Mesenchymal Stem Cell Exosomes Promote Functional Osteochondral Repair in a Clinically Relevant Porcine Model

Area of Science:

• Regenerative Medicine
• Biomaterials Science
• Orthopedic Surgery

Background:

• Previous research indicated mesenchymal stem cell (MSC) exosome efficacy in small animal models for osteochondral defect repair.
• However, validation in a large, clinically relevant animal model was lacking.

Purpose of the Study:

• To assess the safety and efficacy of human MSC exosomes for osteochondral repair in a micropig model.
• To evaluate MSC exosomes in combination with hyaluronic acid (HA) for cartilage and subchondral bone regeneration.

Main Methods:

• Bilateral osteochondral defects were created in 12 micropigs.
• Groups received intra-articular injections of MSC exosomes + HA or HA alone at specific intervals.
• Assessment included MRI, macroscopic, histological, biomechanical, and micro-CT analyses.

Main Results:

• The Exosome+HA group showed significantly improved MRI scores at multiple time points.
• Enhanced cartilage and subchondral bone repair was observed in the Exosome+HA group, with superior macroscopic, histological, and biomechanical outcomes.
• Micro-CT revealed increased bone volume and trabecular thickness in the subchondral bone of the Exosome+HA group.
• No adverse events were reported in any animal.

Conclusions:

• Combined MSC exosomes and HA injections promote functional cartilage and subchondral bone repair in a porcine model.
• The treatment demonstrated improved morphological, histological, and biomechanical results.
• Findings support initiating Phase 1/2 clinical trials for osteochondral lesions.