Antibacterial Chitin-Based Sponges with Enhanced Water Absorbency and Mechanical Properties for Hemostasis and Wound Healing

The development of antibacterial sponges with both high water-absorbing and mechanical properties is highly desirable for attaining efficient hemostasis and closure of noncompressible wounds, but remains challenging. General methods, such as increasing porosity, to improve the water absorption of sponges inevitably compromise their mechanical properties. Herein, a chitin (CT)/quaternized chitosan (QCS) sponge with the desirable properties was fabricated by freeze-drying the chemically and physically dual cross-linked CT/QCS hydrogel with enhanced hydrophilicity. The obtained CT/QCS sponge possessed improved water (5906%) and blood absorption rates (6374%), robust mechanical strength (compressive stress at 90% strain = 0.52 MPa), and rapid water-triggered shape recovery ability (less than 5.3 s). In addition to good biocompatibility, the CT/QCS sponge also showed high <i>in vitro</i>/<i>in vivo</i> hemostatic efficacy and remarkable bacteriostasis rates against <i>E. coli</i> (85.4%) and <i>S. aureus</i> (91.6%) due to its hydrophilic and positively charged porous structure. The CT/QCS sponge exhibited significant healing efficacy in infected wounds compared to commercial gauze and gelatin sponge. This work demonstrates that the antibacterial CT/QCS sponge with enhanced water-absorbing and mechanical properties is promising for treating noncompressible bleeding and infected wounds.