Pt–N Coordination Rendering the Chemotherapeutic Agent with Photoactivated ROS Generation and Self-Reporting Cell Uptake

The performance of chemotherapeutic agents has been largely restrained by the dose-dependent toxic side effects. In this work, cisplatin (CDDP) was endowed with the capability of photoactivated reactive oxygen species (ROS) generation and self-reporting cell uptake via coordination with a small organic molecule MSN. In the resultant MSN–Pt, the Pt–N coordination could obviously enhance the intermolecular charge transfer (ICT) process that allows the integration of fluorescence imaging, photogenerated ROS, and chemotherapeutic performance. The resultant MSN–Pt can recognize between normal and cancer cells and quickly penetrate the cancer cell membrane, self-reporting the cell uptake. Upon light illumination, mitochondria and nuclei were severely damaged. An in vivo mouse model demonstrated that MSN–Pt completely inhibited the tumor growth, exhibiting a higher efficacy compared with that of CDDP. This work provides a facile strategy to develop chemotherapy (CT) drugs for drug-resistant cancers

Unveiling the Impact of Light-Induced Acceptor-Generated ROS on Device Stability in Organic Photovoltaics

The intrinsic stability of the acceptor is a crucial component of the photovoltaic device stability. In this study, we investigated the efficiency and stability of the nonfused-ring acceptors LC8 and BC8 under indoor light conditions. Interestingly, we found that devices based on BC8 with terminal side chains exhibited a higher indoor efficiency and stability. Through accelerated aging experiments, we discovered that the acceptors generate singlet oxygen under light exposure with BC8 demonstrating lower levels of ROS compared to LC8. We attribute this difference to the modulation of the acceptor aggregation orientation. Furthermore, the generated reactive oxygen species (ROS) further deteriorate the acceptor structure, and this phenomenon is also observed in high-efficiency acceptor structures, such as Y6. Our research reveals important mechanisms of acceptor photo-oxidation processes, providing a theoretical basis for enhancing the intrinsic stability of acceptors

Systematic Study and Imaging Application of Aggregation-Induced Emission of Ester-Isophorone Derivatives

The dicyanoisophorone derivatives show obvious AIE behaviors in our previous work. To study the bioimaging application of these chromophores with AIE/AIEE properties, the ester groups substituted for one cyan to form a new family based on isophorone (2a–2e). 2a–2d exhibit obvious AIE/AIEE phenomena, while 2e shows fluorescence quenching in the aggregate state. The morphology and size of aggregates with different water contents were investigated using SEM and DLS, indicating that a large number of smaller globular or quadrate nanoparticles with average diameters in the range 78.79–392.7 nm in mixed solutions are related to these AIE/AIEE or ACQ behaviors. We also made comparative analyses of their optical properties in different states. The crystal data of 2a–2d reveal that the multiple intra- and intermolecular interactions leads to the molecular conformation being more stable, increases the planarity of compounds, restricts the intramolecular motions, and promotes the formation of J-type aggregate, enabling chromophores 2a–2d to emit intensely in the solid state. In addition, the frontier molecular orbital energy and band gap calculated by density functional theory are quite consistent with the experimental results. Finally, these AIE/AIEE-active compounds could be used in bioimaging applications, which immensely provide a new strategy to the application of some AIE/AIEE systems

Four-Photon Absorption Iron Complex for Magnetic Resonance/Photoacoustic Dual-Model Imaging and an Enhanced Ferroptosis Process

Four-photon absorption (4PA) multimodal therapeutic agent applied to tumor ferroptosis process tracking is rarely reported. In this paper, two functionalized terpyridine iron complexes (TD-FeCl3, TD-Fe-TD) with four-photon absorption properties were designed and synthesized. The four-photon absorption cross sections of TD-FeCl3 reached 6.87 × 10–74cm8·s3·photon–3. Due to its strong near-infrared absorption, TD-FeCl3 has excellent photoacoustic imaging (PAI) capability for accurate PA imaging. TD-FeCl3 has an efficient longitudinal electron relaxation rate (r1 = 2.26 mM–1 s–1) and high spatial resolution, which can be applied as T1-weighted magnetic resonance imaging (MRI) contrast agent for tumor imaging in vivo. In addition, Fe3+ as a natural ferroptosis tracer, TD-FeCl3, is able to deplete glutathione (GSH) effectively, which can further enhance the ferroptosis process. We found that the series of cheap transition metal complexes has four-photon absorption activity and can be used as multimodal (MRI/PAI) diagnostic agents for tumor tracing processes

Four-Photon Absorption Iron Complex for Magnetic Resonance/Photoacoustic Dual-Model Imaging and an Enhanced Ferroptosis Process

Four-photon absorption (4PA) multimodal therapeutic agent applied to tumor ferroptosis process tracking is rarely reported. In this paper, two functionalized terpyridine iron complexes (TD-FeCl3, TD-Fe-TD) with four-photon absorption properties were designed and synthesized. The four-photon absorption cross sections of TD-FeCl3 reached 6.87 × 10–74cm8·s3·photon–3. Due to its strong near-infrared absorption, TD-FeCl3 has excellent photoacoustic imaging (PAI) capability for accurate PA imaging. TD-FeCl3 has an efficient longitudinal electron relaxation rate (r1 = 2.26 mM–1 s–1) and high spatial resolution, which can be applied as T1-weighted magnetic resonance imaging (MRI) contrast agent for tumor imaging in vivo. In addition, Fe3+ as a natural ferroptosis tracer, TD-FeCl3, is able to deplete glutathione (GSH) effectively, which can further enhance the ferroptosis process. We found that the series of cheap transition metal complexes has four-photon absorption activity and can be used as multimodal (MRI/PAI) diagnostic agents for tumor tracing processes

Systematic Study and Imaging Application of Aggregation-Induced Emission of Ester-Isophorone Derivatives

The dicyanoisophorone derivatives show obvious AIE behaviors in our previous work. To study the bioimaging application of these chromophores with AIE/AIEE properties, the ester groups substituted for one cyan to form a new family based on isophorone (2a–2e). 2a–2d exhibit obvious AIE/AIEE phenomena, while 2e shows fluorescence quenching in the aggregate state. The morphology and size of aggregates with different water contents were investigated using SEM and DLS, indicating that a large number of smaller globular or quadrate nanoparticles with average diameters in the range 78.79–392.7 nm in mixed solutions are related to these AIE/AIEE or ACQ behaviors. We also made comparative analyses of their optical properties in different states. The crystal data of 2a–2d reveal that the multiple intra- and intermolecular interactions leads to the molecular conformation being more stable, increases the planarity of compounds, restricts the intramolecular motions, and promotes the formation of J-type aggregate, enabling chromophores 2a–2d to emit intensely in the solid state. In addition, the frontier molecular orbital energy and band gap calculated by density functional theory are quite consistent with the experimental results. Finally, these AIE/AIEE-active compounds could be used in bioimaging applications, which immensely provide a new strategy to the application of some AIE/AIEE systems

Nanoporous Vinylene-Linked 2D Covalent Organic Frameworks for Visible-Light-Driven Aerobic Oxidation

Exploring vinylene-linked nanoporous covalent organic framework (COF) materials has become a valuable research focus due to their various outstanding properties. However, only a few examples have been reported to construct vinylene-linked COFs, which seriously restricted their applications. Herein, two COFs linked by olefins TC-PT and TC-PB via the Knoevenagel condensation of 1,3,5-tris(4-cyanomethylphenyl) benzene and 2,4,6-tris (4-formylphenyl)-1,3,5-triazine or 1,3,5-tris (4-formylphenyl) benzene were designed and constructed, which possessed high crystallinity, remarkable porosity, and high structural, chemical, and thermal stability. The two nanoporous organic framework materials prepared can be used for catalytic organic reaction of phenylboric acid and its derivatives driven efficiently by visible light. It is noted that TC-PT with a donor–acceptor structure presented excellent activity, yield, and recyclability. We believed that this work would provide some precious insights for developing functional vinylene-linked COFs

Coordination-Regulated Terpyridine–Mn(II) Complexes for Photodynamic Therapy Guided by Multiphoton Fluorescence/Magnetic Resonance Imaging

The synergy of multiphoton fluorescence imaging (MP-FI) and magnetic resonance imaging (MRI) provides an imaging platform with high resolution and unlimited penetration depth for early disease detection. Herein, two kinds of terpyridine–Mn­(II) complexes (FD–Mn–O2NO and FD–Mn–FD) possessing seven and six coordination modes, respectively, were designed rationally for photodynamic therapy (PDT) guided by MP-FI/MRI. The complexes obtain different multiphoton fluorescence/magnetic resonance properties by adjusting the number of terpyridine ligands. Among them, FD–Mn–FD exhibits the following superiorities: (1) The optimal three-photon excitation wavelength of FD–Mn–FD falls at 1450 nm (NIR-II), which brings high sensitivity and deep tissue penetration in MP-FI. (2) FD–Mn–FD has effective longitudinal relaxation efficiency (r1 = 2.6 m M–1 s–1), which can be used for T1-weighted MRI, overcoming the problems of limited tissue penetration depth and low spatial resolution. (3) FD–Mn–FD generates endogenous 1O2 under irradiation by 808 nm light, thereby enhancing the PDT effect in vitro and in vivo. To the best of our knowledge, the complex FD–Mn–FD is the first complex to guide PDT through MP-FI/MRI, providing a blueprint for accurate and effective early detection and timely treatment of the complex in the early stages of cancer

Cancer Cell Membrane Labeling Fluorescent Doppelganger Enables In Situ Photoactivated Membrane Dynamics Tracking via Two-Photon Fluorescence Imaging Microscopy

Various suborganelles are delimited by lipid bilayers, in which high spatial and temporal morphological changes are essential to many physiological and pathological processes of cells. However, almost all the amphiphilic fluorescent molecules reported until now are not available for in situ precise tracking of membrane dynamics in cell apoptosis. Here, the MO (coumarin pyridine derivatives) was devised by engineering lipophilic coumarin and cationic pyridine salt, which not only lastingly anchored onto the plasma membrane in dark due to appropriate amphipathicity and electrostatic interactions but also in situ reflected the membrane damage and heterogeneity with secretion of extracellular vesicles (EVs) under reactive oxygen species regulation and was investigated by two-photon fluorescence lifetime imaging microscopy. This work opens up a new avenue for the development of plasma membrane staining and EV-based medicines for the early diagnosis and treatment of disease

Solvatochromic Two-Photon Fluorescent Probe Enables <i>In Situ</i> Lipid Droplet Multidynamics Tracking for Nonalcoholic Fatty Liver and Inflammation Diagnoses

Intracellular lipid storage and regulation occur in lipid droplets, which are of great significance to the physiological activities of cells. Herein, a lipid droplet-specific fluorescence probe (lip-YB) with a high quantum yield (QYlip‑YB = 73.28%), excellent photostability, and quickly polarity sensitivity was constructed successfully. Interestingly, lip-YB exhibited remarkable two-photon (TP) characteristics, which first realized real-time monitoring of the lipid droplet multidynamics process, diagnosing nonalcoholic fatty liver disease (NAFLD) and inflammation in living mice via TP fluorescence imaging. It is found that the as-prepared lip-YB provides a new avenue to design lipid droplet-specific imaging probes, clarifies its roles and mechanisms in cell metabolism, and can timely intervene in lipid droplet-related diseases during various physiological and pathological processes