During an arthritis flare-up, a joint becomes inflamed and slightly more acidic than the surrounding tissue. If used as an artificial cartilage in arthritic joints, this approach could allow for the continuous treatment of arthritis, improving the efficacy of drugs to relieve pain and fight inflammation. Arthritis affects more than 10 million people in the UK, costing the NHS an estimated £10.2 billion annually. While extensive clinical trials are needed before the material can be used in patients, the researchers say their approach could improve outcomes for people with arthritis, and for those with other conditions including cancer. The researchers say this could pave the way for longer-lasting, targeted arthritis treatments that automatically respond to flare-ups, boosting effectiveness while reducing harmful side effects.