• Journal of Pharmaceutical Investigation
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• v.40 no.spc
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• pp.75-82
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• 2010

Specific diseases like cancer and acquired immune deficiency syndrome (AIDS) occur at various organs including lymphatics and spread through lymphatic system. Thus, if therapeutic agents for such diseases are more distributed or targeted to lymphatic system, we can obtain several advantages like reduction of systemic side effect and increase of efficacy. For these reasons, much interest has been focused on the nature of lymphatics and a lot of studies for lymphatic delivery of drugs have been carried out. Because lymphatics consist of single layer endothelium and have high permeability compared with blood capillaries, especially, the studies using nano-sized carriers have been performed. Polymeric nano-particle, liposome, and lipid-based vehicle have been adopted for lymphatic delivery as carriers. According to the administration route and the kind of carrier, the extent of lymphatic delivery efficiency of nano-sized carriers has been changed and influenced by several factors such as size, charge, hydrophobicity and surface feature of carrier. In this review, we summarized the key factors which affect lymphatic uptake and the major features of carriers for achieving the lymphatic delivery. Lymphatic delivery of drug using nano-sized carriers has many fold improved ability of lymphatic delivery compared with that of conventional dosage forms, but it has not shown whole lymph selectivity yet. Even though nano-sized carriers still have the potential and worth to study as lymphatic drug delivery technology as before, full understanding of delivery mechanism and influencing factors, and setting of pharmacokinetic model are required for more ideal lymphatic delivery of drug.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.1-1
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• 2011

We developed a new generalized synthetic procedure, called as "heat-up process," to produce uniform-sized nanocrystals of many transition metals and oxides without a size selection process. We were able to synthesize uniform magnetite nanocrystals as much as 1 kilogram-scale from the thermolysis of Fe-oleate complex. Clever combination of different nanoscale materials will lead to the development of multifunctional nano-biomedical platforms for simultaneous targeted delivery, fast diagnosis, and efficient therapy. In this presentation, I would like to present some of our group's recent results on the designed fabrication of multifunctional nanostructured materials based on uniform-sized magnetite nanoparticles and their medical applications. Uniform ultrasmall iron oxide nanoparticles of <3 nm were synthesized by thermal decomposition of iron-oleate complex in the presence of oleyl alcohol. These ultrasmall iron oxide nanoparticles exhibited good T1 contrast effect. In in vivo T1 weighted blood pool magnetic resonance imaging (MRI), iron oxide nanoparticles showed longer circulation time than commercial gadolinium complex, enabling high resolution imaging. We used 80 nm-sized ferrimagnetic iron oxide nanocrystals for T2 MRI contrast agent for tracking transplanted pancreatic islet cells and single-cell MR imaging. We reported on the fabrication of monodisperse magnetite nanoparticles immobilized with uniform pore-sized mesoporous silica spheres for simultaneous MRI, fluorescence imaging, and drug delivery. We synthesized hollow magnetite nanocapsules and used them for both the MRI contrast agent and magnetic guided drug delivery vehicle.

• Journal of Information Technology Services
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• v.15 no.4
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• pp.25-39
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• 2016

The drone is an unmanned aerial vehicle which has no human pilot. Drones can be classified into military drones, commercial drones, and personal drones by usage. Also, drones can be classified from large-sized to nano-sized drone by size and autonomous, remote controlled drone by control type. Especially, military drones can be classified into low-altitude drones, medium-altitude, and high-altitude drones by altitude. Recently, the drone industry is one of the fast growing industries in the world. As drone technologies have become more advanced and cost-effective, Korean government has set its goal to become a top-level country in drone business. However, the government's strict regulation for drone operations is one of the biggest hurdles for the development of the related technologies in Korea and other countries. For example, critical problems for drone delivery can be classified into technical issues and institutional issues. Technical issues include durability, conditional awareness, grasp and release mechanisms, collision avoidance systems, drone operating system. Institutional issues include pilot and operator licensing, privacy rules, noise guidelines, security rules, education for drone police. This study analyzes the trends of the drone industry from the viewpoint of technology and regulation. Also, we define the business areas of drone utilization. Especially, the drone business types or models for public sector are proposed. Drone services or functions promoting public interests need to be aligned with the business reference model of Korean government. To define ten types of drone uses for public sector, we combine the business types of government with the future uses of drones that are proposed by futurists and business analysts. Future uses of drones can be divided into three sectors or services. First, drone services for public or military sectors include early warning systems, emergency services, news reporting, police drones, library drones, healthcare drones, travel drones. Second, drone services for commercial or industrial services include parcel delivery drones, gaming drones, sporting drones, farming and agriculture drones, ranching drones, robotic arm drones. Third, drone services for household sector include smart home drones.

• Molecular & Cellular Toxicology
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• v.5 no.2
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• pp.172-178
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• 2009

Nanoparticles are small-scale substances (<100 nm) with unique properties, complex exposure and health risk implications. Aluminum oxide ($Al_2O_3$) nanoparticles (NP) have been widely used as abrasives, wear-resistant coatings on propeller shafts of ships, to increase the specific impulse per weight of composite propellants used in solid rocket fuel and as drug delivery systems to increase solubility. However, recent studies have shown that nano-sized aluminum (10 nm in diameter) can generate adverse effects, such as pulmonary response. The cytotoxicity and genotoxicity of $Al_2O_3$ NP were investigated using the dye exclusion assay, the comet assay, and the mouse lymphoma thymidine kinase (tk$^{+/-}$) gene mutation assay (MLA). IC$_{20}$ values of $Al_2O_3$ NP in BEAS-2B cells were determined the concentration of 273.44 $\mu$g/mL and 390.63 $\mu$g/mL with and without S-9. However IC$_{20}$ values of $Al_2O_3$ NP were found nontoxic in L5178Y cells both of with and without S-9 fraction. In the comet assay, L5178Y cells and BEAS-2B cells were treated with $Al_2O_3$ NP which significantly increased 2-fold tail moment with and without S-9. Also, the mutant frequencies in the $Al_2O_3$ NP treated L5178Y cells were increased compared to the vehicle controls with S-9. The results of this study indicate that $Al_2O_3$ NP can cause primary DNA damage and cytotoxicity but not mutagenicity in cultured mammalian cells.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.286-290
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• 2011

Ginsenoside Rg3 was reported to have important biological activities. We demonstrate conjugation and quantification procedures of ginsenoside Rg3 to gold nanoparticles for future biological and medical applications. Ginsenoside Rg3 was conjugated to spherical gold nanoparticles using a bifunctional heptaethylene glycol linker. The sulfhydryl group of heptaethylene glycol was adsorbed onto gold nanoparticles, and carboxylic acid end of heptaethylene glycol was bonded through a hydroxyl group of Rg3 via ester bond formation. The conjugation of Rg3 was characterized with various spectroscopic techniques, high resolution-transmission electron microscopy, and using Rg3 monoclonal antibody. The Rg3- functionalized gold nanoparticles were $4.7{\pm}1.0$ nm in diameter with a surface charge of -4.12 mV. The total number of Rg3 molecules conjugated to a 3.6 mL solution of gold nanoparticle was determined to be $9.5{\times}10^{14}$ corresponding to ~6 molecules of Rg3/gold nanoparticle. These results suggest that ginsenoside Rg3 is successfully conjugated to gold nanoparticles via heptaethylene glycol linker. The quantification was performed by using Rg3 monoclonal antibody without interference of gold's intrinsic color.