The Evaluation of Equine Allogeneic Tenogenic Primed Mesenchymal Stem Cells in a Surgically Induced Superficial Digital Flexor Tendon Lesion Model.
Authors: Depuydt Eva, Broeckx Sarah Y, Van Hecke Lore, Chiers Koen, Van Brantegem Leen, van Schie Hans, Beerts Charlotte, Spaas Jan H, Pille Frederik, Martens Ann
Journal: Frontiers in veterinary science
Summary
# Editorial Summary: Tenogenic Primed Mesenchymal Stem Cells for Equine Superficial Digital Flexor Tendon Lesions Superficial digital flexor tendon injuries remain a significant cause of athletic wastage in horses, with reinjury rates necessitating novel regenerative approaches. Depuydt and colleagues evaluated the safety and efficacy of allogeneic tenogenic primed mesenchymal stem cells (tpMSCs) versus saline placebo in a surgically induced lesion model, using eight horses with bilateral tendon injuries followed over 112 days and assessed via ultrasound tissue characterisation, lameness examination, and histological analysis. Treatment with tpMSCs proved safe, with only transient mild swelling by day 11, yet demonstrated measurable benefit: the stem cell-treated tendons showed significantly improved echogenicity scores, fibre alignment, reduced anterior-posterior thickness, and superior ultrasound tissue characterisation patterns compared to saline controls. Histological findings at 16 weeks revealed the tpMSC group had substantially higher collagen type I deposition and von Willebrand factor expression—markers of mature, organised tissue—whilst collagen type III and smooth muscle actin were reduced, suggesting a shift toward more organised, less inflammatory healing. These findings indicate that a single intralesional injection of allogeneic tpMSCs warrants further investigation in clinical populations, particularly given the objective tissue remodelling observed and the absence of adverse events, though practitioners should note this represents a controlled research model rather than field-trial evidence.
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Practical Takeaways
- •Allogeneic tpMSC injection appears safe for treating SDFT lesions with minimal adverse effects and only temporary mild swelling
- •Treated tendons showed improved structural organization and collagen remodeling toward mature tissue (increased type I, decreased type III collagen) suggesting enhanced healing
- •A single injection may be sufficient to promote healing, though longer-term reinjury risk and return to athletic function require further investigation in larger populations
Key Findings
- •Allogeneic tenogenic primed mesenchymal stem cells (tpMSCs) were well-tolerated with no serious adverse events over 112 days
- •tpMSC-treated tendons showed significantly improved echogenicity, fiber alignment, and reduced anterior-posterior thickness compared to saline controls
- •Immunohistochemistry revealed tpMSC-treated tendons had higher collagen type I and Von Willebrand factor but lower collagen type III and smooth muscle actin
- •Single intralesional tpMSC injection produced only transient moderate swelling by day 11 with no difference in local heat or pain compared to saline