Department of Materials Science and Engineering, Faculty of Engineering, Monash University, Clayton, VIC 3800, Australia; Manufacturing, Commonwealth Scientific and Industrial Research Organisation, Research Way, Clayton, VIC 3168, Australia.
Manufacturing, Commonwealth Scientific and Industrial Research Organisation, Research Way, Clayton, VIC 3168, Australia.
Biomater Adv. 2022 Jun;137:212818. doi: 10.1016/j.bioadv.2022.212818. Epub 2022 Apr 23.
Lipids are interesting biological materials that can offer a number of pharmaceutical benefits when used as carriers for drug delivery. However, 3D printing of lipids alone by fused deposition processing techniques is very difficult as they have very poor mechanical properties that cause their filaments to fail when they are loaded into a fused deposition 3D printer. If this problem could be overcome, then lipids could be 3D printed into bespoke tablets and assist progress towards such personalised medicines. This work aims to improve the mechanical properties of lipid filaments by developing novel lipid-EVA (ethylene vinyl acetate) blends suitable for 3D printing. Different types of lipids in varying proportions were melt blended with EVA and extruded using a micro compounder. The ultimate printability of the materials was tested by feeding the filaments into a material extrusion 3D printer. Flexural testing of the extruded blends demonstrates that a good balance between the strength and flexibility is required for a material to be printable and it was found that a filament has to have a modulus/strength ratio between 8 and 25 in order to be printable. SEM analysis of the fracture surface shows a network structure within the lipid matrix that could be playing a role in the improved properties of the best performing blends. DSC thermograms show a shift in thermal transitions, suggesting some level of miscibility of the components that could have contributed to a more robust structure. The TGA results show an onset of degradation of the blends greater than 200 °C, indicating that the materials can readily withstand the extrusion and printing temperatures. This study demonstrates the successful extrusion and 3D printing of novel EVA-lipid blends with lipid contents of up to 90%.
脂质是一种有趣的生物材料，可用作药物输送的载体，提供多种药物效益。然而，通过熔融沉积加工技术单独打印脂质非常困难，因为它们的机械性能非常差，当将其装入熔融沉积 3D 打印机时，其长丝会失效。如果能够克服这个问题，那么脂质就可以 3D 打印成定制的片剂，从而有助于推进个性化药物的发展。本工作旨在通过开发适合 3D 打印的新型脂质-EVA（乙烯-醋酸乙烯酯）共混物来改善脂质长丝的机械性能。将不同比例的不同类型的脂质与 EVA 熔融共混，并使用微型混炼机进行挤出。通过将长丝送入材料挤出 3D 打印机来测试材料的最终可打印性。挤出共混物的弯曲测试表明，为了使材料可打印，需要在强度和柔韧性之间取得良好的平衡，并且发现长丝的模量/强度比必须在 8 到 25 之间才能进行打印。对断裂面的扫描电镜（SEM）分析表明，脂质基质内存在网络结构，这可能在改善性能最佳的共混物的性能方面发挥作用。差示扫描量热法（DSC）热图谱显示出热转变的位移，表明组分具有一定程度的混溶性，这可能有助于形成更坚固的结构。热重分析（TGA）结果表明，共混物的降解起始温度大于 200°C，表明这些材料能够轻易承受挤出和打印温度。本研究成功地挤出和 3D 打印了新型 EVA-脂质共混物，其脂质含量高达 90%。
