Multifunctional phototheranostic agent ZnO@Ag for anti-infection through photothermal/photodynamic therapy

Enoch Obeng; Jiayao Feng; Danyan Wang; Dongyang Zheng; Bailin Xiang; Jianliang Shen

doi:10.3389/fchem.2022.1054739

Multifunctional phototheranostic agent ZnO@Ag for anti-infection through photothermal/photodynamic therapy

Front Chem. 2022 Nov 9:10:1054739. doi: 10.3389/fchem.2022.1054739. eCollection 2022.

Authors

Enoch Obeng¹, Jiayao Feng², Danyan Wang³, Dongyang Zheng³, Bailin Xiang⁴, Jianliang Shen^{1

3}

Affiliations

¹ School of Ophthalmology and Optometry, School of Biomedical Engineering, Wenzhou Medical University, Wenzhou, Zhejiang, China.
² Ningbo Eye Hospital, Ningbo, Zhejiang, China.
³ Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, China.
⁴ College of Chemistry and Materials Engineering, Huaihua University, Huaihua, China.

Abstract

To overcome the limitations of traditional therapeutics, nanotechnology offers a synergistic therapeutic approach for the treatment of bacterial infection and biofilms that has attracted attention. Herein, we report on a ZnO@Ag nanocomposite with good biocompatibility synthesized by doping ZnO NPs with silver nanoparticles (Ag NPs). ZnO@Ag nanocomposites were synthesized with varying ratios of Ag NPs (0.5%, 2%, 8%). Under the same experimental conditions, ZnO@8%Ag exhibited outstanding properties compared to the other nanocomposites and the pristine ZnO NPs. ZnO@8%Ag demonstrated excellent photothermal and photodynamic properties. Also, ZnO@8%Ag demonstrated over 99% inhibition of Staphylococcus aureus (S. aureus) under photothermal therapy (PTT) or photodynamics therapy (PDT) as a result of the excessive generation of reactive oxygen species (ROS) by the Ag⁺ released, while the pristine ZnO showed an insignificant inhibition rate compared to the PBS group (control). Furthermore, ZnO@8%Ag completely disrupted S. aureus biofilm under a combined PTT/PDT treatment, a synergetic trimodal therapy, although the molecular mechanism of biofilm inhibition remains unclear. Hence, the excellent photothermal, photodynamic, biocompatibility, and bactericidal properties of ZnO@8%Ag present it as an appropriate platform for bacterial and biofilm treatment or other biomedically related applications.

Keywords: ZnO@Ag nanocomposite; anti-infective therapy; photodynamic therapy; photothermal therapy; synergistic effect.