Fig. 1 Schematic diagram of preparation and potential applications of Mg particle-modified gelatin/alginate macroporous hydrogels

Fig. 2 a Photos of hydrogels with different contents of Mg-Cu. b Foaming volume ratio of hydrogels containing different contents of Mg-Cu. Data?=?mean?±?standard deviation (n?=?3). c Compressive stress-strain curves of hydrogels. d Dependence of G’, G’’ of the hydrogels on the frequency of oscillation. e Water absorption behavior of hydrogels with different contents of Mg-Cu. Data?=?mean?±?standard deviation (n?=?3). f Water-vapor transmission rate (WVTR) of hydrogels with different contents of Mg-Cu. Data?=?mean?±?standard deviation (n?=?3). * p?<?0.05, ** p?<?0.01

Fig. 3 a X-ray diffraction patterns of hydrogels with different contents of Mg-Cu alloy immersed in deionized water for different time periods. pH values b, Mg2+ c and Cu2+ d concentrations in Hanks’ solution after soaking for different time periods

Fig. 4 a Relative proliferation rates of HUVECs and NIH/3T3 fibroblasts cultured with hydrogel extracts or cell culture media for 1 and 3 days. Data?=?mean?±?standard deviation (n?=?3). b Microscopic photographs of HUVECs cultured with hydrogel extracts or cell culture media for 0, 12, 24, 36 and 48 h, and calculated relative cell migration area. Data?=?mean?±?standard deviation (n?=?3). * p?<?0.05, ** p?<?0.01, NS: no statistical significance

Fig. 5 a Representative images of viable colonies of S. aureus, E. coli and P. aeruginosa grown on agar plates after contacting with hydrogels. b The corresponding bacterial inhibition rate of different hydrogels against S. aureus, E. coli and P. aeruginosa. Data?=?mean?±?standard deviation (n?=?3). ** p?<?0.01, NS: no statistical significance

Fig. 6 Healing of full-thickness skin defect wound with SAG hydrogels. a Photographs of wounds at 0, 5th and 15th day after treatments with commercial film dressing (Tegaderm™) (control), SAG-0MC, SAG-2M and SAG-2MC, respectively. b Wound contraction ratios of different treatment groups. Data?=?mean?±?standard deviation (n?=?3) c Representative images of H&E, Masson and CD31 immunohistochemical staining of wound tissues after different treatments at 15 days post-surgery. d-g Epidermal thickness d, granulation tissue thickness e, collagen deposition f and percentage of vessel area g at the wound site after different treatments for 15 days. Data?=?mean?±?standard deviation (n?=?3). * p?<?0.05, ** p?<?0.01, NS: no statistical significance