| 초록 |
Biodegrdable hydrogels have been widely used for sustained delivery of bioactive macromolecules. Among them, synthetic polymer hydrogels have been prepared by free radical polymerization of vinyl monomers with divinyl crosslinker or by intra-molecular crosslinking of functionalized polymer chains using a bi-functional crosslinker. This study aimed the fabrication of biodegradable hydrogel for local sustained drug delivery of angiogenic growth factors such as basic FGF. In order to promote loading of bFGF into the hydrogels and to achieve sustained release of the growth factor, vinyl-conjugated heparin was blended with di-acryloyl Pluronic. Polymer blend hydrogels were prepared by photo-polymerization. Release profiles of bFGF from the Pluronic hydrogels and Pluronic/heparin blend hydrogels were comparatively evaluated. The presence of heparin in the hydrogels retarded bFGF release due to its affinity to bFGF. bFGF release from the Pluronic/heparin hydrogel showed prolonged sustained profiles than that from Pluronic hydrogels. The sustained release mode of bFGF continued over 30 days. On the contrary, bFGF release from Pluronic hydrogels exhibited sustained release only for 15 days. In this point of view, the incorporation of heparin in the Pluronic hydrogels is critical to control bFGF release over an extended period, which has potential for local delivery of bFGF for neovascularization. The released bFGF fraction from Pluronic/heparin hydrogels retained its bioactivity for stimulation of HUVEC proliferation during the incubation period. The Pluronic/heparin hydrogels implanted in the subcutaneous region enhanced microvessel formation in peripheral tissues of the implant site after 15 day |
