Wrapping of tendon tissues with diclofenac-immobilized polycaprolactone fibrous sheet improves tendon healing in a rabbit model of collagenase-induced Achilles tendinitis

Herein, we suggest that wrapping of collagenase-treated tendon tissues with DFN/PCL fibrous sheet as a long-term local drug delivery system is more effective in improving tendon restoration via the great suppression of inflammation. [Display omitted] •DFN/PCL fibrous sheets were fabricated to improve tendon healing of Achilles tendinitis.•DFN/PCL sheets suppressed pro-inflammatory cytokines in vitro and in vivo.•DFN/PCL sheets increased anti-inflammatory cytokines in vivo.•Wrapping of tendon tissues with DFN/PCL sheets exert excellent tendon healing effects. We fabricated diclofenac-immobilized polycaprolactone (DFN/PCL) fibrous sheets to improve tendon healing of rabbits with collagenase-induced Achilles tendinitis. DFN/PCL have anti-inflammatory effects related to suppression of mRNA levels of pro-inflammatory factors including COX-2, IL-6, TNF-α, and MMP-3 in inflamed tenocytes and tendon tissues of rabbits with Achilles tendinitis as well as those of anti-inflammatory cytokines including IL-4, IL-10, and IL-13. In vivo studies, wrapping of tendon tissues with DFN/PCL fibrous sheets may afford superior tendon healing, with decreased inflammatory cells, increased collagen content, restored collagen fiber organization, and improved mechanical strength. This approach will be a promising treatment from Achilles tendinitis.