Dual Modality FeS Nanoparticles with Reactive Oxygen Species-Induced and Photothermal Toxicity toward Pathogenic Bacteria

Shrish Agnihotri; Tarun Mohan; Diksha Jha; Hemant Kumar Gautam; Indrajit Roy

doi:10.1021/acsomega.9b03177

Dual Modality FeS Nanoparticles with Reactive Oxygen Species-Induced and Photothermal Toxicity toward Pathogenic Bacteria

ACS Omega. 2020 Jan 3;5(1):597-602. doi: 10.1021/acsomega.9b03177. eCollection 2020 Jan 14.

Authors

Shrish Agnihotri¹, Tarun Mohan¹, Diksha Jha², Hemant Kumar Gautam², Indrajit Roy¹

Affiliations

¹ Department of Chemistry, University of Delhi, Delhi 110007, India.
² Institute of Genomics and Integrative Biology, Sukhdev Vihar, Mathura Road, Delhi 110025, India.

Abstract

Bacterial infections pose a major threat to human health, primarily because of the evolution of mutated strains that are resistant to antibiotic treatment. As a viable alternative, several nanoparticles have emerged as attractive antibacterial agents. Herein, we report the development of iron sulfide (FeS) nanoparticles that show dual-modality therapy: namely reactive oxygen species (ROS)-induced toxicity and red-laser induced photothermal therapy. The aqueous synthesized nanoparticles have been characterized based on their size, shape, crystallinity, and magnetic and optical properties. These nanoparticles showed sustained release of Fe²⁺ ions in an aqueous dispersion. They also have a high absorption cross-section in the visible and near infra-red regions and could be excited by a continuous wave diode laser of wavelength 635 nm leading to significant hyperthermia. Nanoparticle treatment, followed by light irradiation, led to significant cell death in two ghastly pathogenic bacterial strains. Stepwise enhancement of intrabacterial ROS levels, as a result of nanoparticle treatment followed by light activation, has been identified as the primary antibacterial mechanism.