A new hybrid printer developed by researchers at the Wake Forest Institute for Regenerative Medicine (WFIRM; Winston-Salem, NC) simplifies the production of implantable cartilage, according to an article published by the Institute of Physics (London). The system could eventually be used to fabricate cartilage for use in such applications as joint reconstruction.
Combining two low-cost fabrication techniques, ink-jet printing and electrospinning, the printer has enabled the researchers to build structures made from both natural and synthetic materials. While the synthetic materials impart strength to the construct, the natural gel materials promote cell growth.
Employing an electrical current to generate very fine fibers from a polymer solution, the electrospinning machine allows users to control the composition of the polymers, thereby producing porous structures that encourage cells to integrate into surrounding tissue. “This is a proof of concept study and illustrates that a combination of materials and fabrication methods generates durable implantable constructs,” remarks James Yoo, WFIRM professor and an author of a study published in the journal Biofabrication. "Other methods of fabrication, such as robotic systems, are currently being developed to further improve the production of implantable tissue constructs."
In this study, flexible mats of electrospun synthetic polymer were combined, layer-by-layer, with a solution of cartilage cells from a rabbit ear that were deposited using a traditional ink-jet printer. A week after testing the strength of the mats, the researchers tested them to determine whether the cartilage cells were still alive. Then, to determine how the mats performed, the scientists inserted them into mice for two, four, and eight weeks. Following implantation for eight weeks, the constructs appeared to have developed the structures and properties that are typical of elastic cartilage.