以鹼性溶液與熱處理法進行鈦合金表面改質之研究

Abstract

本研究針對先前所開發之高強度、低楊氏係數與含低毒性元素之Ti-Nb合金－Ti-30Nb-1Fe-1Hf與Ti-40Nb-1Hf，以鹼性溶液與熱處理進行表面改質，再以體外骨母細胞培養實驗來評估其生物相容性，並與商用純鈦及Ti-6Al-4V合金作一比較。藉由鹼性溶液及熱處理可於商用純鈦及Ti-6Al-4V表面成長多孔性的表面組織，而對於Ti-30Nb-1Fe-1Hf及Ti-40Nb-1Hf之表面則會形成不規則裂痕的形貌。又，利用鹼性溶液及熱處理可增加鈦合金表層氧及氫氧根的含量，有效改善表面潤濕性。對於表層化學組成而言，經鹼性溶液及熱處理可促使純鈦及Ti- 6Al-4V的表層生成TiO2，而促使Ti-30Nb-1Fe-1Hf及Ti-40Nb- 1Hf的表層生成TiO2與Nb2O5。對於Ti-30Nb-1Fe-1Hf及Ti-40Nb- 1Hf合金而言，以鹼性溶液及熱處理法作表面改質之後，表面所形成之不規則狀裂痕形貌、表層氧及氫氧根的含量增加，而提升表面潤濕性，以及在表層所生成之TiO2與Nb2O5等，均有利於骨母細胞的貼附及增殖。體外生物相容性實驗結果顯示，Ti-30Nb-1Fe-1Hf及Ti-40Nb- 1Hf之細胞貼附形貌、細胞總數與MTT吸光值分析皆與商用純鈦及Ti- 6Al-4V合金相近。綜上所述，本研究以鹼性溶液及熱處理法對於Ti-30Nb-1Fe- 1Hf及Ti-40Nb-1Hf合金進行表面改質之後，可增進該合金之生物相容性。

The previously developed titanium-niobium alloys – Ti-40Nb-1Hf and Ti-30Nb-1Fe-1Hf alloys – exhibit relatively high strength and low elastic modulus and are considered quite suitable for implants application. This study employed alkali solution treatment and heat treatment to modify the surfaces of Ti-40Nb-1Hf and Ti-30Nb-1Fe-1Hf alloys together with the commercially pure Ti and Ti-6Al-4V alloy, and then the biocompatibility of the treated alloys was analyzed by means of osteoblast cell culture in vitro. The results indicate that porous surfaces were obtained for pure Ti and Ti-Al-4V, while surfaces with irregular cracks were obtained for Ti-40Nb-1Hf and Ti-30Nb-1Fe-1Hf alloys, after surface modification. Also, the surface wettability was improved after alkali solution treatment and heat treatment due to the increase of oxygen and hydroxyl on the surface layer. In addition, both alkali and heat treatments enhanced the growth of TiO2 on the surface layer of the commercially pure Ti and Ti-6Al-4V, and TiO2 and Nb2O5 for Ti-40Nb-1Hf and Ti-30Nb-1Fe-1Hf alloys. The formation of irregular cracks on the treated surfaces together with the increase in oxygen and hydroxyl, and TiO2 and Nb2O5 on the surface layer had been found to improve surface wettability and also the osteoblast attachment and proliferation of the surface-treated alloys. This has also been confirmed in vitro study, where the cell morphology, cell number and MTT optical assay of Ti-40Nb-1Hf and Ti-30Nb-1Fe-1Hf alloys are similar to those of pure Ti and Ti-6Al-4V alloy.