Jun 30, 2020

Xiuping Pang,1,* Shuang Liang,1,* Tianqi Wang,1 Shuangjiang Yu,2 Rui Yang,1 Teng Hou,1 Yongjun Liu,1 Chaoliang He,2 Na Zhang1 1Department of Pharmaceutics, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong Province 250012, People’s Republic of China; 2Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People’s Republic of China *These authors contributed equally to this work Correspondence: Chaoliang He; Na Zhang Email clhe@ciac.ac.cn; zhangnancy9@sdu.edu.cn Purpose: Combined chemotherapeutic drug and protein drug has been a widely employed strategy for tumor treatment. To realize both tumor accumulation and deep tumor penetration for drugs with different pharmacokinetics, we propose a structure-transformable, thermo-pH dual responsive co-delivery system to co-load granzyme B/docetaxel (GrB/DTX). Methods: Thermo-sensitive hydrogels based on diblock copolymers (mPEG-b-PELG) were synthesized through ring opening polymerization. GrB/DTX mini micelles (GDM) was developed by co-loading these two drugs in pH-sensitive mini micelles, and the GDM-incorporated thermo-sensitive hydrogel (GDMH) was constructed. The thermo-induced gelation behavior of diblock copolymers and the physiochemical properties of GDMH were characterized. GDMH degradation and deep tumor penetration of released mini micelles were confirmed. The pH-sensitive disassembly and lysosomal escape abilities of released mini micelles were evaluated. In vitro cytotoxicity was studied using MTT assays and the in vivo antitumor efficacy study was evaluated in B16-bearing C57BL/6 mice. Results: GDMH was gelatinized at body temperature and can be degraded by proteinase to release mini micelles. The mini micelles incorporated in GDMH can achieve deep tumor penetration and escape from lysosomes to release GrB and DTX. MTT results showed that maximum synergistic antitumor efficacy of GrB and DTX was observed at mass ratio of 1:100. Our in vivo antitumor efficacy study showed that GDMH inhibited tumor growth in the subcutaneous tumor model and in the post-surgical recurrence model. Conclusion: The smart-designed transformable GDMH can facilitate tumor accumulation, deep tumor penetration, and rapid drug release to achieve synergistic chemo-protein therapy. Keywords: structure-transformable, thermo-pH dual responsive, hydrogel, chemo-protein combination therapy This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License . By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms .