Chemical Modification of Adhesion Motif onto Apatite-Collagen Laminated Composites

近年来，人们开始考虑将黏附分子的概念应用于生物材料。在本研究中，我们设计了一种含有RGD-序列的多肽，并将其固定在聚乙二醇-聚苯乙烯接枝共聚物上或连接在胶原分子上，对CO_3磷灰石-胶原复合材料进行了修饰。然后，检测成骨细胞在所得复合材料上的粘附性。结果表明，镁离子对成骨细胞在FGMgCO3AP-胶原复合材料上的黏附有促进作用。下一步的任务是合成含镁的功能梯度Cc3磷灰石，产生从表面到核心的镁浓度负梯度。第二项任务是研究细胞与FGMgCO3磷灰石和胶原混合制成的复合材料的粘附度，以便于粘结和加工。扫描电子显微镜观察表明，成骨样细胞在FGMgCO3AP-胶原复合材料表面附着良好。苏木精-伊红和茜素红染色证实，FGMgCO_3AP-胶原复合材料比CO_3AP-胶原复合材料存在更多的细胞和更厚的细胞外基质层。这些结果证实了镁离子对成骨细胞在FGMgCO3AP-胶原复合材料上黏附的促进作用。动物实验表明，该复合材料具有良好的生物相容性。

Recently, the application of the concept of adhesion molecules to biomaterials was considered. In the present study, we designed a peptide containing the RGD-sequence, and the peptide was immobilized on the PEG-PS graft copolymer or conjugated on a collagen molecule, which modified the CO_3apatite-collagen composite. Then, the adhesive properties of osteoblasts onto the resulting composite were examined. The result demonstrated the acceleration effect of magnesium ions on osteoblast adhesion on the FGMgCO_3Ap-collagen composite. Next task was to synthesize functionally graded CC_3apatite containing Mg, producing a negative gradient of magnesium concentration from the surface toward the core. The second task was to investigate the degree of cell adhesion to a composite that was made by mixing the FGMgCO_3apatite and collagen to facilitate bonding and processing. SEM observation showed that the osteoblast-like cells adhered well to the surface of the FGMgCO_3Ap-collagen composite. Staining with haematoxylin-eosin and alizarin red confirmed the existence of a great many more cells and a thicker extracellular matrix layer on the FGMgCO_3Ap-collagen composite than on the CO_3Ap-collagen composite. These results demonstrated the acceleration effect of magnesium ions on osteoblast adhesion on the FGMgCO_3Ap-collagen composite. Animal experiments showed good biocompatibility of the composites.