FIG. 2.

Adhesive and electroconductive gelatin and PEGDA-based hydrogels can be directly painted onto infarcted myocardium. (A) Schematic depicting a two-step synthesis of HPAE-Py. First, dopamine hydrochloride, PETA, and PEGDA are reacted together using Michael addition to form HPAE. Next, pyrrole is reacted with HPAE using a second Michael addition reaction to form HPAE-Py. (B) Schematic showing Fe³⁺-mediated cross-linking of Gelatin with HPAE-Py, improving gel adhesion through catechol-Fe³⁺ complexation. (C) HPAE-Py/Gelatin hydrogels can be directly applied to infarcted myocardium using a brush-syringe system. Once applied, the gel rapidly adheres to the myocardium without leaking. Adapted from Liang et al.⁵⁹ with permission from John Wiley and Sons. HPAE, hyperbranched poly(amino ester); PEGDA, polyethylene glycol diacrylate; PETA, pentaerythritol triacrylate.