Acid-soluble chitosan microsphere and preparation method thereof

The invention provides acid-soluble chitosan microspheres which are prepared from chitosan and terephthalaldehyde through cross-linking reaction. The particle size of the microspheres is 6-11mu m, and the variable coefficient of the microspheres is 2.7-5%. The preparation method comprises the following steps: (1) preparing ejection liquid and receiving liquid; (2) in a constant temperature environment of 25-45 DEG C, adding the ejection liquid of the temperature identical to that of the constant temperature environment into an injector of electrostatic spinning equipment, pushing the ejection liquid into a metal syringe needle through an ejection pump, exerting high-voltage static electricity to the metal syringe needle so as to form the ejection liquid into ejection liquid droplets, receiving the ejection liquid droplets by using a container with the receiving liquid under the stirring condition, and enabling chitosan in the ejection liquid droplets to be completely cross-linked with terephthalaldehyde in the receiving liquid, thereby obtaining the chitosan microspheres; (3) washing the chitosan microspheres by using isopropanol so as to remove the receiving liquid on the surfaces of the microspheres, and washing with water so as to remove isopropanol.