Microgels could be used to repair damaged spinal discs, say UK scientists. 

Microgels are cross-linked polymer particles that are swollen with solvent. Brian Saunders and colleagues at the University of Manchester have developed a microgel that responds to pH. At low pH, the material is a fluid, but at higher pH, the microgel particles act like sponges and absorb water, creating a stiff gel. 

Saunders injected the material into a damaged bovine intervertebral disc, and increased the pH to biological levels by injecting alkaline solution. The disc returned to its normal height, and regained its mechanical strength.

'Chronic lower back pain due to spinal disc degeneration is a major health problem,' said Saunders. 'The most common treatment is spinal fusion, a major surgical procedure which can result in a significant loss of mobility at the fused and adjacent discs. Our approach has the advantage of being minimally invasive, and being able to restore spinal mobility.' 

To develop the technology into a viable alternative to spinal fusion, Saunders and his team plan to investigate biodegradable microgels that release additives to stimulate the regeneration of spinal disc tissues.

Susan Batten