title: Construction of paclitaxel-loaded poly (2-hydroxyethyl methacrylate)-g-poly (lactide)-1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine copolymer nanoparticle delivery system and evaluation of its anticancer activity.
abstract: BACKGROUND
  There is an urgent need to develop drug-loaded biocompatible nanoscale packages with improved therapeutic efficacy for effective clinical treatment. To address this need, a novel poly (2-hydroxyethyl methacrylate)-poly (lactide)-1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine [PHEMA-g-(PLA-DPPE)] copolymer was designed and synthesized to enable these nanoparticles to be pH responsive under pathological conditions.
  
  
  METHODS
  The structural properties and thermal stability of the copolymer was measured and confirmed by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and thermogravimetric analysis. In order to evaluate its feasibility as a drug carrier, paclitaxel-loaded PHEMA-g-(PLA-DPPE) nanoparticles were prepared using the emulsion-solvent evaporation method.
  
  
  RESULTS
  The PHEMA-g-(PLA-DPPE) nanoparticles could be efficiently loaded with paclitaxel and controlled to release the drug gradually and effectively. In vitro release experiments demonstrated that drug release was faster at pH 5.0 than at pH 7.4. The anticancer activity of the PHEMA-g-(PLA-DPPE) nanoparticles was measured in breast cancer MCF-7 cells in vivo and in vitro. In comparison with the free drug, the paclitaxel-loaded PHEMA-g-(PLA-DPPE) nanoparticles could induce more significant tumor regression.
  
  
  CONCLUSIONS
  This study indicates that PHEMA-g-(PLA-DPPE) nanoparticles are promising carriers for hydrophobic drugs. This system can passively target cancer tissue and release drugs in a controllable manner, as determined by the pH value of the area in which the drug accumulates.
authors.affiliation: Laboratory of Nanomedicine and Nanosafety, Division of Nanomedicine and Nanobiology, National Center for Nanoscience and Technology, Beijing, People's Republic of China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Ma
authors.forename: Huan
authors.initials: H
authors.lastname: Wang
authors.forename: Shubin
authors.initials: S
authors.lastname: Jin
authors.forename: Yan
authors.initials: Y
authors.lastname: Wu
authors.forename: Xing-Jie
authors.initials: XJ
authors.lastname: Liang
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000737:chemistry* / Q000493:pharmacokinetics; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003692:Delayed-Action Preparations; D004337:Drug Carriers / Q000008:administration & dosage / Q000737:chemistry; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008689:Methacrylates / Q000008:administration & dosage / Q000737:chemistry*; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles / Q000737:chemistry*; D017239:Paclitaxel / Q000008:administration & dosage* / Q000737:chemistry* / Q000493:pharmacokinetics; D010714:Phosphatidylethanolamines / Q000008:administration & dosage / Q000737:chemistry*; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D008689:Methacrylates; D010714:Phosphatidylethanolamines; C007510:1,2-dipalmitoyl-3-phosphatidylethanolamine; C005044:hydroxyethyl methacrylate; D017239:Paclitaxel