Inking Orthopaedic Implants During Surgery

University of Wollongong, NSW, Australia
www.uow.edu.au

A hand-held device they call a “BioPen” has been developed by researchers at the University of Wollongong, NSW, Australia, Australian Research Council Centre of Excellence for Electromaterials Science. They say that it will allow surgeons to design customized implants on-site during surgery. (See Figure 1)

Fig. 1 - The Biofen could allow surgeons to design custom bone implants during surgery.

The technology can give surgeons greater control over where the materials are deposited while also reducing the time the patient is in surgery by delivering live cells and growth factors directly to the site of injury, accelerating the regeneration of functional bone and cartilage.

The BioPen works similar to 3D printing methods by delivering cell material inside a biopolymer such as alginate, a seaweed extract, protected by a second, outer layer of gel material. The two layers of gel are combined in the pen head and extruded onto the bone surface as the surgeon maneuvers the pen to draw using the “ink” to literally fill in the damaged bone section. (See Figure 2)

A low powered ultra-violet light source is affixed to the device that solidifies the ink during dispensing, which provides protection for the embedded cells while they are built up layer-by-layer to construct a 3D scaffold in the wound site.

Once the cells are written onto the surgery site they will multiply, become differentiated into nerve cells, muscle cells, or bone cells and will eventually turn from individual cells into a thriving community of cells functioning as a tissue, such as nerves, or a muscle.

Fig. 2 - Materials combine in the pen head and are extruded through the tip.

The device can also be seeded with growth factors or other drugs to assist regrowth and recovery, while the hand-held design allows for precision in the operating room and for ease of transportation.

The BioPen prototype was designed and built using the 3D printing equipment in the labs at the University of Wollongong and was recently released to clinical partners at St. Vincent’s Hospital Melbourne, led by Professor Peter Choong, Director of Orthopaedics at St. Vincent’s and the Sir Hugh Devine Professor of Surgery, University of Melbourne, who will work on optimizing the cell material for use in clinical trials.

The BioPen will help build on recent studies by the university researchers where they were able to grow new knee cartilage from stem cells on 3D-printed scaffolds to treat cancers, osteoarthritis, and traumatic injury.

Choong said: “This type of treatment may be suitable for repairing acutely damaged bone and cartilage, for example from sporting or motor vehicle injuries…the research team brings together the science of stem cells and polymer chemistry to help surgeons design and personalize solutions for reconstructing bone and joint defects in real time.”