Hydrogels that provide mechanical support and sustainably release therapeutics have been used to treat tendon injuries. However, most hydrogels are insufficiently tough, release drugs in bursts, and require cell infiltration or suturing to integrate with surrounding tissue. Here we report that a hydrogel serving as a high-capacity drug depot and combining a dissipative tough matrix on one side and a chitosan adhesive surface on the other side supports tendon gliding and strong adhesion (larger than 1,000 J m⁻²) to tendon on opposite surfaces of the hydrogel, as we show with porcine and human tendon preparations during cyclic-friction loadings. The hydrogel is biocompatible, strongly adheres to patellar, supraspinatus and Achilles tendons of live rats, boosted healing and reduced scar formation in a rat model of Achilles-tendon rupture, and sustainably released the corticosteroid triamcinolone acetonide in a rat model of patellar tendon injury, reducing inflammation, modulating chemokine secretion, recruiting tendon stem and progenitor cells, and promoting macrophage polarization to the M2 phenotype. Hydrogels with ‘Janus’ surfaces and sustained-drug-release functionality could be designed for a range of biomedical applications.

提供机械支撑和可持续释放治疗剂的水凝胶已用于治疗肌腱损伤。然而，大多数水凝胶的韧性不够，会突然释放药物，并且需要细胞浸润或缝合才能与周围组织整合。在这里，我们报道了一种水凝胶作为高容量的药物储存库，并结合一侧的耗散坚韧基质和另一侧的壳聚糖粘合表面，支持肌腱滑动和对肌腱的强粘附（大于1,000 J m ^-2 ）正如我们在循环摩擦载荷期间用猪和人肌腱制剂所展示的那样，水凝胶的相对表面。该水凝胶具有生物相容性，能够牢固地粘附在活体大鼠的髌骨、冈上肌和跟腱上，在跟腱断裂的大鼠模型中促进愈合并减少疤痕形成，并在髌腱损伤的大鼠模型中持续释放皮质类固醇曲安奈德，减少炎症，调节趋化因子分泌，募集肌腱干细胞和祖细胞，并促进巨噬细胞极化至 M2 表型。具有“Janus”表面和持续药物释放功能的水凝胶可以设计用于一系列生物医学应用。