Doxorubicin Delivered via ApoE-Directed Reduction-Sensitive Polymersomes Potently Inhibit Orthotopic Human Glioblastoma Xenografts in Nude Mice

Jia Ouyang,1 Yu Jiang,2 Chao Deng,2 Zhiyuan Zhong,2 Qing Lan1 1Department of Neurosurgery, The Second Affiliated Hospital of Soochow University, Suzhou, 215004, People’s Republic of China; 2Biomedical Polymers Laboratory, College of Chemistry, Chemical Engineering and Materials Science, and State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, People’s Republic of ChinaCorrespondence: Zhiyuan Zhong; Qing Lan Tel/Fax +86-512-65880098Email szlq006@163.com; zyzhong@suda.edu.cnPurpose: Glioblastoma multiforme (GBM) poorly responds to chemotherapy owing to the existence of blood-brain barriers (BBB). It has been a long desire to develop BBB-permeable vehicles to facilitate drug targeting to GBM.Method and Results: Here, we report that doxorubicin hydrochloride loaded in ApoE peptide-functionalized reduction-sensitive polymersomes (ApoE-PS-DOX) induces potent therapy of orthotopic U-87 MG model in nude mice. ApoE-PS-DOX with varying amount of ApoE (10∼ 30 mol%) all had stable DOX loading and small sizes (< 90 nm). As revealed by flow cytometry, confocal microscopy, apoptosis and MTT assays, ApoE-PS-DOX with 20 mol.% ApoE induced the best cellular uptake and inhibitory effect to U-87 MG cells, which were much better than the non-targeted PS-DOX and liposomal doxorubicin (Lipo-DOX) used in the clinic. ApoE-PS-DOX revealed a pharmacokinetic profile comparable to PS-DOX but induced considerably better growth inhibition of orthotopically xenografted U-87 MG tumors in nude mice than PS-DOX and Lipo-DOX, leading to significant survival benefits with a median survival time of 44 days, which was almost doubled relative to the phosphate-buffered saline (PBS) group. Moreover, in contrast to mice treated with Lipo-DOX and PS-DOX, ApoE-PS-DOX group exhibited little body weight loss, signifying that ApoE-PS-DOX not only has low side effects but also can effectively inhibit glioblastoma invasion.Conclusion: This ApoE-docked multifunctional polymersomal doxorubicin induces potent and safe chemotherapy of orthotopic U-87 MG model in nude mice offering an alternative treatment modality for GBM.Keywords: apolipoprotein E, polymersomes, doxorubicin, brain tumor, blood-brain barrier