| 摘要: | 近年來聚醚醚酮(Polyetheretherketone, PEEK)因具有高強度、高可撓性、抗腐蝕及生物相容性等特性，是一個新興的植入物材料。然而PEEK是惰性材料需進行表面改質或製作成複合材料，用以提高PEEK親水性/生物活性。本計畫使用熔積成型技術(FDM)列印PEEK植入物，其粗糙表面可增加細胞附著力，並搭配一個創新的方法─選擇性粉末沉積法，進行PEEK植入物的表面改質。聚乳酸(PLA)的沸點為230℃，而PLA在343℃(PEEK的熔點)將會熱解成氣體。選擇性粉末沉積法的主要流程為：首先，PLA顆粒摻一定比例的氫氧基磷灰石(HA)粉末然後擠製成線材，接著以FDM技術在PEEK列印的每層最外圈先用此PLA-HA線材列印。接著，負責擠出PEEK材料之噴嘴在相同路徑移動。此時PLA會熱解，HA粉末(熔點為1100 °C)會被隨後擠出的PEEK熔融線沾黏而牢牢嵌入於PEEK裡。這種表面嵌覆HA粉末的PEEK列印植入物，可以提高其親水性，不會降低原本PEEK的機械特性，也沒有一般表面塗層容易發生脫落的問題產生。本計畫規劃兩年，第一年著重在建構出適合列印PEEK且可執行選擇性粉末沉積法的FDM機台，並發展PEEK/PLA顆粒摻不同比例HA粉末擠製成線材的製程。第二年則是將選擇性粉末沉積法實作出來，並列印出摻不同比例HA粉末的試片。最後用田口法以親水性(接觸角)為目標函數找出最佳製程參數。預期執行本研究後，將可提高PEEK列印植入物之親水性30%以上且HA粉末嵌入表面不脫落，未來也可進一步規劃細胞實驗，用以驗證PEEK-HA列印植入物的生物活性表現。 ;In recent years, Polyetheretherketone (PEEK) is a new implant material due to its high strength, high flexibility, corrosion resistance, and biocompatibility. However, PEEK is biologically inert that needs to be surface modified or made into a composite material to improve the hydrophilicity/bioactivity of PEEK. This project uses fused deposition modeling (FDM) technology to print PEEK implants. The rough, printed surface can increase cell adhesion. In combination with an innovative method called selective powder deposition (SPD), the surface modification of PEEK implants performs. Polylactic acid (PLA) has a boiling point of 230 °C, and PLA at 343 °C (the melting point of PEEK) will pyrolyze into gas. The SPD main process is: firstly, PLA pellets are mixed with a certain proportion of hydroxyapatite (HA) powder and then extruded into a filament. FDM technology is used to print on the outermost contour of each PEEK printed layer with this PLA-HA filament. Then, the PEEK nozzle moves in the same path. At this time, PLA will be pyrolyzed, and HA powder (melting point: 1100 °C) will be stuck in the PEEK melting strand which is subsequently extruded. In this way, the PEEK printed implants with HA powder embedded into the surface can improve their hydrophilicity, not reduce their mechanical properties, and no shedding problem occurs compared with general surface coatings.The research is planned for a two-year period. The first year focuses on constructing an FDM printer suitable for printing PEEK and performing the SDP method, and developing a process of extruding PEEK / PLA pellets with different proportions of HA powder into filaments. In the second year, the SPD method will implement, and test specimens with different proportions of HA powder will print. Finally, the Taguchi method will use to find the optimal process parameters with hydrophilicity (contact angle) as the objective function. It expects that after the execution of this research, the hydrophilicity of PEEK printed implants will improve by more than 30% and the HA powders will embed on the implant surface without falling off. Cell experiments can be further planned in the future to verify the bioactivity performance of PEEK-HA printed implants. |
