Construction And Characterization Of Polyetheretherketone Loaded With Platelets

Objective(s):Platelet-rich plasma,which contains platelet-derived growth factors,has been proven to promote bone formation.Materials with a rough surface and three-dimensional porous structure are conducive to cell adhesion and growth.In this study,three-dimensional porous polyetheretherketone(PEEK)materials with rough surfaces and different porosity were prepared by 3D printing technology,and concentrated platelet plasma was loaded onto different samples.By observing the surface morphology of each sample,pore size,mechanical properties,and blood platelet loading capacity were measured to obtain mechanical properties can meet clinical needs,pore diameter can be conducive to cell proliferation,and can load more modified PEEK materials enriched in platelet plasma,with a view to improving the ability of PEEK materials to induce bone growth.Methods:A variety of three-dimensional porous PEEK materials with rough surfaces and different porosity were prepared using 3D printing technology.The surface morphology of each sample was observed,and the pore size and mechanical properties were measured to find a three-dimensional porous PEEK material with pore size in a suitable range for cell proliferation and mechanical properties that could meet the needs of clinical use.After that,two methods,physical adsorption and poly dopamine coating mediated adsorption,were used to load platelet enriched plasma onto three-dimensional porous PEEK materials with different porosity,and the platelet adhesion on the samples was observed using scanning electron microscopy;through an in vitro growth factor release experiment,determine whether the growth factors can be released normally,and compare the differences in the release amount of growth factors in each group to reflect the amount of platelets loaded by the modified materials in each group.To predict the ability of platelet-enriched PEEK materials to induce bone growth.Results:Each group of three-dimensional porous PEEK materials prepared obtained rough surface and relatively uniform pore size.The pore size of the three-dimensional porous PEEK materials with 20%porosity is 209.67±1.70um,30%porosity is 273.67±4.19um,40%porosity is 378.33 ±6.13um,50%porosity is 537.00 ± 14.90um,and the three-dimensional porous PEEK materials with 20%,30%and 40%porosity have suitable pore diameter for cell adhesion(100-500um).The axial compression test of the prepared PEEK sample shows that the compression strength of the three-dimensional porous PEEK material islower than that of the solid PEEK material;and with the increase of porosity,the compressive strength of the material decreases gradually,but the compressive strength of all test samples is better than that of cancellous bone(8.69±3.75MPa).Specific values:The compressive yield strength of solid PEEK material is about 42.14± 3.71 MPa,the porosity of 50%PEEK material is 16.55± 1.44MPa,the porosity of 40%PEEK material is 20.27 ± 1.76MPa,the porosity of 30%PEEK material is 27.51 ± 1.72MPa,and the porosity of 20%PEEK material is 32.89 ± 1.53MPa.Using physical adsorption to directly adsorb and enrich platelet plasma has not been successful,but under the mediation of adsorption with a polyamine coating,the platelet-rich plasma can be successfully loaded into PEEK materials.PEEK materials with different porosity can adsorb platelets through the polyamine coating,and the platelet growth factor in them can be released normally,but the release amount is different.Among the two platelet derived growth factors selected for measurement,transforming growth factor-β1(TGF-β1)release amount concentration is the highest for PEEK-PDA-PRP samples with a porosity of 20%,followed by PEEK-PDA-PRP samples with a porosity of 30%,PEEK-PDA-PRP samples with a porosity of 40%,solid PEEK-PDA-PRP samples,and samples with a porosity of 50%.The measured concentration of vascular endothelial growth factor(VEGF)is 40%PEEKPDA-PRP>20%PEEK-PDA-PRP>solidPEEK-PDA-PRP>50%PEEK-PDAPRP>30%PEEK-PDA-PRP.Conclusion(s):1.It is feasible to modify the PEEK material by using the method of changing the surface morphology and loading to promote the bone material.2.Through 3D printing technology,three-dimensional porous PEEK materials with suitable pore sizes and mechanical properties that can meet clinical needs can be prepared.3.Through polydopamine biocoating mediated a dsorption,platelet-enriched plasma,which has osteogenic effects,can be loaded onto the surface of PEEK materials,and growth factors in platelet-enriched plasma can be released normally.This modified PEEK material loaded with platelet-enriched platelets is expected to improve the performance of PEEK materials in inducing bone growth.4.Considering the pore size,mechanical properties,and growth factor release of the modified PEEK material,among the several three-dimensional porous structure modified PEEK materials prepared under this configuration and layer height conditions used in the experiment,the material with a porosity of 20%has the appropriate pore size,optimal mechanical properties,and more growth factors released,which may be the most suitable modified material.However,it is still necessary to conduct in vitro cell experiments and animal experiments to further confirm its osteogenic properties.