In situ fabrication of co-coordinated TCPP-Cur donor-acceptor-type covalent organic framework-like photocatalytic hydrogel for rapid therapy of bacteria-infected wounds

Pathogenic bacterial infection and the presence of drug-resistant bacteria have been threatening the health of human. Phototherapy has attracted increasing attention for treating tissue infections because it is noninvasive and does not lead to drug resistance. Herein, we construct a Cu co-coordinated donor-acceptor type (D-A) covalent organic framework-like (COF-like) and sodium alginate (SA) hydrogel (CTCS hydrogel) with photocatalytic and anti-inflammatory properties for the treatment of wound infection. The COF-like (TCPP-Cur) can be photoexcited with 660 nm light to produce electron-hole pairs that would be separated by donor-acceptor pairs. The co-coordinated Cu can reduce the band gap of TCPP-Cur, increase the separation rate of photogenerated electron-hole pairs, and improve the photocatalytic performance of CTCS hydrogel. Under 660 nm irradiation, the CTCS hydrogel can achieve 99.95% and 98.5% bactericidal activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) within 20 min owing to the synergistic interactions of the photothermal and photocatalytic effects. In vivo tests have shown that CTCS hydrogel can reduce the expression of TNF-α and enhance the expression of IL-10 and VEGF to promote wound healing and tissue regeneration. This photocatalytic hydrogel provides a promising strategy for reconstructing bacterially infected tissues rapidly.