A Spray-Filming Self-Healing Hydrogel Fabricated from Modified Sodium Alginate and Gelatin as a Bacterial Barrier

Self-healing hydrogels as wound dressings still face challenges in infection prevention, especially in the dressing of mass wounds, due to their inflexibility and the slow formation of the protective film on the wound. Therefore, designing a spray-filming (rapid-forming) hydrogel that can serve as a bacterial barrier is of particular significance in the development of wound dressings. Here, a self-healing hydrogel based on adipic acid dihydrazide-modified gelatin (Gel-ADH) and monoaldehyde-modified sodium alginate(SA-mCHO) is prepared. Using dynamic, Schiff base bonds, the hydrogels exhibit excellent self-healing properties. Moreover, the gelation time of SA-mCHO/Gel-ADH (SG) hydrogels is shortened to 2-21 s, resulting in rapid filming by spraying the two precursor solutions. In addition, the rapid spray-filming ability might offer sufficient flexibility and rapidity for dealing with mass and irregular wounds. Notably, the bacterial barrier experiments show that the SG hydrogel films could form an effective barrier to Staphylococcus aureus and Candida albicans for 12 h. Therefore, SG hydrogels could be used in wound dressings and they show great promise in applications associated with mass and irregular traumas.