Quantitative application of flow cytometry for the analysis of circulating human T cells: A preclinical pharmacokinetic study

As the application of flow cytometry to a quantitative pharmacokinetic study with adoptive T cell therapy is new, we aimed to investigate the quantitativity of flow cytometry-based analysis for the pharmacokinetic assessment of circulating human T cells in a preclinical study.We evaluated the selectivity, linearity, accuracy, precision, and sensitivity of flow cytometry-based analysis for human CD8⁺ T cells in immunodeficient mouse blood. The CD3/8/45-positive cell population was successfully distinguished from the negative population. Linear regression analysis for the calibration curve showed good linearity and recovery was approximately 100%. Acceptable inter- and intra-day precision and accuracy were observed and the lower limit of quantification (30 cells/50 μL) was validated with acceptable precision and accuracy. Blood concentrations of human CD8⁺ T cells in immunodeficient mice were then evaluated after administration using this method and the time-concentration profile of human T cells in mice was successfully assessed.The present study is the first to clarify the quantitativity of flow cytometry-based analysis for circulating human T cells in animals. The concept of the present study would be applicable to quantitative pharmacokinetics/efficacy or safety analysis of adoptive T cell therapy.     

Nanotoxicology and in vitro studies: the need of the hour

Nanotechnology is considered as one of the key technologies of the 21st century and promises revolution in our world. Objects at nano scale, take on novel properties and functions that differ markedly from those seen in the corresponding bulk counterpart primarily because of their small size and large surface area. Studies have revealed that the same properties that make nanoparticles so unique could also be responsible for their potential toxicity. Nanotechnology is rapidly advancing, with more than 1000 nanoproducts already on the market. Considering the fact that intended as well as unintended exposure to nanomaterials is increasing and presently no clear regulatory guideline(s) on the testing/evaluation of nanoparticulate materials are available, the in vitro toxicological studies become extremely relevant and important. This review presents a summary of nanotoxicology and a concise account of the in vitro toxicity data on nanomaterials. For nanomaterials to move into the applications arena, it is important that nanotoxicology research uncovers and understands how these multiple factors influence their toxicity so that the ensuing undesirable effects can be avoided.     

HER-2受体放射性配体99Tcm-TP1623的制备及其在正常动物体内的分布

目的 探讨HER-2受体放射性配体 ⁹⁹Tc^m-B2-S22-AFA(⁹⁹Tc^m-TP1623)在健康小鼠体内的生物分布和健康家兔体内的动态显像分布.方法 采用氯化亚锡间接法 ⁹⁹Tc^m标记TP1623,3MM色谱纸层析测定 ⁹⁹Tc^m-TP1623标记率,计算其比活度;通过体外稳定性实验、血清蛋白结合实验和油/水分配实验,鉴定标记产品理化性质;研究 ⁹⁹Tc^m-TP1623于1、5、10、30、60和120 min在健康小鼠体内的生物分布特性;通过SPECT显像,结合感兴趣区(ROI)时间-放射性曲线分析,观察 ⁹⁹Tc^m-TP1623在健康家兔体内的动态分布变化.结果 ⁹⁹Tc^m-TP1623标记率为(96.4±0.1)%,比活度为(24.35±0.06)TBq/mmol,室温下放置6 h后放化纯度为(95.03±0.97)%.油/水分配系数P为－(2.51±0.15).小鼠血液放射性清除快,通过肾脏排泄较快,心、肺、肝、肌肉、骨骼等放射性随时间延长逐渐减低,60 min后放射性呈明显低水平,肠道放射性则随时间缓慢增加.脑放射性始终呈最低水平.健康家兔体内 ⁹⁹Tc^m-TP1623血池影消退迅速,主要通过肾脏排泄,见胆囊、肠道排泄影,胃区和颈部未见放射性浓聚,脑组织始终呈低本底.结论 ⁹⁹Tc^m-TP1623制备方法简便,标记率及产品比活度高,体内、外稳定性好,具有优良的动物体内动力学特性.     

[~(125)I]Spiro-I脑靶向脂质体在小鼠体内分布(英文)

研究[125 I]Spiro-I经长循环脂质体(SSL)和脑靶向脂质体(SSTL)包载后的组织分布, 尤其考察其脑摄入。采用薄膜超声分散法制备[125 I]Spiro-I脂质体, RMP-7通过共价键连在DSPE-PEG上进一步形成靶向脂质体。[125 I]Spiro-I-SSL及 SSTL的包封率分别为97.47%±4.01%, 93.02%±2.98%, 粒径分别为(66.47±0.76) nm, (71.40±0.45) nm。给药后, [125 I]Spiro-I迅速从血液中清除, 长循环组延长了药物在血液中的保留时间, RMP-7提高了[125 I]Spiro-I的脑摄取量。[125 I]Spiro-I-SSTL组的AUC较游离药物组提高了1.52倍。SSTL有望拓展显像剂在中枢神经系统的应用。     

抗前列腺特异膜抗原单克隆抗体的标记及在荷瘤裸鼠体内的分布研究

目的:研究125I标记的抗前列腺特异膜抗原(PSMA)单克隆抗体(125Ⅰ-Ed-5)及正常小鼠IgG(125Ⅰ-NMIgG)在荷人前列腺癌瘤裸鼠体内的分布,探讨应用125Ⅰ-Ed-5进行放射免疫显像诊断和放射免疫治疗实验性人前列腺癌的可行性.方法:建立荷人前列腺癌裸鼠移植瘤模型,用125Ⅰ标记抗PSMA单克隆抗体Ed-5和NMIgG,125Ⅰ-Ed-5和125Ⅰ-NMIgG经尾静脉注入荷瘤裸鼠体内,于注射后24、48、72、120小时分批处死,测定肿瘤和血液、肝、肺等重要脏器的单位重量放射性比值(T/NT)、各组织摄取百分比(%ID/g),研究其在荷瘤裸鼠体内的放射性分布情况.结果:125Ⅰ-Ed-5的标记率为72.3%,放射性比活度为55.2MBq/mg,放射性化学纯度是90.2%,免疫活性分数为63%.在注射125Ⅰ-Ed-5后24～120小时内,裸鼠体内肿瘤部位出现选择性放射性浓聚:各组织的T/NT比值在72h达到最高,其中肿瘤/肌肉高达6.36.而在注射125Ⅰ-NMlgG的对照组中,裸鼠体内未见放射性浓聚,呈全身均匀性分布.结论:标记后的125Ⅰ-Ed-5免疫活性没有改变,在裸鼠体内对前列腺癌移植瘤有靶向定位作用,为进一步应用125Ⅰ-Ed-5进行前列腺癌放射免疫显像和放射免疫治疗的实验研究奠定基础.     

放射性碘化IBZM在大鼠体内的分布与代谢

多巴胺D2受体显像的研究是近几年来研究的热点,多巴胺D2受体显像剂是进行多巴胺D2受体显像的必备条件.作者利用新近合成的(s)-BZM进行放射性碘化标记制备具有与多巴胺D2受体高亲和力和高特异性的放射性配体IBZM,并研究其在大鼠体内的生物学分布和在有关组织中的代谢行为.放射性碘化IBZM的大鼠体内生物分布采用常规的方法进行;代谢研究则按照自行设计的离心萃取和硅胶薄层层析技术进行.结果显示 :放射性碘化IBZM在多巴胺D2受体富集的脑组织中分布较高,并且其有机萃取相的放射性成分主要是原形产物(RCP≥90%),而周围非多巴胺D2受体富集的脑区放射性分布较低, 放射性清除也快.由此提示放射性碘化IBZM是一种较理想的SPECT中枢多巴胺D2受体显像剂 .在其显像研究中,需封闭甲状腺.