Hyoungsu Kim - Academia.edu (original) (raw)

Papers by Hyoungsu Kim

Research paper thumbnail of Magnetosome-like ferrimagnetic iron oxide nanocubes for highly sensitive MRI of single cells and transplanted pancreatic islets

Proceedings of the National Academy of Sciences, 2011

For ultrasensitive magnetic resonance imaging (MRI), magnetic nanoparticles with extremely high r... more For ultrasensitive magnetic resonance imaging (MRI), magnetic nanoparticles with extremely high r2 relaxivity are strongly desired. Magnetosome-like nanoparticles were prepared by coating polyethylene glycol-phospholipid (PEG-phospholipid) onto ferrimagnetic iron oxide nanocubes (FIONs). FIONs exhibited a very high relaxivity (r2) of 324 mM −1 s −1 , allowing efficient labeling of various kinds of cells. The magnetic resonance (MR) imaging of single cells labeled with FIONs is demonstrated not only in vitro but also in vivo. Pancreatic islet grafts and their rejection could be imaged using FIONs on a 1.5 T clinical MRI scanner. The strong contrast effect of FIONs enabled MR imaging of transplanted islets in small rodents as well as in large animals. Therefore, we expect that MR imaging of pancreatic islet grafts using FIONs has the potentials for clinical applications. Furthermore, FIONs will enable highly sensitive noninvasive assessment after cell transplantation.

Research paper thumbnail of Large-Scale Synthesis of Uniform and Extremely Small-Sized Iron Oxide Nanoparticles for High-Resolution T 1 Magnetic Resonance Imaging Contrast Agents

Journal of the American Chemical Society, 2011

Magnetic resonance imaging (MRI) is one of the most powerful medical diagnosis tools because MRI ... more Magnetic resonance imaging (MRI) is one of the most powerful medical diagnosis tools because MRI can provide images with excellent anatomical details based on the soft tissue contrast and functional information in noninvasive and real-time monitoring manner. 1,2 The sensitivity of MRI can be greatly improved by the contrast agents that enhance the contrast of the region of interest from background. The MRI contrast agents are generally categorized according to their effects on longitudinal (T 1 ) and transversal (T 2 ) relaxations, and their ability is referred to as relaxivity (r 1 , r 2 ). The area wherein fast T 1 relaxation takes place appears bright, whereas T 2 relaxation results in the dark contrast in the MR images.

Research paper thumbnail of Large-Scale Synthesis of Bioinert Tantalum Oxide Nanoparticles for X-ray Computed Tomography Imaging and Bimodal Image-Guided Sentinel Lymph Node Mapping

Large-Scale Synthesis of Bioinert Tantalum Oxide Nanoparticles for X-ray Computed Tomography Imaging and Bimodal Image-Guided Sentinel Lymph Node Mapping

Journal of the American Chemical Society, 2011

Ever since Au nanoparticles were developed as X-ray contrast agents, researchers have actively so... more Ever since Au nanoparticles were developed as X-ray contrast agents, researchers have actively sought alternative nanoparticle-based imaging probes that are not only inexpensive but also safe for clinical use. Herein, we demonstrate that bioinert tantalum oxide nanoparticles are suitable nanoprobes for high-performance X-ray computed tomography (CT) imaging while simultaneously being cost-effective and meeting the criteria as a biomedical platform. Uniformly sized tantalum oxide nanoparticles were prepared using a microemulsion method, and their surfaces were readily modified using various silane derivatives through simple in situ sol-gel reaction. The silane-modified surface enabled facile immobilization of functional moieties such as polyethylene glycol (PEG) and fluorescent dye. PEG was introduced to endow the nanoparticles with biocompatibility and antifouling activity, whereas immobilized fluorescent dye molecules enabled simultaneous fluorescence imaging as well as X-ray CT imaging. The resulting nanoparticles exhibited remarkable performances in the in vivo X-ray CT angiography and bimodal image-guided lymph node mapping. We also performed an extensive study on in vivo toxicity of tantalum oxide nanoparticles, revealing that the nanoparticles did not affect normal functioning of organs.

Research paper thumbnail of Innentitelbild: Multifunctional Uniform Nanoparticles Composed of a Magnetite Nanocrystal Core and a Mesoporous Silica Shell for Magnetic Resonance and Fluorescence Imaging and for Drug Delivery (Angew. Chem. 44/2008)

Research paper thumbnail of Multifunctional Uniform Nanoparticles Composed of a Magnetite Nanocrystal Core and a Mesoporous Silica Shell for Magnetic Resonance and Fluorescence Imaging and for Drug Delivery

Angewandte Chemie International Edition, 2008

Research paper thumbnail of Inside Cover: Multifunctional Uniform Nanoparticles Composed of a Magnetite Nanocrystal Core and a Mesoporous Silica Shell for Magnetic Resonance and Fluorescence Imaging and for Drug Delivery (Angew. Chem. Int. Ed. 44/2008)

Angewandte Chemie International Edition, 2008

Core-shell mesoporous silica nanoparticles which consist of a single magnetite nanocrystal core a... more Core-shell mesoporous silica nanoparticles which consist of a single magnetite nanocrystal core and a dye-doped mesoporous silica shell, are presented by T. Hyeon, W. K. Moon and co-workers in their Communication on page 8438 ff. These multifunctional nanoparticles can be used in simultaneous magnetic resonance and fluorescence imaging and can act as a drug delivery vehicle, thus having potential in cancer diagnosis and therapy.

Research paper thumbnail of Nonblinking and Nonbleaching Upconverting Nanoparticles as an Optical Imaging Nanoprobe and T1 Magnetic Resonance Imaging Contrast Agent

Research paper thumbnail of Uniform mesoporous dye-doped silica nanoparticles as a multifunctional drug carrier for in vivo early tumor diagnosis

Uniform mesoporous dye-doped silica nanoparticles as a multifunctional drug carrier for in vivo early tumor diagnosis

Highly versatile nanocomposite nanoparticles were synthesized by decorating the surface of mesopo... more Highly versatile nanocomposite nanoparticles were synthesized by decorating the surface of mesoporous dye-doped silica nanoparticles with multiple magnetite nanocrystals. The superparamagnetic property of the magnetite nanocrystals enabled the nanoparticles to be used as a contrast agent in magnetic resonance (MR) imaging, and the dye molecule in the silica framework imparted optical imaging modality. Integrating a multitude of magnetite nanocrystals on the silica surface resulted in remarkable enhancement of MR signal due to the synergistic magnetism. An anticancer drug, doxorubicin (DOX), could be loaded in the pores and induced efficient cell death. In vivo passive targeting and accumulation of the nanoparticles at the tumor sites was confirmed by both T2 MR and fluorescence imaging. Furthermore, apoptotic morphology was clearly detected in tumor tissues of mice treated with DOX loaded nanocomposite nanoparticles, demonstrating that DOX was successfully delivered to the tumor sites and its anticancer activity was retained.

Research paper thumbnail of Large-Scale Synthesis of Ultrathin Manganese Oxide Nanoplates and Their Applications to T1 MRI Contrast Agents

Large-Scale Synthesis of Ultrathin Manganese Oxide Nanoplates and Their Applications to T1 MRI Contrast Agents

Chemistry of Materials, 2011

We report on the large-scale synthesis of manganese oxide nanoplates of subnanometer thickness. T... more We report on the large-scale synthesis of manganese oxide nanoplates of subnanometer thickness. The nanoplates were applied to a T1 magnetic resonance imaging contrast agent after ligand exchange. Because of their high surface-to-volume ratio, the longitudinal ...

Research paper thumbnail of Magnetosome-like ferrimagnetic iron oxide nanocubes for highly sensitive MRI of single cells and transplanted pancreatic islets

Proceedings of the National Academy of Sciences, 2011

For ultrasensitive magnetic resonance imaging (MRI), magnetic nanoparticles with extremely high r... more For ultrasensitive magnetic resonance imaging (MRI), magnetic nanoparticles with extremely high r2 relaxivity are strongly desired. Magnetosome-like nanoparticles were prepared by coating polyethylene glycol-phospholipid (PEG-phospholipid) onto ferrimagnetic iron oxide nanocubes (FIONs). FIONs exhibited a very high relaxivity (r2) of 324 mM −1 s −1 , allowing efficient labeling of various kinds of cells. The magnetic resonance (MR) imaging of single cells labeled with FIONs is demonstrated not only in vitro but also in vivo. Pancreatic islet grafts and their rejection could be imaged using FIONs on a 1.5 T clinical MRI scanner. The strong contrast effect of FIONs enabled MR imaging of transplanted islets in small rodents as well as in large animals. Therefore, we expect that MR imaging of pancreatic islet grafts using FIONs has the potentials for clinical applications. Furthermore, FIONs will enable highly sensitive noninvasive assessment after cell transplantation.

Research paper thumbnail of Large-Scale Synthesis of Uniform and Extremely Small-Sized Iron Oxide Nanoparticles for High-Resolution T 1 Magnetic Resonance Imaging Contrast Agents

Journal of the American Chemical Society, 2011

Magnetic resonance imaging (MRI) is one of the most powerful medical diagnosis tools because MRI ... more Magnetic resonance imaging (MRI) is one of the most powerful medical diagnosis tools because MRI can provide images with excellent anatomical details based on the soft tissue contrast and functional information in noninvasive and real-time monitoring manner. 1,2 The sensitivity of MRI can be greatly improved by the contrast agents that enhance the contrast of the region of interest from background. The MRI contrast agents are generally categorized according to their effects on longitudinal (T 1 ) and transversal (T 2 ) relaxations, and their ability is referred to as relaxivity (r 1 , r 2 ). The area wherein fast T 1 relaxation takes place appears bright, whereas T 2 relaxation results in the dark contrast in the MR images.

Research paper thumbnail of Large-Scale Synthesis of Bioinert Tantalum Oxide Nanoparticles for X-ray Computed Tomography Imaging and Bimodal Image-Guided Sentinel Lymph Node Mapping

Large-Scale Synthesis of Bioinert Tantalum Oxide Nanoparticles for X-ray Computed Tomography Imaging and Bimodal Image-Guided Sentinel Lymph Node Mapping

Journal of the American Chemical Society, 2011

Ever since Au nanoparticles were developed as X-ray contrast agents, researchers have actively so... more Ever since Au nanoparticles were developed as X-ray contrast agents, researchers have actively sought alternative nanoparticle-based imaging probes that are not only inexpensive but also safe for clinical use. Herein, we demonstrate that bioinert tantalum oxide nanoparticles are suitable nanoprobes for high-performance X-ray computed tomography (CT) imaging while simultaneously being cost-effective and meeting the criteria as a biomedical platform. Uniformly sized tantalum oxide nanoparticles were prepared using a microemulsion method, and their surfaces were readily modified using various silane derivatives through simple in situ sol-gel reaction. The silane-modified surface enabled facile immobilization of functional moieties such as polyethylene glycol (PEG) and fluorescent dye. PEG was introduced to endow the nanoparticles with biocompatibility and antifouling activity, whereas immobilized fluorescent dye molecules enabled simultaneous fluorescence imaging as well as X-ray CT imaging. The resulting nanoparticles exhibited remarkable performances in the in vivo X-ray CT angiography and bimodal image-guided lymph node mapping. We also performed an extensive study on in vivo toxicity of tantalum oxide nanoparticles, revealing that the nanoparticles did not affect normal functioning of organs.

Research paper thumbnail of Innentitelbild: Multifunctional Uniform Nanoparticles Composed of a Magnetite Nanocrystal Core and a Mesoporous Silica Shell for Magnetic Resonance and Fluorescence Imaging and for Drug Delivery (Angew. Chem. 44/2008)

Research paper thumbnail of Multifunctional Uniform Nanoparticles Composed of a Magnetite Nanocrystal Core and a Mesoporous Silica Shell for Magnetic Resonance and Fluorescence Imaging and for Drug Delivery

Angewandte Chemie International Edition, 2008

Research paper thumbnail of Inside Cover: Multifunctional Uniform Nanoparticles Composed of a Magnetite Nanocrystal Core and a Mesoporous Silica Shell for Magnetic Resonance and Fluorescence Imaging and for Drug Delivery (Angew. Chem. Int. Ed. 44/2008)

Angewandte Chemie International Edition, 2008

Core-shell mesoporous silica nanoparticles which consist of a single magnetite nanocrystal core a... more Core-shell mesoporous silica nanoparticles which consist of a single magnetite nanocrystal core and a dye-doped mesoporous silica shell, are presented by T. Hyeon, W. K. Moon and co-workers in their Communication on page 8438 ff. These multifunctional nanoparticles can be used in simultaneous magnetic resonance and fluorescence imaging and can act as a drug delivery vehicle, thus having potential in cancer diagnosis and therapy.

Research paper thumbnail of Nonblinking and Nonbleaching Upconverting Nanoparticles as an Optical Imaging Nanoprobe and T1 Magnetic Resonance Imaging Contrast Agent

Research paper thumbnail of Uniform mesoporous dye-doped silica nanoparticles as a multifunctional drug carrier for in vivo early tumor diagnosis

Uniform mesoporous dye-doped silica nanoparticles as a multifunctional drug carrier for in vivo early tumor diagnosis

Highly versatile nanocomposite nanoparticles were synthesized by decorating the surface of mesopo... more Highly versatile nanocomposite nanoparticles were synthesized by decorating the surface of mesoporous dye-doped silica nanoparticles with multiple magnetite nanocrystals. The superparamagnetic property of the magnetite nanocrystals enabled the nanoparticles to be used as a contrast agent in magnetic resonance (MR) imaging, and the dye molecule in the silica framework imparted optical imaging modality. Integrating a multitude of magnetite nanocrystals on the silica surface resulted in remarkable enhancement of MR signal due to the synergistic magnetism. An anticancer drug, doxorubicin (DOX), could be loaded in the pores and induced efficient cell death. In vivo passive targeting and accumulation of the nanoparticles at the tumor sites was confirmed by both T2 MR and fluorescence imaging. Furthermore, apoptotic morphology was clearly detected in tumor tissues of mice treated with DOX loaded nanocomposite nanoparticles, demonstrating that DOX was successfully delivered to the tumor sites and its anticancer activity was retained.

Research paper thumbnail of Large-Scale Synthesis of Ultrathin Manganese Oxide Nanoplates and Their Applications to T1 MRI Contrast Agents

Large-Scale Synthesis of Ultrathin Manganese Oxide Nanoplates and Their Applications to T1 MRI Contrast Agents

Chemistry of Materials, 2011

We report on the large-scale synthesis of manganese oxide nanoplates of subnanometer thickness. T... more We report on the large-scale synthesis of manganese oxide nanoplates of subnanometer thickness. The nanoplates were applied to a T1 magnetic resonance imaging contrast agent after ligand exchange. Because of their high surface-to-volume ratio, the longitudinal ...