Rapid hemostasis and removal: Oxidized dextran-coated chitosan-alginate sponges via dynamic calcium crosslinking

Simultaneous rapid hemostasis and on-demand removal remains a key challenge for hemostatic materials for deep tissue injury. To address this issue, we developed a chitosan (CS)/sodium alginate (SA) composite sponge utilizing a dual cross-linking strategy with epichlorohydrin and calcium ions (Ca²⁺). The calcium-crosslinked network can be rapidly dissociated through Ca²⁺-Na⁺ ion exchange in a NaOH/Na₂EDTA solution, enabling non-invasive removal of the hemostatic sponge within 5 min, thus meeting clinical demands for controllable material retrieval. Moreover, the sponge surface was coated with oxidized dextran-dopamine (ODP), whose catechol and aldehyde groups effectively promote blood cell adhesion and accelerate the hemostatic response. Moreover, the sponge surface was coated with oxidized dextran-dopamine (ODP), whose catechol and aldehyde groups effectively promote blood cell adhesion and accelerate the hemostatic response. In the rat femoral artery injury model, the hemostasis time was only 86 s, and the blood loss was 64% less than that of commercially available chitosan hemostatic sponges. The hemostatic sponge exhibits a compression strength exceeding 100 kPa and a bacteriostasis rate greater than 99%. This work provides a new method for the development of intelligent response hemostatic materials, breaking through the dilemma of traditional hemostatic materials in wound debridement and residual infection.