Designing Cost-Effective Open-Source Multihead 3D Bioprinters

Over the past decade, additive manufacturing has resulted in significant advances toward fabricating anatomic-size, patient-specific scaffolds for tissue models and regenerative medicine. This can be attributed to the development of advanced bioinks capable of precise deposition of cells and biomaterials. The combination of additive manufacturing with advanced bioinks is enabling researchers to fabricate intricate tissue scaffolds that recreate the complex spatial distributions of cells and bioactive cues found in the human body. However, the expansion of this promising technique has been hampered by the high cost of commercially available bioprinters and proprietary software. In contrast, conventional 3D printing has become increasingly popular with home hobbyists and caused an explosion of both low-cost thermoplastic 3D printers and open-source software to control the printer. In this work, we bring these benefits into the field of bioprinting by converting widely available and cost-effective 3D printers into fully functional, open-source, and customizable multi-head bioprinters. These bioprinters utilize computer-controlled volumetric extrusion, allowing bioinks with a wide range of flow properties to be bioprinted, including non-Newtonian bioinks. We demonstrate the practicality of this approach by designing bioprinters customized with multiple extruders, automatic bed leveling, and temperature controls for approximately $400. These bioprinters were then used for in vitro and ex vivo bioprinting to demonstrate their utility for tissue engineering.

近十年来，增材制造（additive manufacturing）在制备用于组织模型与再生医学的解剖尺寸、患者专属支架方面取得了显著进展。这一进展可归因于能够精准沉积细胞与生物材料的先进生物墨水（bioinks）技术的发展。增材制造与先进生物墨水的结合，正助力研究人员制备出能够复现人体中细胞与生物活性信号复杂空间分布的精细组织支架。然而，这一极具前景的技术的推广却受到市售生物打印机（bioprinters）与专有软件高昂成本的掣肘。与之形成对比的是，传统3D打印技术在家庭爱好者群体中日渐普及，催生了大量低成本热塑性3D打印机与用于控制打印机的开源软件。在本研究中，我们将这些优势引入生物打印领域：将市面易得且性价比优异的3D打印机改装为功能完备、开源且可定制的多喷头生物打印机。此类生物打印机采用计算机控制的体积挤出技术，可打印具有宽泛流动特性范围的生物墨水，包括非牛顿型生物墨水。我们通过设计搭载多挤出头、自动调平与温度控制系统的生物打印机，以约400美元的成本验证了该方案的实用性。随后，我们利用此类生物打印机开展体外（in vitro）与离体（ex vivo）生物打印实验，验证其在组织工程领域的应用价值。