Brian Cunningham at the University of Illinois at Urbana-Champaign, US, and colleagues have used rubber moulds as a new and controlled way of growing replacement cartilage scaffolds. 

The researchers poured a liquid form of chitosan, a biodegradable material derived from sea shells, into a polydimethylsiloxane mould. The mould contains long, narrow channels, down to just one micrometre wide. Once the chitosan had solidified, the newly formed chitosan fibres could be lifted out of the mould.

The researchers say the fibres could be used as a scaffold material for hosting the growth of cartilage cells, where the cell-populated scaffold would be used as replacement tissue for patients with damaged knee, elbow, or hip joints. Because the scaffolds would be seeded with cells from the patient, the resulting tissue should not be rejected by the immune system.

Natural cartilage has a fibrous structure, so cartilage cells are most likely to grow and differentiate correctly when they are within a fibrous environment, as compared to the sponge-like surface-textured environment most commonly used for scaffolds today, said Cunningham.

Cunningham's team are currently working on a trial to seed the scaffolds with cartilage cells and grow the cells in both bioreactors and within microwell plate wells. 

'The team is also working on new fabrication methods that can accurately produce fibres with diameters below one micrometre,' said Cunningham.

Elinor Richards