Abstract The use of FDM/FFF in 3D printing for medical sciences is becoming common. This is due to the high availability and decent price of both 3D printers and filaments useful for FDM/FFF. Currently, researchers' attention is focused mainly on the study of medical filaments based on PLA, PCL or their modifications. This contributes to insufficient diversity of medical-grade filaments on the market. Moreover, due to the lack of specified standards for filaments testing, manufacturers often provide merely the characteristics of the raw materials, which were used for filaments fabrication. This lack of comprehensive data can be problematic when considered as a filament of medical 3DP application. As a consequence of this overview, we have performed a comprehensive evaluation of a flexible medical-grade filament for FDM/FFF 3DP - Bioflex® (Filoalfa). We have performed complex characterization of Bioflex® through a variety of methods and techniques including spectroscopic analysis (FTIR, Raman), dynamic mechanical analysis (DMA), thermal properties (DSC, TGA), rheological characteristic (MFR). In the next step, Bioflex® was used for 3DP and obtained printouts were utilized to characterize the material behaviour after 3D printing process. The mechanical analysis allowed to estimate how the material strength decreases after the printing process according to the values given in the technical data sheet of Bioflex®. The contact angle measurements determined wettability of the Bioflex® printouts. Performed series of in vitro studies were carried out to assess its potential as constructs having direct contact with the human body as implantable structures. In conclusion, 3D printing process did not affect the printouts biocompatibility (ISO 10993:5). Accelerated degradation studies indicated elevated hydrolysis resistance of printed samples. In turn, performed incubation in simulated body fluid (SBF) solution, revealed carbonated hydroxyapatite (HAp) deposition on printouts surface indicating their bioactive properties. Thus, studied filament Bioflex® seems to be a suitable candidate for further development of FDM/FFF 3DP structures for advanced biological and medical application.

中文翻译：

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对作为医疗应用潜在材料的柔性 FDM/FFF 3D 打印丝的综合评估

摘要 FDM/FFF 在医学 3D 打印中的使用正变得越来越普遍。这是由于 3D 打印机和用于 FDM/FFF 的灯丝的高可用性和合理的价格。目前，研究人员的注意力主要集中在基于 PLA、PCL 或其变体的医用长丝的研究上。这导致市场上医用级长丝的多样性不足。此外，由于缺乏细丝测试的特定标准，制造商通常仅提供用于细丝制造的原材料的特性。当被视为医疗 3DP 应用的细丝时，缺乏全面数据可能会带来问题。由于这种概述，我们对用于 FDM/FFF 3DP 的柔性医用级灯丝 - Bioflex® (Filoalfa) 进行了全面评估。我们通过各种方法和技术对 Bioflex® 进行了复杂的表征，包括光谱分析（FTIR、拉曼）、动态力学分析（DMA）、热性能（DSC、TGA）、流变特性（MFR）。在下一步中，Bioflex® 用于 3DP，并利用获得的打印输出来表征 3D 打印过程后的材料行为。机械分析允许根据 Bioflex® 技术数据表中给出的值估计打印过程后材料强度如何下降。接触角测量确定了 Bioflex® 打印输出的润湿性。进行了一系列体外研究，以评估其作为可植入结构与人体直接接触的构造的潜力。总之，3D 打印过程不会影响打印输出的生物相容性 (ISO 10993:5)。加速降解研究表明印刷样品的耐水解性提高。反过来，在模拟体液 (SBF) 溶液中进行孵育，显示打印输出表面上的碳酸羟基磷灰石 (HAp) 沉积表明它们的生物活性特性。因此，经过研究的长丝 Bioflex® 似乎是进一步开发用于高级生物和医学应用的 FDM/FFF 3DP 结构的合适候选者。3D 打印过程不影响打印输出的生物相容性 (ISO 10993:5)。加速降解研究表明印刷样品的耐水解性提高。反过来，在模拟体液 (SBF) 溶液中进行孵育，显示打印输出表面上的碳酸羟基磷灰石 (HAp) 沉积表明它们的生物活性特性。因此，经过研究的长丝 Bioflex® 似乎是进一步开发用于高级生物和医学应用的 FDM/FFF 3DP 结构的合适候选者。3D 打印过程不影响打印输出的生物相容性 (ISO 10993:5)。加速降解研究表明印刷样品的耐水解性提高。反过来，在模拟体液 (SBF) 溶液中进行孵育，显示打印输出表面上的碳酸羟基磷灰石 (HAp) 沉积表明它们的生物活性特性。因此，经过研究的长丝 Bioflex® 似乎是进一步开发用于高级生物和医学应用的 FDM/FFF 3DP 结构的合适候选者。