An Acceptor-Donor-Acceptor Semiconductor Conjugated Polymer-Based Composite Hydrogel for Photothermal/Photodynamic Dual Phototherapy of Infected Wounds.

Bacterial infections impede wound healing and are exacerbated by antibiotic resistance. In this study, three semiconductor conjugated polymer (SCP) nanomaterials (DFPE, DTBA, and DTID) with integrated photodynamic/photothermal therapeutic functions are developed by employing different electron donor groups. Compared to DFPE and DTBA, the introduction of a benzo[e]indole unit endows DTID with a distinct A-D-A electronic configuration. DTID exhibits strong near-infrared absorption, excellent photothermal conversion efficiency (38.4%), and efficient reactive oxygen species (ROS) generation. Furthermore, the composite hydrogel HGJD is constructed by coloading DTID and curcumin into a sodium alginate/chitosan hydrogel. HGJD integrated the hydrogel's inherent moisturizing capacity and biocompatibility, DTID's dual phototherapy, and curcumin's antioxidant and anti-inflammatory activities. HGJD effectively kills Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and exhibits antioxidant activity. In the S. aureus-infected mouse model, HGJD with light irradiation eliminates bacteria, reduces inflammation, and accelerates wound healing. This work presents a promising strategy for designing hydrogel dressings with dual phototherapy and anti-inflammatory functions.