Scarless Wound Closure by a Mussel-Inspired Poly(amidoamine) Tissue Adhesive with Tunable Degradability

[Image: see text] Burn, trauma, and various medical conditions including bacterial infection, diabetes complication, and surgery could lead to an acute cutaneous wound and scar formation. Application of tissue glues instead of sutures could minimize the additional trauma and scar formation. Despite the countless efforts devoted to the development of high-strength tissue glues, little attention has been paid to their influence on the scar formation. Here, we report the development of a new tissue glue with excellent biocompatibility and tunable degradability for scarless wound closure. A series of catechol-containing poly(amidoamine) (CPAA) polymers were synthesized via the one-step Michael addition of dopamine and bisacrylamide. The tertiary amino group in the polymer backbone was used to introduce a zwitterionic sulfobetaine group by one-step ring-opening polymerization. The introduction of the zwitterionic sulfobetaine group could easily tune the hydrophilicity and the degradability of CPAA without influencing the density of the catechol group in the polymer. Lap-shear tests on the porcine skin demonstrated a high adhesion strength of 7 kPa at 1 h, rising to 24 kPa by 12 h. Addition of silica nanoparticles could further enhance the adhesion strength by 50%. In vivo studies further confirmed that the CPAA tissue glue could effectively accelerate the healing process of incisional wounds on the back of Sprague Dawley rats compared with suture and reduce the scar formation.