A handheld “biopen” capable of 3D printing cartilage tissue could for the first time be used during surgery to treat cartilage injuries and osteoarthritis. The extrusion-based device, which prints live stem cells embedded in a hydrogel material, produces constructs that look and behave just like natural articular tissue (Biofabrication 10 045006).
“This is in stark contrast to conventional reparative cartilage made of fibrocartilage, which is very different in structure to physiological cartilage, inferior in quality and not durable,” say the researchers, a multidisciplinary team that includes surgeons, biologists, physicists and engineers. “Our technique and the scaffolds we are able to produce provide much hope for treating patients suffering from cartilage injuries and osteoarthritis.”
Cartilage is a highly specialized tissue that has so far proved difficult to replicate using conventional tissue engineering techniques. Its special mechanical properties arise from the fact that it contains only a few cells, does not contain blood vessels, and has a distinct 3D collagen fibre structure comprising aggregated proteoglycans in an organized matrix.
While some success has been reported for surgical treatments that exploit engineered cartilage tissue, existing procedures require two separate operations: one to remove the damaged tissue, and another to replace the tissue once it is repaired. What’s more, surgeons report a high failure rate – partly because pre-fabricated scaffolds might not perfectly match the defect, and partly because the implanted tissue is not similar enough to natural cartilage to survive for long inside the body.
Researchers believe that treatments using human stem cells could offer a solution, but few studies have been reported to date. In this new work, reported in the journal Biofabrication, scientists from the University of Melbourne, the University of Wollongong and the St Vincent’s Hospital of Melbourne provide in vitro evidence that their new biopen could enable human stem cells to be 3D printed inside the operating theatre. The ultimate aim is to enable surgeons to “sculpt” patient-specific structures in real time, creating scaffolds that perfectly match the geometry of the defect and achieve the best possible contact between the bioscaffold and the host tissue.
Image Credit: C Onofrillo