Bone-Adhesive Anisotropic Tough Hydrogel Mimicking Tendon Enthesis

摘要

Tendon consists of soft collagen, yet it is mechanically strong and firmlyadhered to the bone owing to its hierarchically anisotropic structure andunique tendon-to-bone integration (enthesis), respectively. Despite the recentadvances in biomaterials, hydrogels simultaneously providing tendon-likehigh mechanical properties and strong adhesion to bone-mimicking enthesisis still challenging. Here, a strong, stiff, and adhesive triple-network (TN)anisotropic hydrogel that mimics a bone-adhering tendon is shown. Thetough adhesive TN hydrogel is developed by combining imidazole-containingpolyaspartamide (providing multiple hydrogen bonds to the bone surface)and energy-dissipative alginate–polyacrylamide double-network. To mimicthe anisotropic structure and high mechanical properties of tendons, thebone-adhered TN hydrogel is linearly stretched and subsequently fixed viasecondary cross-linking. The resulting hydrogel exhibits high tensile modulusand strength while maintaining a high bone adhesion without chemical modificationof the bone surface. Furthermore, a bone–ligament–bone structurewith strong bone adhesion reminiscent of the natural ligament is realized.