Antitumor Activity of α-Linolenic Acid-Paclitaxel Conjugate Nanoparticles: In vitro and in vivo

Mei-Qi Xu,1,2 Yan-Li Hao,1,2 Jing-Ru Wang,1,2 Zhuo-Yue Li,1,2 Hui Li,1 Zhen-Han Feng,1,2 Hui Wang,1,2 Jing-Wen Wang,1,2 Xuan Zhang1,2 1Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery Systems, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, People’s Republic of China; 2Department of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, People’s Republic of ChinaCorrespondence: Xuan ZhangDepartment of Pharmaceutics, School of Pharmaceutical Sciences, Peking University, Xueyuan Road 38, Beijing, 100191, People’s Republic of ChinaTel +86-10-82805765Fax +86-10-8280576Email xuanzhang@bjmu.edu.cnPurpose: Small molecule modified antitumor drug conjugate nanoparticles have the advantages of high drug loading, simple synthesis and preparation, and better biocompatibility. Due to the large demand for exogenous α-linolenic acid (ALA) by tumor cells, we synthesized α-linolenic acid-paclitaxel conjugate (ALA-PTX) and prepared α-linolenic acid-paclitaxel conjugate nanoparticles (ALA-PTX NPs), in order to obtain better tumor cellular uptake and antitumor activity in vitro and in vivo.Methods: We synthesized and characterized ALA-PTX, and then prepared and characterized ALA-PTX NPs. The cellular uptake, uptake pathways, intracellular behavior, in vitro and in vivo antitumor activity of ALA-PTX NPs were evaluated.Results: The size of ALA-PTX NPs was approximately 110.7± 1.7 nm. The drug loading was approximately 90% (w/w) with CrEL-free and organic solvent-free characteristics. The cellular uptake of ALA-PTX NPs was significantly higher than that of PTX injection by MCF-7, MCF-7/ADR and HepG2 cells. In these three cell lines, the cellular uptake of ALA-PTX NPs at 6h was approximately 1.5– 2.6 times higher than that of PTX injection. ALA-PTX NPs were ingested through clathrin-mediated endocytosis, then transferred to lysosomes, and could dissolve in cells to play an antitumor activity. The in vitro and in vivo antitumor activity of ALA-PTX NPs was confirmed in MCF-7/ADR and HepG2 cell models and tumor-bearing nude mouse models.Conclusion: ALA-PTX NPs developed in our study could provide a new method for the preparation of nano-delivery systems suitable for antitumor therapy that could increase tumor cellular uptake and enhance antitumor activity.Keywords: α-linolenic acid, α-linolenic acid-paclitaxel conjugate, α-linolenic acid-paclitaxel conjugate nanoparticles, cellular uptake, antitumor activity