title: Synthesis and in vitro evaluation of pH-sensitive PEG-I-dC16 block polymer micelles for anticancer drug delivery.
abstract: OBJECTIVE
  To develop an acid trigger release of antitumour drug delivery carriers, pH-sensitive amphiphilic poly (ethyleneglycol)-imine-benzoic-dipalmitate (PEG-I-dC16 ) polymers were designed and synthesized and the drug-loaded micelles were evaluated in vitro.
  
  
  METHODS
  PEG-I-dC16 synthesized by Schiff base synthetic method and characterized by (1) H-NMR. To determine the drug-loading capacity, doxorubicin (DOX) was encapsulated in the micelles using membrane dialysis method. Zeta potential, particle size, drug-loading capacity, in vitro drug release in different pH conditions and cytotoxicity evaluation of micelles were carried out comparing with non-acid liable PEG-amide-benzoic-dipalmitate (PEG-A-dC16) polymers micelles. The cellular uptake and intracellular distribution of DOX were detected by flow cytometry and confocal laser scanning microscope.
  
  
  RESULTS
  Drug-loading capacity and encapsulation efficiency of micelle (PEG molecular weight 2k) were 12.7 ± 1.1% and 49.8 ± 2.2%, respectively. The average particle size was 72.3 ± 2.5 nm. The DOX release rate of PEG-I-dC16 micelles is much higher at pH 6.5 than at pH 7.4. DOX cellular uptake and nuclear accumulation of PEG-I-dC16 micelles were more efficiency than that of PEG-A-dC16 micelles.
  
  
  CONCLUSIONS
  The pH-sensitive PEG-I-dC16 micelles could be a promising drug delivery system for anticancer drugs.
authors.affiliation: The First People's Hospital of Xiangtan City, Xiangtan, China.
authors.forename: Huang
authors.initials: H
authors.lastname: Rongbin
authors.affiliation: Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics University of South China, Hengyang, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Lei
authors.affiliation: Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics University of South China, Hengyang, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Ying
authors.affiliation: Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics University of South China, Hengyang, China.
authors.forename: Deng
authors.initials: D
authors.lastname: Xiangping
authors.affiliation: Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics University of South China, Hengyang, China.
authors.forename: Cao
authors.initials: C
authors.lastname: Xuan
authors.affiliation: Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics University of South China, Hengyang, China.
authors.forename: Li
authors.initials: L
authors.lastname: Lanfang
authors.affiliation: Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics University of South China, Hengyang, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Cuiyun
authors.affiliation: Mu Dan Jiang You Bo Pharmacertical Co.Ltd, Mudanjiang, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Yanming
authors.affiliation: Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics University of South China, Hengyang, China.
authors.forename: Tang
authors.initials: T
authors.lastname: Guotao
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D001549:Benzamides / Q000138:chemical synthesis*; D002470:Cell Survival / Q000187:drug effects; D003692:Delayed-Action Preparations; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D004337:Drug Carriers; D004339:Drug Compounding; D056945:Hep G2 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008175:Lung Neoplasms / Q000188:drug therapy / Q000473:pathology; D008823:Micelles; D010316:Particle Size; D011092:Polyethylene Glycols / Q000138:chemical synthesis*; D013678:Technology, Pharmaceutical / Q000379:methods
chemical_list: D000903:Antibiotics, Antineoplastic; D001549:Benzamides; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D008823:Micelles; C000618838:poly(ethyleneglycol)-imine-benzoic-dipalmitate; D011092:Polyethylene Glycols; D004317:Doxorubicin
keywords: benzoic-imine bond; drug delivery system; micelle; pH-sensitive