Preparation And Properties Of 3D Printed PCL Artificial Bone Scaffold With NmZnO/CHA Antibacterial Coating

Objective:Objective to study the preparation technology of nanometer zinc oxide coral hydroxyapatite polycaprolactone(nmZnO/CHA/PCL)antibacterial artificial bone scaffold by Fused deposition modeling of 3D printing,to prepare personalized bone repair materials with good mechanical properties and sustained antibacterial properties,and the effect of 3D printing PCL artificial bone scaffolds with nmZnO/CHA antibacterial coating on the proliferation and adhesion of mouse embryonic osteoblast precursor cells(MC3T3-E1)was studied in vitro.Methods:1.Preparation of nanometer zinc oxide coral hydroxyapatite(nmZnO/CHA):(1)Natural coral and diammonium hydrogen phosphate were used as raw materials,through "hydrothermal reaction ",the corals hydroxyapatite particles were obtained.(2)Zinc nitrate and CHA were used as raw materials,poly-ethylene glycol-6000(PEG-6000)was used as dispersant,nmZnO/CHA composites were prepared by sol-gel method.The surface morphology of composites was analyzed by SEM.2.Preparation of 3D printing PCL artificial bone scaffolds with nmZnO/CHA antibacterial coating:(1)Preparation of polycaprolactone(PCL)porous scaffold:①Model design of 3D printing nmZnO/CHA/PCL antibacterial artificial bone scaffold:Refer to the size of commercial bone ring,using solidworks three-dimensional design software,we designed a ring-shaped artificial bone scaffold with an outer diameter of 10 mm,an inner diameter of 3 mm and a height of 3 mm.②Save the designed model file as STL format file recognized by 3D printer,import 3D printer,through FDM technology,Print out the PCL porous scaffold.(2)Preparation of nmZnO/CHA coating on PCL porous scaffolds:①Add polycaprolactone particles into acetone solution and stir to make polycaprolactone fully dissolve in acetone,then,the nmZnO/CHA composite was added and stirred.The nmZnO/CHA/PCL slurry was prepared.②The porous PCL scaffold was immersed in nmZnO/CHA/PCL slurry,and the nmZnO/CHA composite was coated on the surface of PCL scaffold by dip coating method,then the composite scaffold was placed in a 40℃ drying oven for 24 h,nmZnO/CHA/PCL antibacterial artificial bone scaffold was prepared.The mechanical properties,porosity and pore size distribution were measured and analyzed by electronic universal material testing machine and mercury porosimeter.3.Effect of 3D printing PCL artificial bone scaffolds with nmZnO/CHA antibacterial coating on osteogenic activity of mouse embryonic osteoblast precursor cells:MC3T3-E1 cells of the fourth generation were seeded on the surface of nmZnO/CHA/PCL antibacterial artificial bone scaffold at the concentration of 5×104/ml,after 3 days of culture,the growth and adhesion of cells on the scaffold were observed by tungsten filament scanning electron microscope.Results:①The nanometer zinc oxide(nmZnO)modification of CHA was carried out by sol-gel method.When CHA:zinc nitrate:PEG-6000 was 8:2:1,the SEM test results showed that the size and distribution of nmZnO particles on the surface of nmZnO/CHA composite materials were the most ideal,and the particle size was controlled below 100nm,and there was no obvious agglomeration phenomenon.②The mechanical properties of the composite scaffolds were tested by using electronic universal material experimental machine,and the elastic modulus was calculated to be 30.15±4.13 MPa;the porosity of the composite scaffolds was 48.05%and the pore size distribution was 50-200μm by using mercury press.③Scanning electron microscopy showed that MC3T3-E1 cells grew well on the surface of the composite scaffolds,and there was tight adhesion to the surface of the scaffolds.Conclusions:①Using sol-gel method,composites with the surface uniformly distributed nmZnO particles below 100μm can be prepared when CHA:nmZnO:PEG-6000 is 8:2:1.②nmZnO/CHA/PCL antibacterial artificial bone scaffolds exhibited desirable porosity and pore size distribution,as well as good mechanical properties.③nmZnO/CHA/PCL antibacterial artificial bone scaffolds are cytocompatible and can be used as scaffolds for bone tissue engineering.