Near-infrared(NIR) nanoparticles(NPs) based on fluorescence resonance energy transfer(FRET) were prepared by coencapsulation of a red aggregation-induced emission(AIE) molecule, 2-(4-bromophenyl)-3-(4-(4-(diphenylamin...Near-infrared(NIR) nanoparticles(NPs) based on fluorescence resonance energy transfer(FRET) were prepared by coencapsulation of a red aggregation-induced emission(AIE) molecule, 2-(4-bromophenyl)-3-(4-(4-(diphenylamino)styryl)phenyl)fumaronitrile(TB), and a commercial NIR fluorescence dye, silicon 2,3-naphthalocyanine bis(trihexylsilyloxide)(NIR775) with an amphiphilic polymer poly(styrene-co-maleic anhydride)(PSMA). The surface of the NPs, PSMA@TB/NIR775, was modified with poly(ethylene glycol)(PEG) to increase the in vivo biocompatibility of the NPs. The PSMA@TB/NIR775 NPs showed a strong NIR(780 nm) narrow emission and excellent two-photon absorption property. Moreover, the NPs exhibited good monodispersity, stability, and low cytotoxicity.Under the excitation of a 1040 nm femtosecond(fs) laser, the emission peaks at 680 nm of TB and 780 nm of NIR775 excited by FRET were obtained. We utilized PSMA@TB/NIR775 NPs as fluorescent contrast agents for two-photon excited NIR microscopic imaging, and good NIR imaging effect of mouse brain vasculature was obtained with the imaging depth of about 150 μm. The FRET strategy by coencapsulating AIE molecule and NIR dye will be helpful in preparing more narrow emission NIR probes for deep-tissue biological imaging.展开更多
目的活体观察脑血管CO2反应性及初步探讨其反应机制。方法利用双光子成像技术,在磨薄的颅窗下观察5只雄性C57小鼠脑皮层动脉、穿支动脉、皮层静脉及毛细血管共4种脑血管对吸入CO2的反应,分别使用一氧化氮合酶抑制剂L-NAME及前列腺素合...目的活体观察脑血管CO2反应性及初步探讨其反应机制。方法利用双光子成像技术,在磨薄的颅窗下观察5只雄性C57小鼠脑皮层动脉、穿支动脉、皮层静脉及毛细血管共4种脑血管对吸入CO2的反应,分别使用一氧化氮合酶抑制剂L-NAME及前列腺素合成抑制剂吲哚美辛阻断血管扩张通路,观察血管反应性变化。结果吸入1 min 5%CO2后4种脑血管分别出现不同程度的扩张,其中穿支动脉扩张最显著(45.01%±4.45%);使用L-NAME后4种脑血管对CO2反应性较使用前显著下降(P<0.05);使用吲哚美辛后动脉CO2反应性较使用前及使用L-NAME后显著下降(P<0.05),但毛细血管CO2反应性较使用前无下降(P>0.05)。结论 4种脑血管在吸入CO2后出现不同程度的扩张反应,前列腺素类及NO参与介导反应。本实验方法有较好的应用价值。展开更多
基金financially supported by the National Natural Science Foundation of China (Nos. 21835001, 51773080, 21674041, 51573068, and 21221063)Program for Changbaishan Scholars of Jilin Province, Jilin Province (No. 20160101305JC)the "Talents Cultivation Program" of Jilin University
文摘Near-infrared(NIR) nanoparticles(NPs) based on fluorescence resonance energy transfer(FRET) were prepared by coencapsulation of a red aggregation-induced emission(AIE) molecule, 2-(4-bromophenyl)-3-(4-(4-(diphenylamino)styryl)phenyl)fumaronitrile(TB), and a commercial NIR fluorescence dye, silicon 2,3-naphthalocyanine bis(trihexylsilyloxide)(NIR775) with an amphiphilic polymer poly(styrene-co-maleic anhydride)(PSMA). The surface of the NPs, PSMA@TB/NIR775, was modified with poly(ethylene glycol)(PEG) to increase the in vivo biocompatibility of the NPs. The PSMA@TB/NIR775 NPs showed a strong NIR(780 nm) narrow emission and excellent two-photon absorption property. Moreover, the NPs exhibited good monodispersity, stability, and low cytotoxicity.Under the excitation of a 1040 nm femtosecond(fs) laser, the emission peaks at 680 nm of TB and 780 nm of NIR775 excited by FRET were obtained. We utilized PSMA@TB/NIR775 NPs as fluorescent contrast agents for two-photon excited NIR microscopic imaging, and good NIR imaging effect of mouse brain vasculature was obtained with the imaging depth of about 150 μm. The FRET strategy by coencapsulating AIE molecule and NIR dye will be helpful in preparing more narrow emission NIR probes for deep-tissue biological imaging.
文摘目的活体观察脑血管CO2反应性及初步探讨其反应机制。方法利用双光子成像技术,在磨薄的颅窗下观察5只雄性C57小鼠脑皮层动脉、穿支动脉、皮层静脉及毛细血管共4种脑血管对吸入CO2的反应,分别使用一氧化氮合酶抑制剂L-NAME及前列腺素合成抑制剂吲哚美辛阻断血管扩张通路,观察血管反应性变化。结果吸入1 min 5%CO2后4种脑血管分别出现不同程度的扩张,其中穿支动脉扩张最显著(45.01%±4.45%);使用L-NAME后4种脑血管对CO2反应性较使用前显著下降(P<0.05);使用吲哚美辛后动脉CO2反应性较使用前及使用L-NAME后显著下降(P<0.05),但毛细血管CO2反应性较使用前无下降(P>0.05)。结论 4种脑血管在吸入CO2后出现不同程度的扩张反应,前列腺素类及NO参与介导反应。本实验方法有较好的应用价值。
