Inkjet printing technology may have potential for tissue engineering

The printers could quickly layer certain cells that could later develop into bone, skin or cartilage.

Prof. Brian Derby, head of the Ink-Jet Printing of Human Cells Project at the University of Manchester, Englend, holds a model material produced with the inkjet printing technology used in his research lab. The structures have been dyed green for better visualization, but normally would be fairly colorless.

COURTESY OF BRIAN DERBY

Researchers at the University of Manchester in England and other research centers worldwide may have found a way to grow customized three-dimensional tissue, such as skin and bone, using patients' own cells. If successful, the technology could solve many reconstructive problems that orthopedic oncologists and other surgeons encounter.

The work involves cells, such as osteoblasts, osteoclasts and osteocytes, harvested from patients and suspended in a hydrogel. The inkjet technology then precisely layers the harvested cells while inserting them into a custom-designed polymer scaffold, which is based on a computerized tomography scan of the recipient's defect. Once "printed," the cells would replicate following the contours of the scaffold.

"We haven't reached clinical trial stages yet, so it's very much demonstrating the technology, rather than actually producing any sort of objects that would even go into an animal model, at the moment," Brian Derby, MA, PhD, a professor of Material Science at the University of Manchester, told Orthopedics Today

Ink jet technology has been used in industrial applications for about 15 years, primarily to construct solid, three-dimensional (3-D) objects for rapid prototyping in mechanical engineering, Derby said. The printers can continually overprint an area to build thickness.

Along with the Manchester-based UK Tissue Engineering Research Center, the university's Ink-Jet Printing of Human Cells Project, which Derby heads, is working to perfect the design of the resorbable 3-D scaffold that would receive the patient-harvested cells. They are also investigating using osteoinductive materials in the scaffold, including hydroxyapatite.

"You're not printing bone, but you're printing something that would transform into bone within the patient," Derby said.

Cartilage and skin also represent potential applications for the technology, although bone seems the most promising at this stage.

"The attraction of bone is that we know that bone repairs itself within reason. It appears to be an easier target, but that's just our thoughts at the moment," Derby said, noting the technology is probably five to 10 years away from clinical trials.

Researchers at Clemson University, S.C., are also investigating the technology for generating blood vessels, while researchers at other institutions are focused on preserving cells during the printing process.

The Manchester researchers are working with orthopedic and other surgeons, all of whom are excited about the concept, Derby said.