MHz ultrasonic drive-in: Localized drug delivery for osteoarthritis therapy

Osteoarthritis (OA) is a significant musculoskeletal disease with no cure. Current drug delivery techniques feature poor spatial localization (systemic delivery or injection into the synovial capsule). We previously used kHz high-intensity ultrasound to deliver micro- and nano-particles into articular cartilage (AC). Here we investigated whether MHz ultrasound can deliver particles into AC. Using high-intensity focused ultrasound (HIFU) we drove agents into 45% depth of the AC thickness. In addition, laser-induced shock waves showed drive-in effect. Our results demonstrate that MHz ultrasound can locally administer agents into AC. The technique could potentially be used for localized OA drug therapy.