Adhesive

Adhesion

Fibrocartilage

Tendon

Biomedical engineering

Materials science

Layer (electronics)

Achilles tendon

Alternative medicine

Enthesis

Anatomy

Osteoarthritis

Composite material

Ligament

Medicine

Articular cartilage

Pathology

Advanced Materials

Tendon consists of soft collagen, yet it is mechanically strong and firmly adhered to the bone owing to its hierarchically anisotropic structure and unique tendon-to-bone integration (enthesis), respectively. Despite the recent advances in biomaterials, hydrogels simultaneously providing tendon-like high mechanical properties and strong adhesion to bone-mimicking enthesis is still challenging. Here, a strong, stiff, and adhesive triple-network (TN) anisotropic hydrogel that mimics a bone-adhering tendon is shown. The tough adhesive TN hydrogel is developed by combining imidazole-containing polyaspartamide (providing multiple hydrogen bonds to the bone surface) and energy-dissipative alginate-polyacrylamide double-network. To mimic the anisotropic structure and high mechanical properties of tendons, the bone-adhered TN hydrogel is linearly stretched and subsequently fixed via secondary cross-linking. The resulting hydrogel exhibits high tensile modulus and strength while maintaining a high bone adhesion without chemical modification of the bone surface. Furthermore, a bone-ligament-bone structure with strong bone adhesion reminiscent of the natural ligament is realized.

Bone‐Adhesive Anisotropic Tough Hydrogel Mimicking Tendon Enthesis