Bio-inspired lubricant drug delivery particles for the treatment of osteoarthritis.

Osteoarthritis is a chronic and irreversible degenerative disease that often occurs in middle-aged and elderly people. Although many clinical therapeutics like intra-articular drug injection have been widely used for treating osteoarthritis, there are still some shortcomings that need to be overcome such as frequent injection, inflammatory response, and potential overdose. Inspired by the natural biocompatible lubricant substances, hyaluronic acid (HA), a novel bio-inspired lubricant drug delivery microcarrier with pathological-state responsive switches, was developed for osteoarthritis treatment. In this system, a temperature-responsive hydrogel was used to form an inverse opal-structured microsphere scaffold to increase the drug loading efficiency, while HA was employed as a vehicle to encapsulate drugs. Due to the properties of the scaffold, the loaded lubricant and encapsulated drugs can be released when temperature rises in the joint cavity during exercise or osteoarthritis. In contrast, the delivery system will be locked and the drug release process will stop when the arthritis lessens or exercise is stopped. Thus, the designed microcarrier is endowed with the ability of intelligently releasing drugs and lubricants for curing osteoarthritis, demonstrating its great potential in biomedical applications.