3D-printed nose implant ready for trials

You might be able to get by in life without, say, an ear, or with a damaged nose -- but for those experiencing it, looking different can have a massive impact on self esteem and emotional wellbeing. Of course, the best surgical option is using the patient's own cartilage to craft an implant -- such as nine-year-old Kieran Sorkin, who last year received a new ear made from cartilage taken from his own ribs.

But a new technique developed by researchers at ETH Zürich in Switzerland could potentially minimise the amount of surgery a patient needs to receive in order to have an implant created out of their own cartilage. Instead, it relies on bioprinting -- 3D printing lab-grown cartilage from a culture of the patient's own cellular material.

So far, Professor Marcy Zenobi-Wong and her team have created a nose and an ear from a mix of biopolymers and cartilage cells, using a bioprinter in the university's Cartilage Engineering and Regeneration Group laboratory at the Department of Health Sciences and Technology.

The printer is based on a wheel holding eight syringes, each of which can hold a different suspension. A computer uses a 3D model to control the printer, which then prints the material from the syringes with a high degree of precision, depositing the material in layers at high speed -- a cartilage nose, for instance, takes the printer just 16 minutes.

The patient's original cartilage material is taken from a needle biopsy, from a site such as the knee or finger. These cells are then propagated in a laboratory setting and mixed with biopolymer, resulting in a suspension with the consistency of toothpaste. This is then used to print the cartilage implant; the biopolymer acts as a degradable scaffolding, which will be broken down by the body's cartilage after implantation, leaving only the cartilage structure. After a few months, the join would be indistinguishable.

As well as cosmetic procedures, this technique could also be used to restore worn joint cartilage, such as chondromalacia patellae, the deterioration of the cartilage between the knee joint and the kneecap. Although cartilage implants are currently in use, they involve stitching a two-dimensional strip of cartilage to the injury -- a process that leaves scarring, as it doesn't take into account the spatial information of the joint.

The other benefits of the technique, of course, are that, since it uses the body's own cells, there is a decreased chance of immunorejection; and that the cartilage would grow with the patient's own body, particularly important for any children receiving the treatment.

Professor Zenobi-Wong's team's approach would avoid this by printing both the cells and their supporting structure in one step, allowing the cells to retain their original features and generate new cartilage.

The next step is to test the viability of bioprinted implanted in a trial using sheep and goats, which is expected to occur this year. If this trial is successful, then human clinical trials may proceed after that.

This is still at least a year away, however -- and shouldn't be taken as an indication, Professor Zenobi-Wong said, that bioprinting is ready for more advanced applications, such as replacement organs.

"While there's great deal of hype around bioprinting at the moment, our research is a long way from offering things that are already being promised today," she said. "Our expertise is in cartilage, probably the easiest bodily tissue for bioprinting, but even today we know that this is anything but easy to print."