【作者】 刘岚；

【导师】 唐萌；

【作者基本信息】 东南大学 ， 劳动卫生与环境卫生， 2004， 硕士

【摘要】 “纳米”是一种度量单位,1nm为10-9m。纳米材料是结构单元尺寸小于100nm的晶体或非晶体。由于结构上的特殊性使得纳米材料具有一些独特效应,如表面效应和小尺寸效应等,从而在实际应用中,表现出优异的性能和全新的功能,如纳米药物控释系统可缓释药物、靶向输送、延长药物作用时间、提高药物的稳定性、减少给药量,致使全身毒性反应降低[1]。以磁性氧化铁为核心的各种纳米颗粒作为恶性肿瘤的靶向治疗剂,靶向性高,疗效好,可望成为今后肿瘤靶向治疗的主要手段之一。本课题组研究发现,谷氨酸修饰的磁性三氧化二铁纳米颗粒(以下称nano-Fe2O3-Glu)具有理化性质稳定、分散度好、磁靶向性能优越、初步动物实验治疗效果好等优点,但其进入人体后对人体的影响尚未见报道,影响了临床的安全、合理用药。本研究由静脉途径给予实验动物nano-Fe2O3-Glu,对其在机体内的安全性及分布情况进行了研究,根据国家药品监督管理局2002年1月制定的《化学药品和治疗用生物制品研究指导原则》(试行),用急性毒性实验(单次给药实验)、长期毒性实验(重复给药实验)研究nano-Fe2O3-Glu对机体的一般毒性情况;在特殊毒理研究中,采用小鼠骨髓细胞微核实验、小鼠精子畸形实验、鼠伤寒沙门氏菌回复突变实验,从细胞水平和基因水平探讨了nano-Fe2O3-Glu的致突变性。通过药物代谢动力学实验,以59Fe为示踪剂,研究nano-Fe2O3-Glu进入机体后的组织分布及血中浓度的变化情况。通过对nano-Fe2O3-Glu急性毒性、长期毒性研究发现,nano-Fe2O3-Glu静脉给药的昆明种小鼠LD50为247.66mg/( kg?bw),参照日本药学会对医药品的毒性分级, nano-Fe2O3-Glu属于“普通药”。对SD大鼠连续14d腹腔注射后,与同性别阴性对照组比较,除各染毒组大鼠的白细胞均数显著升高,其中中性粒细胞比例增高外,高剂量组雌鼠的血小板增多(p<0.05)。此外,高、中剂量组大鼠的肝/体比下降,高剂量组雌鼠的肺/体比升高,高剂量组大鼠、中剂量组雌鼠丙氨酸氨基转移酶(ALT)下降,高剂量组雌鼠的肌酐(Crea)显著升高,但脏/体比及血生化指标的改变仍在正常范围内。光镜检查未见组织病理学改变。为研究nano-Fe2O3-Glu的致突变性,我们进行了Ames实验、小鼠骨髓嗜多染红细胞微核实验及小鼠精子畸形实验,实验结果均为阴性。提示在本实验条件下,尚未发现nano-Fe2O3-Glu具有致突变性。为了了解nano-Fe2O3-Glu进入机体后的代谢分布情况,给临床用药提供依据,我们采用了同位素示踪法,在合成nano-Fe2O3-Glu的同时加入59Fe作为示踪剂,合成终产物经鉴定为直径15nm的nano-59Fe-Fe2O3-Glu。以5.12mg/( kg?bw)小鼠尾静脉给药,分别于0min、10 min、20min、30min、60min、2h、7h、12h、1d、2d、4d、8d、16d、32d、64d处死,取脏器测量放射性计数率值。结果显示,nano-59Fe- Fe2O3-Glu在各脏器中的分布状况及分布峰时不同,其中在肝脏、脾脏中含量较多,脂肪、肌肉、脑组织、性腺、眼球中含量较少,能通过血脑屏障、血睾屏障、血眼屏障。nano-59Fe-Fe2O3-Glu在心脏中出现峰值的时间为7h和2d;在肝脏中的高峰为60min;在脾脏中的分布曲线呈波浪形改变,在20min和12h时浓度较高;肺脏在给药的一瞬间浓度较大,之后迅速下降,处于较低水平,未见明显波动;肾脏放射性在64d的测定中一直稍高于本底,未见规律性改变;脂肪、肌肉、脑、眼<WP=7>球、性腺的放射性处于较低水平,其中脑在24h和34d时达到高峰,眼球在7h达到高峰,性腺的2个峰分别在2d和64d。另取3只昆明种小鼠,以同一剂量经小鼠尾静脉给药,分别于不同时间点眼球取血20μl,测定计数率值,绘制药—时曲线图,计算代谢动力学参数。结果显示,经静脉给药的nano-59Fe-Fe2O3-Glu符合静脉注射双室模型,方程为c=29.09e-4.29t+1.13e-0.009673t。T1/2(α)=0.16h,T1/2(β)=71.65h。 以上结果表明,nano- Fe2O3-Glu静脉给药对哺乳动物毒性较小,未见有致突变性。nano- Fe2O3-Glu在各主要器官中均有分布,其中肝脏、脾脏中分布最多,血液中的分布与肝脏、脾脏中的分布呈消长关系,可以推测肝脏、脾脏为其靶器官。nano-Fe2O3-Glu能通过血脑屏障、血睾屏障和血眼屏障。更多还原

【Abstract】 Nanometer is a kind of scale unit. One nanometer is 10-9 meter. Nanoparticles are crystals or noncrystals which are less than 100 nanometers. Having some novel features, which are not possessed by corresponding routine materials, they promote more medical advances. In recent years, some medicine coring Fe2O3 for magnetic hyperthermia on tumor have made it become a promising useful therapeutic method. But are these medicine safe? What is the process of pharmacokinetics? Conclusive data about them are notably lacking. To explore the safety and pharmacokinetics of nanoparticles of Fe2O3 coated with Glutamic acid(abbreviation: nano-Fe2O3-Glu), whose diameter is 15 nanometers, a series of tests have been conducted, including acute, sub-acute toxicity tests, mutagenicity tests and pharmacokinetics tests. The results are as follows.①In this experiment system the half lethel dose of nano-Fe2O3-Glu after i.v. in mice is 247.66mg/(kg?bw), and after i.p. continuously in rats for 14 days, nano-Fe2O3-Glu have not led to pathological changes although increasing the quantity of leucocyte cells and the ratio of neutrophilic granulocyte.②Compared with the control group, Ames test, micronucleus test and sperm deformity test in mice show that nano-Fe2O3-Glu can not induce reversion of TA97, TA98, TA100 and TA102 bacterial testing system with or without S9mix, the mutation of bone marrow cells and deformity of sperms in mice.③When 59Fe is used as a tracer to investigate the pharmacokinetics of nano-Fe2O3-Glu, after i.v. in mice by 5.12 mg/(kg?bw), nano-Fe2O3-Glu is found to be distributed widely in various organs, and the concentration of liver and spleen is higher than that of other organs. Moreover, the time of peak concentration of every organ is not unanimous. In addition, nano-Fe2O3-Glu can be surveyed to permeate the barriers of brain, eyes and genitals. The time-concentration curve of nano-Fe2O3-Glu is fit mainly to a two-compartment model[c=29.09e-4.29t+1.13e-0.009673t]. Its T1/2(α)equals about to 0.16 hour and T1/2(β)71.65 hours. In a word, we can draw a conclusion that nano-Fe2O3-Glu do not indicate notable toxicity and mutagenicity. Nano-Fe2O3-Glu are distributed widely in various organs especially in liver and spleen, for which liver and spleen can be thought as target organs of nano-Fe2O3-Glu. Besides, the concentration of nano-Fe2O3-Glu in blood is linked to that in liver and spleen. It should be attached importance to the potential toxicity because nano-Fe2O3-Glu can be observed to permeate the barriers of brain, eyes and genitals.更多还原