3D Bio-Printer Fabricates Human Tissue and Organs

A flexible three-dimensional (3D) biological printing technology platform could soon manufacture many different types of human tissue construction and replacement organs.

The bio printer fits inside a standard bio-safety cabinet for sterile use, and includes two print heads, one for placing human cells, and the other for placing a hydrogel, scaffold, or support matrix. The cell printing head forms the cells into droplets 100 μm - 500 μm in diameter, each containing 10,000-30,000 cells. The droplets retain their shape well and pass easily through the inkjet printing process. The second printing head is used to deposit a sugar-based hydrogel used as scaffolding, which does not interfere with the cells or stick to them. Once the printing is complete, the structure is left for a day or two to allow the droplets to fuse together. For tubular structures, such as blood vessels, the hydrogel is printed in the centre and around the outside of the ring of each cross-section before the cells are added. When the part has matured, the hydrogel is peeled away from the outside and pulled from the centre like a piece of string.

A computer controlled, laser-based calibration system is used to repeatedly position the capillary tip attached to the print head, ensuring that the cells are placed in exactly the right position to within a tolerance micrometer. The 3D bio-printer includes an intuitive software interface that allows engineers to build a model of the tissue construct before the printer commences the physical constructions of the organs, cell-by-cell.

To start with, only simple tissues, such as skin, muscle, and short stretches of blood vessels, will be made. However, once clinical trials are complete, the printers will begin producing blood vessels for use as grafts in bypass surgery procedures. With more research, it should be possible to produce bigger, more complex body parts. For example, as the printer has the ability to make branched tubes, the technology could be used to create the networks of blood vessels needed to sustain larger printed organs, such as kidneys, livers, and even hearts. The bioprinter was built by Invetech (Melbourne, Australia), under contract from Organovo (San Diego, CA, USA), developers of the proprietary NovoGen bioprinting technology.

"Scientists and engineers can use the 3D bio printers to enable placing cells of almost any type into a desired pattern in 3D,” said Keith Murphy, CEO of Organovo. "Researchers can place liver cells on a preformed scaffold, support kidney cells with a coprinted scaffold, or form adjacent layers of epithelial and stromal soft tissue that grow into a mature tooth. Ultimately the idea would be for surgeons to have tissue on demand for various uses, and the best way to do that is to get a number of bio-printers into the hands of researchers and give them the ability to make three dimensional tissues on demand.”

Related Links:
Invetech
Organovo