(256e) Silica-Polysaccharides Nanocomposite Nanoparticles As pH-Responsive Controlled Drug Release Carriers

Biocompatible drug carriers with the ability of controlled therapeutic agent delivery is a promising way to overcome the limitations of conventional therapies. For example, the lack of target specificity and solubility of some drugs results in overdoses to achieve the sufficient therapeutic effects, which increases cost and side effects. Among all types of carriers, silica-based nanocomposites emerged as an encouraging candidate because of several properties of silica. First of all, silica shows acceptable biocompatibility and has high physical as well as chemical stability, which makes it an ideal support for nanomaterials. Secondly, silica has a low effect on light absorption and magnetic field interference, which allows the combined components to keep their original optical and magnetic properties. Finally, the hydroxyl groups on the silica surface give lots of potential for the modification of silica based materials for extended applications. Moreover, polysaccharides, such as alginate and chitosan, can be encapsulated into silica nanoparticles by sol-gel method to make silica based nanocomposite materials. These polymers can provide the pH controlled release ability due to their pH-responsive property. In this study, the pH-responsive silica polysaccharides nanocomposite nanoparticles were made by silica sol-gel method in water in oil microemulsion system, and were characterized by dynamic light scattering, transmission electron microscopy, and thermogravimetric analysis for their size, shape and polymer weight ratio. The release profiles at different pH buffer solutions for different drug molecules were also studied to test the pH-responsive property of these silica polysaccharides nanocomposites nanoparticles.