title: [Preparation and in vitro evaluation of crosslinked polyvinyl alcohol microspheres for embolization].
abstract: OBJECTIVE
  To develop and study the properties of crosslinked polyvinyl alcohol microspheres (PVA-Ms) for embolization.
  
  
  METHODS
  The PVA-Ms were produced by emulsion chemical crosslinking method. Fourier transform infrared spectroscopy (FT-IR) was used to investigate the special functional groups of PVA-Ms; the morphology and particle size of PVA-Ms were determined by optical microscope; the ratio of water absorption and the swelling ratio were also investigated; the compressibility was examined by texture analyzer. A new device was designed to measure the pressure of PVA-Ms during their delivery through catheter for embolization.
  
  
  RESULTS
  The crosslinking reaction of PVA and formaldehyde was proved by FT-IR. The PVA-Ms were round with smooth surface. The average diameter of lyophilized PVA-Ms was 574.2 μm with a range of 80-1 800 μm and of wet PVA-Ms was 602.2 μm with a range of 100-1 900 μm. The average ratio of water absorption was 175% and the swelling ratio was 48.6%. The PVA-Ms were mechanically stable with appropriate elasticity and delivered through the catheter without any difficulty, and the pressure was higher for larger size of microspheres to be delivered.
  
  
  CONCLUSIONS
  PVA-Ms prepared in this study was supposed to be suitable for clinical embolization according to the physicochemical properties. The study provides a series of methods to evaluate the properties of microspheres systemically for embolization in vitro.
authors.affiliation: Department of Pharmaceutics, Peking University School of Pharmaceutical Sciences, Beijing 100191, China.
authors.forename: Shen
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Pharmaceutics, Peking University School of Pharmaceutical Sciences, Beijing 100191, China.
authors.forename: Wen-jing
authors.initials: WJ
authors.lastname: Meng
authors.affiliation: Department of Pharmaceutics, Peking University School of Pharmaceutical Sciences, Beijing 100191, China.
authors.forename: Xiao-jing
authors.initials: XJ
authors.lastname: Lu
authors.affiliation: Department of Pharmaceutics, Peking University School of Pharmaceutical Sciences, Beijing 100191, China.
authors.forename: Ya-nan
authors.initials: YN
authors.lastname: Wu
authors.affiliation: Department of Pharmaceutics, Peking University School of Pharmaceutical Sciences, Beijing 100191, China.
authors.forename: Dun-zhu
authors.initials: DZ
authors.lastname: Ren-Zeng
authors.affiliation: Department of Pharmaceutics, Peking University School of Pharmaceutical Sciences, Beijing 100191, China.
authors.forename: Tian-yuan
authors.initials: TY
authors.lastname: Fan
mesh_terms: D004548:Elasticity; D004621:Embolization, Therapeutic; D004655:Emulsions; D008863:Microspheres; D010316:Particle Size; D011142:Polyvinyl Alcohol; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D004655:Emulsions; D011142:Polyvinyl Alcohol