation of dihydropyrimidone rings on PUs chains. At the same time, with the increase of the content of dihydropyrimidone rings, the fluorescence intensity of PDPMDs also increases, and the emission wavelength shows an obvious red shift. The fluorescence of PDPMDs also showed obvious dependence on excitation wavelength, which further reveals the clusterization‐triggering emission (CTE) mechanism. In summary, the strategy of endowing AIE properties to non‐AIE active polymer by introducing heterocycles into the backbone through multi‐component reaction provides useful guidance for AIE functionalization of other non‐AIE materials. [ABSTRACT FROM AUTHOR]

The novel pyrene-appended Schiff base probe L with aggregation-induced emissions (AIE) relevant to an increase in water fractions (0–90%) is synthesized and applied in sequentially detecting Cu2+ and CN−. The pyrene-based probe L firstly induces the excimer formation in the presence of Cu2+. However, the process can be reversed by sequentially adding CN−, which is demonstrated using the fluorescence “Off-On-Off” response in semi-aqueous media ethanol water (v/v = 7/3) under physiological pH (5 mM HEPES, pH 7.0). The Job’s plot, mass analysis, 1H NMR titrations, and density functional theory (DFT) interrogations confirm the 2:1 stoichiometry of excimer complex L–Cu2+-L*, preferential binding atoms, and CN− tuned complex reversibility. Based on the photoluminescence (PL) titration, the association constant of L to Cu2+ is determined as 4.95 × 106 M−1. From standard deviation and linear fittings, the detection limits (LODs) of Cu2+ and CN− are estimated as 219 nM and 580 nM, respectively. The practicality of Cu2+ and CN− detection is demonstrated using a TLC plate and a blended polymer membrane through which significant color changes under a UV lamp can be monitored. Moreover, utility of the designed probe L towards biological application with low toxicity is demonstrated by detecting Cu2+ and CN− inside HeLa cells. The responses of the probe to Cu(II) ions were also verified using living HeLa cells imaging.

Fluorescent hydrogels have recently become one of the most prominent materials for smart confidential information protection. But it is still quite challenging to develop a 3D anticounterfeiting platform with on‐demand information decryption and transmission capacities, which are of great importance to achieve high‐level data protection security. Herein, robust aggregation‐induced emissive polymeric hydrogels with thermo‐triggered multistate fluorescence switching, shape memory, and self‐healing properties based on supramolecular dynamic lanthanide coordination interactions are presented. By a collective action of these promising properties, a fluorescent hydrogel‐based 3D information encoding platform is demonstrated for on‐demand information decryption, in which information pre‐encrypted in 3D hydrogel structures is stepwise decrypted by the control of external stimuli. Such unique on‐demand information decryption features are further expanded to the transmission of manifold customized messages to multiple receivers. Herein, the possibility of utilizing 3D fluorescent hydrogel structures for high‐level information encryption and on‐demand decryption is opened up.

Fluorescent hydrogels have recently become one of the most prominent materials for smart confidential information protection. But it is still quite challenging to develop a 3D anticounterfeiting platform with on‐demand information decryption and transmission capacities, which are of great importance to achieve high‐level data protection security. Herein, robust aggregation‐induced emissive polymeric hydrogels with thermo‐triggered multistate fluorescence switching, shape memory, and self‐healing properties based on supramolecular dynamic lanthanide coordination interactions are presented. By a collective action of these promising properties, a fluorescent hydrogel‐based 3D information encoding platform is demonstrated for on‐demand information decryption, in which information pre‐encrypted in 3D hydrogel structures is stepwise decrypted by the control of external stimuli. Such unique on‐demand information decryption features are further expanded to the transmission of manifold customized messages to multiple receivers. Herein, the possibility of utilizing 3D fluorescent hydrogel structures for high‐level information encryption and on‐demand decryption is opened up. [ABSTRACT FROM AUTHOR]

In this study we report efficient method for the syntheses of mono- and diarylated diphenyldithienylethene (DPDTE) via a palladium-catalyzed C–H arylation reaction. These new derivatives showed amplified luminescent properties thanks to a change in polarity, particularly in the presence of an electron-withdrawing groups (EWG). Moreover, the arylated DPDTEs showed dual-emissive phenomena, including fluorescence in organic solvents and aggregation-induced emission.

As the core of polymer chemistry, manufacture of functional polymers is one of research hotspots over the past several decades. Various polymers are developed for diverse applications due to their tunable structures and unique properties. However, traditional step‐by‐step preparation strategies inevitably involve some problems, such as separation, purification, and time‐consuming. The multicomponent reactions (MCRs) are emerging as environmentally benign synthetic strategies to construct multifunctional polymers or composites with pendant groups and designed structures because of their features, such as efficient, fast, green, and atom economy. This mini review summarizes the latest advances about fabrication of multifunctional fluorescent polymers or adsorptive polymeric composites through different MCRs, including Kabachnik–Fields reaction, Biginelli reaction, mercaptoacetic acid locking imine reaction, Debus–Radziszewski reaction, and Mannich reaction. The potential applications of these polymeric composites in biomedical and environmental remediation are also highlighted. It is expected that this mini‐review will promote the development preparation and applications of functional polymers through MCRs. [ABSTRACT FROM AUTHOR]

In vivo investigations using small animal models are of great significance for the comprehensive understanding of biological and physiological functions—seeing is believing. Fluorescence imaging can provide real‐time and dynamic information of living systems. During the past few years, aggregation‐induced emission luminogens (AIEgens) are widely and rapidly developed for biological detection, imaging, and medicine, owing to their distinct advantages of structural variety, easy functionalization, strong luminescence, large Stokes shift, high photobleaching‐resistance, good biocompatibility, and so forth. In this review, recent advances in applying AIEgens in living animals are highlighted, including in vivo vascular and tumor‐targeted imaging, monitoring biological processes, disease diagnosis, and image‐guided therapy. The aim of this review is to provide a well‐rounded view of the potential applications of AIEgens for biomedical research at the preclinical animal level for researchers and clinicians, and to inspire more practical inventions that will improve or assist clinical techniques. [ABSTRACT FROM AUTHOR]

The potential threats of ethidium bromide to laboratory staff have drawn more and more attention. Considering that commercial available substitutes still cannot replace ethidium bromide due to some drawbacks, it can be a better solution by functionalizing directly on ethidium bromide moiety. In this work, ethidium bromide is ameliorated via changing the bromide anion into moieties with more twist structures to prevent the aggregation caused quenching in aggregations, and increase more hydrophobic ability to form nanoparticles in aqueous. The nanoparticles of these probes show negative zeta potential, low toxicity, good photostability, and high sensitivity, both in solution tests and gel electrophoresis experiments. Meanwhile, the weak penetration ability through skin constitutes a dual protection for users. Furthermore, the one step synthesis from commercial available ethidium bromide and the convenient purification also do help to these probes in applications. [ABSTRACT FROM AUTHOR]

Targeted killing multidrug-resistant bacteria with high efficiency is urgently needed for the treatment of infection with minimal collateral damage. Herein, a new near-infrared (NIR) fluorescence nanoprobe is designed and synthesized with aggregation-induced emission (AIE) features, which also is excellent reactive oxygen species (ROS) generator. The as-prepared AIE nanoparticles (NPs) present outstanding sterilizing rate on methicillin-resistant Staphylococcus aureus (MRSA) and kanamycin-resistant Escherichia coli (KREC). Meanwhile, considering the differences in the surface structure of animal cells and bacteria, a non-invasive image-guided strategy for precise treatment of bacterial infection has been successfully implemented based on bioorthogonal reaction which can perform and control unnatural chemical reactions inside living organisms. The AIE NPs are thus specifically trapped on the bacterial surface while not on the normal cells, realizing real-time tracking of the infected site distribution in vivo and guiding photodynamic therapy (PDT) for eliminating bacteria in inflammation region. That significantly improves the accuracy and sterilization rate of bacterial-infected wounds with negligible side effects. The investigation developed a potential antibacterial agent and also provides an instructive way for targeting treatment based on bioorthogonal reaction., (© 2023 Wiley-VCH GmbH.)

Fluorescent emitters have regained intensive attention in organic light emitting diode (OLED) community owing to the breakthrough of the device efficiency and/or new emitting mechanism. This provides a good chance to develop new near-infrared (NIR) fluorescent emitter and high-efficiency device. In this work, a D-π-A-π-D type compound with naphthothiadiazole as acceptor, namely, 4,4′-(naphtho[2,3-c][1,2,5]thiadiazole-4,9-diyl)bis( N,N-diphenylaniline) (NZ2TPA), is designed and synthesized. The photophysical study and density functional theory analysis reveal that the emission of the compound has obvious hybridized local and charge-transfer (HLCT) state feature. In addition, the compound shows aggregation-induced emission (AIE) characteristic. Attributed to its HLCT mechanism and AIE characteristic, NZ2TPA acquires an unprecedentedly high photoluminescent quantum yield of 60% in the neat film, which is the highest among the reported organic small-molecule NIR emitters and even exceeds most phosphorescent NIR materials. The nondoped devices based on NZ2TPA exhibit excellent performance, achieving a maximum external quantum efficiency (EQE) of 3.9% with the emission peak at 696 nm and a high luminance of 6330 cd m−2, which are among the highest in the reported nondoped NIR fluorescent OLEDs. Moreover, the device remains a high EQE of 2.8% at high brightness of 1000 cd m−2, with very low efficiency roll-off. [ABSTRACT FROM AUTHOR]

The development of effective strategies for fabrication of fluorescent organic nanoparticles (FONs) with an aggregation-induced emission (AIE) feature has an important impact on the biomedical applications of these AIE-active FONs. In the current work, an ultrafast strategy for fabricating AIE-active FONs is developed through a 'one-pot' microwave-assisted, catalysts-free, and solvent-free Kabachnik-Fields (KF) reaction for the first time. It is demonstrated that such organophosphorous-containing AIE-active block polymers can be synthesized within 2 min under air atmosphere through the microwave-assisted KF reaction. These polymers show amphiphilic properties and can self-assemble into mPEG-CHO-Phe-NH2-DEP FONs, which display high water dispersibility and desirable optical properties. Biological evaluation results suggest that the mPEG-CHO-Phe-NH2-DEP FONs exhibit low toxicity and are potential for biological imaging applications. More importantly, many other multifunctional AIE-active FONs can also be fabricated through the strategy described in this work owing to the universality of KF reaction. Besides, combined with the excellent properties of mPEG-CHO-Phe-NH2-DEP FONs, it is believed that such microwave-assisted KF reaction shall be an effective route for designing various AIE-active nanomaterials for different biomedical applications. [ABSTRACT FROM AUTHOR]

Driven by the high demand for sensitive and specific tools for optical imaging, fluorescent nanoprobes with various working mechanisms and advanced functionalities are flourishing at an incredible speed. This work reports the design and fabrication of aggregation-induced emission (AIE)-active fluorescent organic nanoparticles (FNPs) via forming dynamic phenyl borate between diol containing hydrophobic AIE dye (APD-PhCHO) and phenylboronic acid pendant hydrophilic polymers (PEGMA-VPBA) within 30 min. The final AIE-active APD-PhCHO-PEGMA-VPBA FNPs display high water dispersibility and strong fluorescence emission because of their amphiphilic properties and AIE feature. Biological evaluation suggests that APD-PhCHO-PEGMA-VPBA FNPs possess negative effect on HeLa cells and desirable optical properties for biological imaging. More importantly, phenyl borate is a dynamic bond with pH and glucose responsiveness. Furthermore, different functions can be designed and introduced into these AIE-active systems through adoption of different monomers for good applicability of free radical polymerization. Therefore, this work provides a novel platform for preparation of multifunctional AIE-active nanosystems with responsiveness for various biomedical applications. [ABSTRACT FROM AUTHOR]

Ulcerative colitis (UC) is a prevalent idiopathic inflammatory disease which causes such complications as intestinal perforation, obstruction, and bleeding, and thus deleteriously impacting people's normal work and quality of life. Hence, accurate diagnosis of UC is crucial in terms of planning optimal treatment plan. Herein, a pH/reactive oxygen species (ROS) dual-responsive nanosystem (BM@EP) is developed for UC's detection and therapy. BM@EP is composed of a chromophore-drug dyad and the enteric coating. The chromophore-drug dyad (BOD-XT-DHM) is synthesized by linking the chromophore (BOD-XT-BOH) and a flavonoid drug (dihydromyricetin DHM) through boronate ester bond. The enteric coating includes Eudragit S100 and poly(lactic-co-glycolic acid) (PLGA), the former is commonly employed as a pH-dependent polymer coating excipient so as to attain colon-targeted delivery, and the latter has been widely used as an excipient for the controlled-extended release. After oral administration, BM@EP delivers the dyad (BOD-XT-DHM) into the colon and releases the dyad molecules by being triggered by the alkaline pH in t colon, thereafter upon being stimulated by overexpressed H 2 O 2 in the inflamed colon, the boronate bond in the dyad is broken down and correspondingly the drug DHM is released for UC therapy, simultaneously the chromophore is released for near-infrared second window (NIR-II) fluorescence and optoacoustic imaging for UC diagnosis and recovery evaluation., (© 2022 Wiley-VCH GmbH.)

Infections caused by Gram-positive bacteria, especially those able to invade and survive in host cells, threaten human health severely. It is therefore highly desirable to develop therapeutics that can selectively target and kill intracellular Gram-positive pathogens with minimal toxicity to host cells. Herein, it is described that the aggregation-induced emission luminogen (AIEgen) TPEPy-Et, containing a positively charged pyridinium group and a hydrophobic tetraphenylethylene fragment, is effective for Gram-positive bacteria detection and elimination. The fluorescence of TPEPy-Et is greatly enhanced after incubation with Gram-positive bacteria, which can be used to detect and trace the bacteria in cells. TPEPy-Et also shows excellent killing effects against both extracellular and intracellular Gram-positive bacteria through a membrane depolarization mechanism. The luminescent antibacterial agent TPEPy-Et is thus promising for diagnosis and therapy against intracellular bacterial infection., (© 2021 Wiley-VCH GmbH.)

Hypoxia is an inherent physiologic barrier in the microenvironment of solid tumor and has badly restricted the therapeutic effect of photodynamic therapy (PDT). Meanwhile, the photosensitizer (PS) agents used for PDT applications regularly encounter the tiresome aggregation-caused quenching effect that seriously decreases the production efficiency of cytotoxic reactive oxygen species. The aggregation-induced emission (AIE) PSs with antiquenching characteristics in the aggregate state are considered as a promising tool for achieving highly efficient PDT applications, and plenty of studies have widely demonstrated their advantages in various diseases. Herein, the recent progress of AIE PSs in the battle of antitumor hypoxia issue is summarized and the practical molecular principles of hypoxia-overcoming AIE PSs are highlighted. According to the hypoxia-overcoming mechanism, these representative cases are divided into low O 2 -dependent (type I PDT) and O 2 -dependent tactics (mainly including O 2 -enrichment type II PDT and combination therapy). Furthermore, the underlying challenges and prospects of AIE PSs in hypoxia-overcoming PDT are proposed and thus expect to promote the next development of AIE PSs., (© 2021 Wiley-VCH GmbH.)

In this study we report efficient method for the syntheses of mono- and diarylated diphenyldithienylethene (DPDTE) via a palladium-catalyzed C–H arylation reaction. These new derivatives showed amplified luminescent properties thanks to a change in polarity, particularly in the presence of an electron-withdrawing groups (EWG). Moreover, the arylated DPDTEs showed dual-emissive phenomena, including fluorescence in organic solvents and aggregation-induced emission. [ABSTRACT FROM AUTHOR]