Diamond-Like Carbon Depositing on the Surface of Polylactide Membrane for Prevention of Adhesion Formation During Tendon Repair

Post-traumatic peritendinous adhesion presents a significant challenge in clinical medicine.This study proposes the use of diamond-like carbon(DLC)deposited on polylactic acid(PLA)membranes as a biophysical mechanism for anti-adhesion barrier to encase ruptured tendons in tendon-injured rats.The results indicate that PLA/DLC composite membrane exhibits more efficient anti-adhesion effect than PLA membrane,with histological score decreasing from 3.12±0.27 to 2.20±0.22 and anti-adhesion effectiveness increasing from 21.61%to 44.72%.Mechanistically,the abundant C=O bond functional groups on the surface of DLC can reduce reactive oxygen species level effectively;thus,the phosphorylation of NF-κB and M1 polarization of macrophages are inhibited.Consequently,excessive inflammatory response augmented by M1 macrophage-originated cytokines including interleukin-6(IL-6),interleukin-1β(IL-1β),and tumor necrosis factor-α(TNF-α)is largely reduced.For biocompatibility evaluation,PLA/DLC membrane is slowly absorbed within tissue and displays prolonged barrier effects compared to traditional PLA membranes.Further studies show the DLC depositing decelerates the release of degradation product lactic acid and its induction of macrophage M2 polarization by interfering esterase and PLA ester bonds,which further delays the fibrosis process.It was found that the PLA/DLC membrane possess an efficient biophysical mechanism for treatment of peritendinous adhesion.

Collagen membrane alleviates peritendinous adhesion in the rat Achilles tendon injury model

Background Tendon adhesion is one of the most common causes of disability following tendon surgery. Therefore, prevention of peritendinous adhesion after surgical repair of tendon is a major challenge. The aim of this study was to explore the possible application of a collagen membrane for the prevention or attenuation of peritendinous adhesions. Methods Sprague-Dawley （SD） rat Achilles tendon was cut and sutured by a modified Kessler＇s technique with or without the collagen membrane wrapped. Macroscopic, morphological and biomechanical evaluations were applied to examine the recovery of the injured tendon at 4 and 8 weeks after surgery. Results The surgery group wrapped by collagen membranes had a better outcome than the group with surgery repair only. In the collagen membrane-treated group, less adhesion appeared, stronger tensile strength was detected, and more tendon fibers and collagen I expression were observed morphologically. Conclusion Wrapping the tendon with a collagen membrane may be an efficient approach for tendon repair and preventing tendon adhesion after its ruptures.

Use of a pH-responsive imatinib mesylate sustained-release hydrogel for the treatment of tendon adhesion by inhibiting PDGFRβ/CLDN1 pathway

Adhesion after tendon injury,which can result in limb movement disorders,is a common clinical complication;however,effective treatment methods are lacking.Hyaluronic acid hydrogels are a new biomedical material used to prevent tendon adhesion owing to their good biocompatibility.In addition,potential drugs that inhibit adhesion formation have gradually been discovered.The anti-adhesion effects of a combination of loaded drugs into hydrogels have become an emerging trend.However,current drug delivery systems usually lack specific regulation of drug release,and the effectiveness of drugs for treating tendon adhesions is mostly flawed.In this study,we identified a new drug,imatinib mesylate(IM),that prevents tendon adhesion and explored its related molecular pathways.In addition,we designed a pH-responsive sustained-release hydrogel for delivery.Using the metal-organic framework ZIF-8 as a drug carrier,we achieved controlled drug release to increase the effective drug dose at the peak of adhesion formation to achieve better therapeutic effects.The results showed that IM blocked the formation of peritendon adhesions by inhibiting the PDGFRβ/ERK/STAT3/CLDN1 pathway.Furthermore,the hydrogel with ZIF-8 exhibited better physical properties and drug release curves than the hydrogel loaded only with drugs,showing better prevention and treatment effects on tendon adhesion.