• Macromolecular Research
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• v.11 no.5
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• pp.382-386
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• 2003

Reductive amination of N-succinyl-chitosan (1) and lactose using sodium cyanoborohydride in 1/15 M phosphate buffer (pH 6.0) for 6 d was suitable for the preparation of lactosaminated N-succinyl-chitosan (2). At 8, 24 and 48 h after i.v. administration of fluorescently labeled 1 (1') or 2 (2'), Peyer's patch, mesenteric lymph nodes, testes, prostate, preputial grand, intestine (small intestine plus cecum), femoral muscle, backbone and peritoneum were taken. Peyer's patch and mesenteric lymph nodes were put together as lymph nodes. Over 10% of dose/g tissue was distributed to the prostate and lymph nodes at 48 h post-administration in both l' and 2'.2' was easily distributed into not only the liver but also prostate, intestine, preputial gland and lymph nodes. Although galactose receptors are known to exist not only on the liver parenchymal cells but also on prostate and testes, the selective distribution of 2' into the prostate and the testes were not observed clearly. This study suggested that 1 and 2 should have possibilities for both the prevention and cure of lymph node metastasis as drug carriers.

• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.50-60
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• 1998

I-123 labelled fatty acids are suitable for investigation of regional myocardial metabolism, so they are on the clinical trial. However, the precise properties of these materials are not characterized yet. We have synthesized phenylpentadecanoic acid and labeled this compound with I-123. The purpose of this study was to examine the stability, biodistribution, metabolism and SPECT imaging of [I-123]15-(p-iodophenyl)pentadecanoic acid(I-123-IPPA) that we made. The stability test of I-123-IPPA in serum of rat, mouse and human showed no free I-123 after 1 hour. In biodistribution study in mice for various time intervals after injection(5, 10, 15, 30, 60 minutes), uptake in myocardium was 14.5%ID/g(5 min), and 1.9%ID/heart(5 min), while uptake in muscles was 2.6%ID/g(5 min). Myocardium to blood ratio and myocardium to lung ratio increased for 5 min after injection and then decreased rapidly. Chromatographic data of rat blood and urine showed that little PPA was found in blood and urine at 15-20 min after injection. The myocardial I-123-IPPA SPECT images of a dog with myocardial infarction showed defects similar to those of Tc-99m-MIBI and F-18-FDG. These data suggest that I-123-IPPA is quite stable in vitro and shows favorable biodistribution in mice. SPECT imaging with I-123-IPPA demonstrated infarct zone as photon defect in dog model of myocardial infarction. I-123-IPPA may be used for the evaluation of fatty acid metabolism in clinical trials in Korea.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.105-109
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• 1995

L-3-[$^{123}I$]iodo-${\alpha}$-methyltyrosine([$^{123}I$] IMT) was synthesized by electrophilic radio-iodination using chloramine-T and Iodobead in phosphate buffered solution. And the biodistribution was examined in 9L glioma bearing rats. The radiosynthesis of [$^{123}I$]IMT with iodobead was simpler and higher in radiochemical yield(88%) than the method using chloramine-T(83%) as radioiodinating reagent. The highest yield was obtained from the reaction using 1 piece of Iodobead, $200{\mu}g$ ${\alpha}$-methyltyrosine in $100{\mu}l$ phosphate-buffered solution(pH 5.5) and the reaction was completed in 7min. 24 hours after the injection, the biodistribution in 9L glioma transplanted rats revealed the in vivo deiodination, the excretion via kidney, and 3 times higher uptake in the tumor than normal brain. These results suggest the promising clinical use of [$^{123}I$] IMT in the various malignancies.

• 대한핵의학회:학술대회논문집
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• 2000.05a
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• pp.72.2-72.2
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• 2000

• 대한핵의학회:학술대회논문집
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• 1997.05a
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• pp.185-185
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• 1997

• 대한핵의학회:학술대회논문집
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• 2005.11a
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• pp.322.1-322.1
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• 2005

• The Korean Journal of Nuclear Medicine
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• v.38 no.2
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• pp.121-130
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• 2004

Molecular imaging visualizes cellular processes at a molecular or genetic level in living subjects, and diverse molecular probes are used for this purpose. Radiolabeling methods as well as radioisotopes are very important in preparation of molecular probes, because they can affect the biodistribution in tissues and the excretion route. In this review, the molecular probes are divided into small organic molecules and macromolecules such as peptides and proteins, and their commonly used radiolabeling methods are described.

• IMMUNE NETWORK
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• v.11 no.3
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• pp.163-168
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• 2011

Background: Nanoparticles (NPs) prepared from biodegradable polymers, such as poly (D,L-lactic acid-co-glycolic acid) (PLGA), have been studied as vehicles for the delivery of antigens to phagocytes. This paper describes the preparation of antigen-loaded PLGA-NPs for efficient cross-priming. Methods: NPs containing a similar amount of ovalbumin (OVA) but different sizes were produced using a micromixer-based W/O/W solvent evaporation procedure, and the efficiency of the NPs to induce the cross-presentation of OVA peptides were examined in dendritic cells (DCs). Cellular uptake and biodistribution studies were performed using fluorescein isothiocyanate (FITC)-loaded NPs in mice. Results: The NPs in the range of $1.1{\sim}1.4{\mu}m$ in size were the most and almost equally efficient in inducing the cross-presentation of OVA peptides via $H-2K^b$ molecules. Cellular uptake and biodistribution studies showed that opsonization of the NPs with mouse IgG greatly increased the percentage of FITC-positive cells in the spleen and lymph nodes. The major cell type of FITC-positive cells in the spleen was macrophages, whereas that of lymph nodes was DCs. Conclusion: These results show that IgG-opsonized PLGA-NPs with a mean size of $1.1{\mu}m$ would be the choice of biodegradable carriers for the targeted-delivery of protein antigens for cross-priming in vivo.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.270-276
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• 1993

$Technetium-^{99m}$ labeling method using bifunctional chelating agent cyclic DTPA has been evaluated with human polyclonal nonspecific IgG. IgG was conjugated with cyclic DTPA with various molar ratio. Reduction of $^{99m}Tc$ was done with $Na_2S_2O_4$ with various molar excess. Labeling efficiency and identification of polymer was confirmed with HPLC using TSK4000 SW column. Polymer was purified with 100 cm Sepharose 6LB column. Cultured $1{\times}10^9$ Staphylococcus aureus were injected into rat thigh 24 hours later labeled IgG was injected, and in vivo distribution was observed 4 and 24 hours thereafter. Reduction of $^{99m}Tc$ was optimal with the 10000-50000 times molar excess of $Na_2S_2O_4$. Polymer formation increased with increasing mloar excess of cyclic DTPA to IgG. Three step labeling-labeling DTPA conjugated IgG after reduction of $^{99m}Tc$-made more polymer than two two step labeling-simultaneous mixing DTPA conjugated IgG, $^{99m}Tc$ and $Na_2S_2O_4$. $^{99m}Tc$ blood clearance and lower uptake in the abscess and other organs. IgG conjugated with 200 times molar excess of cyclic DTPA showed slower blood clearance with 200 times molar excess of cyclic DTPA showed slower blood clearance than that of 200 times molar excess of cyclic DTPA showed slower blood clearance than that of 20 times molar excess. In the $^{99m}Tc$ labeling of IgG with cyclic DTPA for the immunoscintigraphy, obtimal labeling condition should be chosen, and effect of the $^{99m}Tc$ labeled IgG polymer should be considered.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.863-871
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• 2015

Bifidobacterium longum subsp. longum BBMN68, isolated from centenarians in Guangxi, China, has been proved to be a promising probiotic strain for its health benefits. In this study, the biodistribution of this strain in the rat gut was first investigated using the quantitative realtime PCR assay and propidium monoazide. Strain-specific primers were originally designed based on the BBMN68 genome sequence. Healthy rats were orally inoculated with either a single dose of BBMN68 (10¹⁰ colony-forming units/kg), or with one dose per day for 7 days and bacterial concentrations were analyzed in detail from the intestinal contents and feces of four different gut locations, including stomach, small intestine, colon, and rectum. Results indicated that strain BBMN68 could overcome the rigors of passage through the upper gastrointestinal tract and transiently accumulate in the colon, even though survival in the stomach and small intestine was not high. A good level of BBMN8 could stay in vivo for 72 h following a 7-day oral administration, and a daily administration is suggested for a considerable and continuous population of BBMN68 to be maintained in the host intestine.