title: [Preparation of basic fibroblast growth factor chitosan microsphere and its properties].
abstract: OBJECTIVE
  To study the release properties of basic fibroblast growth factor (bFGF) chitosan microspheres prepared by cross-linking-emulsion method using chitosan as a carrier material so as to lay a foundation for further study.
  
  
  METHODS
  Using 0.6% sodium tripolyphosphate solution as a crosslinking agent and 1.5% solution of chitosan as a carrier material, bFGF chitosan microspheres were prepared by cross-linking-emulsion method. Laser particle size analyzer and Zeta electric potential analyzer were used to measure the particle diameter distribution, scanning electronic microscope to observe the morphology, and ELISA to determine the drug loading, the encapsulation rate, and the drug release properties.
  
  
  RESULTS
  The particle size of bFGF chitosan microspheres ranged 20.312-24.152 microm. The microspheres were round with a smooth surface and uniform distribution, and it had no apparent porosity. The drug loading and encapsulation rate of microspheres were (7.57 +/- 0.34) mg/g and 95.14% +/- 1.58%, respectively. The bFGF chitosan microspheres could continuously release bFGF for 24 days; the bFGF level increased gradually with time and reached (820.45 +/- 21.34) ng/mL at 24 days; and the microspheres had a burst effect, and the burst rate was 18.08%, and the accumulative release rate of the microspheres reached 82.05% during 24 days.
  
  
  CONCLUSIONS
  It is easy-to-operate to prepare the bFGF chitosan microspheres with the cross-linking-emulsion method. The bFGF chitosan microspheres have smooth surface, uniform distribution, and no apparent porosity.
authors.affiliation: Department of Orthopaedics, People's Hospital of Fengjie County, Fengjie Chongqing 404600, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Zhongqian
authors.initials: Z
authors.lastname: Liu
authors.forename: Yuanhui
authors.initials: Y
authors.lastname: Yue
authors.forename: Lun
authors.initials: L
authors.lastname: Wan
authors.forename: Jiang
authors.initials: J
authors.lastname: Hu
authors.forename: Bo
authors.initials: B
authors.lastname: Lü
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry*; D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding / Q000379:methods*; D004655:Emulsions; D016222:Fibroblast Growth Factor 2 / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D011122:Polyphosphates / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004655:Emulsions; D011122:Polyphosphates; D016222:Fibroblast Growth Factor 2; D048271:Chitosan; C005692:triphosphoric acid