Exosome-Based Cartilage-Targeted Delivery System: Strategies and Applications

With the ageing of the global population, cartilage-related diseases, such as osteoarthritis (OA) and intervertebral disc degeneration (IVDD), have increasingly become significant social problems threatening human health. Therefore, targeted therapy for cartilage is becoming more and more promising. Exosomes, natural cellular derivatives, have emerged as promising therapeutic vectors owing to their inherent biocompatibility, superior biomatrix penetration capabilities, and therapeutic efficacy in cartilage regeneration. Precise targeting of cartilage tissues can be achieved through specific construction strategies, showing potential for treating cartilage-related diseases. However, a review of cartilage-targeted exosomes is still lacking. Previous studies have merely categorized chondrocytes under the broader group of osteocytes, regarding them only as a supplementary component of bone-targeted therapy, or have been limited to a single modification technique. This review specifically focus on cartilage-targeted exosomes, systematically integrating two modification methods-direct surface modification and parental cell engineering-and highlights translational applications in disease contexts. This article elaborates in detail on the construction strategies of cartilage-targeted exosomes and explores their application progress in related diseases such as OA and IVDD, aiming to provide a reference for further research and clinical translation in this field.