Iron Deposition Research Articles

Calcium accumulation or iron deposition: Delving into the temporal sequence of amyotrophic lateral sclerosis pathophysiology in the primary motor cortex.

Amyotrophic lateral sclerosis (ALS) causes progressive motor neuron degeneration, but an in vivo understanding of its early pathology remains limited. A recent study used topographic layer imaging to investigate iron and calcium accumulation in the primary motor cortex (M1) of patients with ALS compared with controls. Despite the preserved cortical thickness, ALS patients showed increased iron in layer 6 and calcium accumulation in layer 5a and the superficial layer. Calcium accumulation was particularly prominent in the low-myelin borders, potentially preceding the demyelination. This study reveals a novel in vivo pathology in ALS, suggesting that calcium dysregulation may precede iron accumulation and contribute to early M1 cell degeneration. Further investigation using quantitative susceptibility mapping and complementary techniques, such as diffusion kurtosis imaging, along with ultrahigh-field magnetic resonance imaging, into the role of calcium and early intervention strategies is warranted.

Kidney R2* Mapping for Noninvasive Evaluation of Iron Overload in Paroxysmal Nocturnal Hemoglobinuria.

The kidney iron deposition can cause kidney damage and renal insufficiency in paroxysmal nocturnal hemoglobinuria (PNH) patients. Assessment of iron deposition in the kidney is essential for the early diagnosis of renal damage in PNH patients. The purpose of this study was to evaluate kidney R2* (T2* reciprocals) values in PNH patients using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ). Two radiologists measured the R2* values of the renal cortex in 14 PNH patients and 13 healthy volunteers using IDEAL-IQ. Lactate dehydrogenase (LDH), a reliable marker of intravascular hemolysis, was also measured in all participants. The kidney R2* values were significantly higher in PNH patients compared with those in healthy volunteers (P < 0.001). High inter-operator reproducibility of the measurements was also acquired using IDEAL-IQ. LDH levels were also significantly higher in PNH patients compared with those in healthy volunteers (P < 0.001). Kidney R2* values strongly correlated with LDH levels in PNH patients. IDEAL-IQ has a possibility of becoming a useful method for the noninvasive evaluation of renal iron overload in PNH patients.

Розвиток ресурсозберігаючих технологій металургійного виробництва на основі українського вугілля

The article shows that the post-war restoration of Ukraine's ferrous metallurgy should be based on a new technical and environmental basis - the so-called ‘green metallurgy’ aimed at reducing the harmful environmental impact of iron and iron-based alloys. One of the main elements of the development of ‘green metallurgy’ is the replacement of traditional blast furnace production with the reduction of iron ore with coke with the technology of direct reduction of iron without the use of coke. It is noted that the most promising for the conditions of Ukraine is the process of direct reduction of iron with synthesis gas, which is obtained during the gasification of low-metamorphosed coal. Ukraine has all the necessary prerequisites for the development of low-carbon metallurgy, namely: large deposits of iron ore and its enrichment facilities, which ensure the production of semi-finished products (pellets) of proper quality; the presence of about two-thirds of fossil coal reserves in Ukraine in the balance sheet of lowmetamorphosed coal grades B, D, DG and G. It is emphasised that the destruction of most coal-fired power generation facilities has led to a surplus of coal mined in Ukraine, which is quite suitable for gasification and synthesis gas production. Therefore, the development of metallurgy based on the use of synthesis gas from low-metamorphosed coal makes it possible not only to provide the country's economy with high-quality steel, but also to preserve the coal industry and, moreover, to provide it with new opportunities by ensuring sustainable sales at affordable prices. It has been shown that in practic carbon neutrality of the technology of iron recovery from ores can be achieved by using pure hydrogen as a reducing agent with the possible use of carbon fuels only to provide heat for the reduction reactions. Therefore, in order to reduce the environmental impact of the proposed iron production technology, it is necessary to find new ways to produce hydrogen. Keywords: ‘green’ metallurgy, coke-free metallurgy, direct reduction of iron, low-metamorphosed coal, coal gasification, hydrogen production. Corresponding author I.V. Shulga, e-mail: ko@ukhin.org.ua

The Nature and Upper Age Limit of the Formation of the Rock Association of the Petrivsky Iron Ore Deposit

The Petrivsky iron ore deposit is located on the left bank of the Ingulets River, southeast of the village Petrovo, Oleksandriysky district, Kirovohrad region. Until recently, the deposit was developed of the quarry method. The quarry revealed an iron ore stratum composed of ferruginous quartzites and crystalline schists, and strongly schistulated gneisses, ore-free quartzites and carbonate rocks occur in sharply subordinate quantities. In some areas of the quarry, the crystalline slates are partially migmatized, and the bundles of ferruginous quartzite are in many places dissected by veins of aplito-pegmatoid granites and pegmatites. According to the nature of the section, the iron ore stratum belongs to the Artemivska suite of the Ingulo-Ingulets series. Optical microscopy methods revealed heterogeneous cores of relict (clastogenic) zircon within the accessory zircon crystals from gneiss, which made it possible to make an assumption about its primary sedimentary nature, and rather high isotopic ratio 87Sr/86Sr = 0.70914 ± 0.00005 in calcite from calciphyre indicates on sediment accumulation in a basin isolated from the world ocean According to the results of uranium-lead isotope dating of different-grained monazite samples (TIMS method), the granites dissect the iron ore stratum of the Petrivske deposit were rooted in the Paleoproterozoic: aplito-pegmatoid granite 2033.3 ± 2.3 million years ago and plagiopegmatite — 2028.5 ± 5.6 million oyears ago. It is proposed to take the age of 2030 million years as the upper age limit of the iron ore stratum.

Modern methods of industrial wastewater treatment and softening

The growing demand for clean water has significantly increased the need for coagulants in wastewater treatment, particularly for agricultural production organizations. In response to this pressing issue, the provision of iron-rich raw materials to enterprises producing coagulants has become a critical priority. To address this challenge, the paper focuses on exploring the potential of producing coagulants from local iron ore raw materials available in the Karakalpakstan and Navoi regions. Ongoing scientific research efforts are dedicated to studying the composition of the iron ore resources in these mines and determining their potential applications. By leveraging the local iron ore deposits, this approach aims to develop a sustainable and cost-effective solution for the production of coagulants, ultimately supporting the growing demand for clean water in the agricultural sector.

Aeromagnetic gradiometry with UAV, a case study on small iron ore deposit

Unmanned aerial vehicles (UAVs), commonly known as drones, offer several advantages over traditional piloted aircraft. They are characterized by enhanced safety, cost-effectiveness, and the ability to operate in closer proximity to targeted sources. Consequently, magnetic sensors have been adapted or specifically designed for integration onto UAV platforms. However, existing sensors are burdened by issues such as weight, cost, and high power consumption. These challenges are particularly pronounced when employing aeromagnetic gradiometry, which necessitates simultaneous measurements from at least two sensors. In response to these limitations, we propose the implementation of a cost-effective, lightweight, and low-power magneto-inductive sensor with satisfactory resolution aboard a UAV. To evaluate its efficacy, a survey was conducted over a small iron ore deposit in Western Iran. To validate our approach, we compare the results with those obtained using only one sensor on the drone. This comparative analysis reveals that employing a gradiometry array leads to a pronounced steepening of magnetic anomaly margins. Specifically, the gradient of magnetic measurements on four selected profiles increases to 3.8, 4.6, 9.3, and 10 nT/m when utilizing the proposed magneto-inductive sensor, in contrast to the conventional method of gradient determination through mathematical derivatives in the z-direction. This research contributes to the advancement of efficient and economical methods for mineral exploration using UAV-based magnetic surveying techniques.

Pubertal Development in Girls with Beta Thalassaemia and Assessment of the Adequacy of Chelation Therapy: A Quasi-experimental Study

Introduction: Beta thalassaemia is the most prevalent hereditary autosomal disorder, significantly impacting endocrine function during pubertal development. The pathology is rooted in the excessive deposition of iron in vital organs. If left untreated, this condition leads to serious morbidity and mortality. Hypogonadism stands as the most common endocrine complication. Aim: To observe pubertal development in girls with thalassaemia and evaluate the adequacy of chelation therapy in such patients by measuring levels of Follicle Stimulating Hormone (FSH), Luteinising Hormone (LH), oestrogen, and serum ferritin. Materials and Methods: A quasi-experimental study was conducted at the Thalassaemia Clinic at the Department of Obstetrics and Gynaecology, Burdwan Medical College, Purba Bardhaman, West Bengal, India involving 300 diagnosed Beta Thalassaemia Major (BTM) (case) patients aged 13 to 17 years over a period of one and a half years (January 2020 to June 2021). The girls in the study groups were sequentially enrolled from the Outpatient Department of the Thalassaemia Clinic after meeting inclusion and exclusion criteria. Demographic data, anthropometric measurements, and Sexual Maturity Rating (SMR) were recorded. Hormonal assays of serum FSH, LH, oestrogen, and serum ferritin levels were conducted. Thalassaemic girls with serum ferritin levels exceeding 500 ng/mL received chelation therapy. Serum ferritin levels were measured at two-month intervals for up to six months, with reassessment of serum FSH, LH, oestrogen, and ferritin levels at the end of the six-month period. Statistical analysis was conducted using Statistical Package for Social Sciences (SPSS) version 27.0, Microsoft excel spreadsheet, and Epi Info 7. Results: A total of 190 (63.3%) of the thalassaemic girls were aged 13 to 15 years, with a mean Body Mass Index (BMI) of 22.5000±2.6100 kg/m2 , and 74 of them (38.94%) experienced menarche in this age group. Out of 300 cases, 269 thalassaemic girls (89.6%) received chelation therapy, and 89 cases (33.09%) reached menarche after chelation therapy. A significant (p&lt;0.0001) increase in mean LH and FSH levels was observed after chelation therapy. The mean ferritin level decreased from 3168.85 ng/mL to 2227.24 ng/mL following chelation therapy. Conclusion: Pubertal development failure is common in beta thalassaemic girls. Intervention in the form of adequate chelation therapy in girls with high serum ferritin levels yielded favourable outcomes, as evident from serum gonadotropin and oestrogen levels.

Geochemical and petrographic Studies of Iron-ore deposits of Timsah Formation at East Aswan area, Egypt

Geochemical and petrographic Studies of Iron-ore deposits of Timsah Formation at East Aswan area, Egypt

Characterization of quantitative susceptibility mapping in the left ventricular myocardium

Myocardial quantitative susceptibility mapping (QSM) may offer better specificity to iron than conventional T2* imaging in the assessment of cardiac diseases, including intra-myocardial hemorrhage. However, the precision and repeatability of cardiac QSM have not yet been characterized. The aim of this study is to characterize these key metrics in a healthy volunteer cohort and show the feasibility of the method in patients. Free breathing respiratory-navigated multi-echo 3D gradient echo images were acquired, from which QSM maps were reconstructed using the Morphology Enhanced Dipole Inversion toolbox. This technique was first evaluated in a susceptibility phantom containing tubes with known concentrations of gadolinium. In vivo characterization of myocardial QSM was then performed in a cohort of 10 healthy volunteers where each subject was scanned twice. Mean segment susceptibility, precision (standard deviation of voxel magnetic susceptibilities within one segment), and repeatability (absolute difference in segment mean susceptibility between repeats) of QSM were calculated for each American Heart Association (AHA) myocardial segment. Finally, the feasibility of the method was shown in 10 patients, including four with hemorrhagic infarcts. The phantom experiment showed a strong linear relationship between measured and predicted susceptibility shifts (R2 >0.99). For the healthy volunteer cohort, AHA segment analysis showed the mean segment susceptibility was 0.00±0.02ppm, the mean precision was 0.05±0.04ppm, and the mean repeatability was 0.02±0.02ppm. Cardiac QSM was successfully performed in all patients. Focal iron deposits were successfully visualized in the patients with hemorrhagic myocardial infarctions. The precision and repeatability of cardiac QSM were successfully characterized in phantom and in vivo experiments. The feasibility of the technique was also successfully demonstrated in patients. While challenges still remain, further clinical evaluation of the technique is now warranted. This work does not report on a health care intervention.

Identification of Cathepsin B as a Therapeutic Target for Ferroptosis of Macrophage after Spinal Cord Injury.

Hemorrhage and immune cell infiltration are the main pathological features of spinal cord injury (SCI). Excessive iron deposition is caused by leaking hemosiderin which may over-activate ferroptosis pathways, resulting in lipid peroxidation and mitochondrial dysfunction in cells. Inhibiting ferroptosis after SCI has been shown to aid functional recovery. However, the essential genes involved in cellular ferroptosis following SCI are still unknown. Here we show that Ctsb is a statistical significance gene by collecting multiple transcriptomic profiles and identifying differentially expressed ferroptosis-related genes, which are abundantly expressed in myeloid cells after SCI and widely distributed at the epicenter of the injury. The expression score of ferroptosis, calculated by ferroptosis driver/suppressor genes, was high in macrophages. Furthermore, we discovered that inhibiting cathepsin B (CTSB), specifically with a small-molecule drug, CA-074-methyl ester (CA-074-me), reduced lipid peroxidation and mitochondrial dysfunction in macrophages. We also found that alternatively activated M2-polarized macrophages are more susceptible to hemin-induced ferroptosis. Consequently, CA-074-me could reduce ferroptosis, induce M2 macrophage polarization, and promote the neurological function recovery of mice after SCI. Our study comprehensively analyzed the ferroptosis after SCI from the perspective of multiple transcriptomes and provided a novel molecular target for SCI treatment.

Intranasal iron administration induces iron deposition, immunoactivation and cell-specific vulnerability in the olfactory bulb of C57BL/6 mice

Intranasal iron administration induces iron deposition, immunoactivation and cell-specific vulnerability in the olfactory bulb of C57BL/6 mice

Krill Oil Ameliorates Liver Injury in Diabetic Mice by Activating Antioxidant Capacity and Inhibiting Ferroptosis.

Diabetic liver injury (DLI) has raised attention in recent years. Liver injury results from type 2 diabetes mellitus (T2DM), and in turn accelerates T2DM development by exacerbating insulin resistance. However, effective approaches for mitigating DLI are surprisingly rare. Krill oil (KO) is an alternative source of omega-3 polyunsaturated fatty acids, possessing antioxidant and anti-inflammatory capacities. Here we investigated the effect of KO supplementation on DLI in a mouse model of T2DM induced by streptozotocin and high-fat diet. The diabetic mice developed glucose intolerance, elevated serum alanine aminotransferase and aspartate aminotransferase, and hepatic pathological injuries such as vacuolation, lipid accumulation and fibrosis deposition, the effects of which were mitigated by KO. Further investigation showed that KO ameliorated the DM-induced expression of fibrotic and inflammatory genes. Notably, KO dramatically reduced hepatic oxidative gene expression, lipid peroxidation and ROS production, all of which are hallmarks of ferroptosis. The inhibitory effect of KO on ferroptosis was confirmed by the KO-decreased hepatic expression of GPX4, COX2 and ACSL4, as well as the KO-reduced hepatic iron deposition. Further, KO restored hepatic NRF2 antioxidant signaling which combats ferroptosis. The present study may provide KO supplementation as a viable approach for the intervention of DLI.

Is Quantifying Iron in the Putamen Important in Neurodegenerative Diseases?

Iron is crucial for the functioning of neurons. However, the accumulation of iron in subcortical structures, particularly in the putamen, has been linked to age-related decline in cognitive function and neurodegeneration. This accumulation leads to oxidative stress, which damages cellular components and contributes to the development of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Quantitative Susceptibility Mapping (QSM) has provided insights into the paramagnetic properties of iron, enabling the non-invasive measurement of iron deposits in brain structures. Studies have shown a significant correlation between increased iron levels in the putamen and the severity of neurodegenerative diseases, highlighting the vulnerability of the putamen to iron-induced toxicity. QSM holds promise as an imaging biomarker for understanding disease mechanisms, assessing disease severity, and monitoring treatment. However, further longitudinal studies are needed to evaluate the progression of iron deposition and its implications for disease pathology.

Asymmetrical parkinsonism due to novel WDR45 variant with beta-propeller protein-associated neurodegeneration (BPAN).

Beta-propeller protein-associated neurodegeneration (BPAN) encompasses a group of refractory neurodegenerative diseases that are caused by excessive iron deposition in the brain, especially in the basal ganglia. We reported a case of BPAN with a novel variant of the WDR45 gene at Xp11.23. Our patient was a 31-year-old woman who has had an intellectual disability since childhood. Approximately 3 years ago, she developed asymmetric parkinsonism affecting the distal right upper and lower limbs. Consistent with her neurological findings, dopamine transporter single-photon emission computed tomography demonstrated the differences between the left and right sides. She was diagnosed as BPAN according to genetic analysis, which showed a novel heterozygous variant (c.345-3C>G) in WDR45. To the best of our knowledge, only a few previous case reports on asymmetric BPAN have described the quantitative differences in neuroimaging parameters between the left and right sides. These neuroimaging features were similar to those of Parkinson's disease, among the other neurodegenerative diseases. Our report may provide clues to elucidate the pathological mechanism of BPAN which is a refractory neurodegenerative disease.

Trial Readiness of Cavernous Malformations With Symptomatic Hemorrhage, Part II: Biomarkers and Trial Modeling.

Quantitative susceptibility mapping (QSM) and dynamic contrast-enhanced quantitative perfusion (DCEQP) magnetic resonance imaging sequences assessing iron deposition and vascular permeability were previously correlated with new hemorrhage in cerebral cavernous malformations. We assessed their prospective changes in a multisite trial-readiness project. Patients with cavernous malformation and symptomatic hemorrhage (SH) in the prior year, without prior or planned lesion resection or irradiation were enrolled. Mean QSM and DCEQP of the SH lesion were acquired at baseline and at 1- and 2-year follow-ups. Sensitivity and specificity of biomarker changes were analyzed in relation to predefined criteria for recurrent SH or asymptomatic change. Sample size calculations for hypothesized therapeutic effects were conducted. We logged 143 QSM and 130 DCEQP paired annual assessments. Annual QSM change was greater in cases with SH than in cases without SH (P=0.019). Annual QSM increase by ≥6% occurred in 7 of 7 cases (100%) with recurrent SH and in 7 of 10 cases (70%) with asymptomatic change during the same epoch and 3.82× more frequently than clinical events. DCEQP change had lower sensitivity for SH and asymptomatic change than QSM change and greater variance. A trial with the smallest sample size would detect a 30% difference in QSM annual change during 2 years of follow-up in 34 or 42 subjects (1 and 2 tailed, respectively); power, 0.8, α=0.05. Assessment of QSM change is feasible and sensitive to recurrent bleeding in cavernous malformations. Evaluation of an intervention on QSM percent change may be used as a time-averaged difference between 2 arms using a repeated measures analysis. DCEQP change is associated with lesser sensitivity and higher variability than QSM. These results are the basis of an application for certification by the US Food and Drug Administration of QSM as a biomarker of drug effect on bleeding in cavernous malformations. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03652181.

Subconjunctival deferoxamine for corneal rust deposits associated with ocular siderosis: A case report

Introduction: Ocular siderosis is a vision-threatening condition resulting from intraocular iron toxicity. This case re-establishes a role for subconjunctival deferoxamine, a chelating agent uncommonly used in ophthalmology, as an adjunctive treatment for ocular siderosis. Case Report: A 37-year-old healthy male presented two months after an injury at work with intermittent pain and blurry vision in the right eye. Presenting visual acuity (VA) was 20/100 in the right eye. With delayed presentation, the patient already had ocular siderosis with corneal rust deposits and retinal damage. The patient underwent pars plana vitrectomy (PPV) with surgical view impaired by corneal deposits and intraocular metallic intraocular foreign body (IOFB) that disintegrated upon attempted removal. At six months postoperatively, VA was 20/70 in the right eye, and examination revealed worsened diffuse, pigmented subepithelial deposits in the central cornea, iris atrophy, cotton wool spots, optic nerve pallor, and a residual IOFB in the anterior vitreous, consistent with worsened ocular siderosis. Superficial keratectomy was performed in combination with repeat PPV to improve surgical visualization and aid in IOFB removal. An amniotic membrane was placed and a subconjunctival injection of deferoxamine was administered. The cornea was well-healed with significantly improved siderosis and no epithelial defects on 2-week postoperative follow-up. Visual acuity was 20/60 at last follow-up two months postoperatively after second surgery. Conclusion: In treating ocular siderosis, subconjunctival injection of deferoxamine can be a useful addition to surgical IOFB removal to prevent the accumulation of iron deposits in the anterior segment of the eye.

Prospects of the Bug mining district as an agglomeration of ore and non-ore mineral deposits for the reconstruction of the national economy of Ukraine in the post-war period

The role and capabilities of Ukrainian geological science, production and investment capital in the reconstruction of the national economy of Ukraine during the war and post-war period are considered here using the example of the Bug mining district (BMD) of the Ukrainian Shield (USh).&#x0D; BMD is characterized by an extremely wide range of deposits and ore of minerals relatively close to the surface, among which the most important ones are graphite, iron ore and iron-manganese, nickel-chromium-cobalt deposits, deposits and ore occurrences of gold discovered by geologists and geophysicists for many years. Numerous deposits of building materials and kaolin are also known here. There are prospects for obtaining local agrochemical raw materials based on the development of apatite-containing ores and calcifers.&#x0D; The article lists and shows the location of mineral deposits and ore occurrences which arethe most well-prepared for industrial development and investments. The composition of ores and the content of useful substances are given for some of them.&#x0D; Two powerful industrial enterprises are located on the BMD square, i.e., the Zavallye graphite factory and the Bug ferronickel plant (currently repurposed for other products). They can be used to process the above-mentioned ore raw materials, with some improvement of technological processes. In this regard, the possibility and practicality of creating two centers (clusters) of integrated mining and industrial development of these useful resources were considered. One of them can be created on the basis of nickel-cobalt and iron ore deposits of BMD with an orientation towards the Bug ferronickel plant. The second center can be created based on the enrichment of iron-manganese oxide ores using the technical capabilities of the Zavallye graphite plant.&#x0D; In case of realization of the entire economic potential of the industrial development of graphite ores of the region, Ukraine could become a world leader in this field and receive significant funds to reconstruct the industry disrupted by the war.&#x0D; The BMD also meets all the geological and economic prerequisites to become the first region on the Ukrainian Shield for industrial gold mining.

Bulk geochemistry, Rb–Sr, Sm–Nd, and stable O–H isotope systematics of the Metzimevin high-grade iron ore deposit, Mbalam iron ore district, southern Cameroon

Bulk geochemistry, Rb–Sr, Sm–Nd, and stable O–H isotope systematics of the Metzimevin high-grade iron ore deposit, Mbalam iron ore district, southern Cameroon

Protective Effects of Hinokitiol on Neuronal Ferroptosis by Activating the Keap1/Nrf2/HO-1 Pathway in Traumatic Brain Injury.

In this study, we investigated the effects of hinokitiol, a small-molecule natural compound, against neuronal ferroptosis after traumatic brain injury (TBI). A controlled cortical impact (CCI) mouse model and excess glutamate-treated HT-22 cells were used to study the effects of hinokitiol on TBI. Hinokitiol mitigated TBI brain tissue lesions and significantly improved neurological function. Neuron loss and iron deposition were ameliorated after hinokitiol administration. Hinokitiol alleviated excessive glutamate-induced intracellular reactive oxygen species (ROS), lipid peroxidation, and Fe2+ accumulation in HT-22. Mechanistically, hinokitiol upregulated heme oxygenase-1 (HO-1) expression, promoted nuclear factor-erythroid factor 2-related factor 2 (Nrf2) nuclear translocation, and inhibited the activation of microglia and astrocyte after TBI. These results suggest that hinokitiol has neuroprotective effects on rescuing cells from TBI-induced neuronal ferroptosis. In summary, hinokitiol is a potential therapeutic candidate for TBI by activating the Nrf2/Keap1/HO-1 signaling pathway.

Exploring Conductive Polymer Coatings to Target Reaction Selectivity in Aqueous All-Iron Redox Flow Batteries

An energy grid that relies on wind and solar farms requires the installation of large-scale energy storage systems to balance their fluctuating output. Especially for developing countries, wide adoption of renewables is coupled to progress in sustainable and cost-effective storage technologies.1 From this perspective, aqueous all-iron redox flow batteries (AIRFBs) stand out as a promising technology, owing to the earth-abundance and low-cost of iron, along with its environmental and operational safety. In this battery, iron is utilized in its three oxidation states (Fe0, Fe2+ and Fe3+) and the negative electrode leverages the iron plating/stripping reactions to sustain charge and discharge. However, the standard potential of iron plating is 0.44 V below the hydrogen evolution reaction (HER), which causes faradaic losses during the charging stage and increases the pH of the solution.2 The catalytic activity of iron towards hydrogen evolution and the precipitation of iron hydroxide at pH above 3.5 further complicates the operation of AIRFBs. Thus, the reaction selectivity of the negative electrode should be targeted to improve the operational time and efficiency. So far, research has focused on electrolyte engineering to hinder adsorption of hydrogen on surfaces or excluding water from the solvent shell of iron.2,3 Alternatively, interfacial engineering of electrode surfaces can be a promising strategy to tune the reaction selectivity, given that hydrogen adsorption and iron nucleation are interfacial phenomena. The challenge here is to prevent a new interface from being created by the plated iron as that would render the modified interface obsolete. We hypothesize that polymeric layers where iron deposition can take place within or underneath the polymer (akin to a solid electrolyte interphase of a Li-ion battery anode) would preserve the HER-inhibiting characteristics of the surface.Here, we propose conductive polymer interfaces to target reaction selectivity during the iron plating reaction. Conductive polymers have been used to engineer HER-inhibiting interfaces and as corrosion protection layers for metals.4,5 Furthermore, they can be conformally coated on porous electrodes, enabling their use in flow reactors.6 We selected two conductive polymer systems: poly(pyrrole) (PPy) owing to its iron-coordinating nitrogen moieties and poly(3,4-ethylenedioxythiophene) (PEDOT) owing to its high conductivity and stability.7 Furthermore, we employed three counterions of different size, chlorine (Cl-), p-toluenesulfonate (pTS-) and poly(styrenesulfonate) (PSS-), to direct the morphology of the coating, resulting in six different polymer systems. On glassy carbon electrodes, all polymers significantly hinder HER at potentials as low as -1.5 V (vs Ag/AgCl) where heavy bubble formation is observed on bare electrodes (Figure 1). To assess the selectivity of the coatings on carbon paper substrates, we are developing an electrochemical protocol with successive plating/stripping cycles that is representative of battery operation. Preliminary results show that all polymer systems hinder the HER, but also the Fe-plating reaction, resulting in lower plating currents than the bare carbon paper electrodes. To validate the methodology, we compare the electrochemically obtained reaction selectivity values with the ones from gravimetric analysis. The ideal polymeric interfaces should inhibit the HER without largely impacting the Fe-plating kinetics, which motivates research into the relationship between the coating thickness, conductivity, and the faradaic efficiency. To understand the plating morphology on polymeric coatings, we investigate the spatial distribution of iron on the surface and the cross-section of plated electrodes using microscopic methods. Hydrogen evolution and limited durability due to complex plating reactions hamper the broad implementation of all-iron redox flow batteries and we hope to tackle these challenges through interfacial electrode engineering. References Rahman et al., in Renewable Energy and Sustainability, Elsevier, 2022, pp. 347–376. Hawthorne et al., J. Electrochem. Soc. 2014, 162, A108.Liu et al., ACS Cent. Sci. 2022, 8, 729.Tian et al., J. Electrochem. Soc. 2013, 161, E23. Deshpande et al., J Coat Technol Res 2014, 11, 473. Boz et al., Adv Materials Inter 2023, 2202497. Mao et al., Energy Environ. Sci. 2011, 4, 3442. Figure 1