NIR-responsive carrier-free nanoparticles based on berberine hydrochloride and indocyanine green for synergistic antibacterial therapy and promoting infected wound healing

Bacterial infections cause severe health conditions, resulting in a significant economic burden for the public health system. Although natural phytochemicals are considered promising anti-bacterial agents, they suffer from several limitations, such as poor water solubility and low bioavailability in vivo, severely restricting their wide application. Herein, we constructed a near-infrared (NIR)-responsive carrier-free berberine hydrochloride (BH, phytochemicals)/indocyanine green (ICG, photosensitizer) nanoparticles (BI NPs) for synergistic antibacterial of an infected wound. Through electrostatic interaction and π–π stacking, the hydrophobic BH and amphiphilic ICG are initially self-assembled to generate carrier-free nanoparticles. The obtained BI NPs demonstrated NIR-responsive drug release behavior and better photothermal conversion efficiency of up to 36%. In addition, BI NPs stimulated by NIR laser exhibited remarkable antibacterial activity, which realized the synergistic antibacterial treatment and promoted infected wound healing. In summary, the current research results provided a candidate strategy for self-assembling new BI NPs to treat bacterial infections synergistically.