激光加工医用聚醚醚酮表面微织构及性能研究OA

Poly ether ether ketone(PEEK),a high-molecular polymer material,has an elastic modulus more similar to that of human cortical bones,which can minimize stress shielding.However,due to its inherent biological inertness,the bone integration ability and biocompatibility of PEEK need to be improved.In this study,orthogonal micro-textures with different center distances were fabricated on the surface of PEEK with ultraviolet laser processing technology to enhance the bone integration ability and biocompatibility of PEEK.After preliminary mechanical property tests,the PEEK samples were polished and ground.Orthogonal micro-textures with center distances of 100 μm,200 μm,300 μm,and 400 μm were fabricated on PEEK materials with dimensions of 10 mm×10 mm×10 mm by an ultraviolet laser processor with an output power of 1.4 W,a scanning speed of 80 mm/s,and a scanning frequency of 90 kHz.After successful fabrication of the orthogonal micro-textures with different center distances,the roughness before and after processing was compared.Then,the samples were immersed in simulated body fluid,maintained in a constant temperature water bath,and the simulated body fluid was replaced every 24 hours.After 14 days of immersion,the samples were taken out,dried,and immediately characterized for the deposition of hydroxyapatite on the surface.After pretreatment,XRD and scanning electron microscopy were used for phase analysis and imaging in a constant temperature and humidity environment,with a focus on medical PEEK materials.Before biocompatibility analysis,cytotoxicity tests were performed on the laser-processed PEEK materials which were then compared with the original PEEK materials.With simulated body fluid as the measurement medium,after ultrasonic cleaning and vacuum drying,the contact angle measurement instrument was set to a droplet volume of 2 μL,a droplet deposition speed of 0.2 μL/ms,and a balance time of 30 seconds.Each group was repeated three times.The PEEK materials with different center distances were prepared into 1 mm thin slices,with three samples in each group.Then,they were ultrasonically cleaned for 10 minutes,sterilized with ultraviolet light,and finally sealed and stored in anhydrous ethanol to ensure a sterile state.The frozen MC3T3-E1 cells were thawed in a 37 ℃ constant temperature water bath and then cultured in DMEM high-glucose medium(10%fetal bovine serum,1%penicillin/streptomycin)in a constant temperature incubator(5%CO2,37 ℃).After digestion and centrifugation of the MC3T3-E1 cells with trypsin,they were diluted and cultured at a constant temperature.Upon the completion of the treatment,the live and dead cells were stained,and the cell adhesion was observed under an inverted fluorescence microscope to quantitatively analyze the cell proliferation.The center distance of the texture had a significant regularity in regulating the surface roughness(Ra):as the center distance increased from 100 μm to 400 μm,the surface roughness gradually decreased from 8.23 μm to 3.05 μm,showing a quasi-linear attenuation trend.Through the simulated body fluid immersion experiment,it was found that the 300 μm center distance group had the best hydroxyapatite deposition ability on the surface,with a continuous mineralization layer and significantly aggregated crystalline particles.The cell experiments showed that the RGR values of all samples were greater than 90%,and the toxicity grade was 0,indicating that the laser-processed PEEK did not introduce biologically harmful by-products.Through comparison,it was found that the contact angle of the 300 μm center distance orthogonal micro-texture was the minimum value of 62.020°,with the greatest improvement in hydrophilicity and the most significant positive regulation of osteoblast behavior.The proliferation activity of cells after 72 hours of culture reached 3.2 times that of the non-textured surface.Microscopic observation showed that the cell pseudopodia extended along the texture grooves in a directional manner,demonstrating typical contact-induced growth characteristics.The laser-processed orthogonal micro-textures can significantly improve the bone integration ability and biocompatibility of PEEK materials by regulating the surface morphology,and the 300 μm center distance orthogonal micro-texture performs the best.