A highly-stretchable and adhesive hydrogel for noninvasive joint wound closure driven by hydrogen bonds

Due to the frequent movements and bending of joint areas such as ankles, knees and wrists, effective wound closure and healing of the skin at joints and moving parts remains a great challenge. Traditional invasive wound closure methods, such as the use of sutures and skin staplers, often result in additional puncture wounds, side effects of anesthesia and severe scarring. Herein, a highly-stretchable, adhesive, transparent and hygroscopic hydrogel for noninvasive joint wound closure is reported. The hydrogel is composed of N-[Tris (hydroxymethyl) methyl] acrylamide (THMA), polyethylene glycol diacrylate (PEGDA) and sodium alginate (SA). THMA contains CC double bonds and a large number of hydroxyl groups, which can form an interpenetrating network structure with PEGDA and SA through chemical and physical double cross-linking. This hydrogel driven by hydrogen bonds exhibits over 700 % elongation and strong adhesion to various surfaces through energy dissipation effects. As a wound repair material, the THMA/PEGDA/SA hydrogel can not only effectively close wounds at moving parts, but also provide a mechanical microenvironment similar to normal skin tissue, promote wound healing and reduce scarring. In addition, the hydrogel can effectively absorb exudate, keep the wound moist and clean, and the transparent appearance facilitates the observation of the wound condition. This adhesive hydrogel is demonstrated to be a promising candidate for wound closure and healing at joints and moving parts.