Iron Oxide Nanoparticles: Green Synthesis and Their Antimicrobial Activity

Abstract

The rise of antimicrobial resistance caused by inappropriate use of these agents in various settings has become a global health threat. Nanotechnology offers the potential for the synthesis of nanoparticles (NPs) with antimicrobial activity, such as iron oxide nanoparticles (IONPs). The use of IONPs is a promising way to overcome antimicrobial resistance or pathogenicity because of their ability to interact with several biological molecules and to inhibit microbial growth. In this review, we outline the pivotal findings over the past decade concerning methods for the green synthesis of IONPs using bacteria, fungi, plants, and organic waste. Subsequently, we delve into the primary challenges encountered in green synthesis utilizing diverse organisms and organic materials. Furthermore, we compile the most common methods employed for the characterization of these IONPs. To conclude, we highlight the applications of these IONPs as promising antibacterial, antifungal, antiparasitic, and antiviral agents.

Initial therapeutic evidence of a borosilicate bioactive glass (BSG) and Fe3O4 magnetic nanoparticle scaffold on implant-associated Staphylococcal aureus bone infection

“…In the context of this study, iron oxide nanoparticles (IONPs) exhibit multifaceted mechanisms of bactericidal activity [ 59 , 60 ]. Firstly, when subjected to the appropriate AMF regimen, IONPs can convert magnetic energy into heat energy to sterilize the implant site without causing tissue damage [ 61 ].…”

Influence of Physicochemical Properties of Iron Oxide Nanoparticles on Their Antibacterial Activity

“…IONPs have distinctive antimicrobial properties due to their physical and chemical characteristics, including the large surface area-to-volume ratio, superparamagnetic properties, and self-assembly. , These attributes are relevant to various factors, including their size, which influences their antimicrobial properties. Different synthesis procedures can influence the range of effective sizes of the IONPs . Moreover, small IONPs exhibited enhanced stability and a higher surface-area-to-volume ratio, increasing free energy content, surface charge, and reactivity.…”

“…The surface charge of the IONPs interacts with the bacterial cell membrane through electrostatic attraction or repulsion and disrupts their integrity by increasing cell permeability, which allows frequent ion exchange into the cell and leads to cell death . Additionally, IONPs adhere to the bacterial cell membrane, and due to their nanosized nature and high surface-to-volume ratio, they can cause physical disruption to the cell membrane. , …”

“…For instance, in the GRS synthesis method, bioreductants, which consist of phytochemicals with prior antimicrobial activity, are used instead of chemicals. , Therefore, a combined mechanism is initiated against eliminating bacteria; hence, the potency of IONPs increases . Additionally, surface modification approaches can help address IONPs’ main drawbacks, such as stability issues, cytotoxicity, biocompatibility, and moderate antibacterial activity. , Biopolymers such as PEG and chitosan are used as coating material to modify the surface of IONPs. , These biopolymers consist of antibacterial and biocompatible properties . Hence, surface-modified IONPs would be more potent as an antimicrobial agent because these biopolymers would compress the size of the particles and increase the surface area to volume ratio, resulting in a combined mechanism against pathogenic bacteria and acquiring increased bioavailability while keeping the cytotoxicity to a minimum by reducing the interaction between IONPs and tissues. − …”