Ink Jet Printer Creates Cartilage

It was only a matter of time before ink jet printers—already modified to produce small parts for machines—would be adapted to create viable tissue. With a goal of creating a framework for cartilage, scientists at Wake Forest University, North Carolina, paired a traditional ink jet printer with an electrospinning machine that can generate fine fibers from a polymer solution. The polymers are porous, a requirement for getting cartilage cells to integrate into the surrounding tissue.

The process, called “bioprinting, ” is an emerging technique used to fabricate 3D tissue constructs through the precise deposition of cells and hydrogels in a layer-by-layer fashion. In this study researchers alternated the electrospinning of polycaprolactone fibers with inkjet printing of cartilage cells from a rabbit’s ear suspended in a fibrin–collagen hydrogel. They were able to fabricate a five-layer tissue construct of 1mm thickness.

The rabbit chondrocytes survived within the printed hybrid construct with more than 80% viability one week after printing. In addition, the cells proliferated and maintained their basic biological properties. The deposition of type II collagen and glycosaminoglycans demonstrated that the fabricated constructs formed cartilage-like tissues both in vitro and in vivo. Researchers tested the cartilage after eight weeks and found that it had developed the structures and properties of real cartilage, thus demonstrating its potential use in humans.

“This is a proof of concept study and illustrates that a combination of materials and fabrication methods generates durable implantable constructs, ” said James Yoo, a professor at the Wake Forest Institute for Regenerative Medicine, and one of the authors of the study. He and his colleagues believe that their study demonstrates the feasibility of constructing a hybrid inkjet printing system using off-the-shelf components to produce cartilage constructs with improved biological and mechanical properties.