University of British Columbia 4060-2332 Main Mall, Vancouver, BC, Canada, V6T 1Z4.
Biofabrication. 2016 Jan 29;8(1):015008. doi: 10.1088/1758-5090/8/1/015008.
Cell motion within a liquid suspension inside a piezoelectrically actuated, cylindrical inkjet printhead was studied using high speed imaging and a low depth of field setup. For each ejected droplet, a cell within the inkjet nozzle was observed to exhibit one of three possible behaviors which are termed: cell travel, cell ejection and cell reflection. Cell reflection is an undesirable phenomenon which may adversely affect an inkjet's capability in dispensing cells and a possible reason why it was previously reported that the rate of cells dispensed did not follow the expected Poisson distribution. Through the study of the cells motions, it was hypothesized that the rheological properties of the media in the cell suspension play an important role in influencing the cell behaviors exhibited. This was experimentally studied with the tracking of cells within the inkjet nozzle in a 10% w/v Ficoll PM400 cell suspension. The effect of cell reflection was eliminated using the higher density and viscosity Ficoll PM400 suspension. The presented work is the first in-depth study of the cell behaviors occurring within a piezoelectric inkjet nozzle during the printing process. The understanding of the hydrodynamics during a droplet ejection and its effect on the suspended cells are imperative towards achieving reliable cell dispensing for biofabrication applications.
在压电驱动的圆柱形喷墨打印头中，在液体悬浮液内的细胞运动使用高速成像和低景深设置进行了研究。对于每个喷出的液滴，观察到喷墨嘴内的一个细胞表现出三种可能行为之一，分别称为细胞移动、细胞喷出和细胞反射。细胞反射是一种不理想的现象，可能会对喷墨的细胞分配能力产生不利影响，这也是为什么以前报告称细胞分配率不符合预期泊松分布的原因之一。通过研究细胞的运动，假设细胞悬浮液中的介质流变性质在影响所表现出的细胞行为方面起着重要作用。这通过在 10%w/vFicollPM400 细胞悬浮液中在喷墨嘴内跟踪细胞来进行实验研究。使用更高密度和粘度的 FicollPM400 悬浮液消除了细胞反射的影响。目前的工作是首次深入研究打印过程中在压电喷墨喷嘴内发生的细胞行为。了解液滴喷出过程中的流体动力学及其对悬浮细胞的影响，对于实现生物制造应用中可靠的细胞分配至关重要。
