Artificial, lab-grown steaks that taste and feel just like the real thing could soon become a reality thanks to a 3D printing breakthrough.
The technique could also help to create working artificial organs for transplant.
Bioengineers can already make 2D structures out of tissue – but attempts to make organs or larger piece of meat usually doesn’t succeed.
University of Pennsylvania researchers have found that 3D printing ‘templates’ of sugar and growing meat over them can actually create living artificial ‘organs’ with blood vessels.
So far, one of the major hindrances in making the jump from 2D to 3D was keeping the cells within large structures from suffocating.
In the new technique the organs are printed ‘inside out’ so that the blood vessels are printed first, then flesh is grown around them.
“Sometimes the simplest solutions come from going back to basics,” the Daily Mail quoted Miller as saying.
“I got the first hint at this solution when I visited a Body Worlds exhibit, where you can see plastic casts of free-standing, whole organ vasculature,” Miller said.
This rapid casting technique centred on the researchers developing a material that is rigid enough to exist as a 3D network of cylindrical filaments but which can also easily dissolve in water without toxic effects on cells.
After much testing, the team was able to find the perfect mix of material properties in sugar.
“We tested many different sugar formulations until we were able to optimize all of these characteristics together,” Miller said.
“Since there’s no single type of gel that’s going to be optimal for every kind of engineered tissue, we also wanted to develop a sugar formula that would be broadly compatible with any cell type or water-based gel,” Miller said.
Since the whole process is quick and inexpensive, it allows the researchers to switch with ease between computer simulations and physical models of multiple vascular configurations.
“This new platform technology, from the cell’s perspective, makes tissue formation a gentle and quick journey because cells are only exposed to a few minutes of manual pipetting and a single step of being poured into the molds before getting nourished by our vascular network,” Chen said.
The researchers showed that human blood vessel cells injected throughout the vascular networks spontaneously generated new capillary sprouts to increase the network’s reach, much in the way blood vessels in the body naturally grow.
The team then created gels containing primary liver cells to test whether their technique could improve their function.
When the researchers pumped nutrient-rich media through the gel’s template-fashioned vascular system, the entrapped liver cells boosted their production of albumin and urea, natural components of blood and urine, respectively, which are important measures of liver-cell function and health.
There was also clear evidence of increased cell survival around the perfused vascular channels.