关键词: 支架材料, 羟基磷灰石, 聚乳酸-聚乙醇酸共聚物, 人牙髓干细胞, 组织工程

Abstract: Objective    To investigate the degradation rate of different proportion of polylactic-co-glycolic acid（PLGA）/hydroxylapatite（HA）composite scaffolds and the effects on proliferation and mineralization of human dental pulp stem cells（hDPSCs）. Methods    PLGA/HA composite scaffolds with different HA contents（10%，20% and 30%）were fabricated by solvent casting/particulate leaching technology，and PLGA without HA was used as the control group. Degradation rate of scaffolds was measured by degradation experiment. The cells were seeded in PLGA/HA composite scaffolds with different proportions. Cell morphology was observed by scanning electron microscopy，and proliferation ability were measured by MTT assay. After hDPSCs were preincubated with scaffolds for 72 h，the composite scaffolds were implanted into nude mice. One month and 3 months later，the scaffolds were removed from the sacrificed nude mice. HE staining was used to observe the histological morphology. Dentin matrix protein 1（DMP1）expression was detected by immunohistochemical staining to further investigate the mineralization degree of hDPSCs. Results    PLGA/HA composite scaffolds containing 10%，20% and 30% HA could all promote the proliferation of hDPSCs compared with PLGA group，and promotion effect increased with increasing HA content. The 10% HA and 20% HA group showed suitable degradation rates. The results of HE staining and immunohistochemical staining showed that HA could promote the dentinogenesis of hDPSCs，and the degree of differentiation was proportional to the content of HA. The 20% HA and 30% HA showed a better degree of mineralization. Conclusion    PLGA/HA composite scaffolds with 20% HA exhibits a better degradation rate and ability to promote proliferation and mineralization of hDPSCs，which can be used as an ideal biomaterial for cell scaffold.

Key words: scaffold；hydroxylapatite, HA；polylactic-co-glycolic acid, PLGA；human dental pulp stem cells, hDPSCs；tissue engineering