title: pH-responsive complexes using prefunctionalized polymers for synchronous delivery of doxorubicin and siRNA to cancer cells.
abstract: A nanocarrier delivery system that can simultaneously deliver a chemotherapeutic drug and siRNA to the tumor is emerging as a promising treatment strategy for cancer treatment. In this study, a multifunctional PHD/PPF/siRNA complexes was developed by one-step assembly of prefunctionalized polymers: PEI-HZ-DOX (PHD) and PEI-PEG-Folate (PPF) with siRNA. The PHD, a conjugate of PEI (polyethylenimine) with doxorubicin (DOX) via a pH-responsive hydrazone linkage, enables pH-controlled drug release. The PPF, a tumor-targeting folate ligand conjugated to PEI using polyethyleneglycol (PEG) as a linker, enables immune evasion and cell-specific targeting. The prefunctionalized PHD and PPF as well as the self-assembly complexes reveals advantage on safety in further application for siRNA delivery. By exploiting distinct triple ratios of PHD, PPF and siRNA during nanocomplexes formulation, the folate surface density, DOX loading amount and siRNA complexation can be precisely and reproducibly changed. The studies showed that the complexes was capable of delivering siRNA and DOX to cancerous cells and release synchronously in cell by acid-triggered manner, i.e. hydrazone bond cleavage and endosome/lysosome escape using flow cytometry and confocal laser scanning microscopy analysis. The results highlight the potential for therapeutic gene silencing in vitro and in vivo using RT-PCR and non-invasive in vivo imaging systems. The PHD/PPF/siRNA complexes can increase DOX and siRNA accumulation in cancerous cells and decrease the nonspecific distribution in normal tissues by the combination of EPR effect of nanocarriers, pH-triggered drug release, folate-mediated targeted delivery, and synergistic action of DOX and siRNA.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Haidian District, Beijing 100191, PR China.
authors.forename: Da-Wen
authors.initials: DW
authors.lastname: Dong
authors.forename: Bai
authors.initials: B
authors.lastname: Xiang
authors.forename: Wei
authors.initials: W
authors.lastname: Gao
authors.forename: Zhen-Zhen
authors.initials: ZZ
authors.lastname: Yang
authors.forename: Jing-Quan
authors.initials: JQ
authors.lastname: Li
authors.forename: Xian-Rong
authors.initials: XR
authors.lastname: Qi
mesh_terms: D000818:Animals; D004317:Doxorubicin / Q000494:pharmacology / Q000627:therapeutic use*; D016503:Drug Delivery Systems; D011992:Endosomes / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005492:Folic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D020868:Gene Silencing / Q000187:drug effects; D018014:Gene Transfer Techniques; D006367:HeLa Cells; D006801:Humans; D006835:Hydrazones / Q000737:chemistry; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D008024:Ligands; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009369:Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry*; D011094:Polyethyleneimine / Q000138:chemical synthesis / Q000737:chemistry*; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000378:metabolism; D014018:Tissue Distribution / Q000187:drug effects
chemical_list: D006835:Hydrazones; D008024:Ligands; D034741:RNA, Small Interfering; C552831:poly(ethylene glycol)-folate; D011092:Polyethylene Glycols; D004317:Doxorubicin; D011094:Polyethyleneimine; D005492:Folic Acid