多西紫杉醇-雙氫青蒿素偶聯前藥自組裝納米粒的穩定性、體外釋放特征及組織分布

李玉潔 李寧 王蓉蓉 張淑秋 任國蓮

中圖分類號 R917;R965 文獻標志碼 A 文章編號 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）-雙氫青蒿素（DHA）偶聯前藥自組裝納米粒（DTX-S-S-DHA NPs）的穩定性、體外釋放特征及組織分布。方法：采用高效液相色譜法進行DTX-S-S-DHA的體外分析;以粒徑、多分散系數（PDI）和包封率（EE）為評價指標，考察DTX-S-S-DHA NPs在不同介質[水、生理鹽水、磷酸鹽緩沖液（PBS，pH 7.4）和RPMI 1640培養基]中的物理穩定性和長期穩定性;以含或不含10 mmol/L二硫蘇糖醇（DTT）的30%乙醇溶液為釋放介質，采用小杯法考察DTX-S-S-DHA NPs中DTX-S-S-DHA的體外釋放特征;采用小動物活體成像儀考察經DiR染料標記的DTX-S-S-DHA NPs（DTX-S-S-DHA/DiR NPs）在乳腺癌荷瘤模型小鼠組織中的分布以及腫瘤靶向性。結果：在穩定性實驗中，DTX-S-S-DHA NPs在水、生理鹽水、PBS、RPMI 1640培養基中振蕩24 h內，其粒徑、PDI、EE均無明顯變化;在4 ℃條件下保存時，隨著保存時間的增加，其在生理鹽水中的粒徑逐漸增大，在PBS中的粒徑逐漸減小，且在兩者中的EE逐漸降低至75%以下，而在水和RPMI 1640培養基中的粒徑、PDI、EE均無明顯變化。在體外釋放實驗中，DTX-S-S-DHA NPs中的DTX-S-S-DHA在含10 mmol/L DTT的釋放介質中基本不釋放;而在不含DTT的釋放介質中，其24 h累積釋放率可達83%，符合一級動力學模型釋放特征。在組織分布實驗中，DTX-S-S-DHA/DiR NPs在小鼠腫瘤組織中的分布明顯多于其他組織（心、肝、脾、肺、腎）。結論：DTX-S-S-DHA NPs在不同介質中均具有良好的物理穩定性，且在水和RPMI 1640培養基中具有良好的長期穩定性;其在還原環境中能迅速釋放出母藥，具有很好的腫瘤靶向性。

關鍵詞 多西紫杉醇;雙氫青蒿素;偶聯前藥;自組裝納米粒;穩定性;體外釋放;組織分布

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.