Department of Materials Science and Engineering, McCormick School of Engineering, Northwestern University, United States; Simpson Querrey Institute for BioNanotechnology, Northwestern University, United States.
Department of Materials Science and Engineering, McCormick School of Engineering, Northwestern University, United States; Simpson Querrey Institute for BioNanotechnology, Northwestern University, United States.
Acta Biomater. 2018 May;72:94-109. doi: 10.1016/j.actbio.2018.03.039. Epub 2018 Mar 27.
We introduce a new process that enables the ability to 3D-print high porosity materials and structures by combining the newly introduced 3D-Painting process with traditional salt-leaching. The synthesis and resulting properties of three 3D-printable inks comprised of varying volume ratios (25:75, 50:50, 70:30) of CuSO salt and polylactide-co-glycolide (PLGA), as well as their as-printed and salt-leached counterparts, are discussed. The resulting materials are comprised entirely of PLGA (F-PLGA), but exhibit porosities proportional to the original CuSO content. The three distinct F-PLGA materials exhibit average porosities of 66.6-94.4%, elastic moduli of 112.6-2.7 MPa, and absorbency of 195.7-742.2%. Studies with adult human mesenchymal stem cells (hMSCs) demonstrated that elevated porosity substantially promotes cell adhesion, viability, and proliferation. F-PLGA can also act as carriers for weak, naturally or synthetically-derived hydrogels. Finally, we show that this process can be extended to other materials including graphene, metals, and ceramics.
Porosity plays an essential role in the performance and function of biomaterials, tissue engineering, and clinical medicine. For the same material chemistry, the level of porosity can dictate if it is cell, tissue, or organ friendly; with low porosity materials being far less favorable than high porosity materials. Despite its importance, it has been difficult to create three-dimensionally printed structures that are comprised of materials that have extremely high levels of internal porosity yet are surgically friendly (able to handle and utilize during surgical operations). In this work, we extend a new materials-centric approach to 3D-printing, 3D-Painting, to 3D-printing structures made almost entirely out of water-soluble salt. The structures are then washed in a specific way that not only extracts the salt but causes the structures to increase in size. With the salt removed, the resulting medical polymer structures are almost entirely porous and contain very little solid material, but the maintain their 3D-printed form and are highly compatible with adult human stem cells, are mechanically robust enough to use in surgical manipulations, and can be filled with and act as carriers for biologically active liquids and gels. We can also extend this process to three-dimensionally printing other porous materials, such as graphene, metals, and even ceramics.
我们介绍了一种新的工艺，通过将新引入的 3D 绘画工艺与传统的盐浸工艺相结合，使 3D 打印高孔隙率材料和结构的能力成为可能。讨论了三种可 3D 打印的油墨的合成和性能，这些油墨的体积比（25:75、50:50、70:30）为硫酸铜盐和聚乳酸-共-羟基乙酸（PLGA），以及它们的原浆和盐浸对照物。得到的材料完全由 PLGA 组成（F-PLGA），但具有与原始 CuSO 含量成比例的孔隙率。三种不同的 F-PLGA 材料的平均孔隙率为 66.6-94.4%，弹性模量为 112.6-2.7 MPa，吸光度为 195.7-742.2%。用成人间充质干细胞（hMSC）进行的研究表明，高孔隙率可显著促进细胞黏附、活力和增殖。F-PLGA 还可以作为弱的天然或合成水凝胶的载体。最后，我们表明，该过程可以扩展到其他材料，包括石墨烯、金属和陶瓷。
孔隙率在生物材料、组织工程和临床医学的性能和功能中起着至关重要的作用。对于相同的材料化学，孔隙率水平可以决定它是否对细胞、组织或器官友好；低孔隙率材料远不如高孔隙率材料有利。尽管其重要性，但是很难创建由具有极高内部孔隙率但又对手术友好的材料（能够在手术操作中处理和利用）组成的三维打印结构。在这项工作中，我们将一种新的以材料为中心的 3D 打印方法扩展到 3D 绘画，3D 绘画，用于打印几乎完全由水溶性盐组成的结构。然后以特定的方式清洗这些结构，不仅可以提取盐，还可以使结构增大。去除盐后，所得的医用聚合物结构几乎完全是多孔的，几乎不含固体材料，但保持其 3D 打印形式，与成人人类干细胞高度兼容，机械强度足以用于手术操作，并且可以填充和充当生物活性液体和凝胶的载体。我们还可以将此过程扩展到其他多孔材料，例如石墨烯、金属，甚至是陶瓷。
