骨水泥自固化法制备磷酸钙多孔材料

FABRICATION OF POROUS CALCIUM PHOSPHATE MATERIALS BY SELF-SETTING METHOD

在αTCP(tricalciumphosphate,磷酸三钙)骨水泥中加入生物明胶,通过明胶在骨水泥自固化反应过程中的溶胀行为,可制备含200～400μm大孔和贯穿式微孔的多孔磷酸钙生物材料。实验表明:骨水泥水化反应初期,体系为弱酸性,αTCP向羟基磷灰石快速转化,使骨水泥获得较高的结合强度;而此阶段明胶溶胀度最小,产生的溶胀力较小,明胶微球成孔空间被保留在骨水泥基体中。随着水化反应的进行,骨水泥的结合强度不断提高,从而抑制明胶溶胀度的进一步增加,继续保留明胶微球成孔空间。水化后,将含明胶微球的骨水泥浸入50℃的水溶液中,明胶微球溶解,即由凝胶态转化为溶胶态,从而获得非烧结多孔磷酸钙材料。

Macroporous calcium phosphate biomaterials based on α-tricalcium phosphate (α-TCP) with porous structure suitable for implantation purposes were prepared by gelatin granules as pore formers. Macroporous calcium phosphate biomaterials with pore sizes of 200-400 μm can be produced by adjusting the swelling behavior of gelatin during the self-setting of gelatin in α-TCP according to the pH value. The experiment indicates that during the early hydration the system is in weak acidity and the α-TCP in the system transfers quickly to hydroxylapatite, thus the adhesive force between matrix particles is strong. The swelling ratio and the selling force of gelatin caused by water uptake is small. Therefore, the space formed by the gelatin micro-spheres in cement matrix will be retained. The swelling behavior of gelatin in cement matrix in the further hydration process is restricted by the surrounding matrix particles along with the increasing of the adhesive force of the cement. A cement matrix sample containing gelatin gel spheres obtained after hydration are immersed in the deionized water of 50°C to dissolve the gelatin spheres, the gelatin spheres is transferred from gel state to sol state. Thus non-sintered macroporous calcium phosphate is obtained.