20世纪90年代初,随着第一代超高场磁共振成像仪的投入使用,因其诸多的优点,如更高的检测信噪比、更好的对比度、更强的BOLD效应和更宽的波谱,超高场磁共振成像成为国际医学磁共振领域最热门的研究方向之一.该文以最新一代的7.0 T MRI成...20世纪90年代初,随着第一代超高场磁共振成像仪的投入使用,因其诸多的优点,如更高的检测信噪比、更好的对比度、更强的BOLD效应和更宽的波谱,超高场磁共振成像成为国际医学磁共振领域最热门的研究方向之一.该文以最新一代的7.0 T MRI成像仪为例,简述超高场磁共振人体成像仪的系统结构、研究进展,并展望其在神经科学、认知科学和医学的应用前景.展开更多
Background Osteosarcoma （OS） is the most common primary malignant tumor of bone. Mouse models of human OS can invariably provide greater insight into the complex mechanisms that underlie the development and pathogen...Background Osteosarcoma （OS） is the most common primary malignant tumor of bone. Mouse models of human OS can invariably provide greater insight into the complex mechanisms that underlie the development and pathogenesis of this aggressive tumor. Bioluminescence technology favored tracing cancer cells in vivo. In this study, an OS model was described and evaluated using human OS cell line, Saos2, labeled with luciferase （Saos2-1uc）. Methods Saos2 cells were infected by lentivirus loading a firefly luciferase gene. Luciferase expression of Saos2-1uc cells was characterized both in vitro and in vivo. Specific biologic and oncologic features of Saos2-1uc cells were analyzed. The OS was established as orthotopic xenografts in nude mice. Both orthotopic tumors and spontaneous lung metastasis were analyzed. Results Tumorigenesis and spontaneous lung metastasis in nude mice could be monitored in vivo through in vivo imaging system. The enhancement in proliferation, migration and invasion abilities and the attenuation in adhesion ability were observed in Saos2-1uc cells compared with Saos2 cells. Furthermore, there were the up-regulation of Osteocalcin, CCRIO, CXCR1 and ID1 and the down-regulation of ALP, collagen I, CCR1, CCR3, CXCR3, NID and N-cadherin in Saos2-1uc cells compare to Saos2 cells. The rate of spontaneous lung metastasis in Saos2-1uc cells was higher than that in Saos2 cells, although without significant difference. Conclusions Lentivirus transfection may cause alteration of gene expression profiles and further biological functions. This model can be used in the elucidation of molecular mechanisms of tumorigenesis and the screening of new therapeutic agents.展开更多
Near-infrared （NIR） persistent-luminescence nanoparticles have emerged as a new class of background-free contrast agents that are promising for in vivo imaging. The next key roadblock is to establish a robust and co...Near-infrared （NIR） persistent-luminescence nanoparticles have emerged as a new class of background-free contrast agents that are promising for in vivo imaging. The next key roadblock is to establish a robust and controllable method for synthesizing monodisperse nanoparticles with high luminescence brightness and long persistent duration. Herein, we report a synthesis strategy involving the coating/etching of the SiO2 shell to obtain a new class of small NIR highly persistent luminescent ZnGa2O4：Cr^3＋,Sn^4＋（ZGOCS） nanoparticles. The optimized ZGOCS nanoparticles have an excellent size distribution of -15 nm without any agglomeration and an NIR persistent luminescence that is enhanced by a factor of 13.5, owing to the key role of the SiO2 shell in preventing nanoparticle agglomeration after annealing. The ZGOCS nanoparticles have a signal-to-noise ratio -3 times higher than that of previously reported ZnGa204：Cr^3＋ （ZGC-1） nanoparticles as an NIR persistent-luminescence probe for in vivo bioimaging. Moreover, the persistent-luminescence signal from the ZGOCS nanoparticles can be repeatedly re-charged in situ with external excitation by a white light- emitting diode; thus, the nanopartides are suitable for long-term in vivo imaging applications. Our study suggests an improved strategy for fabricating novel high-performance optical nanoparticles with good biocompatibility.展开更多
Fluorescent metal nanoclusters（MNCs） have recently emerged as a novel kind of promising fluorescent probes for biological imaging because of their ultrasmall core size（〈2 nm）, strong photoluminescence,facile avai...Fluorescent metal nanoclusters（MNCs） have recently emerged as a novel kind of promising fluorescent probes for biological imaging because of their ultrasmall core size（〈2 nm）, strong photoluminescence,facile availability and good biocompatibility. In this review, we provide an update on recent advances in the development of near infrared（NIR）-emitting MNCs in terms of synthesis strategies and bioimaging applications. We mainly focus on the utilization of NIR-emitting MNCs（including Au, Ag, Cu and alloy NCs） either as single modal imaging（fluorescence intensity-based imaging, fluorescence lifetime imaging, two-photon imaging） probes or as multimodal imaging（such as NIR fluorescence/X-ray computed tomography/magnetic resonance imaging, NIR fluorescence/photoacoustic imaging/magnetic resonance imaging, NIR fluorescence/single photon emission computed tomography） probes in biological cells and tissues. Finally, we give a brief outlook on the future challenges and prospects of developing NIR-emitting MNCs for bioimaging.展开更多
The latest progress of using carbon nanotubes(CNTs) for in vivo cancer nanotechnology is reviewed.CNTs can be functionalized by either covalent or non-covalent chemistry to produce functional bioconjugates for many in...The latest progress of using carbon nanotubes(CNTs) for in vivo cancer nanotechnology is reviewed.CNTs can be functionalized by either covalent or non-covalent chemistry to produce functional bioconjugates for many in vivo applications.In vivo behaviors and toxicology studies of CNTs are summarized,suggesting no significant toxicity of well functionalized CNTs to the treated mice.Owing to their unique chemical and physical properties,CNTs,especially single-walled carbon nanotubes(SWNTs),have been widely used for various modalities of in vivo cancer treatment and imaging.Future development of CNT-based nanomedicine may bring novel opportunities to cancer diagnosis and therapy.展开更多
Spontaneous light emission from living animals can overcome the investigated light signals in small animal luminescence imaging. Despite autofluorescence emission is well studied the spontaneous luminescence backgroun...Spontaneous light emission from living animals can overcome the investigated light signals in small animal luminescence imaging. Despite autofluorescence emission is well studied the spontaneous luminescence background is less known and its importance is growing due to the new born imaging techniques like Cerenkov Luminescence Imaging and Radionuclide Luminescence Imaging in which faint sources are often involved. In order to investigate the spontaneous emission we studied the background luminescence in vivo from health Nu/Nu mice in optical imaging acquisitions and we related it with the optical properties of the diet of the animals. In particular luminescence images of mice feed with normal diet used in animal facilities were acquired using a commercial optical imager. The intensity and the spectral features of the luminescence emission from the animal surface after sunshine exposition and after normal lighting laboratory conditions were measured. The same was done with the pellets of food used to feed the animals. We found a background emission from the entire animal surface and localized light sources in the abdominal/lumbar region. Their intensity can be modulated by the light exposition of the animals before the imaging session and decreases along the time when they are put in darkness. The comparison of the luminescence time decay of animals and pellets suggests that the light sources are related to the persistent luminescence of the molecules contained in the food. So ambient exposure before imaging is important for luminescence imaging in order to keep down the background. The optical properties of food are also important and it necessary to check them before to feed the animals not only in fluorescence imaging but also in luminescence imaging.展开更多
文摘20世纪90年代初,随着第一代超高场磁共振成像仪的投入使用,因其诸多的优点,如更高的检测信噪比、更好的对比度、更强的BOLD效应和更宽的波谱,超高场磁共振成像成为国际医学磁共振领域最热门的研究方向之一.该文以最新一代的7.0 T MRI成像仪为例,简述超高场磁共振人体成像仪的系统结构、研究进展,并展望其在神经科学、认知科学和医学的应用前景.
基金the grants from the National Natural Science Foundation of China，the Shanghai Science and Technology Development Fund，the Program of Key Disciplines of Shanghai Municipal Education Commission，the Doctoral Innovation Foundation of Shanghai Jiaotong University
文摘Background Osteosarcoma （OS） is the most common primary malignant tumor of bone. Mouse models of human OS can invariably provide greater insight into the complex mechanisms that underlie the development and pathogenesis of this aggressive tumor. Bioluminescence technology favored tracing cancer cells in vivo. In this study, an OS model was described and evaluated using human OS cell line, Saos2, labeled with luciferase （Saos2-1uc）. Methods Saos2 cells were infected by lentivirus loading a firefly luciferase gene. Luciferase expression of Saos2-1uc cells was characterized both in vitro and in vivo. Specific biologic and oncologic features of Saos2-1uc cells were analyzed. The OS was established as orthotopic xenografts in nude mice. Both orthotopic tumors and spontaneous lung metastasis were analyzed. Results Tumorigenesis and spontaneous lung metastasis in nude mice could be monitored in vivo through in vivo imaging system. The enhancement in proliferation, migration and invasion abilities and the attenuation in adhesion ability were observed in Saos2-1uc cells compared with Saos2 cells. Furthermore, there were the up-regulation of Osteocalcin, CCRIO, CXCR1 and ID1 and the down-regulation of ALP, collagen I, CCR1, CCR3, CXCR3, NID and N-cadherin in Saos2-1uc cells compare to Saos2 cells. The rate of spontaneous lung metastasis in Saos2-1uc cells was higher than that in Saos2 cells, although without significant difference. Conclusions Lentivirus transfection may cause alteration of gene expression profiles and further biological functions. This model can be used in the elucidation of molecular mechanisms of tumorigenesis and the screening of new therapeutic agents.
文摘Near-infrared （NIR） persistent-luminescence nanoparticles have emerged as a new class of background-free contrast agents that are promising for in vivo imaging. The next key roadblock is to establish a robust and controllable method for synthesizing monodisperse nanoparticles with high luminescence brightness and long persistent duration. Herein, we report a synthesis strategy involving the coating/etching of the SiO2 shell to obtain a new class of small NIR highly persistent luminescent ZnGa2O4：Cr^3＋,Sn^4＋（ZGOCS） nanoparticles. The optimized ZGOCS nanoparticles have an excellent size distribution of -15 nm without any agglomeration and an NIR persistent luminescence that is enhanced by a factor of 13.5, owing to the key role of the SiO2 shell in preventing nanoparticle agglomeration after annealing. The ZGOCS nanoparticles have a signal-to-noise ratio -3 times higher than that of previously reported ZnGa204：Cr^3＋ （ZGC-1） nanoparticles as an NIR persistent-luminescence probe for in vivo bioimaging. Moreover, the persistent-luminescence signal from the ZGOCS nanoparticles can be repeatedly re-charged in situ with external excitation by a white light- emitting diode; thus, the nanopartides are suitable for long-term in vivo imaging applications. Our study suggests an improved strategy for fabricating novel high-performance optical nanoparticles with good biocompatibility.
基金Financial supports from the National 1000 Young Talent ProgramNational Natural Science Foundation of China (NSFC, No. 21705129)Program of Introducing Talents of Discipline to Universities (No. B08040)
文摘Fluorescent metal nanoclusters（MNCs） have recently emerged as a novel kind of promising fluorescent probes for biological imaging because of their ultrasmall core size（〈2 nm）, strong photoluminescence,facile availability and good biocompatibility. In this review, we provide an update on recent advances in the development of near infrared（NIR）-emitting MNCs in terms of synthesis strategies and bioimaging applications. We mainly focus on the utilization of NIR-emitting MNCs（including Au, Ag, Cu and alloy NCs） either as single modal imaging（fluorescence intensity-based imaging, fluorescence lifetime imaging, two-photon imaging） probes or as multimodal imaging（such as NIR fluorescence/X-ray computed tomography/magnetic resonance imaging, NIR fluorescence/photoacoustic imaging/magnetic resonance imaging, NIR fluorescence/single photon emission computed tomography） probes in biological cells and tissues. Finally, we give a brief outlook on the future challenges and prospects of developing NIR-emitting MNCs for bioimaging.
文摘The latest progress of using carbon nanotubes(CNTs) for in vivo cancer nanotechnology is reviewed.CNTs can be functionalized by either covalent or non-covalent chemistry to produce functional bioconjugates for many in vivo applications.In vivo behaviors and toxicology studies of CNTs are summarized,suggesting no significant toxicity of well functionalized CNTs to the treated mice.Owing to their unique chemical and physical properties,CNTs,especially single-walled carbon nanotubes(SWNTs),have been widely used for various modalities of in vivo cancer treatment and imaging.Future development of CNT-based nanomedicine may bring novel opportunities to cancer diagnosis and therapy.
文摘Spontaneous light emission from living animals can overcome the investigated light signals in small animal luminescence imaging. Despite autofluorescence emission is well studied the spontaneous luminescence background is less known and its importance is growing due to the new born imaging techniques like Cerenkov Luminescence Imaging and Radionuclide Luminescence Imaging in which faint sources are often involved. In order to investigate the spontaneous emission we studied the background luminescence in vivo from health Nu/Nu mice in optical imaging acquisitions and we related it with the optical properties of the diet of the animals. In particular luminescence images of mice feed with normal diet used in animal facilities were acquired using a commercial optical imager. The intensity and the spectral features of the luminescence emission from the animal surface after sunshine exposition and after normal lighting laboratory conditions were measured. The same was done with the pellets of food used to feed the animals. We found a background emission from the entire animal surface and localized light sources in the abdominal/lumbar region. Their intensity can be modulated by the light exposition of the animals before the imaging session and decreases along the time when they are put in darkness. The comparison of the luminescence time decay of animals and pellets suggests that the light sources are related to the persistent luminescence of the molecules contained in the food. So ambient exposure before imaging is important for luminescence imaging in order to keep down the background. The optical properties of food are also important and it necessary to check them before to feed the animals not only in fluorescence imaging but also in luminescence imaging.
