Study on Drug Delivery Systems (II) : Synthesis of Stimule Sensitive Polymers for Intelligent Drug Delivery Systems

[Abstract] The stimule-sensitive and responsive hydrogels were synthesized by radiation polymerization. The effects of copolymer composition, hydrolysis and crosslinking monomers on the electrical responsiveness were investigated and compared with those on the temperature responsiveness. It was observed that the content of electrolytic component strongly affected on the stimule responsiveness and the responses showed a maximum at a certain copolymer composition. It was suggested that the responsiveness had an optimum at a suitable polyelectrolyte in the hydrogels. However, the temperature responsiveness was realized in the absence of polyelectrolytic component, while the electrical responsiveness absolutely required the polyelectrolytic content. The on-off switching release of insulin from the hydrogel under electric field was also investigated