Leroux L, Hatim Z, Frèche M, Lacout J L
Laboratoire Interfaces et Matériaux, Physico-Chimie des Phosphates, CNRS UPRESA 5071, ENSCT-INPT, Toulouse, France.
Bone. 1999 Aug;25(2 Suppl):31S-34S. doi: 10.1016/s8756-3282(99)00130-1.
Calcium phosphate cements are well-known orthopedic materials for filling bone. Various formulations are proposed. The current challenge is to place the material in the surgical site by methods as least invasive as possible. One approach consists of making the cement injectable by incorporation of various adjuvants. However, the requirement properties of the cement must be preserved: setting times suited to a convenient delay with surgical intervention, limited disintegration in aqueous medium, and sufficient mechanical resistance. Various additives were studied: in particular, lactic acid, glycerol, chitosan, and sodium glycerophosphate. Injectability, setting time, disintegration, and toughness after 10 days were followed in vitro. Glycerol greatly improved injectability and increased setting time, but decreased mechanical properties. Lactic acid reduced setting time, increased toughness of the material, but limited the dissolution rate. After injection, the cement did not present any disintegration. The effects lactic acid were correlated with the formation of calcium complex. Its association with sodium glycerophosphate is particularly interesting. Chitosan alone improved injectability, increased setting time, and limited the evolution of the cement by maintaining the OCP phase. Only slight disintegration was observed. These first results show that is possible to transform the cement into an injectable paste by addition of adjuvants without fundamentally modifying the chemical reactions occurring during setting and hardening.
磷酸钙骨水泥是用于填充骨骼的著名骨科材料。人们提出了各种配方。当前的挑战是通过尽可能微创的方法将材料放置在手术部位。一种方法是通过加入各种助剂使骨水泥可注射。然而，必须保留骨水泥所需的性能：适合手术干预适当延迟的凝固时间、在水性介质中有限的崩解以及足够的机械阻力。研究了各种添加剂：特别是乳酸、甘油、壳聚糖和甘油磷酸钠。在体外跟踪了可注射性、凝固时间、崩解和10天后的韧性。甘油极大地改善了可注射性并延长了凝固时间，但降低了机械性能。乳酸缩短了凝固时间，提高了材料的韧性，但限制了溶解速率。注射后，骨水泥没有出现任何崩解。乳酸的作用与钙络合物的形成有关。它与甘油磷酸钠的结合特别有趣。单独的壳聚糖改善了可注射性，延长了凝固时间，并通过维持OCP相限制了骨水泥的演变。仅观察到轻微崩解。这些初步结果表明，通过添加助剂可以将骨水泥转化为可注射糊剂，而不会从根本上改变凝固和硬化过程中发生的化学反应。
