Preparation of Iron-Based Sulfides and Their Applications in Biomedical Fields

Abstract

Recently, iron-based sulfides, including iron sulfide minerals and biological iron sulfide clusters, have attracted widespread interest, owing to their excellent biocompatibility and multi-functionality in biomedical applications. As such, controlled synthesized iron sulfide nanomaterials with elaborate designs, enhanced functionality and unique electronic structures show numerous advantages. Furthermore, iron sulfide clusters produced through biological metabolism are thought to possess magnetic properties and play a crucial role in balancing the concentration of iron in cells, thereby affecting ferroptosis processes. The electrons in the Fenton reaction constantly transfer between Fe²⁺ and Fe³⁺, participating in the production and reaction process of reactive oxygen species (ROS). This mechanism is considered to confer advantages in various biomedical fields such as the antibacterial field, tumor treatment, biosensing and the treatment of neurodegenerative diseases. Thus, we aim to systematically introduce recent advances in common iron-based sulfides.

Keywords: Fenton reaction; biomedical application; iron sulfide clusters; iron-based sulfides.

Figure 1

Common forms of [FeS] clusters. These clusters have various functional roles in different proteins. (a) [2Fe-2S] cluster; (b) [3Fe-4S] cluster; (c) [4Fe-3S] cluster; (d) [4Fe-4S] cluster; (e) [4Fe-4S]_RS cluster; (f) siroheme-[4Fe-4S] cluster; (g) [4Fe-5S] cluster; (h) non-cubane [4Fe-4S] cluster and (i) [4Fe-4S]-S_n-[4Fe-4S] clusters (n = 1, 5) [46]. Copyright 2022 Elsevier.

Figure 2

T2-weighted MRI performance of FeS₂@BSA-Ce6 nanodots. (a) MR images of FeS₂@BSA nanodots and IONPs; (b) relative relaxation rate R₂ of FeS₂@BSA nanodots, FeS₂@BSA-Ce6 nanocomplex and iron oxide nanoparticles (IONPs); (c) MR images and (d) quantified MR signals of 4T1 tumor-bearing nude mice before and 8 h after iv injection of FeS₂@BSA-Ce6 nanodots [69]. Means ± SD are shown (n = 3) (*** p < 0.001) Copyright 2017 American Chemical Society.

Figure 3

Antibacterial activity of nFeS. (a) Antibacterial activity of nFeS converted from different organosulfur sources against S. mutans UA159; (b) antibacterial (S. mutans UA159) activity of organosulfur compounds; (c) dependence of antibacterial (S. mutans UA159) efficacy of Cys-nFeS on the amount of cysteine input into the solvothermal synthesis; (d–h) antibacterial activity of nFeS on P. aeruginosa, E. coli, S. enteritidis, S. aureus and S. aureus (MDR), respectively; (i,j) ROS level and lipid peroxidation of bacteria treated with Cys-nFeS; (k) genomic DNA degradation of bacteria treated with Cys-nFeS; (l) SEM image of bacteria treated with Cys-nFeS [106]. Means ± SD are shown (n = 3) (** p < 0.01, *** p < 0.001, **** p < 0.0001) Copyright 2018 Nature Publishing Group.

Figure 4

(a) Degradation behavior and (b) tumor therapy mechanism of FeS-PEG-CAI NPs [72]. Copyright 2022 American Chemical Society.

Figure 5

(a) Schematic illustration of colorimetric detection with H₂O₂ and GSH based on FeS₂ NPs as the sensing platforms; (b) UV–Vis absorption spectra of the reaction system with different reagents; linear calibration plots for the detection of (c) H₂O₂ and (d) GSH. Inset: photographs of corresponding samples [117]. Copyright 2020 Elsevier.