Surgeons can soon use a 3D printing pen to build customized cartilage tissues during surgery. The pen with bio-ink which supports human stem cells can print cells according to the precise geometry of the implant needed.

Australian researchers were able to 'draw' human stem cells in freeform patterns with extremely high survival rates.

Developed by a team from ARC Centre of Excellence for Electromaterials Science (ACES) and orthopaedic surgeons at St Vincent's Hospital, Melbourne, the biopen carries a hydrogel bio-ink which solidifies under a light source to deliver the cartilage implant. The pen delivers a cell survival rate in excess of 97%.

Professor Peter Choong, Director of Orthopaedics at St Vincent's Hospital Melbourne, developed the concept with ACES Director Professor Gordon Wallace.

"The development of this type of technology is only possible with interactions between scientists and clinicians - clinicians to identify the problem and scientists to develop a solution," Professor Choong said.

The BioPen was fabricated using 3D printed medical grade plastic and titanium. It is small, lightweight, ergonomic and sterilisable.

"The biopen project highlights both the challenges and exciting opportunities in multidisciplinary research. When we get it right we can make extraordinary progress at a rapid rate," Professor Wallace said.

The work was is published journal Biofabrication.

Design expertise and fabrication of the BioPen was supported by the Materials Node of the Australian National Fabrication Facility.

Kidneys, blood vessels and windpipes are in various stages of 3D manufacture today. The challenge is to keep the stem cells live while fabricating the tissue or organ.

3D printing or additive manufacturing is a process of making three dimensional objects from a digital file. The object is created by laying down thin successive layers of material until the entire object is created using inbuilt hardware. In the case of organs the material is stem cells.

There is some concern over the mixing of human and non-human stem cells prompting talk of a ban on 3D printing of organs by 2017 when the market for 3D printing is set to soar.