Biodegradable Nanoparticles for Intra-articular Therapy

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by progressive loss of articular cartilage which leads to severe pain and restricted mobility in the patients. Age, excessive joint loading, or sports injury are the factors known to increase the risk of joint degeneration thus leading to OA. Many techniques have been employed in OA therapy but none of them has given satisfactory results in long term. Oral drugs have the disadvantage of having several side effects such as gastrointestinal problems, heart attack, and stroke associated with them. Surgical techniques lead to significant donor site morbidity. Intra-articular (IA) injections of hyaluronic acid (HA), glucocorticoids, have shown symptomatic relief but none of these treatments have been able to show disease modifying effects to an appreciable extent. Nanostructured drug delivery systems using liposomes and nanoparticles (NPs) can be administered as IA injections for sustained release and increased local concentrations of drugs in arthritis. A liposomal formulation of dexamethasone palmitate is currently available for IA drug delivery. Several other NPs of chitosan and biodegradable synthetic polymers like PLGA are in the developmental stages for delivery of steroids, NSAIDs and clodronate. This review highlights some of the promising nanostructured drug delivery systems for IA therapy, the issues involved in developing such systems and the future potential of such therapies for degenerative and inflammatory joint diseases. _____________________________________________________________________________________________________________