The University of Utrecht has a team that is successfully bioprinting “liver units” that are able to do some of the functions of a human liver and may open the door to new medical treatments. This isn’t simply printing a fake liver in a jar though, instead the technique uses optical tomography to rapidly create small structures of about 1 cc of volume in less than 20 seconds.
Apparently, one problem with printing hydrogels full of biological structures is that passing them through a nozzle tends to disturb the delicate structures. This technique uses no nozzle or layers, which makes it useful in this situation.
Of course, there is no free lunch. Using tomographic light techniques requires light to penetrate the hydrogel to form structures and this requires special care to prevent material around the edges from distorting light intended for interior volumes.
The new technique uses a bio-compatible compound often used as a contrast agent to make cells more transparent and, thus, less likely to interfere with the light patterns.
So far, this isn’t going to result in a new liver for you anytime soon. However, it seems to be a first step and there are other reasons small liver analogs can be useful.
This could be a step towards regenerative liver treatments. Maybe one day you’ll just have to get a new part printed to order if you need one.