Dipyridamole-grafted copolymer electrospun nanofiber membranes for suppression of peritendinous adhesions

Post-traumatic tendon adhesions significantly affect patient prognosis and quality of life, primarily stemming from the absence of effective preventive and curative measures in clinical practice. Current treatment modalities, including surgical excision and non-steroidal anti-inflammatory drugs, frequently exhibit limited efficacy or result in severe side effects. Consequently, the use of anti-adhesive barriers for drug delivery and implantation at the injury site to address peritendinous adhesion (PA) has attracted considerable attention. Electrospun nanofiber membranes (ENMs) have been extensively employed as drug-delivery platforms. In this study, we fabricated a polylactic acid (PLA)-dipyridamole (DP)-graft copolymer ENM called PLC-DP. This membrane exhibits enzyme-sensitive features, allowing more controlled and sustained drug release compared with conventional drug-loaded ENMs. In experiments, PLC-DP implantation reduced tissue adhesion by 47 % relative to the control group while not adversely affecting tendon healing. Mechanistically, PLC-DP effectively activates the FXYD domain containing ion-transport regulator 2 (FXYD2) protein, thereby downregulating the fibroblast-transforming growth factor beta (TGF-β)/Smad3 signaling pathway. PLC-DP leverages the anti-adhesive properties of DP and the enzyme-sensitive characteristics of graft copolymers, providing a promising approach for the future clinical treatment and prevention of PA. STATEMENT OF SIGNIFICANCE: Peritendinous adhesions (PA) are a common and disabling condition that seriously affects the prognosis and quality of life of post-trauma patients. Current treatments often have limited efficacy or severe side effects, leaving a serious gap in clinical practice. We developed a significant biomaterial, poly(lactic acid)-dipyridamole graft copolymer electrospun nanofibrous membrane (PLC-DP), specifically for PA inhibition. In addition, this study uniquely combines dipyridamole, an anti-adhesive agent, and enzyme-sensitive copolymers in electrospun nanofibrous membrane. Unlike conventional drug-loaded electrospun nanofibrous membranes, PLC-DPs have enzyme-sensitive drug properties that allow for sustained drug release on demand. Our experiments showed that implantation of PLC-DP was effective in reducing tissue adhesions by 47 % without affecting tendon healing. We elucidated the mechanism behind this phenomenon, suggesting that PCD activates FXYD2 to inhibit TGF-β-induced expression of Col III, which is a key factor in PA development.