A smart adhesive Janus hydrogel for non-invasive cardiac repair and tissue adhesion prevention.

Multifunctional hydrogel with asymmetric and reversible adhesion characteristics is essential to handle the obstructions towards bioapplications of trauma removal and postoperative tissue synechia. Herein, we developed a responsively reversible and asymmetrically adhesive Janus hydrogel that enables on-demand stimuli-triggered detachment for efficient myocardial infarction (MI) repair, and synchronously prevents tissue synechia and inflammatory intrusion after surgery. In contrast with most irreversibly and hard-to-removable adhesives, this Janus hydrogel exhibited a reversible adhesion capability and can be noninvasively detached on-demand just by slight biologics. It is interesting that the adhesion behaves exhibited a molecularly encoded adhesion-adaptive stiffening feature similar to the self-protective stress-strain effect of biological tissues. In vitro and in vivo experiments demonstrated that Janus hydrogel can promote the maturation and functions of cardiomyocytes, and facilitate MI repair by reducing oxidative damage and inflammatory response, reconstructing electrical conduction and blood supply in infarcted area. Furthermore, no secondary injury and tissue synechia were triggered after transplantation of Janus hydrogel. This smart Janus hydrogel reported herein offers a potential strategy for clinically transformable cardiac patch and anti-postoperative tissue synechia barrier.