| 초록 |
The new PEC(polyelectrolyte complex) hydrogels based on chitosan and γ-PGA were developed for the controlled release of a protein. PEC hydrogels were prepared with stable turbid dispersions of PEC by using a freeze-drying method. The in vitro drug release behavior in various pH was studied using BSA(bovine serum albumin) as a model protein. The result showed that the release rate was decreased as the pH of dissolution medium was increased from the pKa point of γ-PGA to the isoelectric point of PEC hydrogels. However, the release rate was increased as the pH of dissoultion medium was increased from the isoelectric point of PEC hydrogels to the pKa point of chitosan. At the isoelectric point, the charge density of PEC hydrogel is zero because amounts of positive charge density of chitosan and negative charge density of γ-PGA are same. At the pKa point, the charge density of PEC hydrogels is maximum. The isoelectric point can be changed by controlling blend ratios of chitosan and γ-PGA. By these results, it was suggested that PEC hydrogels based on chitosan and γ-PGA may be useful for the controlled release system of a protein by pH variation. |
