Dual-Responsive Nanocomposites for Synergistic Antibacterial Therapies Facilitating Bacteria-Infected Wound Healing

The rising dangers of bacterial infections have created an urgent need for the development of a new generation of antibacterial technologies and therapeutics. Antibacterial photodynamic therapy (PDT), considered as a noninvasive treatment with no drug resistance, has become a new promising photochemistry-involved treatment strategy. Titanium oxide (TiO2) is proved to be a very efficient PDT agent among the photosensitive materials, while the property of a large bandgap of TiO2 makes it only be excited by ultraviolet light, which is harmful to organisms. In this work, a novel ligand-to-metal charge transfer (LMCT) mediated TiO2 PDT strategy is proposed via the harmless near-infrared light irradiation. By choosing a mussel-inspired material, polydopamine (PDA) is involved in forming mesoporous TiO2@PDA nanoparticles (mTiO(2)@PDA NPs). The catechol groups of PDA can attach the TiO2 tightly even in colloidal environments, and can also form the LMCT bridge, exciting TiO2 to exert PDT function via 808 nm irradiation. Combining the sonodynamic therapy (SDT) of TiO2 and the photothermal therapy properties of PDA, this simple structure mTiO(2)@PDA enables synergistic antibacterial applications with multiple functions under the dual excitation of NIR and ultrasound. This reliable all-in-one NPs can achieve great antibacterial effect and a rapid repair of infected wounds.

Automated summary

The rising dangers of bacterial infections have created an urgent need for new antibacterial technologies and therapeutics. Antibacterial photodynamic therapy (PDT) is a promising treatment strategy that uses near-infrared light to activate titanium oxide (TiO2), a photosensitive material, for noninvasive treatment with no drug resistance. In this study, a novel nanoparticle structure combining TiO2 and polydopamine (PDA) was developed, enabling synergistic antibacterial effects through photodynamic therapy and sonodynamic therapy under dual excitation of near-infrared light and ultrasound. This all-in-one nanoparticle showed great antibacterial effectiveness and rapid wound healing.