The common solution to fixing damaged tissue, bone and cartilage is based around adding something to the body, usually plastic or metal, or by bone grafting.
Dr Khoon Lim and Professor Tim Woodfield at the University of Otago’s Christchurch Regenerative Medicine and Tissue Engineering (CReaTE) Group are taking a different approach by using the body’s own cells.
“We can’t keep implanting foreign substances into our bodies with the risk of deterioration or rejection when we can engineer a solution that mimics nature,” says Professor Tim Woodfield. “Instead, we’re looking at a future where treatment will be based on cell therapies.”
In simple terms, it’s no different from any 3D printing. A structure, or scaffold, is printed and, in the case of bone, it can match the exact dimensions required to replace the excised bone. However, it’s Dr Lim’s work with hydrogels that makes a critical difference.
Dr Lim’s research focuses on using hydrogels to deliver cells and bioactive molecules (proteins, growth factors and drugs) for tissue engineering and regenerative medicine applications. The hydrogel delivery system is designed to instruct and induce cell signalling down a pathway of tissue organisation and formation.
“Using hydrogels, we can ‘print’ cells onto this scaffold, infuse it with layers of human cells and proteins and fix them in place using light. The result is a usable implant,” says Dr Lim.
“Combining a patient’s own cells with 3D printed biodegradable scaffolds and growth factors mean we can achieve automated construction of living tissue,” says Professor Woodfield.
There are challenges – making the tissue, getting the right structure and creating large enough scaffolds.
This approach can also be used for cartilage repair, bone vascularisation, 3D cancer models for high-throughput drug screening and smart delivery of growth factors for stroke recovery. There is also significant potential in oncology to fill voids left by tumour removal.
The CReaTE group are world-leaders in this area and one of the largest research groups in New Zealand working on bioprinting.
By Prue Scott