Dual setting mineral cements with polymerisable organic matrix based on degradable polymers

由于陶瓷水泥基质的脆性，无机生物水泥在承重缺陷中的应用受到限制。拟议的项目涉及无机-有机复合材料，它由矿物水泥相和溶解在水泥液中的原位可交联聚合物相组成。这种双固化浆体应在无机水泥凝结之前提供高抗压强度和足够的粘聚性，并由于聚合物含量而提高抗弯强度和断裂功。一个总的目标是合成可降解的无机和聚合物相基质，以便通过用天然骨组织替代来获得完全的材料吸收。在酸性或中性条件下形成可降解的水化钙镁磷酸盐的无机水泥相，如钙镁石(CaHPO4*2H2O)或鸟粪石(MgNH4PO4*6H2O)。对有机基质的要求是由聚乙二醇或聚乙二醇缩甲基丙烯酸(交联物)、酯(如丙交酯、降解)和磷酸盐部分(粘结剂)衍生的多功能、水溶性单体和预聚体。材料将在与成骨细胞接触的情况下进行细胞相容性测试，同时通过在材料表面培养破骨细胞来证明材料的降解行为。采用静态和动态两种测试方式对其生物力学性能进行了分析。

An extension of the application of inorganic biocements to load-bearing defects is limited due to the brittle nature of the ceramic cement matrices. The proposed project deals with inorganic-organic composite materials which consist of a mineral cement phase and an in situ cross-linkable polymer phase which is dissolved in the cement liquid. Such dual-setting pastes should provide both a high compressive strength and a sufficient cohesion resistance until inorganic cement setting as well as an improved bending strength and work of fracture due to the polymer content. A general aim is the synthesis of degradable matrices of both the inorganic and the polymer phase such that a full material resorption is obtained with the replacement by native bone tissue. The inorganic cement phase set under acidic or neutral conditions to form degradable, hydrated calcium and magnesium phosphates such as brushite (CaHPO4*2H2O) or struvite (MgNH4PO4*6H2O). Requirements for the organic matrix are multifunctional, water soluble monomers and prepolymers derived from polyethylenglycol or polyglycidols with methacrylic (cross-linking), ester (e.g. lactide, degradation) and phosphate moieties (cement adhesion). The materials will be tested in contact to osteoblasts regarding their cytocompatibility while the degradation behaviour is demonstrated by cultivation of osteoclastic cells on the materials surface. The biomechanical performance is analysed by using both static and dynamic testing regimes.