Bioprinters work like 3D printers, but instead deposit layers of biomaterial, including living cells, to build structures like blood vessels or skin tissue.
Organovo is a company that was set up by a research group lead by Professor Gabor Forgacs from the University of Missouri, and in March 2008 bioprinted functional blood vessels and cardiac tissue using cells obtained from a chicken. Their work relied on a prototype bioprinter with three print heads. The first two of these output cardiac and endothelial cells, while the third dispensed a collagen scaffold -- now termed 'bio-paper' -- to support the cells during printing.
The required cells (e.g. kidney cells, skin cells, etc) are taken from a patient and then cultivated. Adult stem cells, which can develop to form the cells required in different tissues, can also be used. The resulting cultured cells are referred to as the bioink. Cells contained in a bioink spheroid are capable of rearranging themselves after printing. For example, experimental blood vessels have been bioprinted using bioink spheroids comprised of an aggregate mix of endothelial, smooth muscle and fibroblast cells. Once placed in position by the bioprint head, and with no technological intervention, the endothelial cells migrate to the inside of the bioprinted blood vessel, the smooth muscle cells move to the middle, and the fibroblasts migrate to the outside.
Progress in drug testing and regenerative medicine could benefit from laboratory-engineered human tissues built of a variety of cell types with precise 3D architecture. Production of greater than millimeter sized human tissues has been limited by a lack of methods for building tissues with embedded life-sustaining vascular networks.
