First Plastic… Then FLESH
3D-Printed Prosthetic Limbs
What is Cell Printing?
Cell printing is an fascinating emergent technique in the synthetic biology field. Individual cells from a specific cell culture replace the plastic filament traditionally used in a 3D printer and are arranged in three-dimensional space according to a computer-designed model.
This promises a future of medicine with scarless wound closing or infinite organs without the need for donors or anti-immune drugs to fight rejection. We could even perform cosmetic surgery without the plastic, silicone or bum-tissue. Scientists at the University of Newcastle have already managed to 3D print a cornea and the University of Tel Aviv has showcased a mini 3d-printed heart!
Beating heart grown with stem cells by Massachusetts General Hospital and Harvard Medical school, Image credit: https://www.intelligentliving.co/first-3d-printed-hearts-grown-stem-cells/
Infinite organs?
That sounds exciting, sign me up! Only, cells aren’t nearly as simple as plastic filament. They can’t just be arranged in space and then be expected to function, cooperate or even stick together. Human cells also don’t just grow on trees, and require difficult biochemical coaxing in order to grow independent of a body. Once assembled, cells require a constant oxygen supply for respiration - so any 3D model requires inbuilt vasculature. These are just some of the challenges that numerous research groups have attempted to address during the last decade.
In science, mixed results are good - success and failure each advance our knowledge in their own way. I’d like to follow in the footsteps of these giants and build my own cell printer, complete with my own cell culture to print with.
As a casual observer and hobbyist, it’s difficult to know when it is best to jump in to such a swiftly evolving industry. I didn’t know anything about 3D printing, nor much about mammalian cell culture. I had a lot of basic skills to learn before I’d get to build my cell printer.
Why train on a normal 3D printer?
While representing Open Insulin at the 2018 Geneva Health forum, I was introduced to a team with three Delta 3D printers, furiously printing away. They were there to show off methods for creating cheap prosthetic limbs for diabetics in developing nations who’d missed too many insulin doses. I was enthralled by the potential of their project and decided I’d buy my own 3D printer to learn the techniques for myself.
Emerging technologies are great to observe, but the grounded reality is that any incredible new technique will only be available to a restricted, wealthy portion of the population. Developing useable techniques for the meantime still has inherent value. As long as inequality ensures unequal access to insulin, there will always be a demand for dirt-cheap prosthetics. There are some truly excellent projects in this industry, who overtly focus on supplying communities with the capital equipment (see: 3D printers) they need to locally produce complex items - such as prosthetic hands. E-nable have an excellent page of potential designs, and I used this as my entry into the world of 3D printing. I purchased an AnyCubic Kossel Linear Plus printer for a bargain and got to work.
This printer is known as an FDM or “Fused Deposition Modeling” and involves laying down successive layers of plastic on top of one another. This technique was a fascinating insight into the technology behind 3D printing (models, slicing, Arduino, etc.) but would be a terrible way to build a cell printer.
How do you build a cell printer?
3D natives have fascinating articles on the current range of industry
https://www.3dnatives.com/en/3d-bioprinters-main-manufacturers-081020194/