Zinc-doped Prussian blue enhances photothermal clearance of Staphylococcus aureus and promotes tissue repair in infected wounds

Jun Li,Shengli Zhu,Xiangmei Liu,Yanqin Liang,Lei Tan,Kelvin Wai Kwok Yeung,Yufeng Zheng,Xianjin Yang,Zhenduo Cui,Zhaoyang Li,Shuilin Wu,Xianbao Wang

doi:10.1038/s41467-019-12429-6

Abstract

The application of photothermal therapy to treat bacterial infections remains a challenge, as the high temperatures required for bacterial elimination can damage healthy tissues. Here, we develop an exogenous antibacterial agent consisting of zinc-doped Prussian blue (ZnPB) that kills methicillin-resistant Staphylococcus aureus in vitro and in a rat model of cutaneous wound infection. Local heat triggered by the photothermal effect accelerates the release and penetration of ions into the bacteria, resulting in alteration of intracellular metabolic pathways and bacterial killing without systemic toxicity. ZnPB treatment leads to the upregulation of genes involved in tissue remodeling, promotes collagen deposition and enhances wound repair. The efficient photothermal conversion of ZnPB allows the use of relatively few doses and low laser flux, making the platform a potential alternative to current antibiotic therapies against bacterial wound infections.

Highlights

The application of photothermal therapy to treat bacterial infections remains a challenge, as the high temperatures required for bacterial elimination can damage healthy tissues
When the increased temperature caused by photothermal therapy (PTT) is too high for complete bacterial elimination, non-localized heat and hyperthermia usually result in great damage to healthy tissues[11]
Computational models based on density functional theory (DFT) calculations using the Vienna Ab initio Simulation Package (VASP) can shed more light on the geometric and electronic structure modelling of zinc-doped Prussian blue (ZnPB) with various doping levels to guide

Summary

Introduction

The application of photothermal therapy to treat bacterial infections remains a challenge, as the high temperatures required for bacterial elimination can damage healthy tissues. When the increased temperature caused by PTT is too high for complete bacterial elimination, non-localized heat and hyperthermia usually result in great damage to healthy tissues[11]. PB has been used for PTT to generate heat under NIR light irradiation to induce localized damage to tumours, with minimal effect on normal biological tissue[15,16]. Zinc is an essential trace element in the human body and a certain concentration of zinc ions exhibits good bioactivity and is central to many important physiological processes Both Zn and Fe are transition metals and have close atomic numbers, and Zn has a higher number of valence electrons than Fe does. The doping of Zn in PB to replace Fe2+ has great potential to regulate the optical behaviour and bioactivity of PB

Methods

Results

Conclusion