一种可注射体内成孔的磷酸钙骨水泥

背景：磷酸钙骨水泥存在脆性大、抗水溶性(血溶性)差、力学性能不足、降解缓慢等缺点，其临床应用受到一定限制，故需要对其进行改性研究。目的：制备一种具有一定强度、孔隙率、适合骨生长的多孔磷酸钙骨水泥生物支架材料。方法：以磷酸钙骨水泥为基本体系，液相采用壳聚糖的弱酸溶液，以提高磷酸钙骨水泥的可塑性和黏弹性，使骨水泥具有可注射性，显著提升骨水泥的应用范围及应用舒适度。固相为双相磷酸钙(磷酸四钙+磷酸氢钙)粉体，并在固相中添加一定量的甘露醇及聚乳酸-乙醇酸共聚物作为造孔剂，制备磷酸钙支架材料。结果与结论：此材料孔径可达到10~300 μm。添加60%致孔剂时，磷酸钙骨水泥固化体孔隙率可达到(68.3±1.5)%。磷酸钙骨水泥孔隙率的增加使材料的力学性能下降，其抗压强度从最初不含致孔剂时的(53.0±1.4) MPa下降到含60%致孔剂的(2.5±0.2) MPa。实验制备的此种多孔磷酸钙骨水泥材料，是具有一定抗压强度、较好的孔隙率，并能体内降解的可注射生物支架材料。

A type of injectable porous calcium phosphate cement in vivo

BACKGROUND:Calcium phosphate cement (CPC) has the disadvantages of brittleness, low waterborne (blood-soluble), poor mechanical property and conductibility which limit its clinical application in some degree. Therefore its modification research is in need.OBJECTIVE:To prepare a type of porous calcium phosphate cement with certain intensity and porosity for the bone growth. METHODS:This study was based on the CPC system. The liquid phase was the weak acidic solution of chitosan which had favorable biocompatibility and high viscosity to achieve injectable of CPC. It could strongly improve the application and comfort of CPC. The solid phase was biphasic calcium phosphate (four calcium phosphate + calcium hydrogen phosphate) system. The pores of mannitol and lactic-co-glycolic acid were added into solid phase to prepare the calcium phosphate scaffold. RESULTS AND CONCLUSION:The aperture of the prepared material could reach to 10-300 μm. The porosity of the solidified CPC could reach to (68.3±1.5)% when the proportion of the porogen was 60%. The increased porosity of CPC decreased the mechanical properties of the material, the compressive strength of CPC without porogen was (53.0±1.4) MPa initially, and dropped to (2.5±0.2) MPa with 60% porogen. The CPC material has better compressive strength and favorable biocompatibility, and can be degraded in vivo and used as a type of injectable scaffold materials.