Abstract Polylactic acid (PLA) based scaffolds have attracted worldwide attention as promising biodegradable implants in bone tissue engineering. PLA matrix is often incorporated with fillers to engineer composite scaffolds with improved mechanical properties and excellent biocompatibility. In the present study, PLA composite scaffolds were additively manufactured utilizing fused filament fabrication (FFF) process by separately employing two different types of iron-based powders including stainless steel 316L and pure iron. The geometrical, thermal, and mechanical properties of the scaffolds, as well as their in-vitro biodegradation, wettability, and cytocompatibility, were thoroughly assessed. With optimized printing parameters, the scaffolds were manufactured with an accurate pore dimension of 0.80±0.08 mm and homogenously distributed iron-based powders in the PLA matrix. The lower linear coefficient of thermal expansion in both PLA/316L and PLA/Iron scaffolds increased the strut width while reducing the surface roughness. Meanwhile, the addition of iron-based powders both enhanced the compressive and flexural modulus, compressive strength, and compressive fatigue resistance, but exhibited no significant reinforcement on the flexural strength and elongation. The results also showed that PLA/Iron scaffold possessed higher in-vitro degradation resistance, superior hydrophilic wetting behavior, and better cytocompatibility, indicating its remarkable prospects in bone tissue engineering applications.

中文翻译：

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用于组织工程的可生物降解铁基颗粒增强聚乳酸复合支架的增材制造

摘要 基于聚乳酸 (PLA) 的支架作为骨组织工程中具有前景的可生物降解植入物引起了全世界的关注。PLA 基质通常与填料结合，以设计具有改进机械性能和优异生物相容性的复合支架。在本研究中，PLA 复合支架是利用熔丝制造 (FFF) 工艺通过分别使用两种不同类型的铁基粉末（包括不锈钢 316L 和纯铁）增材制造的。对支架的几何、热和机械性能，以及它们的体外生物降解性、润湿性和细胞相容性进行了彻底评估。使用优化的打印参数，制造的支架具有 0.80±0 的精确孔尺寸。08 mm 且均匀分布在 PLA 基质中的铁基粉末。PLA/316L 和 PLA/Iron 支架的较低线性热膨胀系数增加了支柱宽度，同时降低了表面粗糙度。同时，铁基粉末的加入既提高了压缩和弯曲模量、压缩强度和压缩疲劳抗力，但对弯曲强度和伸长率没有显着增强。结果还表明，PLA/Iron 支架具有更高的体外抗降解性、优异的亲水润湿行为和更好的细胞相容性，表明其在骨组织工程应用中具有显着的前景。PLA/316L 和 PLA/Iron 支架的较低线性热膨胀系数增加了支柱宽度，同时降低了表面粗糙度。同时，铁基粉末的加入既提高了压缩和弯曲模量、压缩强度和压缩疲劳抗力，但对弯曲强度和伸长率没有显着增强。结果还表明，PLA/Iron 支架具有更高的体外抗降解性、优异的亲水润湿行为和更好的细胞相容性，表明其在骨组织工程应用中具有显着的前景。PLA/316L 和 PLA/Iron 支架的较低线性热膨胀系数增加了支柱宽度，同时降低了表面粗糙度。同时，铁基粉末的加入既提高了压缩和弯曲模量、压缩强度和压缩疲劳抗力，但对弯曲强度和伸长率没有显着增强。结果还表明，PLA/Iron 支架具有更高的体外抗降解性、优异的亲水润湿行为和更好的细胞相容性，表明其在骨组织工程应用中具有显着的前景。但对弯曲强度和伸长率没有显着增强。结果还表明，PLA/Iron 支架具有更高的体外抗降解性、优异的亲水润湿行为和更好的细胞相容性，表明其在骨组织工程应用中具有显着的前景。但对弯曲强度和伸长率没有显着增强。结果还表明，PLA/Iron 支架具有更高的体外抗降解性、优异的亲水润湿行为和更好的细胞相容性，表明其在骨组织工程应用中具有显着的前景。