Fig. 1 Synthesis and characterization of Ti3C2Tx MXene nanosheets (a) XRD patterns of MAX and MXene nanosheets; (b) SEM image of MAX; (c) TEM image, (d) XPS spectrum, (e) FT-IR spectrum and (f) particle size of MXene

Fig. 2 Preparation and characterization of PCM composite hydrogel (a) Schematic representation of preparation of the PCM hydrogel; (b) Optical image depicting transition of the PCM hydrogel from sol state to gel state; (c) SEM images of the PC (left) and the PCM (right) hydrogels; (d) Self-healing and (e) injectable properties of the PCM hydrogel; (f-h) Rheological properties of the PCM hydrogel: (f) strain scan, (g) frequency scan, (h) cyclic strain scan, and (i) FT-IR spectra of hydrogels. Colorful figures are available on website

Fig. 3 Electrical conductivity of PCM hydrogel (a) PCM hydrogel lit up LED experiment; (b) Conductivity, n=3

Fig. 4 Piezoelectric properties of PCM hydrogel (a) Surface topography, phase, frequency, and phase liner plots; (b) Butterfly pressure-amplitude curves and hysteresis loops

Fig. 5 Current signal curves of PCM hydrogel stimulated by ultrasound

Fig. 6 Antimicrobial properties of the hydrogels (a) Agar plate images; (b, c) Antibacterial rates against (b) S. aureus and (c) E. coli, n=3, **p<0.01, ****p<0.0001; (d) SEM images of S. aureus and E. coli from hydrogels

Fig. 7 Biocompatibility and regulation of cellular behaviors of the hydrogels (a) Optical images of the hemolysis experiments; (b) Hemolysis rates of UPW, DPBS, PVA, PC, and PCM hydrogels; (c) Live/dead staining fluorescent images and (d) cell viability of HUVECs from the control, PVA, PC, and PCM groups with or without ultrasound stimulation; (e) Cell migration images of HUVECs from the control, PVA, PC, and PCM groups with or without ultrasound stimulation and (f) corresponding migration rate; (g) Images of tube formation assay at 0 and 24 h from the control, PVA, PC, and PCM groups with or without ultrasound stimulation and corresponding total number of (h) junctions and (i) meshes n=3, **p< 0.01, ***p<0.001, ****p<0.0001. Colorful figures are available on website

Fig. 8 Evaluation of in vivo therapeutic effect of the hydrogels (a) Representative digital photographs of skin wounds on 0, 3, 5, 7, 10, and 14 d; (b) Schematic diagram of the wounds treated with different groups for 14 d; (c) Agar plate images of E. coli from the control, PC-US, PC+US, PCM-US, and PCM+US groups; (d) Quantitative analysis of the wound healing rates in various groups on 3, 5, 7, 10, and 14 d; (e) Antibacterial rates of the control, PC-US, PC+US, PCM-US, and PCM+US groups against E. coli n=3, *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001. Colorful figures are available on website

Fig. 9 Histologic evaluation of in vivo efficacy of the hydrogels (a) H&E staining of wound tissues on 7 and 14 d; (b) Epidermal thickness of skin tissues on 7 and 14 d; (c) CD31 staining of wound tissues on 7 d; (d) Area proportion of CD31-positive skin tissue on 7 d; (e) Masson staining of wound tissues on 7 d;(f) Proportion of collagen deposition from skin tissues on 7 d n=3, *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001. Colorful figures are available on website

Fig. S1 Zeta potential of MXene nanosheets

Fig. S2 AFM image of MXene nanosheets

Fig. S3 Structural formulation of CGG (a) and PVA (b)

Fig. S4 Conductivity of PCMx hydrogels

Fig. S5 Antibacterial performance testing of PCx hydrogels (a) Agar plate images of S. aureus and E. coli from control, PVA, PC1, PC2, PC3, PC4, PC5, and PC6 groups, respectively, and corresponding antibacterial rates against (b) S. aureus and (c) E. coli

Fig. S6 Comparison of gelation time for hydrogels After 30 min of freezing, the PC4 hydrogel (left) has formed a gel, while the PC3 hydrogel (right) is still in a thick, soluble state after 1 h of freezing

Fig. S7 Biosafety evaluation of experimental samples H&E staining of heart, liver, spleen, lungs, and kidneys

Fig. S8 Blood biosafety evaluation of experimental samples