壓電陶瓷作為生醫植入物之可行性研究

Abstract

本實驗中以傳統粉末製程製作三種壓電陶瓷，分別為鈮酸鈉鉀、鈮酸鋰鈉鉀以及鈦酸鋇。鈮酸鈉鉀粉末經由保存方法的改良，發現有助於之後的燒結並可得到較佳的性質。而經由添加鋰進行改質，可以提高燒結密度、壓電性以及機械強度。另外最佳燒結溫度也隨著之降低，顯示添加鋰可固溶於鈮酸鈉鉀。富鈦的鈦酸鋇粉末燒結後可觀察到異常晶粒成長。壓電塊材經由浸泡在生理食鹽水達28天，可發現三種壓電材料皆顯現高穩定度。同時間可以觀察到非對稱的氯化鈉晶體沈積，亦即晶體皆沈積在塊材的正極面。細胞毒性則是採用老鼠纖維母細胞作為測試細胞，並且採用MTT毒性測試。結果發現使用粉末萃取液當做測試溶液，仍可得到相當高的細胞存活率。其中鈮酸鈉鉀為基材的壓電陶瓷，在模擬活體環境下有高度穩定度及低度細胞毒性，可評估在後續生醫上的應用具有潛力。

In the present study, three kinds of piezoelectric ceramics, including K0.5Na0.5NbO3 (KNN), Li0.06K0.47Na0.47NbO3 (LKNN) and BaTiO3, were prepared by using conventional powder processing. A dry environment for the storage of the KNN and LKNN powders is beneficial for densification. The modification of KNN by doping lithium can improve its density, piezoelectricity and mechanical strength. The optimal sintering temperature is also decreased, indicating that a solid solution of KNN and lithium is formed. The BaTiO3 powder used is a Ti-rich BaTiO3 powder. Relatively large grains are found in the sintered specimens. All three bulk ceramics show high stability after immersion in normal saline for up to 28 days, and anisotropic deposition of NaCl crystal was observed. The cytotoxicity is investigated by using the MTT assay, and L929 fibroblasts were used as the testing cells. The viabilities of cells after treatment of powder extract were all high for three groups. The KNN-based piezoelectric ceramics showed high stabilities and low toxicity in body-simulated environment. Therefore, it is a potential material for further biomedical applications.