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Comparing the cellular activities of four nanomaterials, it was found that S-DCM-2O@PEG@PLL had lower biological toxicity.

Asymmetrical heptamethine cyanine with near-infrared (NIR) absorption has been used for photothermal therapy (PTT) of cancer. Aiming to overcome the drawbacks caused by the high temperature of PTT, the development of asymmetrical heptamethine cyanine with photothermal and photodynamic properties is still an attractive strategy. Different from the traditional method of the heavy atom effect, in this work, the carboxyl or sulfonic groups were introduced into the indole ring or branch chain of asymmetrical heptamethine cyanine to afford a series of new phototherapy agents. Compared with the sulfonic group (BHS-Et, SY-SO

Photothermal therapy (PTT) combined with second near-infrared (NIR-II) fluorescence imaging (FI) has received increasing attention owing to its capacity for precise diagnosis and real-time monitoring of the therapeutic effects. It is of great clinical value to study organic small molecular fluorophores with both PTT and NIR-II FI functions. In this work, we report a skillfully fluorescent lipid nanosystem, the RR9 (RGDRRRRRRRRRC) peptide-coated anionic liposome loaded with organic NIR-II fluorophore IR-1061 and chemotherapeutic drug carboplatin, which is named RRIALP-C4. According to the structural interaction between IR-1061 and phospholipid bilayer demonstrated by molecular dynamics simulations, IR-1061 is rationally designed to possess the H-aggregated state versus the free state, thus rendering RRIALP-C4 with the activated dual-channel integrated function of intravital NIR-II FI and NIR-I PTT. Functionalization of RRIALP-C4 with RR9 peptide endows the specifically targeting capacity for αvβ3-overexpressed tumor cells and, more importantly, allows IR-1061 to transfer the H-aggregated state from liposomes to the tumor cell membrane through enhanced membrane fusion, thereby maintaining its PTT effect in tumor tissues. In vivo experiments demonstrate that RRIALP-C4 can effectively visualize tumor tissues and systemic blood vessels with a high sign-to-background ratio (SBR) to realize the synergistic treatment of thermochemotherapy by PTT synergistically with temperature-sensitive drug release. Therefore, the strategy of enhanced PTT through H-aggregation of NIR-II fluorophore in the tumor cell membrane has great potential for developing lipid nanosystems with integrated diagnosis and treatment function.

Multiple compression tests on rock-like samples of pre-existing cracks with different geometries were conducted to investigate the strength properties and crack propagation behavior considering multi-crack interactions. The progressive failure process of the specimens was segmented into four categories and seven coalescence modes were identified due to different crack propagation mechanisms. Ultimately, a mechanical model of the multi-crack rock mass was proposed to investigate the gradual fracture and damage evolution traits of the multi-crack rock on the basis of exploring the law of the compression-shear wing crack initiation and propagation. A comparison between theory and experimental results indicated that the peak strength of the specimens with multiple fractures decreased initially and subsequently increased with the increase in the fissure inclination angles; the peak strength of specimens decreased with the increase in the density of fissure distribution.

The intricate mechanisms involved in the acquisition and translocation of polycyclic aromatic hydrocarbons (PAHs) in plants have not been elucidated. Phosphate (Pi) is the bioavailable form of essential macronutrient phosphorus, which is acquired and subsequently assimilated for plant optimal growth and development. Rice phosphate overaccumulator 2 (OsPHO2) is a central constituent of the regulation of Pi homeostasis in rice. In the present study, the role of OsPHO2 in regulating the translocation and accumulation of phenanthrene (Phe) and the involvement of Pi in this process were investigated. The temporal study (1 d-35 d) revealed a significant and gradual increase of Phe accumulation in Pi-deprived roots of wild-type (WT) seedlings. Compared with the WT, the concentrations of Phe were significantly higher in the shoots of ospho2 (OsPHO2 mutant) grown hydroponically with Phe (1.5 mg/L) under +Pi (200 μM) and -Pi (10 μM) conditions. The sap experiment clearly showed the significant increases in levels of Phe in the xylem sap of ospho2 than the WT grown hydroponically with Phe and +Pi. Further, the concentrations of both Phe and P were coordinately higher in the culms and flag leaves of the mutants than WT at maturity in potting soil with LPhe (6 mg/kg) and HPhe (60 mg/kg). However, the concentrations of Phe in the seeds were comparable in the WT and mutants, suggesting a pivotal of OsPHO2 in attenuating Phe toxicity in the seed. In +Phe WT, the relative expression level of OsPHO2 in the shoots was significantly lower, while those of Pi transporters (PTs) OsPT4 and OsPT8 were significantly higher in the roots compared with -Phe. Together, the results provided evidence towards the involvement of Pi in OsPHO2-regulated translocation and accumulation of Phe in rice.

Hydrogen sulfide (H2S) as an important gaseous signaling molecule is closely related to numerous biological processes in living systems. To further study the physiological and pathological roles of H2S, convenient and efficient detection techniques for endogenous H2S in vivo are still in urgent demand. In this study, an electrochromic chromophore, dicationic 1,1,4,4-tetra-aryl butadiene (EM1), was innovatively introduced into upconversion nanoparticles (UCNPs) and a nanoprobe, PAAO-UCNPs-EM1, was constructed for the detection of H2S. This nanosystem was made of core-shell upconversion nanoparticles (NaYF4:Yb,Tm@NaYF4:Yb,Er), EM1, and polyacrylic acid (PAA)-octylamine. The EM1 with strong absorption ranging from 500 to 850 nm could serve as an energy acceptor to quench the upconversion luminescence of UCNPs through the Forster resonance energy transfer (FRET) process. In the presence of H2S, the EM1 in the nanoprobe was reduced to a colorless diene (EM2), resulting in the linear enhancement of luminescence emissions at 660 nm and 800 nm under the excitation of 980 nm light because the FRET was switched off. The nanoprobe PAAO-UCNPs-EM1PAAO-UCNPs-EM1 exhibited fast response and high sensitivity to H2S with a LoD of 1.21 × 10-7 M. Moreover, it was successfully employed in detecting the endogenous and exogenous H2S in living cells with high selectivity and low cytotoxicity. Also, this nanoprobe could distinguish normal and tumor cells by an upconversion luminescence imaging of endogenous H2S. Furthermore, the nanoprobe could significantly monitor H2S in a tumor-bearing nude mouse model. Therefore, we anticipate that this novel nanoprobe assembled with an electrochromic chromophore for responding to H2S and for bioimaging this molecule would have a promising prospect in biological and clinical investigations.

Cysteine (Cys) as an essential amino acid for life plays important roles in the synthesis of various proteins and human metabolism. The detection and monitoring of the concentration of cysteine in vitro and in vivo is significant for the diagnosis of related diseases. Herein, we designed and synthesized a novel fluorescent probe NC-Cys for the detection of cysteine, which employed dihydronaphthalene as the fluorophore. After the addition of Cys, colorimetric naked eye detection of Cys was achieved by the color change from purple to bright yellow. Moreover, the fluorescence intensity at 536 nm in the presence of Cys showed about a 90-fold fluorescent signal increase compared to that with no Cys addition. The probe NC-Cys exhibited satisfactory sensitivity and selectivity to Cys. A good linear relationship between I536 and the concentration of Cys (0–100 μM) was also observed with a calculated detection limit of 2.1 × 10−8 M. Importantly, the probe NC-Cys was successfully applied in the fluorescence imaging of Cys in living cells and tissues with low cytotoxicity. This newly developed fluorescent probe would be a potentially useful tool for the imaging of Cys in wider physiological and pathological processes.

Lung metastasis is the principal reason for the majority of deaths from breast cancer. The nonsteroidal anti-inflammatory drug aspirin can prevent lung metastasis in breast tumors via inhibiting heparanase. However, the lack of specific targets and limited accumulation at the site of the tumor have thus far hindered the use of aspirin in oncotherapy. In this study, we developed the nanoplatform FA-BSA@DA and loaded it with the versatile aspirin prodrug DA to visualize and inhibit breast cancer metastasis via targeting heparanase. This nanosystem can be effectively targeted to folic acid (FA)-positive tumor cells, and would then subsequently release a high dose of DA, whose ester bond is specifically ruptured by H2O2 in the tumor microenvironment to afford the therapeutic drug aspirin and near-infrared (NIR) fluorescent reporter DCM. The released aspirin can effectively prevent breast cancer lung metastasis through the inhibition of heparanase activity, and the NIR fluorescent signals emitted from DCM can be used to monitor and evaluate the metastasis levels of breast cancer. Our results showed that the expression of heparanase was significantly decreased, and lung metastasis from breast cancer was effectively monitored and inhibited after treatment with FA-BSA@DA. Furthermore, the collaborative therapy nanoplatform FA-BSA@DA/DOX exhibited strong therapeutic effects in the treatment of breast cancer in vitro and in vivo via the introduction of doxorubicin (DOX) to the system, which resulted in an even stronger result due to its synergistic effects with aspirin. This heparanase-reliant strategy has profound significance for the extended development of nanoplatforms based on versatile aspirin prodrugs, which may offer a solution to clinically prevent breast cancer recurrence and lung metastasis.

Peroxynitrite anion (ONOO-), one of the reactive nitrogen species (RNS), plays momentous roles in physiological and pathological processes especially in a range of oxidative stress-related diseases. Moreover, abundant ONOO- is generated in the liver tissues of drug-induced liver injury. We report herein a novel small molecule fluorescent probe KC-ONOO for monitoring ONOO- based on boronate. The probe displayed high sensitivity and good selectivity towards ONOO-. A good linear relationship was observed between the fluorescent intensity at 530 nm and the concentration of ONOO- ranged 0–10 μM with a detection limit of 1.5 × 10−8 M. Furthermore, our probe was successfully applied for imaging ONOO- in living cells and drug-damaged liver tissues with low cytotoxicity, demonstrating the probe KC-ONOO has great potential to further elucidate more biological roles of ONOO-.

Hydrogen peroxide (H2O2), as an important biomolecule, is involved in various physiology and pathologic processes such as cellular signal transduction, host defense, and pathogen invasion. Thus, convenient and efficient detection of H2O2 in living organisms is of paramount significance and has drawn tremendous interest from researchers worldwide. In the present study, a novel H2O2-recognition moiety, the acetyl group, was proposed. Based on this unique recognition moiety, a new near-infrared (NIR) fluorescence probe was designed and synthesized for detecting H2O2. With numerous advantages including high selectivity and sensitivity, good compatibility and low cytotoxicity, this probe not only has the great competence to monitor endogenous H2O2 in cells, tissues, and in vivo but also has the huge potentiality to be employed in the diagnosis of H2O2-related cancers.

Nowadays, ozone has been widely applied in industry and medical therapies. However, excessive exposure to ozone can lead to lung dysfunction and many respiratory symptoms. As a member of reactive oxygen species (ROS), ozone was also involved in various physiology and pathology process. Given the fact of this, the effective detection of ozone in the atmosphere and biological system is of vital significance. Herein, we reported a novel dicyanomethylene-4H-pyran (DCM)-based fluorescent probe DCM-O3 with butenyl being the recognition moiety for monitoring ozone. The probe displayed high selectivity towards ozone, and its response towards ozone could be completed within 5 min under the optimal condition. Besides, a good linear correlation was obtained between the ozone concentrations (0–50 μM) and the corresponding fluorescent intensity at 560 nm, and the limit of detection (LOD) was calculated to be 6.2 × 10−7 M. Moreover, the probe DCM-O3 showed low cytotoxicity and was successfully applied to detect ozone in live cells. Given all the merits, the probe DCM-O3 could function as a robust tool for researchers to investigate ozone-related diseases in the complex biological environment.

Hydrogen sulfide (H2S) as an important gaseous signaling molecule is closely related to numerous biological processes in living systems. To further study the physiological and pathological roles of H2S, convenient and efficient detection techniques for endogenous H2S in vivo are still in urgent demand. In this study, an electrochromic chromophore, dicationic 1,1,4,4-tetra-aryl butadiene (EM1), was innovatively introduced into upconversion nanoparticles (UCNPs) and a nanoprobe, PAAO-UCNPs-EM1, was constructed for the detection of H2S. This nanosystem was made of core-shell upconversion nanoparticles (NaYF4:Yb,Tm@NaYF4:Yb,Er), EM1, and polyacrylic acid (PAA)-octylamine. The EM1 with strong absorption ranging from 500 to 850 nm could serve as an energy acceptor to quench the upconversion luminescence of UCNPs through the Förster resonance energy transfer (FRET) process. In the presence of H2S, the EM1 in the nanoprobe was reduced to a colorless diene (EM2), resulting in the linear enhancement of luminescence emissions at 660 nm and 800 nm under the excitation of 980 nm light because the FRET was switched off. The nanoprobe PAAO-UCNPs-EM1PAAO-UCNPs-EM1 exhibited fast response and high sensitivity to H2S with a LoD of 1.21 × 10-7 M. Moreover, it was successfully employed in detecting the endogenous and exogenous H2S in living cells with high selectivity and low cytotoxicity. Also, this nanoprobe could distinguish normal and tumor cells by an upconversion luminescence imaging of endogenous H2S. Furthermore, the nanoprobe could significantly monitor H2S in a tumor-bearing nude mouse model. Therefore, we anticipate that this novel nanoprobe assembled with an electrochromic chromophore for responding to H2S and for bioimaging this molecule would have a promising prospect in biological and clinical investigations.

Tracking sulfatase in the living organism is beneficial for the diagnosis of sulfatase-overexpressed cancer and understanding the pathological activities of sulfatase. A nanoprobe (DQM-SULF) with AIE signal amplification for imaging of sulfatase activity was rationally developed. The probe could be self-assembled into nanoparticles in the aqueous solution due to the hydrophobic AIE core and hydrophilic sulfatase-recognition unit. DQM-SULF could be activated by the catalytic domain of sulfatase to afford the AIEgen DQM-OH, which can emit the aggregation-induced fluorescence and further bind to the hydrophobic site of sulfatase resulted in a stronger AIE signal. The nanoprobe exhibited a fast response and high sensitivity to sulfatase. Moreover, it was successfully employed in detecting the endogenous overexpressed sulfatase in tumor cells and tumor tissue. Importantly, the sulfatase activity in a mouse metastatic lung tumor model was imaged using DQM-SULF by pulmonary administration, indicating DQM-SULF has the potential to detect cancer cells as the inhalation contrast medium.

As a member of the reactive nitrogen species (RNS) family, peroxynitrite (ONOO−) as an oxidant and nitrating mediator plays a significant role in some physiopathologic processes. The excessive production of peroxynitrite anion in a drug-damaged liver is a culprit of hepatotoxicity. The detection of peroxynitrite is of vital importance for the treatment of some diseases including cancer and liver injury. In this study, a novel turn-on fluorescent probe IC-ONOO with new chalcone fluorophore was designed and synthesized for the detection of in vitro and in vivo. The probe responded rapidly towards ONOO− (only within 15 min did the fluorescent intensity maximize), and was endowed with high sensitivity and excellent selectivity. Given the fact that the linear correlation between the fluorescent intensity at 560 nm and the concentrations of the probe ranged from 0 to 9 μM, the limit of detection (LOD) was calculated to be 3.1 × 10−8 M. With all the merits, probe IC-ONOO was qualified as a robust tool to monitor peroxynitrite anion under physiopathologic condition. Moreover, it was successfully applied in the imaging of endogenous peroxynitrite in living MCF-7 cells (Human breast carcinoma cells) and mouse drug-damaged liver tissue with low cytotoxicity. Given all the extraordinary merits, great potential has been seen in its application to other peroxynitrite related diseases.

Copper (Cu) plays a significant role in the process of oxygenic photosynthesis in living systems. The detection of copper ion (Cu2+) is valuable and meaningful for further investigating the functions of Cu2+ under physiological and pathological conditions. In this paper, a novel fluorescence probe DCM-Cu based on the near-infrared (NIR) fluorophore dicyanomethylene-4H-pyran (DCM) was designed for Cu2+ detection. The probe DCM-Cu possessed characteristic of “turn-on” fluorescent signal in the presence of Cu2+ through the enhanced ICT process. It exhibited satisfactory sensitivity and selectivity toward Cu2+. A good linear correlation was observed between the concentrations of Cu2+ and the fluorescence intensities at 700 nm. The detection limit (LOD) of DCM-Cu toward Cu2+ was calculated to be 2.54 × 10−8 M. Importantly, DCM-Cu was successfully applied in the detection of Cu2+ in living MCF-7 cells and tumor tissue with low cytotoxicity. Therefore, this probe would have the potential to monitor cellular Cu2+ in the living system and be applied to the diagnosis of related diseases.