T1 Contrast

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Xiaoyuan Chen - One of the best experts on this subject based on the ideXlab platform.

  • engineered iron oxide based nanoparticles as enhanced T1 Contrast agents for efficient tumor imaging
    ACS Nano, 2013
    Co-Authors: Zijian Zhou, Lirong Wang, Lijiao Yang, Wenxiu Zhao, Zhong Chen, Xiaomin Wang, Xiaoyuan Chen
    Abstract:

    We report the design and synthesis of small-sized zwitterion-coated gadolinium-embedded iron oxide (GdIO) nanoparticles, which exhibit a strong T1 Contrast effect for tumor imaging through enhanced permeation and retention effect and the ability to clear out of the body in living subjects. The combination of spin-canting effects and the collection of gadolinium species within small-sized GdIO nanoparticles led to a significantly enhanced T1 Contrast effect. For example, GdIO nanoparticles with a diameter of ∼4.8 nm exhibited a high r1 relaxivity of 7.85 mM–1·S–1 and a low r2/r1 ratio of 5.24. After being coated with zwitterionic dopamine sulfonate molecules, the 4.8 nm GdIO nanoparticles showed a steady hydrodynamic diameter (∼5.2 nm) in both PBS buffer and fetal bovine serum solution, indicating a low nonspecific protein absorption. This study provides a valuable strategy for the design of highly sensitive iron-oxide-based T1 Contrast agents with relatively long circulation half-lives (∼50 min), efficien...

  • a synergistically enhanced T1 t2 dual modal Contrast agent
    Advanced Materials, 2012
    Co-Authors: Zijian Zhou, Zhong Chen, Xiaoyuan Chen, Dengtong Huang, Qiaoli Chen
    Abstract:

    Among various molecular imaging techniques, magnetic resonance imaging (MRI) is one of the most powerful and non-invasive diagnostic tools because MRI can provide images with excellent anatomical details based on the interaction of protons with the surrounding molecules of tissues.[1] MRI Contrast agents, generally in the form of T1 positive Contrast agents and T2 negative Contrast agents, can greatly improve the sensitivity of MRI by increasing the Contrast of the target from the background. For example, superparamagnetic iron oxide (SPIO) nanoparticles with strong magnetic moments are the prevailing T2 Contrast agents, especially in the imaging and detection of lesions from normal tissues.[2] The significant drawbacks of SPIO nanoparticles as T2 Contrast agents are, however, magnetic susceptibility artifacts and negative Contrast effects (i.e., dark MR images),[3] which may limit their clinical applications. On the contrary, T1 imaging, typically using paramagnetic materials as Contrast agents, has excellent resolution between tissues due to its high signal intensity (bright and positive MR images).[4] Although ultrasmall (~3 nm in diameter) iron oxide nanoparticles can be used as T1 Contrast agents,[5] the gadolinium species possessing seven unpaired electrons are still the prevailing T1 Contrast agents in clinical use.[4]

  • HSA coated MnO nanoparticles with prominent MRI Contrast for tumor imaging
    Chemical Communications, 2010
    Co-Authors: Jing Huang, Kai Chen, Lihong Bu, Zhen Cheng, Xingguo Li, Xiaoyuan Chen
    Abstract:

    We report in this Communication a facile, two-step surface modification strategy to achieve manganese oxide nanoparticles with prominent MRI T1 Contrast. In a U87MG glioblastoma xenograft model, we confirmed that the particles can accumulate efficiently in tumor area to induce effective T1 signal alteration.

Zijian Zhou - One of the best experts on this subject based on the ideXlab platform.

  • Geometrically confined ultrasmall gadolinium oxide nanoparticles boost the T1 Contrast ability
    Nanoscale, 2016
    Co-Authors: Kaiyuan Ni, Lirong Wang, Zijian Zhou, Zhenghuan Zhao, Zongjun Zhang, Li Yang, Hua Ai
    Abstract:

    High-performance magnetic resonance imaging (MRI) Contrast agents and novel Contrast enhancement strategies are urgently needed for sensitive and accurate diagnosis. Here we report a strategy to construct a new T1 Contrast agent based on the Solomon–Bloembergen–Morgan (SBM) theory. We loaded the ultrasmall gadolinium oxide nanoparticles into worm-like interior channels of mesoporous silica nanospheres (Gd2O3@MSN nanocomposites). This unique structure endows the nanocomposites with geometrical confinement, high molecular tumbling time, and a large coordinated number of water molecules, which results in a significant enhancement of the T1 Contrast with longitudinal proton relaxivity (r1) as high as 45.08 mM−1 s−1. Such a high r1 value of Gd2O3@MSN, compared to those of ultrasmall Gd2O3 nanoparticles and gadolinium-based clinical Contrast agents, is mainly attributed to the strong geometrical confinement effect. This strategy provides new guidance for developing various high-performance T1 Contrast agents for sensitive imaging and disease diagnosis.

  • A multiple gadolinium complex decorated fullerene as a highly sensitive T1 Contrast agent
    Chemical Communications, 2015
    Co-Authors: Lirong Wang, Xingyan Tang, Changqiang Wu, Zijian Zhou, Shun-liu Deng, Hua Ai
    Abstract:

    We report a simple strategy to construct a multiple gadolinium complex decorated fullerene (CGDn) as an enhanced T1 Contrast agent. The CGDn exhibits much higher T1 relaxivity (∼49.7 mM−1 s−1) than individual Gd-DOTA, and shows excellent T1 Contrast enhancement ability both in vitro and in vivo.

  • Surface and Interfacial Engineering of Iron Oxide Nanoplates for Highly Efficient Magnetic Resonance Angiography
    ACS Nano, 2015
    Co-Authors: Zijian Zhou, Lirong Wang, Changqiang Wu, Zhenghuan Zhao, Ye Xu, Hua Ai
    Abstract:

    Magnetic resonance angiography using gadolinium-based molecular Contrast agents suffers from short diagnostic window, relatively low resolution and risk of toxicity. Taking into account the chemical exchange between metal centers and surrounding protons, magnetic nanoparticles with suitable surface and interfacial features may serve as alternative T1 Contrast agents. Herein, we report the engineering on surface structure of iron oxide nanoplates to boost T1 Contrast ability through synergistic effects between exposed metal-rich Fe3O4(100) facets and embedded Gd2O3 clusters. The nanoplates show prominent T1 Contrast in a wide range of magnetic fields with an ultrahigh r1 value up to 61.5 mM–1 s–1. Moreover, engineering on nanobio interface through zwitterionic molecules adjusts the in vivo behaviors of nanoplates for highly efficient magnetic resonance angiography with steady-state acquisition window, superhigh resolution in vascular details, and low toxicity. This study provides a powerful tool for sophis...

  • engineered iron oxide based nanoparticles as enhanced T1 Contrast agents for efficient tumor imaging
    ACS Nano, 2013
    Co-Authors: Zijian Zhou, Lirong Wang, Lijiao Yang, Wenxiu Zhao, Zhong Chen, Xiaomin Wang, Xiaoyuan Chen
    Abstract:

    We report the design and synthesis of small-sized zwitterion-coated gadolinium-embedded iron oxide (GdIO) nanoparticles, which exhibit a strong T1 Contrast effect for tumor imaging through enhanced permeation and retention effect and the ability to clear out of the body in living subjects. The combination of spin-canting effects and the collection of gadolinium species within small-sized GdIO nanoparticles led to a significantly enhanced T1 Contrast effect. For example, GdIO nanoparticles with a diameter of ∼4.8 nm exhibited a high r1 relaxivity of 7.85 mM–1·S–1 and a low r2/r1 ratio of 5.24. After being coated with zwitterionic dopamine sulfonate molecules, the 4.8 nm GdIO nanoparticles showed a steady hydrodynamic diameter (∼5.2 nm) in both PBS buffer and fetal bovine serum solution, indicating a low nonspecific protein absorption. This study provides a valuable strategy for the design of highly sensitive iron-oxide-based T1 Contrast agents with relatively long circulation half-lives (∼50 min), efficien...

  • a synergistically enhanced T1 t2 dual modal Contrast agent
    Advanced Materials, 2012
    Co-Authors: Zijian Zhou, Zhong Chen, Xiaoyuan Chen, Dengtong Huang, Qiaoli Chen
    Abstract:

    Among various molecular imaging techniques, magnetic resonance imaging (MRI) is one of the most powerful and non-invasive diagnostic tools because MRI can provide images with excellent anatomical details based on the interaction of protons with the surrounding molecules of tissues.[1] MRI Contrast agents, generally in the form of T1 positive Contrast agents and T2 negative Contrast agents, can greatly improve the sensitivity of MRI by increasing the Contrast of the target from the background. For example, superparamagnetic iron oxide (SPIO) nanoparticles with strong magnetic moments are the prevailing T2 Contrast agents, especially in the imaging and detection of lesions from normal tissues.[2] The significant drawbacks of SPIO nanoparticles as T2 Contrast agents are, however, magnetic susceptibility artifacts and negative Contrast effects (i.e., dark MR images),[3] which may limit their clinical applications. On the contrary, T1 imaging, typically using paramagnetic materials as Contrast agents, has excellent resolution between tissues due to its high signal intensity (bright and positive MR images).[4] Although ultrasmall (~3 nm in diameter) iron oxide nanoparticles can be used as T1 Contrast agents,[5] the gadolinium species possessing seven unpaired electrons are still the prevailing T1 Contrast agents in clinical use.[4]

Zhong Chen - One of the best experts on this subject based on the ideXlab platform.

  • Geometrical confinement directed albumin-based nanoprobes as enhanced T1 Contrast agents for tumor imaging.
    Journal of Materials Chemistry B, 2017
    Co-Authors: Lirong Wang, Lengceng Ma, Jiaqi Huang, Ao Li, Tian Zhao, Zhong Chen
    Abstract:

    There is an urgent demand for the development of new magnetic resonance imaging (MRI) Contrast agents (CAs) with high T1 Contrast ability and good biocompatibility. Herein, we report a novel albumin-based nanoprobe loaded with ibuprofen-modified gadolinium chelates, named Ibu-Gd–BSA nanoparticles (NPs). The interfacial pore structure among the albumin molecules endows the Ibu-Gd–BSA NPs with geometrical confinement, which could prolong the rotational correlation time (τR) of CAs and the diffusion correlation time (τD) of water molecules trapped within the pores. As a result, the Ibu-Gd–BSA NPs exhibited an extremely high relaxivity of 48.9 mM−1 s−1, which is about 9 times higher than that of the clinical Contrast agent Gd-DOTA (Dotarem®). In addition, the Ibu-Gd–BSA NPs showed good biocompatibility in vitro and in vivo due to the intrinsically biocompatible property of each component. Moreover, the Ibu-Gd–BSA NPs showed much longer blood circulation half-life and higher accumulation in tumors due to the enhanced permeability and retention effect compared to small molecular CAs. In vivo T1-weighted MR imaging confirmed that Ibu-Gd–BSA NPs could serve as an optimal candidate for sensitive tumor imaging. This study provides a facile strategy to assemble geometrically confined albumin-based nanoparticles as T1 CAs with high biocompatibility and enhanced Contrast ability, which have great potential for diverse uses in biomedical imaging and disease detection.

  • Real-Time Monitoring in Vivo Behaviors of Theranostic Nanoparticles by Contrast-Enhanced T1 Imaging
    Analytical Chemistry, 2015
    Co-Authors: Jiahe Chen, Lirong Wang, Xiaomin Wang, Zhong Chen
    Abstract:

    The innovative applications of engineered nanoparticles (NPs) in medicine, such as diagnosis and therapy, have attracted considerable attention. It is highly important to predict the interactions between engineered NPs and the complex biological system as well as the impacts on the subsequent behaviors in living subjects. Herein, we report the use of T1 Contrast-enhanced magnetic resonance imaging (MRI) to monitor the in vivo behaviors of NPs in a real-time manner. We chose ultrasmall Pd nanosheets (SPNSs) as the object of NPs because of their promise in theranostics and fitness for diverse surface chemistry. SPNSs were modified with different surface coating ligands (e.g., polyethylene glycol, zwitterionic ligands, polyethylenimine) and functionalized with Gd-chelates to render T1 Contrast-enhanced capability. MRI real-time monitoring recorded the location and accumulation of SPNSs in small animals and revealed the prominent roles of surface coating ligands in pharmacokinetics. These results highlighted ...

  • engineered iron oxide based nanoparticles as enhanced T1 Contrast agents for efficient tumor imaging
    ACS Nano, 2013
    Co-Authors: Zijian Zhou, Lirong Wang, Lijiao Yang, Wenxiu Zhao, Zhong Chen, Xiaomin Wang, Xiaoyuan Chen
    Abstract:

    We report the design and synthesis of small-sized zwitterion-coated gadolinium-embedded iron oxide (GdIO) nanoparticles, which exhibit a strong T1 Contrast effect for tumor imaging through enhanced permeation and retention effect and the ability to clear out of the body in living subjects. The combination of spin-canting effects and the collection of gadolinium species within small-sized GdIO nanoparticles led to a significantly enhanced T1 Contrast effect. For example, GdIO nanoparticles with a diameter of ∼4.8 nm exhibited a high r1 relaxivity of 7.85 mM–1·S–1 and a low r2/r1 ratio of 5.24. After being coated with zwitterionic dopamine sulfonate molecules, the 4.8 nm GdIO nanoparticles showed a steady hydrodynamic diameter (∼5.2 nm) in both PBS buffer and fetal bovine serum solution, indicating a low nonspecific protein absorption. This study provides a valuable strategy for the design of highly sensitive iron-oxide-based T1 Contrast agents with relatively long circulation half-lives (∼50 min), efficien...

  • a synergistically enhanced T1 t2 dual modal Contrast agent
    Advanced Materials, 2012
    Co-Authors: Zijian Zhou, Zhong Chen, Xiaoyuan Chen, Dengtong Huang, Qiaoli Chen
    Abstract:

    Among various molecular imaging techniques, magnetic resonance imaging (MRI) is one of the most powerful and non-invasive diagnostic tools because MRI can provide images with excellent anatomical details based on the interaction of protons with the surrounding molecules of tissues.[1] MRI Contrast agents, generally in the form of T1 positive Contrast agents and T2 negative Contrast agents, can greatly improve the sensitivity of MRI by increasing the Contrast of the target from the background. For example, superparamagnetic iron oxide (SPIO) nanoparticles with strong magnetic moments are the prevailing T2 Contrast agents, especially in the imaging and detection of lesions from normal tissues.[2] The significant drawbacks of SPIO nanoparticles as T2 Contrast agents are, however, magnetic susceptibility artifacts and negative Contrast effects (i.e., dark MR images),[3] which may limit their clinical applications. On the contrary, T1 imaging, typically using paramagnetic materials as Contrast agents, has excellent resolution between tissues due to its high signal intensity (bright and positive MR images).[4] Although ultrasmall (~3 nm in diameter) iron oxide nanoparticles can be used as T1 Contrast agents,[5] the gadolinium species possessing seven unpaired electrons are still the prevailing T1 Contrast agents in clinical use.[4]

Lirong Wang - One of the best experts on this subject based on the ideXlab platform.

  • Geometrical confinement directed albumin-based nanoprobes as enhanced T1 Contrast agents for tumor imaging.
    Journal of Materials Chemistry B, 2017
    Co-Authors: Lirong Wang, Lengceng Ma, Jiaqi Huang, Ao Li, Tian Zhao, Zhong Chen
    Abstract:

    There is an urgent demand for the development of new magnetic resonance imaging (MRI) Contrast agents (CAs) with high T1 Contrast ability and good biocompatibility. Herein, we report a novel albumin-based nanoprobe loaded with ibuprofen-modified gadolinium chelates, named Ibu-Gd–BSA nanoparticles (NPs). The interfacial pore structure among the albumin molecules endows the Ibu-Gd–BSA NPs with geometrical confinement, which could prolong the rotational correlation time (τR) of CAs and the diffusion correlation time (τD) of water molecules trapped within the pores. As a result, the Ibu-Gd–BSA NPs exhibited an extremely high relaxivity of 48.9 mM−1 s−1, which is about 9 times higher than that of the clinical Contrast agent Gd-DOTA (Dotarem®). In addition, the Ibu-Gd–BSA NPs showed good biocompatibility in vitro and in vivo due to the intrinsically biocompatible property of each component. Moreover, the Ibu-Gd–BSA NPs showed much longer blood circulation half-life and higher accumulation in tumors due to the enhanced permeability and retention effect compared to small molecular CAs. In vivo T1-weighted MR imaging confirmed that Ibu-Gd–BSA NPs could serve as an optimal candidate for sensitive tumor imaging. This study provides a facile strategy to assemble geometrically confined albumin-based nanoparticles as T1 CAs with high biocompatibility and enhanced Contrast ability, which have great potential for diverse uses in biomedical imaging and disease detection.

  • Geometrically confined ultrasmall gadolinium oxide nanoparticles boost the T1 Contrast ability
    Nanoscale, 2016
    Co-Authors: Kaiyuan Ni, Lirong Wang, Zijian Zhou, Zhenghuan Zhao, Zongjun Zhang, Li Yang, Hua Ai
    Abstract:

    High-performance magnetic resonance imaging (MRI) Contrast agents and novel Contrast enhancement strategies are urgently needed for sensitive and accurate diagnosis. Here we report a strategy to construct a new T1 Contrast agent based on the Solomon–Bloembergen–Morgan (SBM) theory. We loaded the ultrasmall gadolinium oxide nanoparticles into worm-like interior channels of mesoporous silica nanospheres (Gd2O3@MSN nanocomposites). This unique structure endows the nanocomposites with geometrical confinement, high molecular tumbling time, and a large coordinated number of water molecules, which results in a significant enhancement of the T1 Contrast with longitudinal proton relaxivity (r1) as high as 45.08 mM−1 s−1. Such a high r1 value of Gd2O3@MSN, compared to those of ultrasmall Gd2O3 nanoparticles and gadolinium-based clinical Contrast agents, is mainly attributed to the strong geometrical confinement effect. This strategy provides new guidance for developing various high-performance T1 Contrast agents for sensitive imaging and disease diagnosis.

  • Real-Time Monitoring in Vivo Behaviors of Theranostic Nanoparticles by Contrast-Enhanced T1 Imaging
    Analytical Chemistry, 2015
    Co-Authors: Jiahe Chen, Lirong Wang, Xiaomin Wang, Zhong Chen
    Abstract:

    The innovative applications of engineered nanoparticles (NPs) in medicine, such as diagnosis and therapy, have attracted considerable attention. It is highly important to predict the interactions between engineered NPs and the complex biological system as well as the impacts on the subsequent behaviors in living subjects. Herein, we report the use of T1 Contrast-enhanced magnetic resonance imaging (MRI) to monitor the in vivo behaviors of NPs in a real-time manner. We chose ultrasmall Pd nanosheets (SPNSs) as the object of NPs because of their promise in theranostics and fitness for diverse surface chemistry. SPNSs were modified with different surface coating ligands (e.g., polyethylene glycol, zwitterionic ligands, polyethylenimine) and functionalized with Gd-chelates to render T1 Contrast-enhanced capability. MRI real-time monitoring recorded the location and accumulation of SPNSs in small animals and revealed the prominent roles of surface coating ligands in pharmacokinetics. These results highlighted ...

  • A multiple gadolinium complex decorated fullerene as a highly sensitive T1 Contrast agent
    Chemical Communications, 2015
    Co-Authors: Lirong Wang, Xingyan Tang, Changqiang Wu, Zijian Zhou, Shun-liu Deng, Hua Ai
    Abstract:

    We report a simple strategy to construct a multiple gadolinium complex decorated fullerene (CGDn) as an enhanced T1 Contrast agent. The CGDn exhibits much higher T1 relaxivity (∼49.7 mM−1 s−1) than individual Gd-DOTA, and shows excellent T1 Contrast enhancement ability both in vitro and in vivo.

  • Surface and Interfacial Engineering of Iron Oxide Nanoplates for Highly Efficient Magnetic Resonance Angiography
    ACS Nano, 2015
    Co-Authors: Zijian Zhou, Lirong Wang, Changqiang Wu, Zhenghuan Zhao, Ye Xu, Hua Ai
    Abstract:

    Magnetic resonance angiography using gadolinium-based molecular Contrast agents suffers from short diagnostic window, relatively low resolution and risk of toxicity. Taking into account the chemical exchange between metal centers and surrounding protons, magnetic nanoparticles with suitable surface and interfacial features may serve as alternative T1 Contrast agents. Herein, we report the engineering on surface structure of iron oxide nanoplates to boost T1 Contrast ability through synergistic effects between exposed metal-rich Fe3O4(100) facets and embedded Gd2O3 clusters. The nanoplates show prominent T1 Contrast in a wide range of magnetic fields with an ultrahigh r1 value up to 61.5 mM–1 s–1. Moreover, engineering on nanobio interface through zwitterionic molecules adjusts the in vivo behaviors of nanoplates for highly efficient magnetic resonance angiography with steady-state acquisition window, superhigh resolution in vascular details, and low toxicity. This study provides a powerful tool for sophis...

Jeff H Duyn - One of the best experts on this subject based on the ideXlab platform.

  • effects of magnetization transfer on T1 Contrast in human brain white matter
    NeuroImage, 2016
    Co-Authors: Peter Van Gelderen, Xu Jiang, Jeff H Duyn
    Abstract:

    Abstract MRI based on T1 relaxation Contrast is increasingly being used to study brain morphology and myelination. Although it provides for excellent distinction between the major tissue types of gray matter, white matter, and CSF, reproducible quantification of T1 relaxation rates is difficult due to the complexity of the Contrast mechanism and dependence on experimental details. In this work, we perform simulations and inversion-recovery MRI measurements at 3 T and 7 T to show that substantial measurement variability results from unintended and uncontrolled perturbation of the magnetization of MRI-invisible 1H protons of lipids and macromolecules. This results in bi-exponential relaxation, with a fast component whose relative contribution under practical conditions can reach 20%. This phenomenon can strongly affect apparent relaxation rates, affect Contrast between tissue types, and result in Contrast variations over the brain. Based on this novel understanding, ways are proposed to minimize this experimental variability and its effect on T1 Contrast, quantification accuracy and reproducibility.