• 대한핵의학회지
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• 제28권1호
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• pp.106-111
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• 1994

2-iminothiolane is known to bind $NH_2$ group of lysine in the protein and deliver SH group, which can be used to label protein with $^{99m}Tc$. In this study, we looked for the best reaction condition in which 2-iminothiolane is conjugated to human polyclonal IgG and labeling condition with $^{99m}Tc$-glucoheptonate. Labeling yield was measured with TSK G4000SW column and HPLC or precipitation with 10% TCA (trichloroacetic acid) and 1% HSA. In vivo distribution was investigated with Staphylococcal abscess bearing rats. With decreasing glucoheptonate, the labeling yield decreased. Without 2-iminothiolane, $^{99m}Tc$-glucoheptonate was bound to IgG, which seemed to be direct labeling. With increasing 2-iminothiolane upto 20 times higher than IgG, the labeling yield increased, and plateau was seen with higher molar excess of 2-iminothiolane. Polymer formation was not observed. The pH for the conjugation of 2-iminothiolane and IgG was best around 6.4. $^{99m}Tc$-2-iminothiolane-IgG showed faster blood clearance, higher renal activity and lower hepatic and splenic activity than $^{99m}Tc$-DTPA-IgG. The biodistribution of $^{99m}Tc$-2-iminothiolane-IgG with higher molar excess of 2-iminothiolane was not different from that with lower molar excess. Labeling antibodies with $^{99m}Tc$ using 2-iminothiolane can afford a possible route to simple labeling and wide clinical use of the immunoscintigraphy.

• Nuclear Engineering and Technology
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• 제34권2호
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• pp.146-153
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• 2002

To radiolabel bioactive molecules, we synthesized $^{99m}$Tc-tricarbonyl precursor, [$^{99m}$Tc(CO)$_3$($H_2O$)$_3$]$^{+}$ with a low oxidation state ( I ). The [$^{99m}$Tc(CO)$_3$($H_2O$)$_3$]$^{+}$ was prepared by low pressure carbonylation (1 atm of CO) of [$^{99m}$Tc $O_4$)]$^{[-10]}$ in the presence of NaB $H_4$ resulting in higher than 98% of labeling yield and stability up to 8 hrs. We evaluated the characteristics of $^{99m}$Tc- tricarbonyl labeled bioactive molecules by carrying out in vitro and in vitro study. Prepared [$^{99m}$Tc(CO)$_3$($H_2O$)$_3$]$^{+}$ was then reacted with some ligands of significance in modem diagnostic nuclear medicine and some amino acids. Labeling yields were checked by HPLC and found to be usually high, excluding $^{99m}$Tc-tricarbonyl-MDP, -EDTMP and -mIBG. And the biodistribution properties of $^{99m}$Tc-tricarbonyl complexes applied in rabbit showed different appearance comparing with that of the $^{99m}$Tc-labeling by conventional means. From these results, we conclude that [$^{99m}$Tc(CO)$_3$($H_2O$)$_3$]$^{+}$ is a potential precursor for development of radiopharmaceuticals, especially for labeling of biomolecules.

• 대한핵의학회지
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• 제27권2호
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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.

• 핵의학기술
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• 제16권2호
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• pp.131-134
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• 2012

핵의학검사에서 방사성의약품의 표지효율은 검사의 정확성과 신뢰성 측면에서 중요하다. 보통 Brain SPECT검사에 사용되는 $^{99m}Tc$-HMPAO는 화학적으로 불안정하고 불순물의 발생이 많아 표지효율의 저하가 나타나기 쉽다. 이에 본 연구는 $^{99m}Tc$-HMPAO의 표지효율에 영향을 미치는 인자에 대한 실험을 통해 $^{99m}Tc$-HMPAO 표지 및 사용에 도움이 되고자 한다. Brain SPECT에 사용되는 국산 동아제약의 HMPAO vial을 대상으로 실험하였다. 삼영사의 generator 55.5 GBq (1,500 mCi)를 이용하였고, TLC 측정세트(ITLC-SG, butanone, saline, TLC chamber)와 Radio-TLC 스캐너(Bioscan, AR-2000)를 이용하였다. 첫 번째 실험은 generator에서 1, 8, 16, 24, 28시간 간격을 두고 용출한 $^{99m}Tc$-pertechnetate를 각각 HMPAO와 표지하여 표지효율을 측정하였다. 두 번째 실험은 generator에서 용출한 $^{99m}Tc$-pertechnetate를 0, 1, 3, 6시간경과에 따라 1.85GBq (50mCi)/1 ml를 취하여 HMPAO와 표지하여 표지효율을 측정하였다. 세 번째는 $^{99m}Tc$-HMPAO를 표지 후 0, 30분, 3시간, 5시간, 7시간이 경과했을 때 표지효율을 측정하였다. 첫 번째 실험에서 표지효율은 시간 순으로 95.05%, 94.64%, 94.94%, 95.64%, 96.76%로 나타났다. 두 번째 실험에서는 94.38%, 94.23%, 93.26%, 91.03%로 나타났다. 세 번째 실험에서는 95.76%, 94.17%, 88.19%, 83.6%, 76.86%로 나타났다. 첫 번째 실험에서 generator에서 24시간 후에용출한 $^{99m}Tc$-pertechnetate를 사용 한 표지효율은 비교적 높게 측정되었다. 추가실험을 통하여 임상에서의 사용 가능성에 대한 논의가 필요할 것으로 사료된다. 두 번째 실험에서 시간이 지날수록 표지효율은 다소 감소하였으나 6시간 이후에도 91% 이상으로 높게 측정되었다. 보충실험을 통하여 보완이 필요할 것으로 판단된다. 세 번째 실험에서 시간이 흐를수록 표지효율은 급격하게 감소하였다. 특히, 정확한 검사를 위해 표지후 3시간 이내에 사용하는 것이 좋다고 판단된다.

• 대한핵의학회지
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• 제30권3호
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• pp.361-366
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• 1996

본 연구는 $^{99}Mo-^{99m}Tc$ 발생기시스템에서 용출될 수 있는 알루미늄이 $^{99m}Tc$-MDP의 표지효율과 생체내 분포에 어떤 영향을 미치는지를 보기 위한 실험이다. 알루미늄이온 농도 ($0-62.5{\mu}g/ml$)를 증가시킬수록 $^{99m}Tc$-MDP의 표지효율은 급격히 떨어지며 상대적으로 $^{99m}Tc$ pertechnetate와 hydrolyzed reduced $^{99m}Tc$ 부위의 상대적인 양은 증가되었다. $^{99m}Tc$-MDP는 알루미늄 존재하에서도 상당히 안정하였다. 알루미늄에 의해 $^{99m}Tc$-MDP 반응물이 교질을 형성하는지를 보기 위해 $0.22{\mu}m$ syringe filter로 여과한 액은 여과하지 않은 것과 유의한 차이를 나타내지 않았다. 마우스에 대한 생체내 분포실험은 알루미늄에 의해 $^{99m}Tc$-MDP의 표지효율이 떨어지고 $^{99m}Tc$ pertechnetate의 증가로 인해 혈액과 심장의 흡수는 증가하나 간과 뼈의 흡수는 별다른 차이를 나타내지 않았다. 랫트의 골스캔에서는 $5{\mu}g/ml$의 알루미늄농도에서는 영상의 차이가 없으나 $10{\mu}g/ml$ 농도에서는 하복부의 흡수가 높게 나타났다. 이상의 결과는 알루미늄이 $^{99}Mo-^{99m}Tc$ 발생기시스템 칼럼의 용출제한량인 $10{\mu}g/ml$이하에서도 MDP의 표지효율에 상당한 영향을 미칠 수 있다는 것을 보여준다. 따라서$^{99m}Tc$-MDP 골스캔시 연조직에의 흡수가 보이는 경우에도 방사성의약품의 방사화학적 순도에 대한 정도관리가 충분히 이루어 졌다면 $^{99}Mo-^{99m}Tc$ 발생기시스템에서 용출되는 알루미늄에 의한 영향은 배제될 수 있다.

• Archives of Pharmacal Research
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• 제27권9호
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• pp.961-967
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• 2004

The development of an antibody labeling method with $^{99m}$Tc is important for cancer imaging. Most bifunctional chelate methods for $^{99m}$Tc labeling of antibody incorporate a $^{99m}$Tc chelator through a linkage to lysine residue. In the present study, a novel site-specific $^{99m}$Tc labeling method at carbohydrate side chain in the Fc region of 2 antibodies (T101 and rabbit anti-human serum albumin antibody (RPAb)) using dihydrazinophthalazine (DHZ) which has 2 hydrazino groups was developed. The antibodies were oxidized with sodium periodate to pro-duce aldehyde on the Fc region. Then, one hydrazine group of DHZ was conjugated with an aldehyde group of antibody through the formation of a hydrazone. The other hydrazine group was used for labeling with $^{99m}$Tc. The number of conjugated DHZ was 1.7 per antibody. $^{99m}$Tc labeling efficiency was 46-85％ for T101 and 67∼87％ for RPAb. Indirect labeling with DHZ conjugated antibodies showed higher stability than direct labeling with reduced antibodies. High immunoreactivities were conserved for both indirectly and directly labeled antibodies. A biodistribution study found high blood activity related to directly labeled T1 01 at early time point as well as low liver activity due to indirectly labeled T101 at later time point. However, these findings do not affect practical use. No significantly different biodistribution was observed in the other organs. The research concluded that DHZ can be used as a site-specific bifunctional chelating agent for labeling antibody with $^{99m}$Tc. Moreover, $^{99m}$Tc labeled antibody via DHZ was found to have excellent chemical and biological properties for nuclear medicine imaging.edicine imaging.

• 대한방사성의약품학회지
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• 제3권1호
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• pp.38-43
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• 2017

Tc-99m labeled sestamibi ($^{99m}Tc$-MIBI) is one of most widely used radiopharmaceuticals for myocardial SPECT imaging. Radiolabeling of $^{99m}Tc$-MIBI is recommended by heating in $100^{\circ}C$ water bath for 15 min. However, the water bath might be a source of contamination. Thus, if radiolabeling of $^{99m}Tc$-sestamibi can be performed at room temperature, then it would be more convenient to use in clinical application. In this study, we performed the radiolabeling of $^{99m}Tc$-MIBI in different temperature conditions or using different instruments to find out the efficient labeling condition. We studied the $^{99m}Tc$-MIBI labeling at room temperature or $100^{\circ}C$ heating block, and checked the labelling yields every 1 min for 10 min using radio-TLC with 2 different eluents-saline and acetone. From the experiment, we confirmed that the $^{99m}Tc$-MIBI can be labeled over 90% yield but not completed at room temperature. However, the $^{99m}Tc$-MIBI labeling was completed when it was performed in the $100^{\circ}C$ heating block. Finally, we proved that heating is essential for complete $^{99m}Tc$-MIBI labelling, furthermore using heating block is also possible instead of water bath.

• 핵의학기술
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• 제14권1호
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• pp.90-93
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• 2010

서울아산병원 핵의학과에서는 $^{99m}Tc$-RBC의 표지 효율을 높이기 위한 방법으로 기존의 변형 체외 표지 방법(modified in-vitro)의 일부를 변형하여 개선시킨 AMC 적혈구 표지 방법을 제시한 바 있다. 그러나 AMC 적혈구 표지 방법은 3-5분의 원심분리 과정을 한 번 더 시행함으로써 기존의 변형체외 표지 방법보다 추가적인 노력과 시간을 필요로 한다. 이에 본 연구는 AMC 적혈구 표지 방법을 통한 $^{99m}Tc$-RBC표지 시 교반 시간을 줄임으로써 추가 시간 소요의 문제점을 보완하고 안정적인 표지 효율을 유지하는 것에 목적을 두고 연구를 시행하였다. 2009년 5월부터 9월까지 서울아산병원 핵의학과에서 $^{99m}Tc$-RBC를 사용하여 검사받은 환자를 무작위로 선정하여 실험 참여에 동의한 30명을 대상으로 하였다. 환자당 1 cc의 ACD에 5 cc의 혈액을 채취하여 4개의 혈액 샘플을 만들었으며, AMC적혈구 표지 방법을 사용하여 표지를 진행하였다. 이때 교반시간을 5분, 10분, 15분, 20분으로 다르게 하여 각각의 표지효율을 산출하였고 그에 따른 차이를 비교하였다. AMC 적혈구 표지 방법을 사용하여 교반 시간 차이에 따른 $^{99m}Tc$-RBC 표지 효율을 비교한 결과, 각각의 표지 효율은 5분에서 $92.3{\pm}5.0%$, 10분에서 $95.9{\pm}5.0%$, 15분에서 $97.4{\pm}4.9%$, 20분에서 $97.7{\pm}4.8%$였다. 일원분산분석(One- Way ANOVA)을 사용하여 교반 시간 변화에 따른 표지 효율의 차이를 분석하고, Duncan 방법으로 사후 검증하였다. 5분의 교반 시간에서는 표지 효율이 상대적으로 낮았으며, 그 이상에서의 표지 효율은 통계학적으로 유의한 차이가 없었다. AMC 적혈구 표지 방법은 기존의 변형 표지 방법과 비교할 때 원심분리 과정을 한 번 더 거쳐 혈장 성분을 제거함으로써 RBC가 $^{99m}TcO4^-$와 결합하는 데 더 유리한 환경을 제공할 수 있다. 변형 체외 표지 방법을 사용할 경우 20분 정도의 교반 시간을 주어야 안정적인 표지 효율을 획득할 수 있는 반면, AMC 적혈구 표지 방법을 적용할 경우 교반 시간을 10분만 시행하여도 해당 검사에서 원하는 충분한 표지효율을 얻을 수 있었다. 교반 시간의 감소는 원심 분리 과정을 한 번 더 거쳐야 하는 AMC 적혈구 표지 방법을 보완할 수 있으며, 보다 빠른 시간 내에 $^{99m}Tc$-RBC의 표지를 가능하게 하여 G-I bleeding과 같은 응급 환자에게 좀 더 빠른 검사를 제공할 수 있을 것이라 사료된다.

• Journal of Microbiology and Biotechnology
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• 제18권9호
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• pp.1599-1605
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• 2008

Biodistribution and lymphoscintigraphy of cyclosporine A (CyA) and technetium-99m ($^{99m}Tc$) were studied using ${^99m}Tc$-labeled dextran acetate (DxA) including CyA. DxA particles were prepared from dextran with acetic anhydride, and CyA was loaded into them. Lymphatic delivery of ${^99m}Tc$-labeled DxA particles containing CyA was evaluated after subcutaneous injection into the foot pad of rats and compared with those of ${^99m}Tc$-labeled human serum albumin (HSA). The labeling efficiency of CyA-loaded ${^99m}Tc$-DxA particles was about 95% at 30 min. The labeling efficiency maintained stably above 80% for 12 h. The percent injected dose (%ID) of CyA-loaded ${^99m}Tc$-DxA was similar to that of ${^99m}Tc$-HSA at the inguinal lymph node after 40 min. The CyA-loaded ${^99m}Tc$-DxA could be as well distributed as ${^99m}Tc$-HSA through the lymph node. The DxA particles could steadily distribute the CyA as well as the ${^99m}Tc$ radiolabeling through the lymph node.

• 대한핵의학회지
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• 제29권1호
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• pp.110-117
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• 1995

Tc-99m Labeled hexamethylenepropyleneamineoxime ([$^{99m}Tc$]-HMPAO) is a famous amino-oxime compound and is widely used to construct SPECT images of cerebral blood flow. To investigate the relationship between chemical structure and radiolabeling in these kind of diamine-oxime compounds, we synthesized seven compounds by Schiff's base formation and successive reduction with sodium borohydride. They were (RR/SS )-4,8-diaza-3,6,6,9-tetramethylundecane-2,10-dione bisoxime (2), (RR/SS/meso)-4,8-diaza-3,9-dimethy-lundecane-2,10-dione bisoxime (4), (RR/SS/meso)-4,8-diaza-3,10-dimethyldodecane-2,11-dione bisoxime (5), (RR/SS/meso)-4,7-diaza-3,6,6,8-tetramethyldecane-2,9-dione bisoxime (8), (RR/SS/meso)-4,7-diaza-5,6-cyclohexyl-3,8-dimethyldecane-2,9-dione bisoxime (10), (RR/SS/meso)-3,4-bis(1-aza-2-methyl-3-oxime-1-butyl)-benzoic acid (12), and (RR/SS/ meso)-2,3-bis(1-aza-2-methyl-3-oxime-1-butyl) benzophenone (14). Chemical structures of all the synthesized compounds were identified by taking $^1H$ spectrum. Among them, 2 and 4 are propyleneamine oxime (PnAO), 6 is butyleneamine oxime (BnAO) and 8, 10, 12 and 14 are ethyleneamine oxime (EnAO). Each compound (0.5 mg) was incubated with stannous chloride (0.5 g - 8 g), carbonate-bicarbonate buffer (final concentration = 0.1 M, pH 7 - pH 10) and Tc-99m-pertechenate (1 ml). Tc-99m labeling of these compounds were checked by ITLC (acetone), ITLC (normal saline), reverse phase TLC (50 % acetonitrile) and ITLC (ethyl acetate). According to the results, EnAO's were not labeled by Tc-99m in any of above condition. About 11 % of maximum labeling efficiency was obtained with BnAO. However, 4 (PnAO) was labeled with Tc-99m to 85 % which is similar to the labeling efficiency of 2 (HMPAO). Hydrophilic impurity (9 % ) was the most significant problem with the labeling of 4, however, pertechnetate (3 % ) and colloid (3 %) were minor problem. In conclusion, we synthesized seven diamine blsoxlme compounds. Among them, four EnAO compounds were not labeled by Tc-99m. A BnAO was labeled poorly and two PnAO's were labeled well. These labeling can be explained by tertiary structure of their Tc-99m chelate.