title: PEGylated carboxymethyl chitosan/calcium phosphate hybrid anionic nanoparticles mediated hTERT siRNA delivery for anticancer therapy.
abstract: Lack of safe and effective delivery vehicle is the main obstacle for siRNA mediated cancer therapy. In this study, we synthesized a pH-sensitive polymer of PEG grafted carboxymethyl chitosan (PEG-CMCS) and developed anionic-charged hybrid nanoparticles of PEG-CMCS and calcium phosphate (CaP) for siRNA delivery through a single-step self-assembly method in aqueous condition. The formed nanoparticles with charge of around -8.25 mv and average diameter of 102.1 nm exhibited efficient siRNA encapsulation and enhanced colloidal and serum stability. The test in vitro indicated that the nanoparticles entered into HepG2 cells by endocytosis, and achieved endosomal escape of siRNA effectively due to the pH-responsive disassembly of nanoparticles and dissolution of CaP in the endosome. Reporter gene silencing assay showed that luciferase siRNA delivered by the anionic nanoparticles could achieve gene silencing efficacy comparable to that of conventional Lipofectamine 2000. Additionally, dramatic hTERT knockdown mediated by the anionic nanoparticles transfection induced significant apoptosis of HepG2 cells in vitro. After intravenous injection in tumor-bearing BALB/c nude mice, the nanoparticles specifically accumulated into tumor regions by EPR effect, leading to efficient and specific gene silencing sequentially. Most importantly, the nanoparticles carrying hTERT siRNA inhibited tumor growth significantly via silencing hTERT expression and inducing cells apoptosis in HepG2 tumor xenograft. Moreover, comprehensive safety studies of the nanoparticles confirmed their superior safety both in vitro and in vivo. We concluded that the PEG-CMCS/CaP hybrid anionic nanoparticles possessed potential as a safe and effective siRNA delivery system for anticancer therapy.
authors.affiliation: Department of Pharmaceutics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Pharmaceutics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Hongzhi
authors.initials: H
authors.lastname: Qiao
authors.affiliation: Department of Pharmaceutics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Zhigui
authors.initials: Z
authors.lastname: Su
authors.affiliation: Department of Pharmaceutics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Minglei
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Pharmaceutics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Qineng
authors.initials: Q
authors.lastname: Ping
authors.affiliation: Department of Pharmaceutics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China. Electronic address: sun_minjie@163.com.
authors.forename: Minjie
authors.initials: M
authors.lastname: Sun
mesh_terms: D000818:Animals; D000838:Anions; D017209:Apoptosis / Q000235:genetics; D002130:Calcium Phosphates / Q000737:chemistry*; D048271:Chitosan / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D004705:Endocytosis; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D018014:Gene Transfer Techniques; D056945:Hep G2 Cells; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D008027:Light; D008156:Luciferases / Q000378:metabolism; D008163:Luminescent Measurements; D008819:Mice, Nude; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009369:Neoplasms / Q000473:pathology / Q000628:therapy*; D010316:Particle Size; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000378:metabolism; D012542:Scattering, Radiation; D055672:Static Electricity; D019098:Telomerase / Q000235:genetics / Q000378:metabolism*; D014018:Tissue Distribution; D023041:Xenograft Model Antitumor Assays
chemical_list: D000838:Anions; D002130:Calcium Phosphates; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C514968:carboxymethyl-chitosan; D048271:Chitosan; C020243:calcium phosphate; D008156:Luciferases; D019098:Telomerase
keywords: Anionic nanoparticles; Calcium phosphate; Cancer therapy; hTERT; siRNA delivery