February 5, 2013
Scientists Build Embryonic Stem Cells With A 3D Printer
Brett Smith for redOrbit.com - Your Universe Online
As 3D printing methods develop and become more accessible, experts from all different fields are embracing the technology in pursuit of their own unique breakthroughs.According to a new report in the journal Biofabrication, a group of Scottish scientists has used this cutting edge type of construction to arrange human embryonic stem cells (hESC) into novel three-dimensional spheroids.
Previous efforts have resulted in artificial construction of cells and tissues, a method known as biofabrication. However, these advances were typically made using animal cells.
"To the best of our knowledge, this is the first time that hESCs have been printed,” coauthor Will Wenmiao Shu, from Heriot-Watt University in Edinburgh, Scotland, said in a statement. “The generation of 3D structures from hESCs will allow us to create more accurate human tissue models which are essential for in vitro drug development and toxicity-testing. Since the majority of drug discovery is targeting human disease, it makes sense to use human tissues."
In the study, the Scottish researchers used a specially modified valve-based printing technique, which was designed to sensitively handle the delicate hESCs. The cells were loaded into two separate printer chambers and were then deposited into “controllable and repeatable” sizes and shapes, the report said.
After the hESC spheroids were printed, the scientists performed several tests to confirm the effectiveness of their method. They were able to verify the hESCs remained alive after printing and the stem cells maintained their ability to differentiate into various types of cells. They then assessed the concentration, characterization and distribution of the hESCs within the printed structures.
"Using this valve-based method, the printed cells are driven by pneumatic pressure and controlled by the opening and closing of a microvalve,” Shu said. “The amount of cells dispensed can be precisely controlled by changing the nozzle diameter, the inlet air pressure or the opening time of the valve.
"We found that the valve-based printing is gentle enough to maintain high stem cell viability, accurate enough to produce spheroids of uniform size, and, most importantly, the printed hESCs maintained their pluripotency — the ability to be differentiated into any other cell type,” he added.
In developing the new printing method, scientists at the Heriot-Watt University worked in close collaboration with the Scottish biotechnology company Roslin Cellab.
"This world-first printing of human embryonic stem cell cultures is a continuation of our productive partnership with Heriot-Watt,” said Jason King, business development manager of Roslin Cellab. “Normally laboratory grown cells grow in 2D but some cell types have been printed in 3D. However, up to now, human stem cell cultures have been too sensitive to manipulate in this way.”
The scientists said they expect the three-dimensional tissues and structures created with hESCs to be used for a variety of purposes, including improving the drug testing process.
"This is a scientific development which we hope and believe will have immensely valuable long-term implications for reliable, animal-free drug-testing and, in the longer term, to provide organs for transplant on demand, without the need for donation and without the problems of immune suppression and potential organ rejection,” King said.