An All-Natural Polymer-based and Bilayer-Integrated Asymmetrical Janus Hydrogel Bioadhesive Patch for Cardiac Repair

Bioadhesive hydrogels of favorable tribological attributes have attracted intensive attention for their potential usage due to the large benefits they can bring to surgical critical care. We report an all-natural polymer-based and bilayer-integrated asymmetrical Janus hydrogel bioadhesive patch for efficient myocardial infarction (MI) repair. We developed a low-friction polyelectrolyte composite biohydrogel (Bio-PEC hydrogel), CA, using naturally occurring cationic chitosan quaternary ammonium salt (HACC) and anionic sodium hyaluronate (HA). We further developed a high-adhesion Bio-PEC hydrogel, TA@CA, by incorporating tannic acid (TA). Ultimately, we integrated them into a bilayer asymmetrical Janus hydrogel bioadhesive, CA|TA@CA, which exhibited excellent bulk mechanical properties and favorable one-sided adequate adhesion to myocardial tissue (fracture strength 0.98 MPa, fracture strain 330%, and interfacial toughness 50.87 J/m²). Additionally, the in vivo myocardial repair surgery using the CA|TA@CA Janus hydrogel has been shown to inhibit ventricular remodeling more effectively. Such CA|TA@CA Janus hydrogel bioadhesives may have high potential as medical patches for MI repair.