纳米羟基磷灰石前体与胶原自组装成类骨质复合材料的表征

文题释义： 纳米羟基磷灰石前体：纳米羟基磷灰石的悬浮液，制备方程为10Ca(NO₃)₂+6(NH₄)₂HPO₄+8NH₃?H₂O=Ca₁₀(PO₄)₆(OH)₂+ 20NH₄NO₃+6H₂O，反应时pH值10左右，反应完成后静置、洗涤，得到pH值8.0-9.0的纳米羟基磷灰石悬浮液。 自组装：是指基本的结构单元(分子、纳米材料、微米或更大尺度的物质)自发形成有序结构的一种技术。自组装过程中，基本结构单元在非共价键的相互作用下自发的成为一个稳定、外观具有一定规则的结构。 背景：制作类似于天然骨的材料来修复骨缺损，或者作为组织工程支架材料是研究的热点。 目的：探讨以纳米羟基磷灰石的前体及胶原为材料自组装成类骨质复合材料的可行性。 方法：将胶原材料分别浸泡于0.25%戊二醛溶液中0.5 h(A组)，24 h(B组)，72 h(C组)进行交联反应，D组将胶原浸泡于碳化二亚胺中交联4 h，将交联后的各组胶原浸泡于纳米羟基磷灰石前体溶液中7 d，制备类骨质复合材料。分析各组复合材料与天然骨的矿化物物相分析、组成成分及微观结构。 结果与结论：①X射线衍射分析：复合材料的非晶象衍射峰稍高于天然骨，各组复合物中非晶象变化不明显；随戊二醛交联时间的延长，材料晶体峰值有增高趋势；碳化二亚胺交联后材料的晶体衍射峰值较戊二醛交联材料稍低；②傅里叶转换红外光谱分析：复合材料的化学组成与天然骨的组成相似，都是由胶原和羟基磷灰石组成，其中羟基磷灰石中部分PO₄^3-被CO₃^2-离子取代；不同交联方法对材料无机相改变的影响差别不明显；③扫描电镜：胶原的不同交联方法对所形成晶体的形貌影响不明显：胶原纤维互相缠绕，其上有大量的细针样晶体沉积，聚成团，晶体分布均匀，晶体尺寸是纳米量级；④结果表明，以纳米羟基磷灰石前体及胶原为材料可制作自组装成类骨质复合材料。 ORCID: 0000-0003-1620-3673(张雪梅) 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程

Characterization of self-assembled bone-like nano-hydroxyapatite/collagen composites

BACKGROUND:The materials that are similar to natural bone and can be used for repair of bone defects or as tissue engineering material have become the focus of research.OBJECTIVE:To investigate the feasibility of self-assembly of nano-hydroxyapatite/collagen composite.METHODS:Collagen was immersed in 0.25%glutaraldehyde solution for 0.5(group A),24(group B)and 72 hours(group C)for cross-linking reaction.In the group D,collagen was immersed in carbodiimide for 4 hours.After cross-linking reaction,collagen in each group was immersed in nano-hydroxyapatite solution for 7 days to prepare bone-like composite materials.The mineral phase analysis,composition,and microstructure of composite materials and natural bone were analyzed.RESULTS AND CONCLUSION:X-ray diffraction analysis:the amorphous diffraction peaks of the composites were slightly higher than those of the natural bone.The amorphous change of the composite was not obvious.With the prolongation of glutaraldehyde cross-linking time,the peak value of the crystal of the composite tended to increase.The amorphous diffraction peaks of the composites crosslinked with carbodiimide were slightly lower than those crosslinked with glutaraldehyde.Fourier transform infrared spectroscopy analysis:the chemical composition of the composites was similar to that of the natural bone,which was composed of collagen and hydroxyapatite,in which PO43-was partly replaced by CO32-ion in hydroxyapatite.Different cross-linking methods had no obvious effects on inorganic phase change of the materials.Scanning electron microscopy:the effects of different collagen cross-linking methods on the morphology of the formed crystals were not significantly different.Collagen fibers intertwined.A large number of fine needle-like crystals deposited on them,clustered,and were uniformly distributed.The crystal was nano-scaled in size.These results suggest that bone-like composite can be self-assessmbled with nano-hydroxyapatite precursor and collagen.