Biocompatibility Of 3D Printed Polyetheretherketone/Hydroxyapatite Composites

Objective:To construct polyetheretherketone/hydroxyapatite composites prepared by fused deposition molding 3D printing,and investigate its characterize the material,biocompatibility and bone formation ability in vitro.Methods: Polyetheretherketone and polyetheretherketone/hydroxyapatite composite materials(hydroxyapatite mass fraction10%)were prepared by fused deposition molding 3D printing technology,which were denoted as polyetheretherketone group(control group)and polyetheretherketone/hydroxyapatite group(experimental group).Passage 3 mouse preosteoblasts(MC3T3-E1)were co-cultured with the extracts of the two groups of materials,separately.Cells cultured alone were used as positive controls.The survival and proliferation of MC3T3-E1 were detected by Live/Dead fluorescence staining and CCK-8 assay.The adhesion growth and proliferation of MC3T3-E1 on the surface of the materials were observed by scanning electron microscopy.Passage 3 mouse preosteoblasts(MC3T3-E1)were co-cultured with the two groups of materials,separately,to detect the levels of osteocalcin and collagen type I produced by osteoblasts.Results:(1)The appearance of the 3D printed PEEK material was amber,and the printing lines were uniform and neat.After the incorporation of hydroxyapatite,the color of the sample became light and white,and the small hydroxyapatite particles on the surface could be seen,with a rough surface.(2)Live/Dead fluorescence staining exhibited that the MC3T3-E1 cells in two kinds of extracts grew well and presented good viability.The cell survival rate was higher than 90%.The two materials had no obvious cytotoxicity.The cells proliferated well with the extension of culture time.(3)The results of CCK-8 assay showed that the proliferation absorbance value of cells in the experimental group was higher than that of positive control group and control group at 3,5 and 7 days of culture(P < 0.05).(4)The toxicity of PEEH/HA material was rated as grade 1 on the first day and grade 0 on the third,fifth and seventh days,indicating that the cytotoxicity was qualified.(5)Scanning electron microscope observation showed the good adhesion and cell spreading.Matrix secretion of MC3T3-E1 cells was numerous in the experimental group at 1 day of inoculation.The number of cells adhering to the surface of the two groups of materials increased,and more matrixes were secreted at the same time,among which the number of cells adhering to the surface of the experimental group and the secretion of matrix were more at 3 days of inoculation.The overlapping growth of cells appeared on the surface of the two groups of materials,and the cells in the experimental group were more efficient in spreading growth and secreting matrix at 7 days of inoculation.(6)General view of 3D printing of the two materials: The PEEK material cage was amber in appearance,while the PEEK/HA material cage was white in overall color,and the printing pattern of the two groups of material cage was uniform and smooth.Results:These findings verify that the polyetheretherketone/hydroxyapatite composite prepared by 3D printing has good biocompatibility,and are expected to be used as materials for new 3D printing interbody fusion machine.