An antibacterial gradient-pore artificial skin with high exudate-absorption and hemostatic properties

Wounds frequently produce excessive exudation and are highly susceptible to bacterial contamination, posing significant challenges for effective wound management. To address these issues, we prepared a gradient-pore artificial skin capable of high-capacity exudate absorption while providing robust antibacterial and hemostatic functions. Using natural polymer materials (gelatin, chitosan) as raw materials, with protocatechualdehyde, sodium hydroxide, and Ga³⁺ as crosslinking agents, double crosslinked hydrogels were prepared. Then, a three-layer artificial skin with gradient porosity was fabricated by sequential assembly of the hydrogel layers followed by freeze-drying. The artificial skin has excellent degradability, strong antibacterial activity (97% inhibition rate), high liquid absorption (∼8000% swelling rate within 72 hours), and favorable moisturizing properties (80%). The artificial skin demonstrates superior hemostatic performance, achieving minimal blood loss and a rapid clotting time of 67.64 s. When applied to wounds, it can coordinate and regulate inflammation resolution, fibroblast proliferation, and extracellular matrix deposition in the wound. This multilayer design, inspired by natural skin architecture, enables functional tissue regeneration and offers a promising strategy for advanced wound dressings.