Yang Teng, Jin Yuqi, Smith Lee Miller, Dahotre Narendra B, Neogi Arup
Department of Materials Science and Engineering, University of North Texas, Denton, TX, USA.
Department of Physics, University of North Texas, Denton, TX, USA.
Commun Eng. 2024 Nov 9;3(1):162. doi: 10.1038/s44172-024-00318-w.
3D bioprinting has excellent potential in tissue engineering, regenerative medicine, and drug delivery systems due to the ability to fabricate intricate structures that are challenging to make with conventional manufacturing methods. However, the complexity of parametric combinations and lack of product quality control have restricted soft hydrogel bioprinting from practical applications. Here we show an in-situ ultrasound monitoring system that reveals the alginate-gelatin hydrogel's additive manufacturing process. We use this technique to understand the parameters that influenced transient printing behaviors and material properties in approximately real-time. This unique monitoring process can facilitate the detection of minor errors/flaws during the printing. By analyzing the ultrasonic reflected signals in both time and frequency domains, transient printing information can be obtained from 3D printed soft hydrogels during the processes with a depth subwavelength resolution approaching 0.78 . This in-situ technique monitors the printing behaviors regarding the constructed film, interlayer bonding, transient effective elastic constant, layer-wise surface roughness (elastic or plastic), nozzle indentation/scratching, and gravitational spreading. The simulation-verified experimental methods monitored fully infilled printing and gridded pattern printing conditions. Furthermore, the proposed ultrasound system also experimentally monitored the post-crosslinking process of alginate-gelatin hydrogel in CaCl solution. The results can optimize crosslinking time by balancing the hydrogel's stiffness enhancement and geometrical distortion.
由于能够制造出用传统制造方法难以制作的复杂结构，3D生物打印在组织工程、再生医学和药物输送系统方面具有巨大潜力。然而，参数组合的复杂性和缺乏产品质量控制限制了软水凝胶生物打印的实际应用。在此，我们展示了一种原位超声监测系统，该系统揭示了藻酸盐-明胶水凝胶的增材制造过程。我们使用这种技术来实时了解影响瞬态打印行为和材料特性的参数。这种独特的监测过程有助于在打印过程中检测微小的误差/缺陷。通过在时域和频域分析超声反射信号，可以在过程中从3D打印的软水凝胶中获得瞬态打印信息，深度亚波长分辨率接近0.78 。这种原位技术监测关于构建膜、层间粘结、瞬态有效弹性常数、逐层表面粗糙度（弹性或塑性）、喷嘴压痕/划痕和重力扩散的打印行为。经模拟验证的实验方法监测了完全填充打印和网格图案打印条件。此外，所提出的超声系统还通过实验监测了藻酸盐-明胶水凝胶在CaCl溶液中的后交联过程。结果可以通过平衡水凝胶的刚度增强和几何变形来优化交联时间。
