Rotator Cuff Repairs Augmented with Exosomes in a Rabbit Model Are Stronger and Histologically Superior to Repairs Performed in Isolation.

Ongoing research should focus on improving healing of rotator cuff repairs at the tendon-to-bone interface. "Cells, scaffolds, and signals" is useful in categorizing orthobiologic-related approaches to augmenting RCR. Cell-based therapies such as platelet rich plasma (PRP) and bone marrow aspirate concentrate (BMAC) exert positive effects through production of signaling molecules that modulate the inflammatory process, promote angiogenesis, and facilitate new tendon tissue growth. "Scaffolds" refer to structural and non-structural augments that may facilitate concentration of biologically active constituents at the healing site and provide time zero tissue strength of repaired tissues. Owing to challenges associated with the use of cell-based products, isolation and targeted delivery of the signaling molecules represent a promising avenue for optimizing tendon repair healing. "Exosomes" are small extracellular vesicles (30-150 nanometers) secreted by cells that serve as natural carriers of bioactive molecules. The role of exosomes in influencing intercellular communication-modulating inflammation, promoting angiogenesis, and regulating extracellular matrix (ECM) remodeling-makes them uniquely suited for tissue repair applications and a natural target for RCR-related basic science research. The use of exosomes represents a promising adjunct that appears to improve the biomechanical and histological properties of rotator cuff repairs. Rotator cuff repairs augmented with exosomes in a rabbit model may be stronger and histologically superior to repairs performed in isolation.