Nitric Oxide Nanomotor Driving Exosomes-Loaded Microneedles for Achilles Tendinopathy Healing

Tendinopathy describes a complex multifaceted pathology of the tendon, characterized by pain, decline in function and reduced exercise tolerance. The most common overuse tendinopathies involve the rotator cuff tendon, medial and lateral elbow epicondyles, patellar tendon, gluteal tendons and the Achilles tendon. The prominent histological and molecular features of tendinopathy include disorganization of collagen fibres, an increase in the microvasculature and sensory nerve innervation, dysregulated extracellular matrix homeostasis, increased immune cells and inflammatory mediators, and enhanced cellular apoptosis. Although diagnosis is mostly achieved based on clinical symptoms, in some cases, additional pain-provoking tests and imaging might be necessary. Management consists of different exercise and loading programmes, therapeutic modalities and surgical interventions; however, their effectiveness remains ambiguous. Future research should focus on elucidating the key functional pathways implicated in clinical disease and on improved rehabilitation protocols.

Tendinopathy is a multifactorial spectrum of tendon disorders that affects different anatomical sites and is characterized by activity-related tendon pain. These disorders are common, account for a high proportion (∼30%) of referrals to musculoskeletal practitioners and confer a large socioeconomic burden of disease. Our incomplete