Synthesis of Antimicrobial Gallium Nanoparticles Using the Hot Injection Method

Christina Limantoro; Theerthankar Das; Meng He; Dmitry Dirin; Jim Manos; Maksym V Kovalenko; Wojciech Chrzanowski

doi:10.1021/acsmaterialsau.2c00078

Synthesis of Antimicrobial Gallium Nanoparticles Using the Hot Injection Method

ACS Mater Au. 2023 Mar 28;3(4):310-320. doi: 10.1021/acsmaterialsau.2c00078. eCollection 2023 Jul 12.

Authors

Christina Limantoro^{1

2}, Theerthankar Das³, Meng He^{4

5}, Dmitry Dirin^{4

5}, Jim Manos³, Maksym V Kovalenko^{4

5}, Wojciech Chrzanowski^{1

2}

Affiliations

¹ Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia.
² Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia.
³ Department of Infectious Diseases and Immunology, School of Medical Sciences, The University of Sydney, Camperdown, NSW 2006, Australia.
⁴ Department of Chemistry and Applied Biosciences, ETH Zürich-Swiss Federal Institute of Technology Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland.
⁵ Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.

Abstract

Antibiotic resistance continues to be an ongoing problem in global public health despite interventions to reduce antibiotic overuse. Furthermore, it threatens to undo the achievements and progress of modern medicine. To address these issues, the development of new alternative treatments is needed. Metallic nanoparticles have become an increasingly attractive alternative due to their unique physicochemical properties that allow for different applications and their various mechanisms of action. In this study, gallium nanoparticles (Ga NPs) were tested against several clinical strains of Pseudomonas aeruginosa (DFU53, 364077, and 365707) and multi-drug-resistant Acinetobacter baumannii (MRAB). The results showed that Ga NPs did not inhibit bacterial growth when tested against the bacterial strains using a broth microdilution assay, but they exhibited effects in biofilm production in P. aeruginosa DFU53. Furthermore, as captured by atomic force microscopy imaging, P. aeruginosa DFU53 and MRAB biofilms underwent morphological changes, appearing rough and irregular when they were treated with Ga NPs. Although Ga NPs did not affect planktonic bacterial growth, their effects on both biofilm formation and established biofilm demonstrate their potential role in the race to combat antibiotic resistance, especially in biofilm-related infections.