Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Shinmachi, Nishitokyo-shi, Tokyo 202-8585, Japan.
J Mater Sci Mater Med. 2010 Jun;21(6):1921-6. doi: 10.1007/s10856-010-4042-4. Epub 2010 Mar 12.
Alpha-tricalcium phosphate (alpha-TCP) ceramic is a bioresorbable material that degrades in bone tissue after implantation, since it exhibits higher solubility than beta-tricalcium phosphate (beta-TCP) ceramics. The high solubility of alpha-TCP in an aqueous solution causes its transformation into hydroxyapatite (HAp) through hydrolysis. While one expects the formation of hydroxyapatite after exposure to an aqueous solution mimicking a body environment, we occasionally find variation in HAp formation in the simulated body fluid (SBF). In the present study, HAp formation resulting from exposure to SBF was investigated for some types of alpha-TCP ceramics with different porosities and specific surface area. Reduced porosity and large surface area of porous specimens may increase the local density of Ca2+ in the surrounding SBF to increase the degree of supersaturation with respect to HAp. Thus, the porosity and specific surface area are significant parameters for determining not only bioabsorbability but also the ability to form HAp.
α-磷酸三钙（α-TCP）陶瓷是一种可生物降解的材料，在植入后会在骨组织中降解，因为它的溶解度比β-磷酸三钙（β-TCP）陶瓷高。α-TCP 在水溶液中的高溶解度使其通过水解转化为羟基磷灰石（HAp）。虽然人们期望在暴露于模拟体液（SBF）的水溶液中形成羟基磷灰石，但我们偶尔会发现模拟体液中 HAp 形成的变化。在本研究中，研究了具有不同孔隙率和比表面积的几种α-TCP 陶瓷在 SBF 中的 HAp 形成情况。减少多孔标本的孔隙率和大的表面积可能会增加周围 SBF 中 Ca2+的局部密度，从而增加相对于 HAp 的过饱和度。因此，孔隙率和比表面积是决定生物吸收能力和形成 HAp 能力的重要参数。
