5-HT_(1A)受体拮抗剂~(11)C-WAY-100635的自动化合成

为自动化合成用于5-羟色胺(5-HT_(1A))受体显像~(11)C标记的N-[2-[4-(2-甲氧基苯基)-1-哌嗪基]乙基]-N-2-吡啶基环己烷甲酰胺(~(11)C-WAY-100635),采用自动化合成模块,以去甲基WAY-100635为前体,经甲基化,HPLC纯化和Sep-Pak Plus C18柱去除有机溶剂制得~(11)C-WAY-100635注射液。结果显示,合成方法共耗时约40 min,~(11)C-WAY-100635注射液的未校正放化产率10%~20%,放化纯度97%;静脉注射日本大耳白兔~(11)C-WAY-100635(约111 MBq)后,脑组织放射性摄取显著,且明显高于头颅等其他组织。自动化合成5-HT_(1A)受体显像剂~(11)C-WAY-100635方法简单,反应时间较短,放化纯度高,产率稳定可靠,可在临床中推广应用。     

18F-FLT的制备及其microPET显像

[摘要] 本文制备了增殖显像剂18F-FLT,考察其稳定性及研究其在肿瘤模型鼠的microPET显像。本文以3-N-t-叔丁氧羰基-1-[5’-O-(4,4’-二甲氧基三苯甲基)-2’-脱氧-3’-O-(4-硝基苯磺酰基-β-1)-苏戊呋喃糖]胸腺嘧啶脱氧核苷(N-BOC-FLT)为标记前体进行氟代亲核置换反应,用HPLC检测放射化学纯度（RCP）,进行稳定性研究和正常小鼠体内分布试验和肿瘤模型鼠microPET显像;研究结果 显示RCP〉95%,6h内稳定,正常小鼠体内分布显示,在60min时,肾,脾,肠摄取较多,心,肝,肺,膀胱摄取次之;肿瘤模型鼠microPET显像能够清晰地观察到接种部位的放射性浓聚。     

一种~(99)Tc~m标记的5-HT_(1A)受体显像剂的合成与标记

合成了一种99Tcm标记的5-HT1A受体显像剂。该显像剂先由二硫二氮与6-溴己酰氯结合,再与2-(1-哌嗪)苯甲醚结合,经还原、脱保护反应得到标记前体,再对前体进行99Tcm标记。标记率达90%以上,薄层层析测得标记物放化纯度大于95%。     

肿瘤PET分子探针3-O-(2-~(18)F-氟乙基)-L-多巴的合成及初步生物学评价

正电子类氨基酸显像剂是~(18)F-氟代脱氧葡萄糖(~(18)F-Fluorodeoxyglucose,~(18)F-FDG)在临床肿瘤PET显像应用中的重要补充。针对6-~(18)F-氟-L-多巴(~(18)F-FDOPA)前体制备及标记过程的复杂性,本研究设计合成了一种新型~(18)F标记的氨基酸类肿瘤PET显像剂3-O-(2-~(18)F-氟乙基)-L-多巴(3-O-(2-~(18)Ffluoroethyl-L-DOPA,~(18)F-FEDOPA),并对其内生物分布及肿瘤PET显像进行了评价。以L-多巴(LDOPA)为原料经多步反应合成标记前体化合物N-叔丁氧羰基-(3-O-甲苯磺酸酯乙基-4-O-叔丁氧羰基)-L-多巴甲酯,通过~(18)F亲核取代反应实现放射性标记,经半制备高效液相色谱纯化、盐酸水解、NaOH中和后得到~(18)F-FEDOPA注射液。放化合成时间为90min,放化产率(33±6)%(n=10,衰减校正),放射性比活度为55GBq/μmol,放化纯度99%,4h后测定放化纯度95%,稳定性良好。小鼠体内生物分布表明,~(18)F-FEDOPA主要经肾脏代谢,心脏和脑组织摄取值较低,骨骼摄取随时间无明显变化。microPET/CT显像显示,~(18)F-FEDOPA在H22和S180肿瘤组织有明显摄取;与~(18)F-FDG相比,~(18)FFEDOPA在注射60min时肿瘤与心(或脑)的比值高。因此,~(18)F-FEDOPA有望成为一种新型氨基酸代谢类肿瘤PET显像剂。     

~(99m)Tc标记生长抑素类似物KE108的制备及生物学评价

为了探讨生长抑素类似物~(99m)Tc-HYNIC-KE108用于生长抑素受体阳性肿瘤显像的可行性,本研究设计合成了新型的生长抑素类似物HYNIC-KE108,并进行~(99m)Tc标记,优化标记条件,测定标记物的脂水分配系数和体外稳定性,研究其在正常小鼠及荷瘤鼠体内的生物分布。在优化条件下,~(99m)TcHYNIC-KE108的标记率90%,经Waters Oasis HLB小柱纯化后,放化纯度98%,标记物的脂水分配系数logP为0.43±0.02(n=3),体外稳定性良好。标记物在正常小鼠体内血液清除快,主要通过肾脏代谢,在胃、肺和肝脏中放射性摄取相对较高。荷瘤鼠体内分布结果表明,标记物注入体内4h时在肿瘤中的放射性摄取为(1.14±0.91)%ID·g-1,肿瘤与血、肌肉、心脏的放射性摄取比(T/NT)为1.78、8.14、3.35。本工作为进一步研究~(99m)Tc标记的KE108作为生长抑素受体阳性肿瘤显像剂提供了实验依据。     

~(68)Ga标记放射性药物的制备及应用研究进展

<正>电子发射计算机断层显像(positron emission tomography,PET)为核医学领域的显像方法之一,广泛应用于肿瘤研究,灵敏度高,分辨率佳。近年来,~(68)Ge/~(68)Ga发生器的开发促进了~(68)Ga标记的PET显像药物的研究和应用。~(68)Ga放射性药物主要应用于肿瘤显像,如生长抑素受体、人表皮生长因子受体、叶酸等受体分子的靶向显像;也可用于心肌灌注、肺灌注和通气、炎症和感染显像等。本文主要介绍~(68)Ga标记放射性药物相关的生产,标记涉及的受体及衍生物,以及显像研究等应用进展。     

~(18)F标记多巴胺D2受体显像剂在老龄及正常SD大鼠脑分布研究

为探索多巴胺D2受体与衰老的关系,采用亲核反应制备多巴胺D2受体PET显像剂~(18)F-Fallypride,研究显像剂在老龄及正常SD大鼠的脑分区分布。通过尾静脉注射老龄及正常SD大鼠(3.7 MBq),注射显像剂后15min行microPET显像,勾画纹状体为感兴趣区域,计算其标准化摄取值;PMOD软件对显像图融合分区,定量分析各脑分区标准化摄取值;显像后心室灌注,取全脑,冰冻切片,层厚20μm,苏木素-伊红(HE)染色观察大鼠脑组织结构变化情况。结果表明,~(18)F-Fallypride标记率95%,放化纯度98%,PBS放置2h,放化纯仍大于95%。注射后15min老龄及正常SD大鼠纹状体摄取~(18)F-Fallypride的值分别为(0.58±0.11)%ID/g、(0.39±0.14)%ID/g;PMOD分区正常鼠扣带皮层、岛叶、下丘脑、嗅球、中脑等摄取值(分别为(0.120±0.012)%ID/g、(0.182±0.002)%ID/g、(0.111±0.002)%ID/g、(0.127±0.007)%ID/g、(0.083±0.012)%ID/g)低于老龄SD大鼠((0.154±0.013)%ID/g、(0.344±0.014)%ID/g、(0.244±0.019)%ID/g、(0.263±0.020)%ID/g、(0.216±0.012)%ID/g)(P0.05);HE染色显示老龄SD大鼠部分神经元嗜酸性变或核破碎,偶伴有海绵状变形、层状或局灶性神经元坏死,其余无明显形态学改变。PET显像证实了多巴胺D2受体表达和脑老化之间的相关性,可为进一步深入研究疾病和药效的方法学提供依据。     

多发性硬化症显像剂~(11)C-CIC的合成

自动化合成了靶向髓磷脂(myelin)的PET显像剂4-(4-(4-氨基苯乙烯基)-2,5-二甲氧基苯乙烯基)-[N-甲基-11碳]苯胺(11 C-CIC),通过研究其在小鼠生物体及大鼠大脑中的分布,判断其作为多发性硬化(multiple sclerosis,MS)诊断或疗效评价的可行性。在多功能模块上将11 C-CH3-Triflate直接与前体反应,经HPLC分离、纯化得到11 C-CIC,采用NH小鼠用于研究11 C-CIC的生物学分布,Wistar大鼠行Micro PET/CT显像。11 C-CIC合成效率为55%~65%(n10),放化纯度大于99%,比活度为60GBq/μmol。11 C-CIC的体外稳定性较差,加入10g/L的抗坏血酸能防止其分解。11 C-CIC初始脑摄取为2.78%ID/g,放射性主要通过肝、肾排泄。Micro PET/CT显像表明,大鼠大脑对11 C-CIC摄取较好。结果表明,制备11 C-CIC时需加入抗坏血酸以提高其体外稳定性,11 C-CIC有可能应用于髓鞘斑显像,用于诊断或评价MS的进展。     

~(99)Tc~m(CO)_3-IDA-FAC11的制备及生物分布

放射性核素标记脂肪酸作为心肌代谢显像剂可进行局部缺血定位及评价梗塞区心肌的活力。在SPECT显像药物中,锝[99Tcm]药物占有主导地位,因此,99Tcm标记的心肌脂肪酸代谢显像剂将有非常好的应用前景。本实验对象为二(N-乙酸)-十一烷酸(HOOC(CH2)10N(CH2COOH)2,IDA-FAC11),以[99Tc     

骨显像剂~(99m)Tc-HMDP的合成和标记

~(99m)Tc-HMDP是骨的核素显像剂,具有在骨骼中浓集度高和显像清晰的特点。对原发性及继发性的骨肿瘤或骨质代谢病变,由于具有在血和肌肉内的放射性本底低,通过显像都能获得清晰的图像,临床诊断具有重要意义和价值。为此我们进行了HMDP的合成,用~(99m)Tc进行标记,并对标记化合物进行放射化学纯度鉴定。 HMDP的化学名称为羟甲叉二膦酸二钠盐:Hydroxymethylene sodium diphosphonate,     

多巴胺转运蛋白显像剂11C-β-CFT的全自动化合成

通过对反应条件的优化及合成模块的改进,探索了一种高效、全自动化合成¹¹C-β-CFT的方法。以¹¹CO₂为起始原料与LiAlH₄、HI或HBr反应生成¹¹CH₃I（或¹¹CH₃Br）,再转化成Triflate-¹¹CH₃,最后与nor-β-CFT进行甲基化反应合成¹¹C-β-CFT。整个合成工艺实现了全自动化,产品校正放化产率为70.2%±1.8%,放化纯度大于95%。用新方法合成的¹¹C-β-CFT无菌注射液经pH测定、HPLC检测、内毒素检查、细菌培养及异常毒性检查,均符合注射液要求。用制备的¹¹C-β-CFT对正常志愿者与帕金森病患者进行PET显像,PET显像显示正常对照者双侧纹状体影像清晰,帕金森病患者双侧纹状体不对称性摄取减低。该工艺实现了¹¹C-β-CFT全自动化,放化产率高,工艺简单,有利于工作人员放射防护,显像效果良好,可满足临床需要。     

Semi-automated synthesis, validation and microPET imaging of 18F-FP-DTBZ as a vesicular monoamine transporter ligand

This work was to develop a semi-automated synthesis of 18F-9-fluoropropyl-9-desmethyl-DTBZ (18F-FP-DTBZ) and validate its potential as a vesicular monoamine transporter 2 (VMAT2) ligand.18F-FP-DTBZ was synthesized by a semi-automated procedure in a 21-35% yield without decay correction and with a radiochemical purity of >98%.Bioistribution in rats exhibited a favorable brain uptakes of the ligand (0.31±0.04 ID% at 60min post injection,n=8).The highest radioactivity located in VMAT2 enriched striatal tissue.The target-to-nontarget ratio (striatum/cerebellum,ST/CB) was 4.81±0.84.Blocking studies implied that striatum uptake could be blocked by DTBZ (a VMAT2 inhibitor) but could not by CFT (a dopamine transporter inhibitor).MicroPET imaging with 18F-FP-DTBZ in normal rats gave high quality images in which high radioactivity were observed in the striatal tissue.Time-and-activity curves revealed good retention in the target (striatum) and rapid clearance in the background (cerebellum),which resulted in a maximum ST/CB ratio of 5.08±0.81 (n=3) in 80-120min.By contrast,the 6-hydroxydopamine unilateral lesioned rats gave asymmetrical striata images with higher 18F-FP-DTBZ concentration on the unlesioned side (unlesioned-ST/CB=5.21±0.38,n=3) than the lesioned (lesioned-ST/CB=2.34±0.51).The results validated that 18F-FP-DTBZ is a favorable PET ligand binding to VMAT2.     

Preparation of 6—[^18F]fluoro—L—DOPA and its biodistribution in normal and unilateral PD model rats

No-carrier-added 6-[18F]fluoro-L-DOPA (6-FDOPA) was synthesized via a multistep procedure from a commercial available precursor, 6-nitroveratraldehyde. The total synthesis time was 75min, with a radiochemical yield of (10±3)%, high radiochemical purity (>99%) and high enantiomeric purity (>95%). The biodistri-butions of 6-FDOPA in normal and unilateral PD model rats were measured. The results from normal rats showed the expected high concentration of radioactivity in striatum and low distributions in cerebrum, cortex and cerebellum. The ratio of the radioactivity in striatum to cerebellum reached a peak value (5.9) at 60min. In unilateral PD model rats, whose substania nigra of the right side had been damaged by pre-treated with 6-OHDA, the radioactive concentration in striatum of the damaged side was significantly lower than that of the undamaged side or that of both sides in striatum of control groups.     

Distribution of Dopamine D2 Receptor PET Imaging Agent 18F-Fallypride in the Brain of Normal and Aged Rats

With the progress of population aging, the incidence of age related disease has greatly increased. The dopamine D2 receptor is closely related to the age-related diseases, such as PD and AD. The PET imaging of the dopamine D2 receptor can provide noninvasive, dynamic, early and quantitative information on the function of the brain. So we intend to prepare dopamine D2 receptor PET imaging agent¹⁸F-Fallypride and to study the disturbution of the agent in the brain of normal and aged rats, further to explore the relationship between dopamine D2 receptor and senility.¹⁸F-Fallypride was prepared by nucleophilic reaction. And the PET image was performed in aged and normal rats 15 minutes after injection of the agent .Striatums were delineated as the region of interesting (ROI), the standard uptake value (SUV) of which was calculated. PMOD was used for image fusion ,partition and quantitative analysis of standard uptake values of each brain area. After imaging, cardiac ventricle was perfused. The brain was obtained and frozen. The contour structure was observed by HE staining.The results showed that the labeling yield was over 95% and the radiochemical purity was higher than 98%. The stability was still over 95% 2 hours after incubation with PBS. The striatum uptake of¹⁸F-Fallypride radioactivity in aged and normal rats 15 minutes after injection were (0.58±0.11)%ID/g, (0.39±0.14)%ID/g. The uptake of cortex cingulate, cortex insular, hypothalamus, olfactory, midbrain in normal rats ((0.120±0.012)%ID/g, (0.182±0.002)%ID/g, (0.111±0.002)%ID/g, (0.127±0.007)%ID/g, (0.083±0.012)%ID/g respectively) were inferior to aged rats ((0.154±0.013)%ID/g, （0.344±0.014）%ID/g, （0.244±0.019）%ID/g, （0.263±0.020）%ID/g, （0.216±0.012）%ID/g), which was displayed by PMOD. HE staining showed severe brain injury in elderly SD rats. Some neurons in the aged SD rats appeared acidophil change or nuclear fragmentation, accompanied by spongy deformation, lamellar or focal neuronal necrosis, and no obvious morphological changes. The relevance between dopamine D2 receptor and senility was demonstrated by PET imaging, which provided a basis for further research on the methodology of disease and pharmacodynamics research.     

PET示踪剂~(11)C-氟马西尼的合成及质量控制

为制备满足临床应用需要的~(11)C-氟马西尼,以~(11)C-CH3I为甲基化试剂,使用国产PET-CM-3H-IT-I型模块对~(11)C-氟马西尼的制备及纯化方法进行改进。用液相法合成~(11)C-CH3I,研究反应溶剂、碱性强度、碱量、反应温度对合成效率的影响,优化~(11)C-氟马西尼的合成条件。优化后的条件为:先将~(11)C-CH3I在室温下通入含1mg去甲基氟马西尼前体和1mg氢化钠的200μL DMF溶液中,加热至55℃恒温反应2min。反应物经半制备HPLC分离收集粗产品,再经SEP-PAK C-18柱固相萃取,对产品质量进行分析。结果表明,以捕获~(11)C-CO2计算,~(11)C-氟马西尼合成时间为(26±2)min,经衰减校正后放化产率为(45±4)%(n=10),产品放化纯度大于99%,放射性浓度为370~550 MBq/mL,比活度为4.7TBq/mmol,产品细菌和热源检测结果符合规定。通过优化反应条件,大幅度提高了标记率,用国产合成模块能够制备高质量、高比活度的~(11)C-氟马西尼,满足临床应用需求。     

The preclinical pharmacological study of dopamine transporter imaging agent ^18F-FP-β-CIT

The paper is to study pharmacologic characteristics of 18F-FP-β-CIT (18F-N-(3-fluoropropyl)-2β-carbomethoxy-3β- (4-iodophenyl)nortropane) as an imaging agent for dopamine transporter. The radiochemical purity of 18F-FP-β-CIT in aqueous solution was over 95% after standing at room temperature for 4h. Biodistribution displayed rapid uptake in rat brain (1.375 %ID/organ at 5min and 0.100 %ID/organ at 180 min) and the striatal uptake was 1.444, 0.731, 0.397, 0.230 and 0.146 %ID/g at 5, 30, 60, 120 and 180 min, respectively. The values of striatum/cerebellum, striatum /frontal cortex and striatum / hippocampus in rat's brain at 30 min were 3.38, 2.17 and 2.40 respectively. The uptake in striatum can be blocked by β-CFT, suggesting that 18F-FP-β-CIT binds to DAT peculiarly. The compound was rapidly cleared from monkey's blood. The striatal uptake was bilaterally decreased in the left-sided lesioned PD rats, compared with normal control. Brain PET imaging studies in normal monkey showed that 18F-FP-β-CIT was concentrated in striatum. The test of undue toxicity showed that the dose received by mice was 1250 times as by human, which indicates that 18F-FP-β-CIT is very safe. So 18F-FP-β-CIT is a promising PET imaging agent for DAT with safety and validity.     

Animal biodistribution, safety and validation study of dopamine transporter PET imaging agent ^18F-FECNT

This work was to investigate the pharmacologic characteristics of 18F-FECNT (2β-carbomethoxy-3β-(4-chlorophenyl)-8-(2-[18F]fluorcethyl)nortropane) as a dopamine transporter (DAT) PET imaging agent.Its partition coefficients were determined in n-octanol and phosphate buffer (PB) (pH 7.0 and pH 7.4).6-Hydroxydopamine (6-OHDA) left-sided lesioned Parkinsonian rats were established and validated by rotational behavior tests.Biodistribution in vivo in mice,autoradiography in normal and hemi-Parkinsonian rat brains,and toxicity test were performed.The results showed that partition coefficients were 34.14 (pH 7.0) and 56.41 (pH 7.4),respectively.Biodistribution exhibited rapid uptake and favorable retention in the mice brains.The major radioactivity was metabolized by the hepatic system.The autoradiography showed that 18F-FECNT was highly concentrated in striaturn,and that the left and the tight striatal uptake were symmetrical in normal SD rat brains.In left-sided lesioned PD rat brains,the striatal uptake of 18F-FECNT bilaterally decreased in comparison with normal rats.No significant uptake was visible in the 6-OHDA lesioned-sided striatal areas.The results demonstrated that 18F-FECNT binds to DAT was specific.Toxicity trial displayed that the acceptable dose per kilogram to mice was 625 times greater than that to human.These indicate that 18F-FECNT is a potentially safe and useful DAT PET imaging agent in the brain.     

Synthesis of 11C-CIC for PET Imaging of Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory neurodegenerative disorder of central nervous system. Imaging of myelin tracts in vivo would greatly improve the diagnosis and monitoring of MS. The ¹¹C-CIC was synthesized with¹¹C-CH₃-Triflate at high yields, and was confirmed by biodistribution and imaging. ¹¹C-CH₃-Triflate was distilled and trapped into a reaction vial containing the 2 mg precursor. The final production was purified by semi-HPLC to get¹¹C-CIC. The in vitro stability of¹¹C-CIC was studied at RT with or without Vc. The normal NH mice were sacrificed at different time after injection of¹¹C-CIC for biodistribution. The micro PET/CT was performed at 30 min post-injection. The radiochemical yield was 55% 65% decay corrected to¹¹CH₃-Triflate. The radiochemical purity was over 99% at specific activity of 60 GBq/μmoL. The HPLC showed the poor stability of¹¹C-CIC in vitro. The¹¹C-CIC was very stable after the 10 g/L Vc used as stabilizer. The initial uptake of the cerebrum was 2.78%ID/g. The radioactivity were excreted from the digestive system and urine. The micro PET/CT imaging showed good uptake in the cerebrum. The stability of¹¹C-CIC can be improved with Vc as stabilizer. The¹¹C-CIC was a candidate for imaging of myelin tracts for diagnosis or monitor MS.     

淀粉样蛋白显像剂~(11)C-PIB的自动化制备优化及临床初步应用

采用国产自动化碘代甲烷仪,通过氢化锂铝/四氢呋喃(LAH/THF)还原法制得的~(11)C-碘代甲烷(~(11)CH3I),在线转换成活性更高的~(11)C-三氟磺酸甲酯(~(11)CH3OTf),通入锥形反应瓶内,和1.0mg PIB前体6-OH-BTA-0丁酮溶液在盐冰浴条件下反应,利用改进的HPLC方法纯化产品,并对最终产品进行质量控制。用昆明小鼠进行急性毒性试验,并行4例临床AD患者及1例正常人PET/CT显像。结果表明,改进后的自动化制备工艺,最终得到可供注射的~(11)C-PIB 10%乙醇溶液,改进后使用前体原料更少,产率稳定。改进后的~(11)C-PIB制备路线稳定可靠,初步临床研究表明,制备的~(11)C-PIB显像剂可以用于阿尔茨海默病诊断。     

~(18)F-Fallypride的比活度对多巴胺D_2受体显像的影响

采用亲核反应制备~(18)F-Fallypride。将不同浓度的~(19)F-Fallypride与~(18)F-Fallypride混匀模拟比活度变化,经尾静脉注射正常小鼠(3.7 MBq)后10min行Micro PET显像,勾画纹状体为感兴趣区域,计算其摄取~(18)F-Fallypride的变化。结果表明,各组纹状体摄取~(18)F-Fallypride的量随比活度降低而降低,摄取值与19F-Fallypride的浓度对数呈S型曲线变化。~(18)F-Fallypride的比活度不低于1.35PBq/mol时,可保证~(18)F-Fallypride PET显像的准确性。结果可见,~(18)F-Fallypride比活度是多巴胺D2受体显像的重要影响因素。