Modification Properties of Heparinized Apatite-Collagen Composites

羟基磷灰石与周围组织具有良好的生物相容性，是一种有用的植入式材料。磷灰石已被应用于牙科，以填补拔牙后被吸收的骨和下颌骨的缺损区域。然而，大多数商业羟基磷灰石是烧结的。此外，常规块状羟基磷灰石难以加工成复杂的形态，粒状羟基磷灰石不易保持所需的形态。为了获得更好的处理性能，本研究合成了化学成分和结晶度与人骨相似的碳酸盐-磷灰石，并将其与胶原蛋白溶液混合。作为颗粒，该复合材料与软硬组织均具有良好的生物相容性。紫外线照射后的样品在较长时间内保持其形状。此外，肝素被结合到复合材料上，附着骨形态蛋白（BMP），它具有诱导骨形成的能力。成功地进行了肝素分析。然而，由于肝素对BMP的亲和力不足以应用，进一步的研究正在进行中。

Hydroxyapatite is useful as an implantable material because of its good biocompatibility with surrounding tissues. Apatites have been applied in dentistry to fill up resorbed bone after tooth extraction and in defective areas of mandibular bone. However, most commercial hydroxyapatites are Sintered. Furthermore, conventional block-type hydroxyapatite is difficult to process into complex form and granular-type hydroxyapatite does not readily retain the required form. In this study to obtain better handling properties, carbonate-apatite with chemical composition and crystallinity similar to those of human bone, was synthesized and mixed with collagen solution. As a pellet, the composite was well biocompatible with soft and hard tissues. UV-irradiated samples kept their shape for longer periods. Furthermore, heparin was bound onto the composites to attach the bone morphological protein (BMP), which has an ability to induce bone formation. Analysis of heparin was carried out successfully. However, since the affinity of heparin for BMP was not enough to apply, further investigations are in progress.