Ultrasonic Formation of Fe₃O₄-Reduced Graphene Oxide–Salicylic Acid Nanoparticles with Switchable Antioxidant Function

Abstract

We demonstrate a single-step ultrasonic in situ complexation of salicylic acid during the growth of Fe3O4-reduced graphene oxide nanoparticles (∼10 nm) to improve the antioxidant and antiproliferative effects of pristine drug molecules. These nanoparticles have a precisely defined electronic molecular structure with salicylic acid ligands specifically complexed to Fe­(III)/Fe­(II) sites, four orders of magnitude larger electric surface potential, and enzymatic activity modulated by ascorbic acid molecules. The diminishing efficiency of hydroxyl radicals by Fe3O4-rGO-SA nanoparticles is tenfold higher than that by pristine salicylic acid in the electro-Fenton process. The H+ production of these nanoparticles can be switched by the interaction with ascorbic acid ligands and cause the redox deactivation of iron or enhanced antioxidation, where rGO plays an important role in enhanced charge transfer catalysis. Fe3O4-rGO-SA nanoparticles are nontoxic to erythrocytes, i.e., human peripheral blood mononuclear cells, but surpassingly inhibit the growth of three cancer cell lines, HeLa, HepG2, and HT29, with respect to pristine salicylic acid molecules.

Fenton-Hydroxyl Radical Antioxidant Efficiency of Ibuprofen-Fe3O4-GO Nanospheres

“…Modification of NSAIDs has been performed via metal ion complexation, e.g., mefenamic acid with Mn, Fe, Co, Ni, Cu, or Zn; diclofenac with Mn; indomethacin with Cu; iron-salicylate complex to produce antioxidant metallodrugs with ameliorated efficiency at the cellular level in comparison with pristine NSAIDs . Previously, we have shown that complexation of pristine salicylic acid with Fe 3 O 4 -graphene oxide (GO) results in the formation of nanoparticles with intracellular switchable antioxidant function . Magnetite nanoparticles (NPs) are biocompatible and exhibit negligible cytotoxicity, while GO provides a large surface active area, versatile chemistry, and enhanced stability of complexed molecules.…”

“…16 Previously, we have shown that complexation of pristine salicylic acid with Fe 3 O 4 -graphene oxide (GO) results in the formation of nanoparticles with intracellular switchable antioxidant function. 17 Magnetite nanoparticles (NPs) are biocompatible and exhibit negligible cytotoxicity, while GO provides a large surface active area, versatile chemistry, and enhanced stability of complexed molecules. Fe 3 O 4 -GO nanoplatform is regarded as a promising contrast agent for magnetic resonance imaging (MRI) and can significantly increase the loading capacity of organic molecules due to the π−π stacking and hydrogen bonding.…”

New 3D Vortex Microfluidic System Tested for Magnetic Core-Shell Fe3O4-SA Nanoparticle Synthesis

“…Given its appealing properties, salicylic acid (SA) was chosen for the shell layer to create a protective organic coating around the iron oxide core. Its enhanced biocompatibility, well-recognized as SA is present in natural products or as derivatives in medicines utilized by large populations [ 42 , 43 ], further allows the use of fabricated nanomaterials for biomedical and/or environmental applications.…”