多西紫杉醇-双氢青蒿素偶联前药自组装纳米粒的稳定性、体外释放特征及组织分布

李玉洁 李宁 王蓉蓉 张淑秋 任国莲

中圖分类号 R917;R965 文献标志码 A 文章编号 1001-0408（2021）19-2371-07

DOI 10.6039/j.issn.1001-0408.2021.19.11

摘 要 目的：研究多西紫杉醇（DTX）-双氢青蒿素（DHA）偶联前药自组装纳米粒（DTX-S-S-DHA NPs）的稳定性、体外释放特征及组织分布。方法：采用高效液相色谱法进行DTX-S-S-DHA的体外分析;以粒径、多分散系数（PDI）和包封率（EE）为评价指标，考察DTX-S-S-DHA NPs在不同介质[水、生理盐水、磷酸盐缓冲液（PBS，pH 7.4）和RPMI 1640培养基]中的物理稳定性和长期稳定性;以含或不含10 mmol/L二硫苏糖醇（DTT）的30%乙醇溶液为释放介质，采用小杯法考察DTX-S-S-DHA NPs中DTX-S-S-DHA的体外释放特征;采用小动物活体成像仪考察经DiR染料标记的DTX-S-S-DHA NPs（DTX-S-S-DHA/DiR NPs）在乳腺癌荷瘤模型小鼠组织中的分布以及肿瘤靶向性。结果：在稳定性实验中，DTX-S-S-DHA NPs在水、生理盐水、PBS、RPMI 1640培养基中振荡24 h内，其粒径、PDI、EE均无明显变化;在4 ℃条件下保存时，随着保存时间的增加，其在生理盐水中的粒径逐渐增大，在PBS中的粒径逐渐减小，且在两者中的EE逐渐降低至75%以下，而在水和RPMI 1640培养基中的粒径、PDI、EE均无明显变化。在体外释放实验中，DTX-S-S-DHA NPs中的DTX-S-S-DHA在含10 mmol/L DTT的释放介质中基本不释放;而在不含DTT的释放介质中，其24 h累积释放率可达83%，符合一级动力学模型释放特征。在组织分布实验中，DTX-S-S-DHA/DiR NPs在小鼠肿瘤组织中的分布明显多于其他组织（心、肝、脾、肺、肾）。结论：DTX-S-S-DHA NPs在不同介质中均具有良好的物理稳定性，且在水和RPMI 1640培养基中具有良好的长期稳定性;其在还原环境中能迅速释放出母药，具有很好的肿瘤靶向性。

关键词 多西紫杉醇;双氢青蒿素;偶联前药;自组装纳米粒;稳定性;体外释放;组织分布

Stability， in vitro Release and Tissue Distribution of Docetaxel-dihydroartemisinin Conjugated Prodrug Self-assembled Nanoparticles

LI Yujie，LI Ning，WANG Rongrong，ZHANG Shuqiu，REN Guolian（School of Pharmacy， Shanxi Medical University，Shanxi Jinzhong 030619， China）

ABSTRACT   OBJECTIVE： To study the stability， in vivo release characteristics and tissue distribution of  docetaxel （DTX）- dihydroartemisinin （DHA） conjugated prodrug self-assembled nanoparticles （DTX-S-S-DHA NPs）. METHODS： HPLC method was adopted to analyze DTX-S-S-DHA in vitro. The phycial and long-term stability of DTX-S-S-DHA NPs in mediums [water， saline， phosphate buffer （PBS， pH 7.4） and RPMI 1640 medium] were investigated by using particle size， polydispersity index （PDI） and encapsulation efficiency （EE） as evaluation indexes. The in vitro release characteristics of DTX-S-S-DHA released from DTX-S-S-DHA NPs was also investigated with small glass method， using 30% ethanol solution with or without 10 mmol/L dithiothreitol （DTT） as medium. The small live animal imager was adopted to investigate the tissue distribution and tumor targeting capability of DiR-labeled DTX-S-S-DHA NPs （DTX-S-S-DHA/DiR NPs）in breast cancer bearing mice. RESULTS： In stability test， there was no statistical difference in particle size， PDI and EE of DTX-S-S-DHA NPs incubated in water， normal saline， PBS and RPMI 1640 medium for 24 h. When stored at 4 ℃， with the increase of storage time， the particle size of DTX-S-S-DHA NPs in normal saline gradually increased， while those in PBS gradually decreased; EE of both gradually decreased to less than 75%， but there was no significant change in particle size， PDI and EE of DTX-S-S-DHA NPs in water and RPMI 1640 medium. In the in vitro release experiments， DTX-S-S-DHA in DTX-S-S-DHA NPs was not released in the release medium containing 10 mmol/L DTT; at 24 h， the cumulative release rate of DTX-S-S-DHA released from DTX-S-S-DHA NPs in release medium without DTT was about 83%， which was in line with first-order kinetic model. In tissue distribution test， the distribution of DTX-S-S-DHA/DiR NPs in tumor sites of mice was significantly more than in other tissues （heart， liver， spleen， lung and kidney）. CONCLUSIONS： DTX-S-S-DHA NPs show good physical stability in different mediums， especially have good long-term stability in water and RPMI 1640 medium; they can quickly release the parent drug in the reduction environment and has good tumor targeting.