Chitosan hydrogel microsphere-templated microcapsules carrying heparin via layer-by-layer self-assembly / 中国组织工程研究

ABSTRACT

BACKGROUND: Electrostatic layer-by-layer (LbL) self-assembly is a simple, effective and novel approach to carrying macromolecules into microcapsule carriers.OBJECTIVE: To prepare chitosan (CS) microcapsules to control the releasing of heparin (Hep) by LbL.METHODS: CS microspheres were fabricated by a sodium sulfate-based precipitation process and then used as positively charged templates for polyelectrolyte multilayer coatings to carry heparin by the LbL self-assembly technique. The polycation was CS and the polyanion was Hep. The microcapsule was formed via coating {CS/Hep}3 on CS hydrogel template. The microcapsules composed of {CS/ Hep}3 on CS hydrogel templates were confirmed by fluorescence inverted microscopy, confocal laser scanning microscopy and laser particle size analysis. The assembly of polyelectrolyte layers on CS hydrogel microspheres was monitored by Zeta Potential Analyzer.RESULTS AND CONCLUSION: The resulting microcapsules were about 1 μm in average diameter, and allowed spontaneous loading of heparin through electrostatic interaction, with the encapsulation efficiency and carrying capacity of 83.8% and 3.05%, respectively.