2009 年 18 巻 2 号 p. 71-76
The in-vitro response of the biphasic calcium phosphate (BCP) ceramics hydroxyapatite (HAP) and β-tricalcium phosphate (TCP) prepared by tape-casting was investigated. BCP ceramic slurries were prepared to HAP/β-TCP weight ratios of 75/25 (H75-T25), 50/50 (H50-T50), and 25/75 (H25-T75). Additionally, 100% HAP (H100) and 100% β-TCP (T100) were prepared as control. BCP ceramic sheets fabricated by tape-casting were sintered at 1200°C for 4 h. After sintering at 1200°C, thin-film X-ray diffraction confirmed that β-TCP in the BCP ceramics was partially transformed to α-TCP; HAP showed no change. Field-emission scanning electron microscope observation showed that the surfaces of H25-T75 and T100 were completely covered with precipitate after 90 d' immersion in phosphate-buffered saline solution with pH 7.4 at 37°C. After osteoblast-like (MC3T3-E1) cell cultivation for 7 d, H25-T75 showed a significantly higher cell number than H100, H75-T25, and H50-T50 (Fisher's PLSD test, p<0.05). These results indicate that the determination of an optimal balance of biological stability and biodegradation rate is important to fabricating BCP ceramics because it directly affects the in-vitro response. Within the limitation of this study, it is concluded that BCP ceramics with a HAP/TCP ratio of 25/75 prepared by a tape-casting technique has high cellular activity.
