Preparation of Dendritic Mesoporous Silica/Phenylboronic Acid-Modified Hydroxypropyl Chitosan and Its Glucose-Responsive Performance

The glucose-responsive insulin release system was proved to be an effective way to deliver insulin. Here, dendritic mesoporous silica and phenylboronic acid were used to prepare a simple insulin delivery system, and its glucose-responsive properties were studied. Briefly, dendritic mesoporous silica was prepared by the biphase stratification approach. 3-Fluoro-4-carboxyphenylboronic acid was grafted on the hydroxypropyl chitosan to obtain phenylboronic acid-modified hydroxypropyl chitosan. In a weakly acidic environment, insulin was loaded on the dendritic mesoporous silica. The loading capacity and encapsulation efficiency could reach 32.1 and 94.6%, respectively. After that, modified hydroxypropyl chitosan was coated on the insulin-loaded dendritic mesoporous silica to obtain an insulin release system. Then sodium alginate was coated on insulin release system followed by calcium ion crosslinking to obtain another insulin release system. The results demonstrated that both systems had excellent performance in sustained insulin release. Glucose-responsive behavior was observed in the case of the former insulin release system.