Open-source hybrid 3D-bioprinter for simultaneous printing of thermoplastics and hydrogels

3D-bioprinting is a promising technology applicable in areas such as regenerative medicine or in vitro organ model development. Various 3D-bioprinting technologies and systems have been developed and are partly commercially available. Here, we present the construction and characterization of an open-source low-cost 3D-bioprinter that allows the alternated microextrusion of hydrogel and fused deposition modeling (FDM) of thermoplastic filaments.
The presented 3D-bioprinter is based on a conventional Prusa i3 MK3 printer and features two independent printheads: the original FDM-head and a piston-driven microextrusion system for soft materials. Modifications were designed modularly to fit various syringe formats or heating elements to the device. The bioprinter is the first hybrid DIY 3D-bioprinter that allows switching between materials as often as required during a print run to produce complex multi-material constructs with arbitrary patterns in each layer.
For validation of the printer, two designs suitable for relevant bioprinting applications were realized. First, a porous plastic construct filled with hydrogel was printed, serving as a mechanically stable bone replacement tissue model. Second, a plastic chamber, which might be used in organ-on-a-chip applications, was printed with an extruded silicone sealing that enables the liquid-tight attachment of glass slides to the top and bottom of the chamber.

三维生物打印技术作为一种极具潜力的技术，适用于再生医学或体外器官模型开发等领域。各类三维生物打印技术和系统已相继研发并部分实现商业化。本报告中，我们展示了开源低成本三维生物打印机的构建与表征，该打印机能够实现水凝胶的交替微挤出与热塑性丝材的熔融沉积建模（FDM）。该三维生物打印机基于传统的Prusa i3 MK3打印机，具备两个独立喷头：原始的FDM喷头以及用于软材料的活塞驱动微挤出系统。对设备进行的改进设计采用模块化方式，以适应各种注射器格式或加热元件。该生物打印机是首个混合DIY三维生物打印机，能够在打印过程中根据需求灵活切换材料，以生产具有任意层间图案的复杂多材料结构。为验证打印机性能，实现了两个适用于相关生物打印应用的方案。首先，打印了一种孔隙率塑料结构，填充有水凝胶，作为机械稳定的骨替代组织模型。其次，打印了一个可能用于器官芯片应用的塑料腔室，并使用挤出硅密封件，该密封件能够实现液体密封的玻璃载片与腔室上下方的紧密连接。