| 초록 |
pH-sensitive and biodegradable hydrogels based on Pluronic F-127 tri-block copolymer containing PLGA(poly lactic-co-glycolic acid 50:50) microspheres were prepared by a photo-polymerization method for controlled release of bioactive molecules such as proteins, genes, and cells. The PLGA microspheres were entrapped within Pluronic hydrogel in order to modulate local pH environment by acidic degradation productds of PLGA. The PLGA microspheres slowly degraded to generate acidic local micro-environment, which facilitated the cleavage of ester-linkage in the di-acrylated Pluronic terminal end in the hydrogel network. When BSA, a model protein drug, was loaded in the Pluronic hydrogels, the presence of PLGA microspheres accelerated the degradation of Pluronic hydrogels and enhanced protein release rate. Protein release showed a sustained release kinetic profile which followed a mass erosion pattern. The release kinetics of model drug could be controlled by the entrapment of PLGA microspheres. |
