Shape memory polymers (SMP) with better biodegradability and better stability have great potential applications in biomedical fields, such as the drug carriers or the tissue engineering scaffolds. In this study, poly(ε-caprolactone)(PCL)-based polyurethane(PU) microfibers were fabricated with the containing of hydroxyapatite(HA) to enhance the biodegradability and to exhibit excellent shape memory performance. The composition, the morphology, the thermal stability, and the mechanical properties of the microfibers were characterized and detected using Fourier transform infrared spectroscopy (FTIR), 1 H nuclear magnetic resonance ( 1 HNMR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC). and dynamic mechanical analysis (DMA), etc. And dexamethasone was selected as drug model to investigate the delivery and release behaviors of the carrier of the microfibers. It was revealed that HA enhanced the degradation rate of the shape memory polyurethane (SMPU) fibers, and the fibers could guarantee a sustained long time drug release. The detection on the shape memory performance found that, with the different addition amounts of HA, the composite microfibers of (SMPU) and HA exhibited the different shape memory transition temperature ( T trans ) values. And with the addition of 3 wt% of HA, the excellent shape recovery ratios of R r (> 97%) and the shortest recovery time of ~ 6 s could be obtained. With further increase of the amounts of HA, the recovery force and the recovery time were reduced and prolonged, respectively. The obtained results proved that the biodegradable SMPU/HA composite microfibers have more valuable application prospects in biomedical fields.

中文翻译：

---

基于电纺 PCL 的聚氨酯/HA 微纤维作为地塞米松的药物载体，具有增强的生物降解性和形状记忆性能

具有更好生物降解性和更好稳定性的形状记忆聚合物（SMP）在生物医学领域具有巨大的潜在应用，例如药物载体或组织工程支架。在这项研究中，聚（ε-己内酯）（PCL）基聚氨酯（PU）微纤维制备含有羟基磷灰石（HA）以提高生物降解性并表现出优异的形状记忆性能。使用傅里叶变换红外光谱（FTIR）、 1 H 核磁共振（ 1 HNMR）、扫描电子显微镜（SEM）、差示扫描量热法对微纤维的组成、形貌、热稳定性和机械性能进行表征和检测。 (DSC)。和动态力学分析（DMA）等。并选择地塞米松作为药物模型研究微纤维载体的递送和释放行为。结果表明，HA提高了形状记忆聚氨酯（SMPU）纤维的降解率，并且该纤维可以保证药物的长时间持续释放。对形状记忆性能的检测发现，随着HA添加量的不同，(SMPU)和HA的复合微纤维表现出不同的形状记忆转变温度(T trans )值。并且添加 3 wt% 的 HA，可以获得优异的 R r (> 97%) 形状恢复率和~6 s 的最短恢复时间。随着HA用量的进一步增加，恢复力和恢复时间分别减少和延长。