Experimental Study Of 3D Printed PCL/Mg And PCL/CuO Scaffolds For Repairing Bone Defects

ObjectiveBone defects caused by trauma,tumor and infections have always been a serious challenge in the field of orthopedics.Currently,there are two main types of methods for repairing bone defects: bone grafts and synthetic materials or natural derivatives.With the development of the bone tissue engineering,bone repair scaffolds have become the research focus of bone tissue engineering,bringing a new direction for bone defect repair.Polycaprolactone(PCL)is a synthetic polymer material with good biocompatibility,complete degradability,mechanical strength,and has been widely used in the bone tissue engineering.Traditional methods of manufacturing 3D porous PCL scaffolds,such as thermal phase separation,solution-particle leaching,gas foaming,wire-network molding,etc.,lack of accurate control of pore structure and have poor repeatability,making them difficult to produce scaffolds with complex shapes.Therefore,if bone scaffolds have both personalized morphological structure and biological function,the research progress of bone tissue engineering and the therapeutic effects of bone defects could be greatly improved.Content and MethodsIn this study,PCL modified by melt blending method and manufactured by FDM printing technology,can meet the personalized needs of implant internal structure,especially biological function.The aim of this study is to improve the therapeutic effect of bone repairing,which involved two mainly parts:Part one: Magnesium(Mg)was incorporated into PCL by melt blending method to prepare PCL/Mg composites and porous scaffolds were manufactured with personalized spatial structure by FDM printing method.The effects of different Mg contents on scaffold degradation behavior and biological properties were investigated by cell and animal experiments.Part two: Cupric oxide(Cu O)was mixed into PCL by melt blending method to prepare PCL/Cu O composites and porous scaffolds were manufactured with personalized spatial structure by FDM printing method.The effects of different Cu O contents on the osteogenic and antibacterial properties of scaffolds were studied by cell and anti-bacterial experiments.ResultsFDM printing technology can be used to manufacture PCL/Mg porous scaffolds with different Mg concentrations(wt.5%,10%,15%).The results of in vitro degradation and cell experiments showed that PCL/10%Mg group had the best degradation performance and osteogenic properties.By promoting the adhesion,proliferation and osteogenic differentiation of r BMSCs in vivo,satisfactory repair results were obtained for the cranial defects of SD rats.FDM printing technology can be used to manufacture PCL/Mg porous scaffolds with different Cu O concentrations(wt.5%,10%).The results of in vitro degradation and cell experiments showed that PCL/10%Cu O group,could promote the adhesion,proliferation and osteogenic differentiation of r BMSCs,and inhibite the growth of methicillin-resistant staphylococcus aureus.ConclusionsIn summary,based on melt blending method and FDM printing technology,porous PCL/Mg and PCL/Cu O scaffolds were manufactured for complicated bone defects,which provided a favorable insight and approach for 3D bioprinting technology and application of Mg and Cu in bone repair.