Functional regeneration and repair of tendons using biomimetic scaffolds loaded with recombinant periostin.

Tendon injuries disrupt the balance between stability and mobility, causing compromised functions and disabilities. The regeneration of mature, functional tendons remains a clinical challenge. Here, we perform transcriptional profiling of tendon developmental processes to show that the extracellular matrix-associated protein periostin (Postn) contributes to the maintenance of tendon stem/progenitor cell (TSPC) functions and promotes tendon regeneration. We show that recombinant periostin (rPOSTN) promotes the proliferation and stemness of TSPCs, and maintains the tenogenic potentials of TSPCs in vitro. We also find that rPOSTN protects TSPCs against functional impairment during long-term passage in vitro. For in vivo tendon formation, we construct a biomimetic parallel-aligned collagen scaffold to facilitate TSPC tenogenesis. Using a rat full-cut Achilles tendon defect model, we demonstrate that scaffolds loaded with rPOSTN promote endogenous TSPC recruitment, tendon regeneration and repair with native-like hierarchically organized collagen fibers. Moreover, newly regenerated tendons show recovery of mechanical properties and locomotion functions.