Surface Functionalization of Iron Oxide Nanoparticles with Gallic Acid as Potential Antioxidant and Antimicrobial Agents

Abstract

In this research, we report the size-controlled synthesis and surface-functionalization of magnetite with the natural antioxidant gallic acid (GA) as a ligand, using in situ and post-synthesis methods. GA functionalization provided narrow size distribution, with an average particle size of 5 and 8 nm for in situ synthesis of gallic acid functionalized magnetite IONP@GA1 and IONP@GA2, respectively, which are ultra-small particles as compared to unfunctionalized magnetite (IONP) and post functionalized magnetite IONP@GA3 with average size of 10 and 11 nm respectively. All the IONPs@GA samples were found hydrophilic with stable aggregation state. Prior to commencement of experimental lab work, PASS software was used to predict the biological activities of GA and it is found that experimental antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and antimicrobial studies using well diffusion method are in good agreement with the simulated results. Furthermore, the half maximal inhibitory concentration (IC50) values of DPPH antioxidant assay revealed a 2–4 fold decrease as compared to unfunctionalized IONP. In addition to antioxidant activity, all the three IONP@GA proved outstanding antimicrobial activity while testing on different bacterial and fungal strains. The results collectively indicate the successful fabrication of novel antioxidant, antimicrobial IONP@GA composite, which are magnetically separable, efficient, and low cost, with potential applications in polymers, cosmetics, and biomedical and food industries.

Polydopamine functionalized hydrogel beads as magnetically separable antibacterial materials

“…This is due to the size effect and is in accordance with the previous reported literature. 44,45 Also, the remnant magnetization (M r ) and coercivity (H c ) values were close to zero. While at 5 K, Alg/Fe 3 O 4 nanoparticles were superparamagnetic with M s value 36.18 emu g À1 .…”

“…47 XRD data also conrms that coating did not affect the phase of iron oxide. 45 The formation of Alg/Fe 3 O 4 nanoparticles was further studied by the FT-IR analysis. As shown in Fig.…”

Nanoantioxidants: Recent Trends in Antioxidant Delivery Applications

“…However, the tailoring of Fe 2 O 3 NPs via different strategies including coating with carbon [55], carboxymethyl-inulin [56], and poly(GA) [57], surface functionalization with natural antioxidant (GA) [27], as well as curcumin in magnetic-silk core-shell nanoparticles [58], was successfully accomplished. These tailored Fe 2 O 3 NP composites showed better dispersibility and stability and were evaluated for the efficient antioxidant properties, antimicrobial activities, and targeted drug delivery to the specific organs, as well as being analyzed for their cytotoxicity and biocompatibility/hemocompatibility [27,[55][56][57][58][59]. Surface-functionalized Fe 2 O 3 NPs with GA by in situ and post-synthesis with an average particle size of 5 and 8 nm, respectively, exhibited a 2-4 fold enhanced IC50 values of DPPH antioxidant assay compared to nonfunctionalized Fe 2 O 3 NPs.…”

“…Surface-functionalized Fe 2 O 3 NPs with GA by in situ and post-synthesis with an average particle size of 5 and 8 nm, respectively, exhibited a 2-4 fold enhanced IC50 values of DPPH antioxidant assay compared to nonfunctionalized Fe 2 O 3 NPs. The free radical scavenging property is most probably due to electron transfer from Fe 2 O 3 -NP@GA to free radicals located at the central nitrogen atom of DPPH, hence enhanced free radical scavenging for Fe 2 O 3-NP@GA due to the synergistic effect of Fe 2 O 3 -NP and GA [27]. On the other hand, magnetite nanoparticles coated with GA-shell (PGA@MNPs) polymerized in situ at the surface of the particles in a soft and reagent-free process were tested for the antioxidant capacity in Jurkat cells in the presence of H 2 O 2 as ROS, along with hemocompatibility and blood cell viability experiments.…”

The Use of Nanomedicine for Targeted Therapy against Bacterial Infections

“…Moreover, natural gallic acid conjugated with magnetite iron oxide at concentration of 100 mg/mL showed powerful bactericidal effect when tested on diverse bacterial strains. The high antibacterial potency was attributed to increased penetration of cells with impairment of cell wall by destroying β-1,4-glyosidic bond leading to cell wall decomposition [48].…”