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Molecular probes which can be modulated, functionalized and used to visualize the processes are highly desirable for understanding and manipulating biological systems. Geometric cis and trans isomers of tetraphenylethene (TPE) emerge as attractive candidates to fulfill these tasks thanks to the unique aggregation‐induced emission properties, tailorable structures, and responsiveness to external stimuli. This minireview focuses on cis and trans isomers of TPE derivatives that are functionalized with molecular recognition units for fluorescence detection, bioimaging and cancer therapy. The effects of molecular geometry on fluorescence property, target binding ability and biological activity are summarized. The feasibility to in vitro and in vivo switch molecular configuration and thus bio‐activity is discussed. Finally, the future development and challenges are discussed in view of TPE‐based stereoisomers for targeted sensing and imaging‐guided modulation of biological processes. [ABSTRACT FROM AUTHOR]

Tuning autophagy in a controlled manner could facilitate cancer therapy but it remains challenging. Pyridinium‐substituted tetraphenylethylene salts (PTPE 1—3), able to target mitochondria and disrupt autophagy after forming complexes with albumin, are reported. Mitochondrion affinity and autophagy‐inducing activity are improved by prolonging the length of alkyl chains in PTPE 1–3. PTPE 1–3 demonstrate proautophagic activity and a mitophagy blockage effect. Failure of autophagosome–lysosome fusion in downstream autophagy flux results in cancer cell death. Moreover, fast formation of complexes of PTPE 1–3 with albumin in blood can facilitate biomimetic delivery and deep tumor penetration. Efficient tumor accumulation and effective tumor suppression are successfully demonstrated with in vitro and in vivo studies. PTPE 1–3 salts exhibit dual functionality: they target and image mitochondria because of aggregation‐induced emission effects and they are promising for cancer therapy. [ABSTRACT FROM AUTHOR]

Imaging-guided photodynamic therapy (PDT) has been regarded as a promising strategy for precise cancer treatment. Because of their excellent modifiability and drug-loading capacity, nanoparticles have played an important role in PDT. Nonetheless, when traditional photosensitizers are made into nanoparticles, both their fluorescence and reactive oxygen species generation efficacy decrease due to a phenomenon known as aggregation-caused quenching. Fortunately, in recent years, several kinds of organic dyes with “abnormal” properties (termed aggregation-induced emission, AIE) were developed. With enhanced fluorescence emission in the nanoaggregation state, the traditional obstacles mentioned above may be overcome by AIE luminogens. Herein, we provide a better combination of photosensitizers and nanoparticles, namely, dual-function AIE nanoparticles capable of producing reactive oxygen species, to implement targeted and imaging-guided in vivo PDT. Good contrast of in vivo imaging and obvious therapeutic efficacy were observed at a low dose of AIE nanoparticles and low irradiance of light, thus resulting in negligible side effects. Our work shows that AIE nanoparticles may play a promising role in imaging-guided clinical PDT for cancer in the near future. [ABSTRACT FROM AUTHOR]

Apart from sensing and imaging, luminogens with aggregation-induced emission (AIE) are also interesting for photosensitizing. The photosensitizing behavior and bacteria-killing performance of a pyridinium-substituted tetraphenylethylene with an alkyne group ( TPE-A-Py+) is reported herein. Interestingly, TPE-A-Py+ exhibits higher photosensitizing efficiency than TPE-Py+ (without alkyne group) when I− was used as a counteranion. This is well explained by the fact that the Δ ΕST between the excited singlet state ( S1) and triplet state ( T1) was lower for TPE-A-Py+ than for TPE-Py+, according to theoretical calculations. Moreover, replacement of I− with other anions (PF6−, N(SO2CF3)2− and BPh4−) led to a decrease of photosensitizing efficiency for TPE-A-Py+. Notably, TPE-A-Py+ could be used as an efficient photosensitizer to photo-inactivate ampicillin-resistant (ampr) E. coli at low concentration under white-light irradiation very quickly. [ABSTRACT FROM AUTHOR]

In this Review, the configuration-dependent molecular recognition, aggregation-induced emission and bioactivities of I cis i / I trans i tetraphenylethene-based isomers are summarized. Aggregation-induced emission, fluorescence, molecular recognition, stereoisomers, tetraphenylethene Keywords: aggregation-induced emission; fluorescence; molecular recognition; stereoisomers; tetraphenylethene EN aggregation-induced emission fluorescence molecular recognition stereoisomers tetraphenylethene 1 1 1 05/30/23 20230526 NES 230526 Tetraphenylethene derivatives with adjustable molecular geometry emerge as an attractive paradigm for the development of smart and versatile chemical probes. [Extracted from the article]

Smart molecular probes and flexible methods are attracting remarkable interest for the visualization of cancer-related biological and chemical events. In this work, a new fluorescence turn-on probe with dual-recognition characteristics for the specific imaging of cancer cells is reported. This new bioprobe is rationally designed by linking tetraphenylethylene (TPE), an aggregation-induced emission (AIE) fluorophore, with the small peptide IHGHHIISVG (referred to as AP2H), a targeting ligand to the broad-spectrum cancer-related protein LAPTM4B. The binding of the probe TPE-AP2H with the target, both in solution and at the cellular level, switches on the fluorescence of TPE because of the inhibition of internal rotations within the TPE framework. Accordingly, this bioprobe allows the real-time monitoring and subcellular localization of LAPTM4B in cancer cells, with a very high target-to-background ratio for the imaging. Furthermore, brighter fluorescence images are detected after incubation of TPE-AP2H with tumor cells at lower pH values. Thus, this new bioprobe is more advantageous because it can simultaneously target the LAPTM4B protein and sense the characteristic low-pH environment of tumor cells. In addition, TPE-AP2H displays high photostability and low cytotoxicity. Therefore, this new bioprobe is promising for the more accurate and reliable imaging of tumor markers in live cancer cells. [ABSTRACT FROM AUTHOR]

Frontispiz: Pyridinium-Substituted Tetraphenylethylenes Functionalized with Alkyl Chains as Autophagy Modulators for Cancer Therapy Keywords: aggregation-induced emission; autophagy; inhibitors; pyridinium-substituted tetraphenylethylenes; tumors EN aggregation-induced emission autophagy inhibitors pyridinium-substituted tetraphenylethylenes tumors 1 1 1 06/08/20 20200615 NES 200615 B Tumortherapeutika b Pyridiniumsubstituierte Tetraphenylethylen-Salze können Autophagie induzieren und gleichzeitig den Autophagieflux hemmen. Aggregation-induced emission, autophagy, inhibitors, pyridinium-substituted tetraphenylethylenes, tumors. [Extracted from the article]

Semiconducting polymer nanoparticles (SPNs) have potential in biological applications. While some SPNs have significant photothermal conversion efficiencies (PCEs) as photothermal and photoacoustic agents, other SPNs offer high fluorescence yields as photoluminescent agents. However, the energy balance distribution in SPNs inhibits their successful applications in photoluminescence/photoacoustic (PL/PA) dual‐modality imaging. Additionally, the ultrastability of SPNs in vivo may cause damage to organisms. This work reports nanocomposite semiconducting polymer and tetraphenylethene nanoparticles (STNPs) constructed by semiconducting polymers (SPs) and tetraphenylethene aggregation‐induced emission luminogens (TPE AIEgens). The SP SPC10 endows good photothermal conversion ability, and the AIEgen TPBM supports enhanced photoluminescence of the STNPs. The results show that the STNPs can act as PL/PA dual‐modality imaging agents. The signal‐to‐noise (S/N) ratio in the PL modality reaches 8.7, and the imaging depth in the PA modality is 5.8 mm. The SPC10 in the STNPs can be decomposed under 90 mW cm−2 white light irradiation in 6 h without any other additional agents. Furthermore, the STNPs are sufficient for the treatment of xenograft 4T1 tumor‐bearing mice based on photothermal therapy. The nanocomposite STNPs achieve optimized dual‐modality PL/PA imaging and the AIEgen‐triggered in situ photodegradation of SPNs. These properties indicate the significant potential of STNPs in clinical diagnosis and noninvasive therapy. [ABSTRACT FROM AUTHOR]

The level of anti-SARS-CoV-2 neutralizing antibodies (NAb) is an indispensable reference for evaluating the acquired protective immunity against SARS-CoV-2. Here, we established an ultrabright nanoparticles-based lateral flow immunoassay (LFIA) for one-step rapid semi-quantitative detection of anti-SARS-CoV-2 NAb in vaccinee's serum. Once embedded in polystyrene (PS) nanoparticles, the aggregation-induced emission (AIE) luminogen, AIE 490 , exhibited ultrabright fluorescence due to the rigidity of PS and severe inhibition of intramolecular motions. The ultrabright AIE 490 -PS nanoparticle was used as a fluorescent marker of LFIA. Upon optimized conditions including incubation time, concentrations of coated proteins and conjugated nanoparticles, amounts of antigens modified on the surface of nanoparticles, dilution rate of serum samples, and so on, the ultrabright nanoparticles-based LFIA could accurately identify 70 negative samples and 63 positive samples from human serum (p < 0.0001). The intra- and inter-assay precisions of the established method are above 13% and 16%, respectively. The established LFIA has tremendous practical value of generalization as a rapid semi-quantitative detection method of anti-SARS-CoV-2 NAb. Meanwhile, the AIE 490 -PS nanoparticle is also promising to detect many other analytes by altering the protein on the surface. [ABSTRACT FROM AUTHOR]