RÉSUMÉ
Polysialic acid(PSA)is a homopolymer consisting of N-acetylneuraminic monomers linked by α-2,8 and(or)α-2,9 glucoside bonds.As an endogenous polysaccharide,PSA has good biocompatibility,biodegradability,high hydrophilicity,non-immunogenicity,long-term circulation,easy modification and specific targeting to selectins.In the field of drug delivery research,PSA not only can be connected with small molecule drugs,active peptides or proteins,but also can be grafted or electrostatic cross-linked with polymers to build a variety of drug delivery systems,such as nanogels,polymer micelles,liposomes,etc.It has shown great potential value in the treatment of various disease models such as tumors,inflammatory diseases and neurological diseases.In this paper,the biological functions of PSA,the classification of drug delivery systems based on PSA and its application progress were reviewed,in order to provide reference for further application and research of PSA.