硫酸鈣(CaSO4)與碳酸鈣(CaCO3)由於良好的生物相容性,並且為人體骨骼內主要成分,兩者都廣泛應用於骨缺陷修補材料。此類填充材料的特點為硫酸鈣植入骨缺陷處會在體內降解並被人體吸收,同時產生鈣離子促進骨頭生長,但是若降解後新生骨骼還未生長成型,易形成缺陷而阻礙骨生長。於硫酸鈣中添加碳酸鈣,碳酸鈣因降解速率慢,當硫酸鈣被人體降解吸收時,周遭碳酸鈣依然存在,因而形成孔洞促進骨細胞生長。將硫酸鈣與碳酸鈣複合成型,製成之骨替代之材料,可解決單一材料的不足性。本實驗依不同重量百分比混合硫酸鈣與碳酸鈣粉末,並水合硬化製成複合材料。再由SEM顯微分析及XRD繞射分析從結晶結構探討添加碳酸鈣對硫酸鈣的物理性質以及機械強度的影響,並量測其降解率及生物相容性(In Vitro研究)。添加後二水硫酸鈣結晶結構之改變,使材料孔隙度上升、抗彎抗壓強度上升、並影響其降解率以及生物相容性。實驗針對試片分析材料降解步驟,轉換成趨勢圖推導出化學反應動力學公式,從而來瞭解此生醫複合材料之降解反應機制。
In this study, we mixed different proportion of calcium sulfate and calcium carbonate powders for hydration hardening to make up composite materials for bone replacement. SEM and XRD were used to analyze the crystalline structure of these composite products to determine the effects of adding calcium carbonate on the physical properties of calcium sulfate and composite mechanical strength. We conducted MTT cell growth tests to investigate the biocompatibility of the composite materials. Results showed that adding a small amount of calcium carbonated can increase the mechanical strength and pore structure to improve the degradation characteristics and to stimulate bone cell proliferation.