Nano zero-valent iron-mediated sodium alginate/polyacrylic acid composite hydrogel: evaluation of hemostatic effects on post-extraction bleeding in anticoagulated mice

Objectives This study evaluated the hemostatic efficacy, biocompatibility, and wound healing promotion of a sodium alginate/polyacrylic acid composite hydrogel (SPI hydrogel) mediated by nano zero-valent iron (nZVI) in anticoagulated mice with post-extraction bleeding. Materials and methods Primary human gingival fibroblasts were cultured in media containing different concentrations (1%, 10%, 25%, 50% concentration) of SPI hydrogel extracts and tested for biocompatibility using the cck8 assay. CD-1 mice were modeled for anticoagulation using oral anticoagulants. After confirming modeling success via INR assessment, mice were divided into cotton (Control), gelatin sponge (GS), and hydrogel (SPI) groups. Experiments included tooth extraction hemostasis and tail amputation tests, alongside postoperative healing observation of extraction sockets and comparative histopathological analysis. Results The hydrogel extract at 50% concentration showed slight cytotoxicity and the remaining concentrations were biocompatible. Post-extraction bleeding volume in the SPI group (40 ± 21 mg) was lower than in the Control (265 ± 93 mg) and GS (133 ± 41 mg) groups. Following tail amputation, SPI group bleeding volume (7.90 ± 5.15 mg) was lower than the control group (22.70 ± 12.86 mg), and hemostasis time (1020 ± 115.11 s) was shorter than control group (1500 ± 151.24 s). HE and Masson test of wound tissue revealed superior healing, reduced inflammation, and normal collagen formation in the SPI group. Conclusion SPI hydrogel has acceptable biocompatibility, hemostatic efficacy and wound healing properties, surpassing conventional materials in treating anticoagulant-induced post-extraction bleeding. Clinical relevance It provides a potential alternative for managing anticoagulant-induced bleeding after tooth extraction clinically. Graphical abstract