A photostable AIE luminogen with near infrared emission for monitoring morphological change of plasma membrane.

The morphology of plasma membrane is dynamic and keeps changing in order to maintain its homeostasis. Abnormality in cell membrane shape could be viewed as a sign of unhealthy cells. A lipophilic cyanostilbene derivative (AS2CP-TPA) composed of a hydrophilic pyridinium salt and a hydrophobic triphenylamino group was designed for staining the cell membrane and monitoring membrane morphology under different conditions. Due to strong donor-acceptor interaction and aggregation-induced emission property, AS2CP-TPA emits weak emission in aqueous solution, but it lights up the plasma membrance of HeLa cells with near infrared fluorescence under an excitation wavelength of 460 nm. With merits of high photostability and high specificity to plasma membrane, AS2CP-TPA is capable of long-term monitoring of the morphological changes of cell membrane during Hg2+ and trypsin treatments.

Mitochondrion-Anchoring Photosensitizer with Aggregation-Induced Emission Characteristics Synergistically Boosts the Radiosensitivity of Cancer Cells to Ionizing Radiation.

The first mitochondrion-anchoring photosensitizer that specifically generates singlet oxygen (1 O2 ) in mitochondria under white light irradiation that can serve as a highly effective radiosensitizer is reported here, significantly sensitizing cancer cells to ionizing radiation. An aggregation-induced emission luminogen (AIEgen), namely DPA-SCP, is rationally designed with α-cyanostilbene as a simple building block to reveal AIE, diphenylamino (DPA) group as a strong electron donating group to benefit red emission and efficient light-controlled 1 O2 generation, as well as a pyridinium salt as the targeting moiety to ensure specific mitochondrial localization. The AIE signature endows DPA-SCP with the capacity to visualize mitochondria in a fluorescence turn-on mode. It is found that under optimized experimental condition, DPA-SCP with white light does not lead to apoptosis/death of cancer cells, whereas provides an elevated 1 O2 environment in the mitochondria. More importantly, increasing intracellular level of 1 O2 originated from mitochondria is demonstrated to be a generic method to enhance the radiosensitivity of cancer cells with a supra-additive synergistic effect of "0 + 1 > 1." Noteworthy is that "DPA-SCP + white light" achieves a high SER10 value of 1.62, which is much larger than that of the most popularly used radiosensitizers, gold nanoparticles (1.19), and paclitaxel (1.32).

A red-emissive antibody-AIEgen conjugate for turn-on and wash-free imaging of specific cancer cells.

An antibody-AIEgen conjugate is designed and developed as a "turn-on" fluorescent probe for wash-free specific cancer cell imaging. The cetuximab-conjugated AIEgen shows red fluorescence only when it is internalized and accumulated in cancer cells with overexpressed epidermal growth factor receptor through endocytosis. The probe first lights up the lysosomes. After hydrolysis, its residue is accumulated in mitochondria, making them highly emissive with a long cell retention time. Compared with conventional "always-on" fluorescent probes, the antibody-AIEgen conjugate exhibits a very good image contrast during wash-free cancer cell imaging and less interference from normal cells. To the best of our knowledge, this is the first time "turn-on" antibody-AIEgen conjugates have been reported. This new strategy can be further extended to many proteins and water-soluble AIEgens, and many of their potential applications such as real-time tracking of cell dynamics and cancer theranostics will be explored. The present work is expected to inspire more marvellous research in the fields of AIE and cancer imaging.

A photostable AIEgen for nucleolus and mitochondria imaging with organelle-specific emission.

Dynamic visualization of the morphology of membrane-bound organelles offers useful insights for studying various intracellular activities. Fluorescent probes with superior specificity and photostability are desirable for long-term tracking of these processes. In this work, we present the design and synthesis of an α-cyanostilbene derivative, abbreviated as ASCP, with the aggregation-induced emission (AIE) characteristic, and its application in cell imaging. ASCP can simultaneously label mitochondria and nucleolus in live cells with distinct fluorescence, which is demonstrative of a single molecule with dual-colour organelle imaging.

Real-time monitoring of the mitophagy process by a photostable fluorescent mitochondrion-specific bioprobe with AIE characteristics.

An isothiocyanate-functionalized tetraphenylethene is synthesized and used as a fluorescent bioprobe for mitochondrion imaging with high specificity and photostability. The covalent conjugation of the bioprobe to mitochondrial proteins endows it with high resistance to microenvironmental changes, enabling it for real-time monitoring of mitophagy.

Photostable AIE fluorogens for accurate and sensitive detection of S-phase DNA synthesis and cell proliferation.

Two azide-functionalized tetraphenylethene derivatives with AIE features are synthesized and used as fluorescent agents for detecting S-phase DNA synthesis and cell proliferation based on EdU assay. Compared to the Alexa-azide dye, a commercial DNA bioprobe, the AIE fluorogens show better photostability and sensitivity, making them promising alternatives.

A tetraphenylethene-based caged compound: synthesis, properties and applications.

A tetraphenylethene-based caged compound (TPE-C) is designed and synthesized. TPE-C is non-fluorescent either in solution or in aggregated state, but its emission can be induced to emit strong cyan emission in the aggregated state by UV irradiation. This property enables TPE-C to be applied in photo-patterning and anti-counterfeiting related areas.