| 초록 |
The needs for injectable porous beads made of biodegradable polymers have gradually increased with the developments of drug delivery systems, tissue engineering, and regenerative medicine. The porous beads have been prepared by several methods, including suspension polymerization, w/o/w emulsion solvent extraction/evaporation, incorporating gas pocket, and coacervation. However, their low and nonhomogeneous porosity, difficulty of pore size control, complex fabrication process, and residual organic solvents are still remained as some limitations. To overcome these problems, we developed a novel fabrication method to prepare injectable porous beads by the combination of temperature-induced phase separation (for nonporous bead fabrication) and the following melt-molding particulate leaching (for porous bead fabrication) methods which do not use any organic solvents. We could easily fabricate various biodegradable polymer beads, such as poly(ε-caprolactone), poly(p-dioxanone), poly(L-lactic acid), and poly(lactic-co-glycolic acid) by this fabrication method. The prepared porous beads were evaluated to determine optimum fabrication conditions (applied pressure and temperature, polymer bead/salt particle ratio etc.) for each biodegradable polymer. The various microbeads with easily injectable sizes (200-300, 300-400, and 400-500 μm) and pore sizes (25-50, 50-100, and 100-200 μm) fabricated in this study can be utilized for various cell culture or tissue regeneration. |
