ORCID Profile
0009-0007-1525-2015
Current Organisation
Hong Kong University of Science and Technology
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Publisher: Wiley
Date: 31-10-2022
Abstract: Molecular aggregates with environmental responsive properties are desired for their wide practical applications such as bioprobes. Here, a series of smart near‐infrared (NIR) luminogens for hyperlipidemia (HLP) diagnosis is reported. The aggregates of these molecules exhibit a twisted intramolecular charge‐transfer effect in aqueous media, but aggregation‐induced emission in highly viscous media due to the restriction of the intramolecular motion. These aggregates, which can autonomously respond to different environments via switching the aggregation state without changing their chemical structures are described, as “smart aggregates”. Intriguingly, these luminogens demonstrate NIR‐II and NIR‐III luminescence with ultralarge Stokes shifts ( nm). Both in vitro detection and in vivo imaging of HLP can be realized in a mouse model. Linear relationships exist between the emission intensity and multiple pathological parameters in blood s les of HLP patients. Thus, the design of smart aggregate facilitates rapid and accurate detection of HLP and provides a promising attempt in aggregate science.
Publisher: American Chemical Society (ACS)
Date: 17-04-2023
Publisher: American Chemical Society (ACS)
Date: 10-08-2022
DOI: 10.1021/JACS.2C07443
Abstract: Fluorescence imaging in the second near-infrared window (NIR-II, 1000-1700 nm) using small-molecule dyes has high potential for clinical use. However, many NIR-II dyes suffer from the emission quenching effect and extremely low quantum yields (QYs) in the practical usage forms. The AIE strategy has been successfully utilized to develop NIR-II dyes with donor-acceptor (D-A) structures with acceptable QYs in the aggregate state, but there is still large room for QY improvement. Here, we rationally designed a NIR-II emissive dye named TPE-BBT and its derivative (TPEO-BBT) by changing the electron-donating triphenylamine unit to tetraphenylethylene (TPE). Their nanoparticles exhibited ultrahigh relative QYs of 31.5% and 23.9% in water, respectively. By using an integrating sphere, the absolute QY of TPE-BBT nanoparticles was measured to be 1.8% in water. Its crystals showed an absolute QY of 10.4%, which is the highest value among organic small molecules reported so far. The optimized D-A interaction and the higher rigidity of TPE-BBT in the aggregate state are believed to be the two key factors for its ultrahigh QY. Finally, we utilized TPE-BBT for NIR-II photoluminescence (PL) and chemiluminescence (CL) bioimaging through successive CL resonance energy transfer and Förster resonance energy transfer processes. The ultrahigh QY of TPE-BBT realized an excellent PL imaging quality in mouse blood vessels and an excellent CL imaging quality in the local arthrosis inflammation in mice with a high signal-to-background ratio of 130. Thus, the design strategy presented here brings new possibilities for the development of bright NIR-II dyes and NIR-II bioimaging technologies.
Publisher: American Chemical Society (ACS)
Date: 24-02-2022
Publisher: Wiley
Date: 06-04-2023
Abstract: Optogenetics has been plagued by invasive brain implants and thermal effects during photo‐modulation. Here, two upconversion hybrid nanoparticles modified with photothermal agents, named PT‐UCNP‐B/G, which can modulate neuronal activities via photostimulation and thermo‐stimulation under near‐infrared laser irradiation at 980 nm and 808 nm, respectively, are demonstrated. PT‐UCNP‐B/G emits visible light (410–500 nm or 500–570 nm) through the upconversion process at 980 nm, while they exhibit efficient photothermal effect at 808 nm with no visible emission and tissue damage. Intriguingly, PT‐UCNP‐B significantly activates extracellular sodium currents in neuro2a cells expressing light‐gated channelrhodopsin‐2 (ChR2) ion channels under 980‐nm irradiation, and inhibits potassium currents in human embryonic kidney 293 cells expressing the voltage‐gated potassium channels (KCNQ1) under 808‐nm irradiation in vitro. Furthermore, deep‐brain bidirectional modulation of feeding behavior is achieved under tether‐free 980 or 808‐nm illumination (0.8 W cm −2 ) in mice stereotactically injected with PT‐UCNP‐B in the ChR2‐expressing lateral hypothalamus region. Thus, PT‐UCNP‐B/G creates new possibility of utilizing both light and heat to modulate neural activities and provides a viable strategy to overcome the limits of optogenetics.
Publisher: Wiley
Date: 05-2023
Abstract: Tumor‐targeted photodynamic therapy (PDT) is desirable as it can achieve efficient killing of tumor cells with no or less harm to normal cells. Herein, a facile molecular engineering strategy is developed for photosensitizers (PSs) with aggregation induced emission (AIE) characteristics and responsive properties to the acidic tumor microenvironment (TME). By the marriage of pH‐sensitive sulfonamide moieties with AIE PSs, two near‐infrared AIE luminogens called DBP‐SPy and DBP‐SPh are designed and synthesized. Both luminogens can form negatively charged nanoaggregates in the aqueous medium at physiological pH. The DBP‐SPy nanoaggregates undergo surface charge conversion to become positive at pH close to the signature pH of TME, while DBP‐SPh nanoaggregates show no such property. The endowed response to acidic TME enables the enhanced cellular uptake of DBP‐SPy at pH = 6.8. By contrast, its cellular uptake is much sacrificed at pH 7.4. As a result, under white light irradiation, DBP‐SPy nanoaggregates demonstrate a considerable photodynamic therapeutic effect on cancer cells in vitro and excellent tumor growth inhibition in vivo. Hence, this study not only provides an acidic TME‐responsive AIE PS for precise PDT, but also inspires new design strategies for AIE‐based theragnostic systems with targeting characteristics.
No related grants have been discovered for Feiyi Sun.