Abstract In this study, a novel hydroxyapatite (HA)/polyurethane (PU) composite porous 3D scaffold was developed by in situ polymerization. Aliphatic hexamethylene diisocyanate (HDI) as a nontoxic and safe agent was adopted to produce the rigid segment in PU polymerization. HA powder was compounded in a PU polymer matrix during the polymeric process. The macrostructure and morphology as well as mechanical strength of the scaffolds were characterized by FTIR, XRD and SEM. The results show that the HDI can react mildly with hydroxyl (–OH) groups of polytetramethylene ether glycol and a mild foaming action caused by the release of CO2 gas occurred simultaneously in the reactive process, thus producing a uniform porous structure of HA/PU scaffold. The HA/PU composite scaffold with a high HA content of about 30 wt% has a porosity of more than 60% and a pore size from 100 to 800 μm. After immersed in simulated body fluid, the scaffolds were investigated by weight loss experiments and FTIR. The results show that polymerized component of HA/PU scaffolds degraded gradually in vitro, while HA component presented a classic trend of dissolution then deposition procedure. Three hydrolysis processes may happen in the PU degradation. The HA/PU scaffolds should be a promising material for bone tissue regeneration in clinic.

中文翻译：

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用于骨组织工程的多孔 3D 羟基磷灰石/聚氨酯复合支架及其体外降解行为

摘要 在这项研究中，通过原位聚合开发了一种新型羟基磷灰石 (HA)/聚氨酯 (PU) 复合多孔 3D 支架。采用脂肪族六亚甲基二异氰酸酯（HDI）作为一种无毒且安全的试剂，用于生产聚氨酯聚合中的刚性链段。HA 粉末在聚合过程中混合在 PU 聚合物基质中。通过FTIR、XRD和SEM表征了支架的宏观结构和形貌以及机械强度。结果表明，HDI 可以与聚四亚甲基醚二醇的羟基（-OH）基团温和反应，并且在反应过程中同时发生由释放 CO2 气体引起的温和发泡作用，从而产生均匀多孔结构的 HA/PU 支架. HA含量约为30wt%的HA/PU复合支架，孔隙率超过60%，孔径为100~800 μm。浸入模拟体液后，通过失重实验和FTIR对支架进行研究。结果表明，HA/PU支架的聚合组分在体外逐渐降解，而HA组分呈现出溶解然后沉积的经典趋势。PU降解过程中可能发生三个水解过程。HA/PU支架应该是临床骨组织再生的一种很有前途的材料。而 HA 组分呈现出溶解然后沉积过程的经典趋势。PU降解过程中可能发生三个水解过程。HA/PU支架应该是临床骨组织再生的一种很有前途的材料。而 HA 组分呈现出溶解然后沉积过程的经典趋势。PU降解过程中可能发生三个水解过程。HA/PU支架应该是临床骨组织再生的一种很有前途的材料。