December 08, 2017
December 08, 2017
Curated by Aurelien Forget, PhD
Scientists have used live bacteria-containing inks – bioinks – to print 'living materials' that can change their shape over time. This technology can help us discover new drugs more quickly and introduce bacteria-containing sensors and decontamination equipment.
In 10 seconds? 4D printing generates objects that self-assemble over time. Combined with bioinks, it is set to lead to breakthroughs in medicine and turn bacteria into useful tools for detecting and cleaning up pollutants in the environment. (Read about the science of 4D bioprinting)
So, why is 4D better than 3D? Well, we know what 3D printing is. 4D is about adding ‘time’ as an extra dimension – so that the material rearranges or grows into a pre-determined shape after printing. The really amazing thing is the addition of bacteria or cell-containing bioinks, which open the path to artificial human tissue or non-medical bio-tools, such as pesticide detectors and filters to clean up oil spills by degrading pollutants. (Find out more here)
Wow, that means we’ll be printing organs soon? That’s complicated as we would need to print nerves, blood vessels and more in order to integrate the printed organs with the recipient's body. More realistic is the creation of less complex tissues. Scientists have already printed a material combining marine algae and human stem cells that assembles into super-thin blood vessels over two weeks. (Read more here)
What’s the use of less complex tissues if printed organs are far away?They can give more useful results in drug testing, as we’ll be able to print models that reproduce aspects of human organs, such as heart muscles or parts of the liver. This is important, because even promising animal tests don’t guarantee a drug fit for human use. Other solutions include bioprinting tissue substitutes – such as skin to repair burns or cartilage that protects our knees. (Read more here)
And how do the materials self-assemble? 4D-printed material can react to chemical or physical stimuli and turn into pre-programmed shapes. Plastic objects can be designed to have moving parts that force them to assemble for implanting into the body. Adding naturally occurring proteins, scientists have also printed hydrogels that were programmed to assume plant-like shapes when immersed into water. (Find out how)
You mentioned this tech has wider uses too… Indeed. A non-medical application is likely to be a 4D-printed microbial biosensor that can detect toxins in water or pesticides in food. Another bioprinted application would be filters that help to clean up oil spills, by using bacteria to break down pollutants. (Read the full text here)
How a synthetic leaf can become a fuel cell
Canadian researchers managed to print a ‘leaf’ that combines nanoparticles, carbon nanotubes and membrane made from proteins.
The 4D printing technique enabled them to create an object that reacts to different environments and materials.
The ‘leaf’ swells under UV light when immersed in water, and then splits the water molecule to create hydrogen, like fuel cells.
Psst, Aurelien distilled 6 research papers to save you 430.6 minutes.