Polymer-Silica Hybrid Materials and Their Applications for Controlled Drug Release

Polymer carriers for drug release have the advantages such as controlled concentration of the released drug, high drug bioavailability in organism and targeting therapy. However, some polymers have disadvantages such as low mechanical strength, poor chemical stability and undesirable biocompatibility. Silica is porous and non-toxic and possesses advantages such as good biocompatibility, high chemical and mechanical stabilities and easy surface functionalization. But for some silica carriers, it is difficult to load large drug molecules, have high drug loading or achieve targeting therapy. Polymer-silica hybrid materials may combine the advantages of polymer and silica carriers in drug delivery and eliminate their disadvantages. Based on the properties of the polymers and the functions of the polyrner/silica hybrid materials, controlled drug release systems, including temperature-sensitive polymer/silica, polyelectrolyte/silica, biopolymer/silica, and other polymer/silica hybrid materials are reviewed in this article. The research trends of this field are also briefly discussed.