University of Oxford Develops New 3D Bioprinting Method

As 3D bioprinting continues to advance, there are still challenges that plague most methods of 3D printing tissue. One of those challenges involves properly positioning the 3D printed cells within their scaffolds so that the structures don’t collapse on themselves. But a group of researchers at the University of Oxford have developed a new method of bioprinting that involves self-contained, self-supporting cells.

In a paper entitled “High-Resolution Patterned Cellular Constructs by Droplet-Based 3D Printing,” which you can read here, the researchers, led by Chemical Biology Professor Hagan Bayley, describe how they 3D printed cells that were contained within protective nanolite droplets and wrapped in a coating of oil. The technique improved the survival rate of individual cells and allowed the scientists to create tissue at higher resolutions by building it one drop at a time.

“We were aiming to fabricate three-dimensional living tissues that could display the basic behaviours and physiology found in natural organisms,” said Dr. Alexander Graham, lead author of the study and 3D Bioprinting Scientist at Oxford Synthetic Biology (OxSynBio). “To date, there are limited examples of printed tissues, which have the complex cellular architecture of native tissues. Hence, we focused on designing a high-resolution cell printing platform, from relatively inexpensive components, that could be used to reproducibly produce artificial tissues with appropriate complexity from a range of cells including stem cells.”

Using a droplet-based 3D bioprinter developed in earlier work, the researchers 3D printed human embryonic kidney (HEK) cells and ovine mesenchymal stem cells (oMSCs) at a high droplet resolution of one nL. On average, the 3D printed cells showed 90% viability, which is high, and the HEK cells within their printed structures proliferated under culture conditions. In addition, a five-week tissue engineering study showed that the 3D printed oMSCs could be differentiated down the chondrogenic lineage to create cartilage-like structures containing type II collagen.

Future work will involve the development of new complementary 3D printing techniques that will allow for the use of a wider range of living and hybrid materials and the production of tissues at industrial scale. According to the team, the applications for the 3D bioprinted tissue are numerous: personalized treatments using cells sourced from individual patients, for example, or for drug or toxin screening.

“The bioprinting approach developed with Oxford University is very exciting, as the cellular constructs can be printed efficiently at extremely high resolution with very little waste,” said Dr. Adam Perriman from the School of Cellular and Molecular Medicine at the University of Bristol. “The ability to 3D print with adult stem cells and still have them differentiate was remarkable, and really shows the potential of this new methodology to impact regenerative medicine globally.”

3D printed tissues are only as good as their ability to behave like natural tissue, and natural tissue is complex and multi-functional, which is why 3D printing tissue that functions as well as its natural counterparts has been such a challenge. The 3D printing technique developed by the research team at the University of Oxford, however, is another promising step forward.

Authors of the paper include Alexander D. Graham, Sam N. Olof, Madeline J. Burke, James P.K. Armstrong, Ellina A. Mikhailova, James G. Nicholson, Stuart J. Box, Francis G. Szele, Adam W. Perriman and Hagan Bayley. Discuss in the University of Oxford forum at 3DPB.com.