Multiscale and cell-preserving 3D bioprinting of human cells by nozzle-free acoustic droplet ejection (AcousticBioprinting)

通过无喷嘴声学液滴喷射对人体细胞进行多尺度和细胞保存 3D 生物打印 (AcousticBioprinting)

• 批准号: 423054768
• 负责人: Professor Dr.-Ing. Horst Fischer
• 金额: --
• 依托单位: Lehr- und Forschungsgebiet Zahnärztliche Werkstoffkunde und Biomaterialforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/423054768?language=en
• 关键词: Multiscale; cell; preserving; 3D; bioprinting

In established bioprinting processes, the print nozzles used are the limiting factor, because they limit the print resolution. If the nozzle diameter is too small, the nozzles become clogged. In addition, the shear stress on the cells increases significantly as the nozzle diameter is reduced. Above a critical shear stress, the printed cells are mecha¬nically irreversibly damaged. These limitations and problems could be successfully addressed by the Acoustic Droplet Ejection (ADE) method. In the first phase of the project, we could show that cell-laden hydrogel structures can be built up three-dimensionally on a millimeter scale using the ADE technique. Human mesenchymal stem cells embedded in the single droplets showed a very high viability after the printing process. Using fluid mechanics finite element simulations, we were able to show that the shear stress when printing cells using ADE technology is almost three times lower compared to bioprinting using a microvalve-based inkjet process. In a second project phase, we want to find answers to a number of fundamental scientific questions that have not yet been conclusively answered in the first research phase. In line with these scientific questions, we have stated four working hypotheses for the second phase of the project: 1.) The fact that the ADE process does not require a nozzle means that, in contrast to established bioprinting techniques, it is also possible to print droplets with extremely high cell concentrations close to the physiological cell density. 2) By combining ADE and microfluidics, single cells are seperated, transferred to the ejection spot and can be precisely 3D printed. 3) Gels with complex gelation techniques can also be processed using ADE. 4) The analysis and process control of the behavior of the cell-laden droplets upon impact on the build platform is a basic prerequisite for understanding how three-dimensional cell-laden hydrogel structures can be reproducibly built using ADE technology. An essential key to test the working hypotheses in the second phase of the research project is the additional implementation of high-precision 3D measurement technology to the acoustic bioprinting system. This will make it possible to measure the printed objects even during the printing process and to investigate in detail the effects of density, velocity, droplet diameter, and surface tension on the impact of the cell-laden droplets on the building platform and the fusion of the droplets with each other, as well as the process-related response of the bioprinted cells. Based on the expected results and new findings from the second project phase, the acoustic bioprinting method can finally be comprehensively scientifically evaluated in direct comparison with established nozzle-based printing processes.

在已建立的生物打印过程中，所使用的打印喷嘴是限制因素，因为它们限制了打印分辨率。如果喷嘴直径太小，喷嘴会堵塞。此外，随着喷嘴直径的减小，细胞上的剪切应力显著增加。在临界剪切应力以上，打印的细胞被机械地不可逆地损坏。这些限制和问题可以通过声学液滴喷射（ADE）方法成功地解决。在该项目的第一阶段，我们可以证明，细胞负载水凝胶结构可以建立三维毫米尺度使用ADE技术。嵌入单个液滴中的人类间充质干细胞在打印过程后显示出非常高的活力。使用流体力学有限元模拟，我们能够证明，与使用基于微阀的喷墨工艺的生物打印相比，使用ADE技术打印细胞时的剪切应力几乎低三倍。在第二个项目阶段，我们希望找到一些基本科学问题的答案，这些问题在第一个研究阶段尚未得到最终答案。根据这些科学问题，我们为项目的第二阶段提出了四个工作假设：1。ADE过程不需要喷嘴的事实意味着，与已建立的生物打印技术相比，也可以打印具有接近生理细胞密度的极高细胞浓度的液滴。2)通过结合ADE和微流体技术，单细胞被分离，转移到喷射点，并可以精确地3D打印。3)具有复杂凝胶化技术的凝胶也可以使用ADE加工。4)载有细胞的液滴在撞击构建平台时的行为的分析和过程控制是理解如何使用ADE技术可再现地构建三维载有细胞的水凝胶结构的基本先决条件。在研究项目的第二阶段测试工作假设的关键是在声学生物打印系统中额外实施高精度3D测量技术。这将使得即使在打印过程中也可以测量打印物体，并详细研究密度、速度、液滴直径和表面张力对构建平台上载有细胞的液滴的影响以及液滴彼此融合的影响，以及生物打印细胞的过程相关响应。根据第二阶段项目的预期结果和新发现，声学生物打印方法最终可以与现有的基于生物打印的打印工艺进行直接比较，从而进行全面的科学评估。