Xu Changxue, Zhang Meng, Huang Yong, Ogale Amod, Fu Jianzhong, Markwald Roger R
Department of Mechanical Engineering and ‡Department of Chemical Engineering, Clemson University , Clemson, South Carolina 29634, United States.
Langmuir. 2014 Aug 5;30(30):9130-8. doi: 10.1021/la501430x. Epub 2014 Jul 21.
Biofabrication offers a great potential for the fabrication of three-dimensional living tissues and organs by precisely layer-by-layer placing various tissue spheroids as anatomically designed. Inkjet printing of living cell-laden bioink is one of the most promising technologies enabling biofabrication, and the bioink printability must be carefully examined for it to be a viable biofabrication technology. In this study, the cell-laden bioink droplet formation process has been studied in terms of the breakup time, droplet size and velocity, and satellite formation using a time-resolved imaging approach. The bioink has been prepared using fibroblasts and sodium alginate with four different cell concentrations: without cells, 1 × 10(6), 5 × 10(6), and 1 × 10(7) cells/mL to appreciate the effect of cell concentration on the droplet formation process. Furthermore, the bioink droplet formation process is compared with that during the inkjetting of a comparable polystyrene microbead-laden suspension under the identical operating conditions to understand the effect of particle physical properties on the droplet formation process. It is found that (1) as the cell concentration of bioink increases, the droplet size and velocity decrease, the formation of satellite droplets is suppressed, and the breakup time increases, and (2) compared to the hard bead-laden suspension, the bioink tends to have a less ejected fluid volume, lower droplet velocity, and longer breakup time.
生物制造通过按照解剖学设计精确地逐层放置各种组织球体，为三维活体组织和器官的制造提供了巨大潜力。喷墨打印负载活细胞的生物墨水是实现生物制造最有前景的技术之一，要使其成为可行的生物制造技术，必须仔细研究生物墨水的可打印性。在本研究中，使用时间分辨成像方法，从破裂时间、液滴大小和速度以及卫星液滴形成方面研究了负载细胞的生物墨水液滴形成过程。生物墨水是用成纤维细胞和海藻酸钠制备的，具有四种不同的细胞浓度：无细胞、1×10⁶、5×10⁶和1×10⁷个细胞/毫升，以了解细胞浓度对液滴形成过程的影响。此外，在相同操作条件下，将生物墨水液滴形成过程与喷墨打印含有类似聚苯乙烯微珠的悬浮液的过程进行比较，以了解颗粒物理性质对液滴形成过程的影响。研究发现：（1）随着生物墨水细胞浓度的增加，液滴大小和速度减小，卫星液滴的形成受到抑制，破裂时间增加；（2）与含有硬珠的悬浮液相比，生物墨水往往具有较少的喷射流体体积、较低的液滴速度和较长的破裂时间。
