인공지지체의 공극 구조가 산소 확산에 미치는 영향에 관한 연구

Abstract

The aim of this study was to maximize an oxygen diffusion capability within three-dimensional scaffold to enhance the cell viability and proliferation effect. We designed and analyzed novel pore architectures with gradient of pore size from the interior to the exterior of scaffolds fabricated by solid free-form fabrication (SFF) technology. First of all, in order to analyze the effect of pore architectures on mass transport, we performed a numerical analysis on the distribution of oxygen concentration in constructs with two pore architectures, named by cylinder shape and cone shape. In the results of numerical analysis, oxygen concentration of cone shape was higher than that of cylinder shape at same location. In addition, the hypoxia regions of cylinder shape were widely observed by high cell density compared to those of cone shape. 2D constructs with different pore architectures were fabricated by micro-stereolithography technology, which is one of SFF technology, and sacrificial molding process. With these constructs and MC3T3-E1 cells, we performed cell viability and proliferation experiments. Cell viability experiment showed that most of cells were alive in all part of cone shape, whereas some dead cells were observed in the middle and inner part of cylinder shape. Cell proliferation result of cone shape was better than that of cylinder shape.To evaluate the effect of cell interaction on pore architecture, three-dimensional scaffolds with the pore architecture of cylinder shape (CY) and cone shape (CO) were also fabricated by micro-stereolithography technology and sacrificial molding process. In addition, modified scaffolds with a hole in the center of each scaffold were fabricated to enhance the effect on mass transport. With these scaffolds (CY, CO, Modified-CY (M-CY), and Modified-CO (M-CO)), cell viability and proliferation experiments were performed to know the effect on pore architectures. In the point of pore architecture, CO scaffold had better effect on oxygen diffusion from peripheral boundaries to inner regions than CY scaffold. Furthermore, in the cell proliferation study with modified scaffolds, cell proliferation result of M-CY scaffold was better compared to that of CY scaffold.Based on these results, we demonstrated that cone shape had better cell viability and proliferation than cylinder shape. Additionally, a hole in the center of scaffold will be a promising tool for effective mass transport in the interior of scaffolds.