Study On Biocompatibility Of A Macroporouscomposite Scaffold Built By 3D Printer

Part ?The isolation,Culture and identification of BMSCsObjective: This studywas undertaken to isolate bone marrowmesenchymal stem cells(BMSCs) from SD rats, assess surface markers and multi-directional differentiation capacity of BMSCs, in order to provide a seed cell with clear background for the subsequent investigations. Methods 1. By the whole bone marrow adherence method,the BMSCs were isolated, cultured and purified. 2.BMSCs were assessed for their multi-differentiation ability including osteogenic differentiation and adipogenic differentiation. 3.Cell surface CD marker expression profiles of BMSCs were assessed with flow cytometry. Results 1.The BMSCs from rats were fusiform and arranged radially. 2.Osteogenic differentiation test showed that BMSCs were positively stained by Alkaline Phosphatase, Alozarin Red. Adipogenic diffentiation test showed that BMSCs were positively stained by Oil Red O. 3.At the third passage, BMSCs werepositive for CD44 and CD90. Conclusion: By the whole bone marrow adherence method,the BMSCs which were isolated, cultured and purified have a clear background for the subsequent investigations.Part?Building of 3D macroporouscomposite scaffold and study on itsbiocompatibility Objective This study tried to fabricate macroporouscomposite scaffold with compounds of polylactide(PLA)and hydroxyapatite(HA) and evaluate its biocompatibility in vitro and in-vivo. Methods 1.PLA/HA macroporouscomposite scaffold was built by 3D printer and its structure was scanned by Micro CT and observed by SEM. 2.The cyctotoxic effects of four different concentrations of leaching liquor(100%,50%,25%,and 12.5%)prepared from the scaffold were evaluated by CCK-8 assay. 3.The cells adhesion cultured on scaffold after 1,3,5 and7 days were evaluated by CCK-8 assay. 4.The BMSCs were seed on the scaffolds, and the composites were observed by fluorescence microscope and SEM to explore morphological changes of cells. 5.PLA/HA scaffoldsubcutaneous implantation experiments with SD rats. Results 1.3D macroporouscomposite scaffold was successfullymade,which had a multi-scaledporous structure scanned by Micro CT and observed by SEM. 2.The levels of toxicity of different concentrations of leaching liquor ranged from 0 to 1.(The extraction solution had no cytotoxicity) 3.According to CCK-8 assay, the absorbance values among each tested groupswere different at 1,3,5 and 7 d after cells seeded.(p<0.05). 4.The BMSCs adhered, proliferated, migrated on the scaffold, showing good cell compatibility. 5.The results of subcutaneous implantation showed that as the time increased, the number of inflammatory cells decreased while the VECs(vascular endothelial cells) increased. Conclusion:This study suggested that different biological composite scaffolds could be produced by 3D printing technology, and showed that 3D printing PLA/HA composite macporous scaffolds had good cell compatibility and tissue compatibility.