title: A specific drug targeting system based on polyhydroxyalkanoate granule binding protein PhaP fused with targeted cell ligands.
abstract: Polyhydroxyalkanoates (PHA) is a family of intracellular biopolyesters produced by many bacteria. PHA granule binding protein PhaP is able to bind to hydrophobic polymers via strong hydrophobic interaction. A receptor-mediated drug delivery system was developed in this study based on PhaP. The system consists of PHA nanoparticles, PhaP and polypeptide or protein ligands fused to PhaP. The PHA nanoparticles were used to package mostly hydrophobic drugs; PhaP fused with ligands produced by over-expression of their corresponding genes in Pichia pastoris, or E. coli was able to attach to hydrophobic PHA nanoparticle. At the end, the ligands were able to pull the PhaP-PHA nanoparticles to the targeted cells with receptors recognized by the ligands. It was found in this study that the receptor-mediated drug specific delivery system ligand-PhaP-PHA nanoparticles were taken up by macrophages, hepatocellular carcinoma cell BEL7402 in vitro and liver, hepatocellular carcinoma cells in vivo, respectively, when the ligands were mannosylated human alpha1-acid glycoprotein (hAGP) and human epidermal growth factor (hEGF), respectively, which were able to bind to receptors of macrophages or hepatocellular carcinoma cells. The nanoparticle system was clearly visible in the targeted cells and organs (liver or tumor) under fluorescence microscopy when rhodamine B isothiocyanate (RBITC) was used as a delivery model drug due to the specific targeting effect created by specific ligand and receptor binding. The delivery system of hEGF-PhaP-nanoparticles carrying RBITC was found to be endocytosed by the tumor cells in tumorous model mice. Thus, the ligand-PhaP-PHA specific drug delivery system was proven effective both in vitro and in vivo.
authors.affiliation: Multidisciplinary Research Center, Shantou University, Shantou 515063, Guangdong, China.
authors.forename: Yong-Chao
authors.initials: YC
authors.lastname: Yao
authors.forename: Xiao-Yong
authors.initials: XY
authors.lastname: Zhan
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Xiang-Hui
authors.initials: XH
authors.lastname: Zou
authors.forename: Zhi-Hui
authors.initials: ZH
authors.lastname: Wang
authors.forename: Yu-Cui
authors.initials: YC
authors.lastname: Xiong
authors.forename: Jiong
authors.initials: J
authors.lastname: Chen
authors.forename: Guo-Qiang
authors.initials: GQ
authors.lastname: Chen
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism*; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D016503:Drug Delivery Systems; D004705:Endocytosis; D004815:Epidermal Growth Factor / Q000378:metabolism; D004926:Escherichia coli; D005453:Fluorescence; D005629:Frozen Sections; D008024:Ligands; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D053758:Nanoparticles / Q000648:ultrastructure; D009961:Orosomucoid / Q000378:metabolism; D010843:Pichia; D054813:Polyhydroxyalkanoates / Q000737:chemistry / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D023041:Xenograft Model Antitumor Assays
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D008024:Ligands; D009961:Orosomucoid; C118828:PHAP protein, Bacteria; D054813:Polyhydroxyalkanoates; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D004815:Epidermal Growth Factor