Bioinspired Synthesis of Magnetic Nanoparticles Based on Iron Oxides Using Orange Waste and Their Application as Photo-Activated Antibacterial Agents

Abstract

Magnetic nanoparticles based on iron oxides (MNPs-Fe) have been proposed as photothermal agents (PTAs) within antibacterial photothermal therapy (PTT), aiming to counteract the vast health problem of multidrug-resistant bacterial infections. We present a quick and easy green synthesis (GS) to prepare MNPs-Fe harnessing waste. Orange peel extract (organic compounds) was used as a reducing, capping, and stabilizing agent in the GS, which employed microwave (MW) irradiation to reduce the synthesis time. The produced weight, physical–chemical features and magnetic features of the MNPs-Fe were studied. Moreover, their cytotoxicity was assessed in animal cell line ATCC RAW 264.7, as well as their antibacterial activity against Staphylococcus aureus and Escherichia coli. We found that the 50GS-MNPs-Fe sample (prepared by GS, with 50% v/v of NH4OH and 50% v/v of orange peel extract) had an excellent mass yield. Its particle size was ~50 nm with the presence of an organic coating (terpenes or aldehydes). We believe that this coating improved the cell viability in extended periods (8 days) of cell culture with concentrations lower than 250 µg·mL−1, with respect to the MNPs-Fe obtained by CO and single MW, but it did not influence the antibacterial effect. The bacteria inhibition was attributed to the plasmonic of 50GS-MNPs-Fe (photothermal effect) by irradiation with red light (630 nm, 65.5 mW·cm−2, 30 min). We highlight the superparamagnetism of the 50GS-MNPs-Fe over 60 K in a broader temperature range than the MNPs-Fe obtained by CO (160.09 K) and MW (211.1 K). Therefore, 50GS-MNPs-Fe could be excellent candidates as broad-spectrum PTAs in antibacterial PTT. Furthermore, they might be employed in magnetic hyperthermia, magnetic resonance imaging, oncological treatments, and so on.

Iron Oxide Nanoparticles: Green Synthesis and Their Antimicrobial Activity

“…A new effort to expand the use of agro-wastes as sources of biomolecules in green nanotechnology has received considerable attention, and various agro-wastes have been documented for their relevance in nanobiotechnology [145]. As a result, a range of metallic nanoparticles have been successfully synthesized from agro-industrial wastes, and extracts from these residues have been employed as reducing and stabilizing agents in the majority of cases [146]. The nanoparticles produced in this way have a wide range of activities, including antimicrobial, antioxidant, anticorrosive, and cytotoxic against cancer cells, among others [146][147][148][149].…”

“…As a result, a range of metallic nanoparticles have been successfully synthesized from agro-industrial wastes, and extracts from these residues have been employed as reducing and stabilizing agents in the majority of cases [146]. The nanoparticles produced in this way have a wide range of activities, including antimicrobial, antioxidant, anticorrosive, and cytotoxic against cancer cells, among others [146][147][148][149]. In general, extracts containing active biomolecules that promote the formation of nanoparticles can be prepared using a simple hot water extraction process of dried and ground agrowaste materials [145].…”

An Overview of Nanomaterial Applications in Pharmacology

“…Das et al synthesized carbon dots from Apium graveolens , which were demonstrated as effective hydrogels against bactericidal activities, and controlled release of phytomedicines [ 24 ]. García et al synthesized magnetic NPs based on iron oxide from wastes of oranges, which had shown antibacterial activities [ 25 ]. Lyu et al prepared mannose-coated serum albumin NPs which targeted neutrophils for the therapy of arthritis [ 26 ].…”