摘要：自从约10年前把一台普通的办公室喷墨打印机的墨水盒换成载细胞的盒舱，打印机喷射出含细胞的液滴来制造活组织，科学家和工程师们再也没有像原先那样来看待办公设备。他们梦想着用一种专门的生物喷墨打印机来生长用于器官移植的新的身体部件或用于病体再生医学修理的组织。这两种新疗法均始于一个精心打印的胚胎干细胞聚团。现在已在打印初始干细胞聚团方面有所进展。
通过延展其应用声波从液体中产生液滴的开创性声学工作，哈佛医学院（布里格姆与妇女医院）医学生物声学微机电系统实验室的Utkan Demirci博士及其小组报道了在干细胞生涯中一个被称为胚体形成的早期关键时期的一些鼓舞人心的初步结果。他们的研究成果被发表在美国物理联合会出版的《生物微流体》(Biomicrofluids)杂志上，https://bmf.aip.org/。
使胚体正确形成且无机械损伤是保持干细胞具有能发育成任何所需组织之惊人能力的关键。他们这种新的自动化生物打印方法似乎比利用传统的“挂滴”手工移液的方法在这方面做得更好。
Demirci博士的注释：“掌握在高通量环境中重复可靠地操纵细胞，无论是对单液滴中的单个或数以万计的细胞而言，都有可能使医学和工程领域内的许多问题获得潜在的解决方案。”
三项研究成果脱颖而出：
•改善了液滴尺寸均匀度及控制液滴尺寸的能力。这些是关键因素，因为它们决定了胚体将如何生长。
•实现一个可以打印含有单细胞或者含有数以万计细胞的单液滴的可扩展系统，-- 一种先前没有的精确操纵水平。
•更快的液滴形成。新系统提供每秒160滴的速度，相比而言挂滴法需10分钟。
下一步将涉及评估这两种方法对细胞功能的不同影响。 Demirci博士说：“我们渴望把它上升到一个新水平。”
生物探索推荐英文原文：
New Technique Advances Bioprinting of Cells
Ever since an ordinary office inkjet printer had its ink cartridges swapped out for a cargo of cells about 10 years ago and sprayed out cell-packed droplets to create living tissue, scientists and engineers have never looked at office equipment in quite the same way. They dream of using a specialized bio-inkjet printer to grow new body parts for organ transplants or tissues for making regenerative medicine repairs to ailing bodies. Both these new therapies begin with a carefully printed mass of embryonic stem cells. And now there's progress on getting that initial mass of stem cells printed.
By extending his pioneering acoustical work that applied sound waves to generate droplets from fluids, Dr. Utkan Demirci and his team at Harvard Medical School's (Brigham and Women's Hospital) Bio-Acoustic Mems in Medicine Laboratory have made encouraging preliminary findings at an early and crucial point in a stem cell's career known as embroid body formation. Their research results appear in the journal Biomicrofluids, published by the American Institute of Physics.
Getting the embroid body formed correctly and without mechanical trauma is key to preserving the stem cells' astounding ability to develop into any desired tissue. Their new automated bioprinting approach appears to do this better than manual pipetting in the "hang-drop" method traditionally used.
Notes Dr. Demirci: "To have the capability to manipulate cells in a high-throughput environment reliably and repeatedly, whether it is a single cell or tens of thousands of cells in a single droplet, has the potential to enable potential solutions to many problems in medicine and engineering."
Three research results stand out:
•Enhanced uniformity of size and ability to control droplet size. These are key variables because they determine how the embroid bodies will grow.
•Achieving a scalable system that can print one cell or tens of thousands per droplet -- a level of precise manipulation not previously available.
•Faster droplet formation. The new system delivers 160 droplets/seconds, versus 10 minutes for the hang-drop method.
The next step involves assessing the two methods to compare their effects on cell function. Says Dr. Demirci: "We are eager to take it to the next level."
