Supramolecular Peptide Hydrogel-Mediated Synergistic Antibiotic-Photothermal Therapy for Potent Antibacterial Applications

Abstract

Bacterial infection usually exacerbates inflammation and is one of the important factors impeding wound healing. At present, dressings for treating wound infections often include antibiotics, silver ions, fibers, etc., but the therapeutic efficacy is still limited. To enhance antibiotic effectiveness and overcome drug resistance, developing efficient drug delivery systems is imperative. Herein, we rationally designed a three-component peptide hydrogel Nap-Phe-Phe-Thr-Asp-Asp-Tyr (NapFFTDDY) co-encapsulating the photosensitizer indocyanine green (ICG) and ciprofloxacin (Cip) to establish a novel antibacterial strategy combining antibiotic therapy with photothermal treatment. This system enables synergistic eradication of diverse bacteria. The peptide molecule could co-assemble with ICG and Cip to form hydrogel networks. Under near-infrared (NIR) irradiation, the ICG loaded with this hydrogel can rapidly heat up and generate hyperthermia, acting as an antibacterial factor together with the released antibiotics, simultaneously achieving potent photothermal therapy and long-term sustained release of drugs. In vitro and in vivo experimental results demonstrated that the peptide hydrogel loaded with both Cip and ICG exhibited a superior bacterial clearance effect compared to free Cip or peptide hydrogel encapsulated only with Cip. Moreover, it significantly alleviated inflammation in the mouse wound model with bacterial infection and significantly accelerated wound closure. This tri-component supramolecular peptide hydrogel offers a novel perspective for developing other advanced antimicrobial agents against infected wounds.