title: Phagocytic uptake and ROS-mediated cytotoxicity in human hepatic cell line of amphiphilic polyphosphazene nanoparticles.
abstract: The pH-responsive amphiphilic polyphosphazenes bearing N,N-diisopropylethylenediamine (DPA) have been proven to be promising nanovehicles for drug antitumor therapy. To further modify these amphiphilic polyphosphazenes with fluorescent labeling agent or other biochemical functional groups, serine methyl ester containing active chemical group NH(2) was chosen to be introduced to get a novel polymer [NP(PEG)(0.24) (DPA)(0.5)(SME)(1.26) (n) (PDS-NH(2) ). Considering the possible toxic effect of -NH(2) group, the biocompatibility in bloodstream and nanotoxicity on human normal hepatic L-02 cells was evaluated in this study. The polymer [NP(PEG)(0.24)(DPA)(0.5)(SME-BOC)(1.26)](n) (PDS-BOC) linked with tert-butyloxycarbonyl groups to protect and hide -NH(2) group was applied as the comparison. First, the bovine serum albumin (BSA) adsorption and phagocytic uptake behavior in human THP-1 macrophages were performed. The results suggested that only a minor percentage of the nanoparticles were involved in BSA binding and phagocytic uptake as the result of PEGylation on the particulate surface. To determine the nanotoxicity on human normal hepatic L-02 cells, we measured cell viability, apoptosis and necrosis, reactive oxygen species generation, the loss of mitochondrial membrane potential, and the levels of the apoptotic signaling proteins in L-02 cells after the cells being exposed to nanoparticles of different concentrations (0.1, 0.2, and 0.5 mg/mL) for 24 h. Our data indicated that the two nanoparticles induced cytotoxicity in a dose-dependent manner; PDS-NH(2) caused more cytotoxicity than PDS-BOC as a result of -NH(2) exposure. The increased expression of caspase-3 and caspase-9 suggested that they triggered apoptosis through mitochondria-dependent pathways in L-02 cells.
authors.affiliation: Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China. lyqiu@zju.edu.cn
authors.forename: Liyan
authors.initials: L
authors.lastname: Qiu
authors.forename: Yue
authors.initials: Y
authors.lastname: Chen
authors.forename: Menghua
authors.initials: M
authors.lastname: Gao
authors.forename: Cheng
authors.initials: C
authors.lastname: Zheng
authors.forename: Qinghe
authors.initials: Q
authors.lastname: Zhao
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000327:Adsorption / Q000187:drug effects; D000818:Animals; D002021:Buffers; D020169:Caspases / Q000378:metabolism; D002417:Cattle; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005453:Fluorescence; D022781:Hepatocytes / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity; D009943:Organophosphorus Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D010587:Phagocytosis / Q000187:drug effects; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013194:Staining and Labeling; D055672:Static Electricity; D013501:Surface-Active Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism
chemical_list: D002021:Buffers; D009943:Organophosphorus Compounds; D011108:Polymers; D017382:Reactive Oxygen Species; D013501:Surface-Active Agents; C108974:poly(phosphazene); D012710:Serum Albumin, Bovine; D000255:Adenosine Triphosphate; D020169:Caspases; D016650:Fluorescein-5-isothiocyanate