Biodegradable composite materials represent one of the major areas of investigation for bone tissue engineering due to their tuneable compositional and mechanical properties, which can potentially mimic those of bone and potentially avoid the removal of implants, mitigating the risks for the patient and reducing the overall clinical costs. In addition, the introduction of additive manufacturing technologies enables a strict control over the final morphological features of the scaffolds. In this scenario, the optimisation of 3D printable resorbable composites, made of biocompatible polymers and osteoinductive inorganic phases, offers the potential to produce a chemically and structurally biomimetic implant, which will resorb over time. The present work focuses on the development and process optimisation of two hybrid composite filaments, to be used as feedstock for the fused filament fabrication 3D printing process. A Poly L-lactic acid matrix was blended with either rod-like nano-hydroxyapatite (nano-HA) or nanoparticles of mesoporous bioactive glasses, both partially substituted with strontium (Sr²⁺), due to the well-known pro-osteogenic effect of this ion. Both inorganic phases were incorporated into Poly L-lactic acid using an innovative combination of processes, obtaining a homogeneous distribution throughout the polymer whilst preserving their ability to release Sr²⁺. The filament mechanical properties were not hindered after the incorporation of the inorganic phases, resulting in tensile strengths and moduli within the range of cancellous bone, 50 ± 10 MPa and 3 ± 1 GPa. Finally, the rheological characterization of the hybrid composites indicated a shear thinning behaviour, ideal for the processing with fused filament fabrication, proving the potential of these materials to be processed into 3D structures aiming bone regeneration.

可生物降解的复合材料由于其可调节的成分和机械性能而成为骨组织工程研究的主要领域之一，它们可以潜在地模仿骨骼的性质和潜在的避免植入物的去除，从而减轻了患者的风险并降低了整体临床费用。另外，增材制造技术的引入使得能够严格控制支架的最终形态特征。在这种情况下，由生物相容性聚合物和骨诱导性无机相制成的3D可印刷可吸收复合材料的优化提供了产生化学和结构仿生植入物的潜力，该植入物将随着时间的推移而吸收。目前的工作集中在两种混合复合长丝的开发和工艺优化上，用作熔融长丝制造3D打印过程的原料。将聚L-乳酸基质与棒状纳米羟基磷灰石（nano-HA）或介孔生物活性玻璃的纳米颗粒混合，二者均被锶（Sr²⁺），这是由于该离子的众所周知的促成骨作用。使用创新的工艺组合将两种无机相掺入聚L-乳酸中，在整个聚合物中获得均匀分布，同时保留其释放Sr ²⁺的能力。掺入无机相后，丝的机械性能没有受到阻碍，从而在松质骨，50±10 MPa和3±1 GPa的范围内产生了拉伸强度和模量。最终，杂化复合材料的流变学特性表明了剪切稀化行为，非常适合融合丝制造工艺，证明了将这些材料加工成3D结构以实现骨再生的潜力。