壳聚糖-聚丙烯酸磁性纳米微球的制备和表征

壳聚糖是一种具有氨基和羟基的天然高分子多糖，具有无毒和良好的生物相容性、生物可降解性。本研究采用二巯基二乙酸修饰磁性纳米颗粒，利用壳聚糖的氨基和磁性纳米颗粒表面的羧基之间的静电吸附作用使纳米颗粒与壳聚糖紧密吸附，然后加入丙烯酸通过聚合作用形成磁性微球。

DMSA-coated MNP suspension were suspended in CS solution. After sufficient adsorption between carboxyl groups from MNP and positively charged amino groups of CS. the polymerization of AA was initiated by K2S2O8. When the polymerization of AA reached a certain level, the inter- and intra-molecular linkages occurred between carboxyl groups from PAA and positively charged amino groups of CS. These linkages could make the macromolecular chains of CS rolling up, which was responsible for the formation of the gelation of the CS solution. As the polymerization time extended, the amount of PAA in the solution increased, the CS-PAA polymer magnetic nanospheres were formed.