Organovo has demonstrated the 3-D printing of small amounts of functional liver tissue, suitable for use in research. The limiting factor for printing larger masses is at this time largely the challenge of creating a suitable blood vessel network - something that researchers are still working on.
For the first time, human liver tissues have been generated that are truly three-dimensional, being up to 500 microns in thickness in the smallest dimension, and consisting of multiple cell types arranged in defined spatial patterns that reproduce key elements of native tissue architecture. The tissues, fabricated using Organovo's [bioprinting] platform, are highly reproducible and exhibit superior performance compared to standard 2D controls.
"We have achieved excellent function in a fully cellular 3D human liver tissue. We've combined three key features that set our 3D tissues apart from 2D cell-culture models. First, the tissues are not a monolayer of cells; our tissues are approximately 20 cell layers thick. Second, the multi-cellular tissues closely reproduce the distinct cellular patterns found in native tissue. Finally, our tissues are highly cellular, comprised of cells and the proteins those cells produce, without dependence on biomaterials or scaffold for three-dimensionality. They actually look and feel like living tissues. Not only can these tissues be a first step towards larger 3D liver, laboratory tests with these samples have the potential to be game changing for medical research. We believe these models will prove superior in their ability to provide predictive data for drug discovery and development, better than animal models or current cell models."