Drug release of pH/temperature-responsive calcium alginate/poly(N-isopropylacrylamide) semi IPN beads

摘要

A series of semi-interpenetrating, polymernetwork (semi-IPN), hydrogel beads, composed of calciumalginate (Ca-alginate) and poly(N-isopropylacrylamide)(PNIPAAM), were prepared for a pH/temperature-sensitivedrug delivery study. The equilibrium swelling showed theindependent pH- and thermo- responsive nature of thedeveloped materials. At pH¼2.1, the release amount ofindomethacin incorporated into these beads was about 10%within 400 min, while this value approached to 95% atpH¼7.4. The release rate of the drug was higher at 37 8Cthanthat at 25 8C and increased slightly with increasingPNIPAAM content. These results suggest that the Caalginate/PNIPAAM beads have the potential to be used asan effective pH/temperature sustainable delivery system ofbioactive agents.