Study On Promoting Osteogenic Regeneration Using 3D Printed PCL Scaffolds Loaded With Magnetic Iron Oxide

Objective:The preparation of superparamagnetic nanoparticles of iron oxide(IONPs)composite scaffolds was studied,and the characterization,biocompatibility and osteogenic properties were studied,hoping to improve the repair ability of bone defects and promote the research progress of bone tissue engineering.Methods:Polycaprolactone(PCL)scaffold was prepared by 3D printing technology,and a composite scaffold(PPI)was prepared by loading IONPs with different concentrations on the scaffold by polydopamine(PDA).In this study,rabbit mesenchymal stem cells(rBMSCs)were used to evaluate the cytocompatibility of the composite scaffold through cytotoxicity(CCK-8)and proliferation tests,and alkaline phosphatase(ALP)and alizarin red staining were used to promote bone differentiation.Finally,the osteogenic effect of the composite scaffold was verified by in vivo experiment.Results:As the basic skeleton of composite scaffolds,PCL scaffolds can provide good mechanical support for bone repair,and their uniform pores can promote the deposition and construction of osteogenic matrix.At the same time,PDA can effectively improve the hydrophobicity of PCL,which is conducive to cell adhesion and extracellular matrix(ECM)protein deposition.CCK-8 assay showed that the scaffold was non-toxic to cells,and the optimal IONPs concentration was 460 μg/ml combined with cell proliferation assay.Through the study on osteogenic differentiation,it was found that composite scaffolds could significantly promote the osteogenic differentiation of rBMSCs on the 14th day.PCL group and PCL/PDA group had no significant effect on the differentiation of rBMSCs.However,PPI composite scaffolds in 460 μg/ml group showed statistical significance in promoting osteogenic regeneration,and showed good in vitro biocompatibility and great potential in promoting bone regeneration and differentiation.The results of in vivo experiments showed that IonPs-loaded composite scaffolds significantly promoted osteogenic regeneration.Conclusions:In this study,the PCL surface was modified by PDA to improve the hydrophilicity of the base scaffold,and the IONPs was successfully loaded on the PCL scaffold to prepare PPI composite scaffold.The scaffolds play a good role in promoting osteogenic repair and have potential development value and application prospect in osteogenic regenerative medicine and clinical transformation.