Dublin: novel tissue for lost cartilage

Collaboration opportunity

Professor Mohamed Al-Rubeai, at the Centre for Biochemical Engineering at University College Dublin, Ireland, has developed an novel tissue engineering approach for restoring damaged or lost knee cartilage tissue.

Currrent techniques involve removing a patient’s own mature cartilage cells, or chondrocytes, and culturing them in vitro. Once the cells have multiplied the patient must then undergo a second surgical procedure for implanting them into the knee. With luck, the implanted chondrocytes will then help to produce healthy cartilage.

“There are a number of new transplantation products in clinical trials that all use chondrocytes,” says Al-Rubeai. “However, these cells have limitations because when they divide they lose the potential to form cartilage, and the overall treatment is expensive.”

In a previous post at Birmingham University in the UK, Al-Rubeai collaborated with Smith & Nephew in developing tissue culture techniques using adult stem cells. These retain their ability to form cartilage when grown in vitro and enable the generation of large cell banks.

“Routine tissue culturing methodologies cannot cope with the scale of cell production required to create world stem cell banks for engineering knee cartilage tissue,” says Al-Rubeai. To overcome this he has optimised the tissue culture techniques for growing stem cells in vitro that have the characteristics and structure of in vivo stem cells.

“This is the first study to factor in economics. A key objective of our work is to develop a model for the biopharmaceutical industry by generating a cell bank using an affordable technique,” said Al-Rubeai. “A 17-fold expansion factor has been achieved, and large numbers of stem cells for tissue culture engineering were obtained.”

Once the stem cells are expanded they must be engineered into new cartilage tissue for implantation into the knee. To do this stem cells are supported on a bioactive scaffold that shapes the cells.

Engineers at the University College Dublin School of Chemical and Bioprocess Engineering are now beginning to look at biodegradable gels to make a cartilage construct. These hydrogels will form the new cartilage tissue, and once implanted the gel will biodegrade.

“Presently we are using bovine stem cells, but we would like to progress to using human stem cells,” said Al-Rubeai. “Our aim now is to collaborate with clinicians so we can move this work into the clinic.”