Deferoxamine topical cream superior to patch in rescuing radiation-induced fibrosis of unwounded and wounded skin.

Topical patch delivery of deferoxamine (DFO) has been studied as a treatment for this fibrotic transformation in irradiated tissue. Efficacy of a novel cream formulation of DFO was studied as a RIF therapeutic in unwounded and excisionally wounded irradiated skin. C57BL/6J mice underwent 30 Gy of radiation to the dorsum followed by 4 weeks of recovery. In a first experiment, mice were separated into six conditions: DFO 50 mg cream (D50), DFO 100 mg cream (D100), soluble DFO injections (DI), DFO 1 mg patch (DP), control cream (Vehicle), and irradiated untreated skin (IR). In a second experiment, excisional wounds were created on the irradiated dorsum of mice and then divided into four treatment groups: DFO 100 mg Cream (W-D100), DFO 1 mg patch (W-DP), control cream (W-Vehicle), and irradiated untreated wounds (W-IR). Laser Doppler perfusion scans, biomechanical testing, and histological analysis were performed. In irradiated skin, D100 improved perfusion compared to D50 or DP. Both D100 and DP enhanced dermal characteristics, including thickness, collagen density and 8-isoprostane staining compared to untreated irradiated skin. D100 outperformed DP in CD31 staining, indicating higher vascular density. Extracellular matrix features of D100 and DP resembled normal skin more closely than DI or control. In radiated excisional wounds, D100 facilitated faster wound healing and increased perfusion compared to DP. The 100 mg DFO cream formulation rescued RIF of unwounded irradiated skin and improved excisional wound healing in murine skin relative to patch delivery of DFO.

Bile Acid-Targeted Hyaluronic Acid Nanoparticles for Enhanced Oral Absorption of Deferoxamine.

Patients with ß-thalassemia and sickle cell disease often rely on blood transfusions which can lead to hemochromatosis and chronic oxidative stress in cells and tissues. Deferoxamine (DFO) is clinically approved to treat hemochromatosis but is suboptimal to patients due to its poor pharmacokinetics which requires long-term infusion regimens. Although the oral route is preferable, DFO has limited oral bioavailability. Studies have shown that hyaluronic acid (HA) and bile acid (BA) can enhance the oral absorption of poorly absorbed drugs. To improve upon the oral delivery of DFO, we report on the synthesis and characterization of HA (MW 15 kD) conjugated to two types of BA, deoxycholic acid (DOCA) and taurocholic acid (TCA), and DFO. The resulting seven polymeric conjugates all formed self-assembled nanoparticles. The degree of BA and DFO conjugation to the HA polymer was confirmed at each step through nuclear magnetic resonance, Fourier transform infrared spectroscopy, and UV-Vis spectroscopy. The best formulations for further in vitro testing were determined based on physicochemical characterizations and included HA-DFO, TCA9-HA-DFO, and DOCA9-HA-DFO. Results from in vitro assays revealed that TCA9-HA-DFO enhanced the permeation of DFO the most and was also less cytotoxic to cells compared to the free drug DFO. In addition, ferritin reduction studies indicated that the conjugation of DFO to TCA9-HA did not compromise its chelation efficiency at equivalent free DFO concentrations. This research provides supportive data for the idea that TCA conjugated to HA may enhance the oral absorption of DFO, improve its cytocompatibility, and maintain its iron chelation efficiency.

Purification and Characterization of Desferrioxamine B of Pseudomonas fluorescens and Its Application to Improve Oil Content, Nutrient Uptake, and Plant Growth in Peanuts.

Microorganisms produce siderophores, which are low-molecular-weight iron chelators when iron availability is limited. The present analyzed the role of LNPF1 as multifarious PGPR for improving growth parameters and nutrient content in peanut and soil nutrients. Such multifarious PGPR strains can be used as effective bioinoculants for peanut farming. In this work, rhizosphere bacteria from Zea mays and Arachis hypogaea plants in the Salem area of Tamil Nadu, India, were isolated and tested for biochemical attributes and characteristics that stimulate plant growth, such as the production of hydrogen cyanide, ammonia (6 µg/mL), indole acetic acid (76.35 µg/mL), and solubilizing phosphate (520 µg/mL). The 16S rRNA gene sequences identified the isolate LNPF1 as Pseudomonas fluorescens with a similarity percentage of 99% with Pseudomonas sp. Isolate LNPF1 was evaluated for the production of siderophore. Siderophore-rich supernatant using a Sep Pack C18 column and Amberlite-400 Resin Column (λmax 264) produced 298 mg/L and 50 mg/L of siderophore, respectively. The characterization of purified siderophore by TLC, HPLC, FTIR, and 2D-NMR analysis identified the compound as desferrioxamine, a hydroxamate siderophore. A pot culture experiment determined the potential of LNPF1 to improve iron and oil content and photosynthetic pigments in Arachis hypogaea L. and improve soil nutrient content. Inoculation of A. hypogea seeds with LNPF1 improved plant growth parameters such as leaf length (60%), shoot length (22%), root length (54.68%), fresh weight (47.28%), dry weight (37%), and number of nuts (66.66) compared to the control (untreated seeds). This inoculation also improved leaf iron content (43.42), short iron content (38.38%), seed iron (46.72%), seed oil (31.68%), carotenoid (64.40%), and total chlorophyll content (98.%) compared to control (untreated seeds). Bacterized seeds showed a substantial increase in nodulation (61.65%) and weight of individual nodules (95.97) vis-à-vis control. The results of the present study indicated that P. fluorescens might be utilized as a potential bioinoculant to improve growth, iron content, oil content, number of nuts and nodules of Arachishypogaea L., and enrich soil nutrients.

Biosynthesis of novel desferrioxamine derivatives requires unprecedented crosstalk between separate NRPS-independent siderophore pathways.

Iron is essential to many biological processes but its poor solubility in aerobic environments restricts its bioavailability. To overcome this limitation, bacteria have evolved a variety of strategies, including the production and secretion of iron-chelating siderophores. Here, we describe the discovery of four series of siderophores from Streptomyces ambofaciens ATCC23877, three of which are unprecedented. MS/MS-based molecular networking revealed that one of these series corresponds to acylated desferrioxamines (acyl-DFOs) recently identified from S. coelicolor. The remaining sets include tetra- and penta-hydroxamate acyl-DFO derivatives, all of which incorporate a previously undescribed building block. Stable isotope labeling and gene deletion experiments provide evidence that biosynthesis of the acyl-DFO congeners requires unprecedented crosstalk between two separate non-ribosomal peptide synthetase (NRPS)-independent siderophore (NIS) pathways in the producing organism. Although the biological role(s) of these new derivatives remain to be elucidated, they may confer advantages in terms of metal chelation in the competitive soil environment due to the additional bidentate hydroxamic functional groups. The metabolites may also find application in various fields including biotechnology, bioremediation, and immuno-PET imaging.IMPORTANCEIron-chelating siderophores play important roles for their bacterial producers in the environment, but they have also found application in human medicine both in iron chelation therapy to prevent iron overload and in diagnostic imaging, as well as in biotechnology, including as agents for biocontrol of pathogens and bioremediation. In this study, we report the discovery of three novel series of related siderophores, whose biosynthesis depends on the interplay between two NRPS-independent (NIS) pathways in the producing organism S. ambofaciens-the first example to our knowledge of such functional cross-talk. We further reveal that two of these series correspond to acyl-desferrioxamines which incorporate four or five hydroxamate units. Although the biological importance of these novel derivatives is unknown, the increased chelating capacity of these metabolites may find utility in diagnostic imaging (for instance, 89Zr-based immuno-PET imaging) and other applications of metal chelators.

The impact of chelation compliance in health outcome and health related quality of life in thalassaemia patients: a systematic review.

Understanding consequences of poor chelation compliance is crucial given the enormous burden of post-transfusional iron overload complications. We systematically reviewed iron-chelation therapy (ICT) compliance, and the relationship between compliance with health outcome and health-related quality of life (HRQoL) in thalassaemia patients. Several reviewers performed systematic search strategy of literature through PubMed, Scopus, and EBSCOhost. The preferred reporting items of systematic reviews and meta-analyses (PRISMA) guidelines were followed. Of 4917 studies, 20 publications were included. The ICT compliance rate ranges from 20.93 to 75.3%. It also varied per agent, ranging from 48.84 to 85.1% for desferioxamine, 87.2-92.2% for deferiprone and 90-100% for deferasirox. Majority of studies (N = 10/11, 90.91%) demonstrated significantly negative correlation between compliance and serum ferritin, while numerous studies revealed poor ICT compliance linked with increased risk of liver disease (N = 4/7, 57.14%) and cardiac disease (N = 6/8, 75%), endocrinologic morbidity (N = 4/5, 90%), and lower HRQoL (N = 4/6, 66.67%). Inadequate compliance to ICT therapy is common. Higher compliance is correlated with lower serum ferritin, lower risk of complications, and higher HRQoL. These findings should be interpreted with caution given the few numbers of evidence.

Chelating Effect of Siderophore Desferrioxamine-B on Uranyl Biomineralization Mediated by Shewanella putrefaciens.

In contaminated water and soil, little is known about the role and mechanism of the biometabolic molecule siderophore desferrioxamine-B (DFO) in the biogeochemical cycle of uranium due to complicated coordination and reaction networks. Here, a joint experimental and quantum chemical investigation is carried out to probe the biomineralization of uranyl (UO22+, referred to as U(VI) hereafter) induced by Shewanella putrefaciens (abbreviated as S. putrefaciens) in the presence of DFO and Fe3+ ion. The results show that the production of mineralized solids {hydrogen-uranium mica [H2(UO2)2(PO4)2·8H2O]} via S. putrefaciens binding with UO22+ is inhibited by DFO, which can both chelate preferentially UO22+ to form a U(VI)-DFO complex in solution and seize it from U(VI)-biominerals upon solvation. However, with Fe3+ ion introduced, the strong specificity of DFO binding with Fe3+ causes re-emergence of biomineralization of UO22+ {bassetite [Fe(UO2)2(PO4)2·8(H2O)]} by S. putrefaciens, owing to competitive complexation between Fe3+ and UO22+ for DFO. As DFO possesses three hydroxamic functional groups, it forms hexadentate coordination with Fe3+ and UO22+ ions via these functional groups. The stability of the Fe3+-DFO complex is much higher than that of U(VI)-DFO, resulting in some DFO-released UO22+ to be remobilized by S. putrefaciens. Our finding not only adds to the understanding of the fate of toxic U(VI)-containing substances in the environment and biogeochemical cycles in the future but also suggests the promising potential of utilizing functionalized DFO ligands for uranium processing.

Efficacy and safety of deferoxamine, deferasirox and deferiprone triple iron chelator combination therapy for transfusion-dependent ß-thalassaemia with very high iron overload: a protocol for randomised controlled clinical trial.

INTRODUCTION: Despite the improvement in medical management, many patients with transfusion-dependent ß-thalassaemia die prematurely due to transfusion-related iron overload. As per the current guidelines, the optimal chelation of iron cannot be achieved in many patients, even with two iron chelators at their maximum therapeutic doses. Here, we evaluate the efficacy and safety of triple combination treatment with deferoxamine, deferasirox and deferiprone over dual combination of deferoxamine and deferasirox on iron chelation in patients with transfusion-dependent ß-thalassaemia with very high iron overload. METHODS AND ANALYSIS: This is a single-centre, open-label, randomised, controlled clinical trial conducted at the Adult and Adolescent Thalassaemia Centre of Colombo North Teaching Hospital, Ragama, Sri Lanka. Patients with haematologically and genetically confirmed transfusion-dependent ß-thalassaemia are enrolled and randomised into intervention or control groups. The intervention arm will receive a combination of oral deferasirox, oral deferiprone and subcutaneous deferoxamine for 6 months. The control arm will receive the combination of oral deferasirox and subcutaneous deferoxamine for 6 months. Reduction in iron overload, as measured by a reduction in the serum ferritin after completion of the treatment, will be the primary outcome measure. Reduction in liver and cardiac iron content as measured by T2* MRI and the side effect profile of trial medications are the secondary outcome measures. ETHICS AND DISSEMINATION: Ethical approval for the study has been obtained from the Ethics Committee of the Faculty of Medicine, University of Kelaniya (Ref. P/06/02/2023). The trial results will be disseminated in scientific publications in reputed journals. TRIAL REGISTRATION NUMBER: The trial is registered in the Sri Lanka Clinical Trials Registry (Ref: SLCTR/2023/010).

Preconditioning of human umbilical cord mesenchymal stem cells with deferoxamine potentiates the capacity of the secretome released from the cells and promotes immunomodulation and beta cell regeneration in a rat model of type 1 diabetes.

This study aimed to examine the effects of the secretome released by human umbilical cord-mesenchymal stem cells (MSC) as a result of preconditioning with deferoxamine (DFX), a hypoxia mimetic agent, on type 1 diabetes (T1D), by comparing it with the secretome produced by untreated MSCs. Initially, the levels of total protein, IL4, IL10, IL17, and IFNγ in the conditioned medium (CM) obtained from MSCs subjected to preconditioning with 150 µM DFX (DFX-CM) were analyzed in comparison to CM derived from untreated MSCs (N-CM). Subsequently, the CMs were administered to rats with T1D within a specific treatment plan. Following the sacrification, immunomodulation was evaluated by measuring serum cytokine levels and assessing the regulatory T cell (Treg) ratio in spleen mononuclear cells. Additionally, ß-cell mass was determined in the islets by immunohistochemical labeling of NK6 Homeobox 1 (Nkx6.1), Pancreatic duodenal homeobox-1 (Pdx1), and insulin antibodies in pancreatic sections. In vitro findings indicated that the secretome levels of MSCs were enhanced by preconditioning with DFX. In vivo, the use of DFX-CM significantly increased the Treg population, and accordingly, the level of inflammatory cytokines decreased. In ß-cell marker labeling, D + DFX-CM showed significantly increased PDX1 and insulin immunoreactivity. In conclusion, while the factors released by MSCs without external stimulation had limited therapeutic effects, substantial improvements in immunomodulation and ß-cell regeneration were seen with DFX-preconditioned cell-derived CM.

Chelation of Mitochondrial Iron as an Antiparasitic Strategy.

Iron, as an essential micronutrient, plays a crucial role in host-pathogen interactions. In order to limit the growth of the pathogen, a common strategy of innate immunity includes withdrawing available iron to interfere with the cellular processes of the microorganism. Against that, unicellular parasites have developed powerful strategies to scavenge iron, despite the effort of the host. Iron-sequestering compounds, such as the approved and potent chelator deferoxamine (DFO), are considered a viable option for therapeutic intervention. Since iron is heavily utilized in the mitochondrion, targeting iron chelators in this organelle could constitute an effective therapeutic strategy. This work presents mitochondrially targeted DFO, mitoDFO, as a candidate against a range of unicellular parasites with promising in vitro efficiency. Intracellular Leishmania infection can be cleared by this compound, and experimentation with Trypanosoma brucei 427 elucidates its possible mode of action. The compound not only affects iron homeostasis but also alters the physiochemical properties of the inner mitochondrial membrane, resulting in a loss of function. Furthermore, investigating the virulence factors of pathogenic yeasts confirms that mitoDFO is a viable candidate for therapeutic intervention against a wide spectrum of microbe-associated diseases.

Important Constituents of Heavy Water-containing Solution for Cold Storage and Subsequent Reperfusion on an Isolated Perfused Rat Liver.

The University of Wisconsin (UW) solution is the most effective preservation solution currently used; however, to safely use expanded-criteria donor grafts, a new cold storage solution that alleviates graft injury more effectively is required. We prepared a heavy water (D2O)-containing buffer, Dsol, and observed strong protective effects during extended cold storage of rat hearts and livers. In the current study, we modified Dsol (mDsol) and tested its efficacy. The aim of the present study was to determine whether mDsol could protect the rat liver more effectively than the UW solution and to clarify the roles of D2O and deferoxamine (DFX). Rat livers were subjected to cold storage for 48 hours in test solutions: UW, mDsol, mDsol without D2O or DFX (mDsol-D2O[-], mDsol-DFX[-]), and subsequently reperfused on an isolated perfused rat liver for 90 minutes at 37°C. In the UW group, the liver was dehydrated during cold storage and rapidly expanded during reperfusion. Accordingly, the cumulative weight change was the highest in the UW group, together with augmented portal veinous resistance and ALT leakage and decreased oxygen consumption rate and bile production. These changes were significantly suppressed in the mDsol-treated group. In the mDsol-D2O(-) and mDsol-DFX(-) groups offered partial protection. In conclusion, mDsol appeared to be superior to the UW solution for simple cold storage of the rat liver, presumably due to improved microcirculation in the early phase of reperfusion. Both heavy water and deferoxamine are essential for alleviating seamless organ swelling that occurs during cold storage and subsequent reperfusion.

A Water-Soluble Chitosan Derivative for the Release of Bioactive Deferoxamine.

Deferoxamine (DFO) is a water-soluble iron chelator used pharmacologically for the management of patients with transfusional iron overload. However, DFO is not cell-permeable and has a short plasma half-life, which necessitates lengthy parenteral administration with an infusion pump. We previously reported the synthesis of chitosan (CS) nanoparticles for sustained slow release of DFO. In the present study, we developed solid dispersions and nanoparticles of a carboxymethyl water-soluble chitosan derivative (CMCS) for improved DFO encapsulation and release. CS dispersions and nanoparticles with DFO have been prepared by ironical gelation using sodium triphosphate (TPP) and were examined for comparison purposes. The successful presence of DFO in CMCS polymeric dispersions and nanoparticles was confirmed through FTIR measurements. Furthermore, the formation of CMCS nanoparticles led to inclusion of DFO in an amorphous state, while dispersion of DFO in the polymeric matrix led to a decrease in its crystallinity according to X-ray diffraction (XRD) and differential scanning calorimetry (DSC) results. An in vitro release assay indicated sustained release of DFO from CS and CMCS nanoparticles over 48 h and 24 h, respectively. Application of CMCS-DFO dispersions to murine RAW 264.7 macrophages or human HeLa cervical carcinoma cells triggered cellular responses to iron deficiency. These were exemplified in the induction of the mRNA encoding transferrin receptor 1, the major iron uptake protein, and the suppression of ferritin, the iron storage protein. Our data indicate that CMCS-DFO nanoparticles release bioactive DFO that causes effective iron chelation in cultured cells.

Deferoxamine-related bilateral maculopathy with optical coherence tomography findings.

BACKGROUND: We present a case of bilateral maculopathy associated with deferoxamine mesylate (DFO) treatment. METHODS: A 53-year-old man with myelodysplastic syndrome (MDS) received DFO therapy due to elevated ferritin levels. He was then referred to ophthalmology clinic due to blurred vision. He was diagnosed as bilateral neurosensory retinal detachment of the macula. During follow up, best corrected visual acuity (BCVA), optical coherence tomography (OCT), fundus fluorescein angiography (FFA), and fundus autofluorescence (FAF) were evaluated. RESULTS: At first visit, OCT showed bilateral foveal neurosensory detachment. Hyperfluorescence of the macula and the peripapillary region were found on FFA. After discontinuation of DFO, BCVA improved from 20/120 to 20/60 with resolution of the foveal detachments on OCT scan. Four weeks later, FAF showed bilateral mottled hyperautofluorescence and hypoautofluorescence at the macula and the peripapillary region. CONCLUSION: Deferoxamine can cause acute retinal toxicity. Haematologists should be alert to visual complaints associated with DFO therapy, as early diagnosis and discontinuation of the medication allows recovery of visual function with residual fundus findings.

Biodistribution and pharmacokinetics of [89Zr]-anti-VEGF mAbs using PET in glioblastoma rat models.

INTRODUCTION: Glioblastomas present intensive angiogenesis, thus anti-Vascular Endothelial Growth Factor (VEGF) antibodies (mAbs) have been proposed as promising therapies. However, the results of clinical trials reported moderate toxicity and limited effectiveness. This study evaluates the in vivo pharmacokinetics and biodistribution of these mAbs in a growing model of glioblastoma in rats using Positron Emission Tomography (PET). MATERIAL: &Methods: mAbs were radiolabeled with zirconium-89. Four days after the model induction, animals were injected with 2.33 ± 1.3 MBq of [89Zr]-DFO-bevacizumab (n = 8) or 2.35 ± 0.26 MBq of [89Zr]-DFO-aflibercept (n = 6). PETs were performed at 0H, 48H, 168H, 240H, and 336H post-injection. Tumor induction was confirmed using [18F]-Fluorodeoxyglucose-PET and immunohistochemistry. Radiotracer uptake was estimated in all pre-defined Volumes-of-Interest. RESULTS: Anti-VEGF mAbs showed 100 % Radiochemical-Purity. [89Zr]-DFO-bevacizumab showed a significantly higher bioavailability in whole-blood. A significant increase in the tumor uptake was detectable at 168H PET with [89Zr]-DFO-bevacizumab meanwhile with [89Zr]-DFO-aflibercept it was only detectable at 336H. [89Zr]-DFO-bevacizumab tumor uptake was significantly higher than that of [89Zr]-DFO-aflibercept in all the scans. Tumor induction was confirmed in all animal models. CONCLUSION: MAbs detect VEGF-expression in glioblastoma models. Tumors were earlier targeted by Bevacizumab. The lower blood availability of aflibercept resulted in a lower tumor uptake than bevacizumab in all the scans.

Deferoxamine reduces endothelial ferroptosis and protects cerebrovascular function after experimental traumatic brain injury.

Cerebrovascular dysfunction resulting from traumatic brain injury (TBI) significantly contributes to poor patient outcomes. Recent studies revealed the involvement of iron metabolism in neuronal survival, yet its effect on vasculature remains unclear. This study aims to explore the impact of endothelial ferroptosis on cerebrovascular function in TBI. A Controlled Cortical Impact (CCI) model was established in mice, resulting in a significant increase in iron-related proteins such as TfR1, FPN1, and FTH, as well as oxidative stress biomarker 4HNE. This was accompanied by a decline in expression of the ferroptosis inhibitor GPX4. Moreover, Perls' staining and nonhemin iron content assay showed iron overload in brain microvascular endothelial cells (BMECs) and the ipsilateral cortex. Immunofluorescence staining revealed more FTH-positive cerebral endothelial cells, consistent with impaired perfusion vessel density and cerebral blood flow. As a specific iron chelator, deferoxamine (DFO) treatment inhibited such ferroptotic proteins expression and the accumulation of lipid-reactive oxygen species following CCI, enhancing glutathione peroxidase (GPx) activity. DFO treatment significantly reduced iron deposition in BMECs and brain tissue, and increased density of the cerebral capillaries as well. Consequently, DFO treatment led to improvements in cerebral blood flow (as measured by laser speckle imaging) and behavioral performance (as measured by the neurological severity scores, rotarod test, and Morris water maze test). Taken together, our results indicated that TBI induces remarkable iron disorder and endothelial ferroptosis, and DFO treatment may help maintain iron homeostasis and protect vascular function. This may provide a novel therapeutic strategy to prevent cerebrovascular dysfunction following TBI.

Audiologic and vestibular assessment in children and adolescents with transfusion dependent beta thalassemia major: The era of deferasirox film coated tablet.

BACKGROUND: Hearing impairment has frequently been described in ß-thalassemia patients with a significant impact on the patients' quality of life. Most studies provided evidence of deferoxamine (DFO) dose-related ototoxicity, however, the data is scarce regarding deferasirox (DFX) as a sole iron chelator. AIM: We aimed to assess the prevalence and risk factors of sensorineural hearing loss (SNHL) and vestibular dysfunction in regularly transfused ß-thalassemia patients who had been treated with DFX film coated tablets. METHODS: We conducted a case control study on 57 transfusion dependent ß-thalassemia patients with a mean age of 15.3 years who received DFX FCT as monotherapy for at least one consecutive year, and 57 healthy age and sex-matching controls. Comprehensive audiological evaluations using pure tone audiometry (PTA) and transient evoked otoacoustic emission (TEOAE) as well as vestibular evaluation using Video-nystagmography (VNG) were done. RESULTS: SNHL was identified in 12 patients (21.1 %) using PTA and a statistically significant difference was detected between controls and patients at 6 KHz and 12 KHz frequencies. A higher incidence of SNHL was detected using TEOAE, 22 patients (43.1 %) failed to pass TEOAE, with a statistically significant decrease in the signal at frequencies 1, 4 KHz bilaterally and at frequencies 1.5, 2 KHz in the right ear compared to controls. Canal paresis was detected in 21 (36.8 %) of thalassemic children using bithermal caloric test with significantly more unilateral weakness than control children (P = 0.008). We found no significant correlation between audio-vestibular dysfunction and age, sex, serum ferritin, frequency of blood transfusion and dose of DFX FCT in thalassemic children. CONCLUSION: We conclude that the incidence of SNHL and vestibular dysfunction was high among transfusion dependent ß-thalassemia patients. Therefore, we recommend performing pre-treatment baseline audio-vestibular assessment and yearly audio-vestibular monitoring to early detect high risk patients and initiate timely management to prevent permanent damage.

Deferoxamine protects cochlear hair cells and hair cell-like HEI-OC1 cells against tert-butyl hydroperoxide-induced ototoxicity.

Oxidative stress is the common mechanism of sensorineural hearing loss (SNHL) caused by many factors, such as noise, drugs and ageing. Here, we used tert-butyl hydroperoxide (t-BHP) to cause oxidative stress damage in HEI-OC1 cells and in an in vitro cochlear explant model. We observed lipid peroxidation, iron accumulation, mitochondrial shrinkage and vanishing of mitochondrial cristae, which caused hair cell ferroptosis, after t-BHP exposure. Moreover, the number of TUNEL-positive cells in cochlear explants and HEI-OC1 cells increased significantly, suggesting that t-BHP caused the apoptosis of hair cells. Administration of deferoxamine (DFOM) significantly attenuated t-BHP-induced hair cell loss and disordered hair cell arrangement in cochlear explants as well as HEI-OC1 cell death, including via apoptosis and ferroptosis. Mechanistically, we found that DFOM treatment reduced t-BHP-induced lipid peroxidation, iron accumulation and mitochondrial pathological changes in hair cells, consequently mitigating apoptosis and ferroptosis. Moreover, DFOM treatment alleviated GSH depletion caused by t-BHP and activated the Nrf2 signalling pathway to exert a protective effect. Furthermore, we confirmed that the protective effect of DFOM mainly depended on its ability to chelate iron by constructing Fth1 knockout (KO), TfR1 KO and Nrf2 KO HEI-OC1 cell lines using CRISPR/Cas9 technology and a Flag-Fth1 (overexpression) HEI-OC1 cell line using the FlpIn™ System. Our findings suggest that DFOM is a potential drug for SNHL treatment due to its ability to inhibit apoptosis and ferroptosis by chelating iron and scavenging reactive oxygen species (ROS).

Development of a [89Zr]Zr-labeled Human Antibody using a Novel Phage-displayed Human scFv Library.

PURPOSE: Tax-interacting protein 1 (TIP1) is a cancer-specific radiation-inducible cell surface antigen that plays a role in cancer progression and resistance to therapy. This study aimed to develop a novel anti-TIP1 human antibody for noninvasive PET imaging in patients with cancer. EXPERIMENTAL DESIGN: A phage-displayed single-chain variable fragment (scFv) library was created from healthy donors' blood. High-affinity anti-TIP1 scFvs were selected from the library and engineered to human IgG1. Purified Abs were characterized by size exclusion chromatography high-performance liquid chromatography (SEC-HPLC), native mass spectrometry (native MS), ELISA, BIAcore, and flow cytometry. The labeling of positron emitter [89Zr]Zr to the lead Ab, L111, was optimized using deferoxamine (DFO) chelator. The stability of [89Zr]Zr-DFO-L111 was assessed in human serum. Small animal PET studies were performed in lung cancer tumor models (A549 and H460). RESULTS: We obtained 95% pure L111 by SEC-HPLC. Native MS confirmed the intact mass and glycosylation pattern of L111. Conjugation of three molar equivalents of DFO led to the optimal DFO-to-L111 ratio of 1.05. Radiochemical purity of 99.9% and specific activity of 0.37 MBq/µg was obtained for [89Zr]Zr-DFO-L111. [89Zr]Zr-DFO-L111 was stable in human serum over 7 days. The immunoreactive fraction in cell surface binding studies was 96%. In PET, preinjection with 4 mg/kg cold L111 before [89Zr]Zr-DFO-L111 (7.4 MBq; 20 µg) significantly (P < 0.01) enhanced the tumor-to-muscle standard uptake values (SUVmax) ratios on day 5 compared with day 2 postinjection. CONCLUSIONS: L111 Ab targets lung cancer cells in vitro and in vivo. [89Zr]Zr-DFO-L111 is a human antibody that will be evaluated in the first in-human study of safety and PET imaging.

Longitudinal prospective comparison of pancreatic iron by magnetic resonance in thalassemia patients transfusion-dependent since early childhood treated with combination deferiprone-desferrioxamine vs deferiprone or deferasirox monotherapy.

BACKGROUND: In transfusion-dependent thalassemia patients who started regular transfusions in early childhood, we prospectively and longitudinally evaluated the efficacy on pancreatic iron of a combined deferiprone (DFP) + desferrioxamine (DFO) regimen versus either oral iron chelator as monotherapy over a follow-up of 18 months. MATERIALS AND METHODS: We selected patients consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia network who received a combined regimen of DFO+DFP (No.=28) or DFP (No.=61) or deferasirox (DFX) (No.=159) monotherapy between the two magnetic resonance imaging scans. Pancreatic iron overload was quantified by the T2* technique. RESULTS: At baseline no patient in the combined treatment group had a normal global pancreas T2* (≥26 ms). At follow-up the percentage of patients who maintained a normal pancreas T2* was comparable between the DFP and DFX groups (57.1 vs 70%; p=0.517).Among the patients with pancreatic iron overload at baseline, global pancreatic T2* values were significantly lower in the combined DFO+DFP group than in the DFP or DFX groups. Since changes in global pancreas T2* values were negatively correlated with baseline pancreas T2* values, the percent changes in global pancreas T2* values, normalized for the baseline values, were considered. The percent changes in global pancreas T2* values were significantly higher in the combined DFO+DFP group than in either the DFP (p=0.036) or DFX (p=0.030) groups. DISCUSSION: In transfusion-dependent patients who started regular transfusions in early childhood, combined DFP+DFO was significantly more effective in reducing pancreatic iron than was either DFP or DFX.

Deferoxamine Mitigates Ferroptosis and Inflammation in Hippocampal Neurons After Subarachnoid Hemorrhage by Activating the Nrf2/TXNRD1 Axis.

Ferroptosis is a distinct peroxidation-driven form of cell death tightly involved in subarachnoid hemorrhage (SAH). This study delved into the mechanism of deferoxamine (DFO, an iron chelator) in SAH-induced ferroptosis and inflammation. SAH mouse models were established by endovascular perforation method and injected intraperitoneally with DFO, or intraventricularly injected with the Nrf2 pathway inhibitor ML385 before SAH, followed by detection of neurological function, blood-brain barrier (BBB) permeability, and brain water content. Apoptotic level of hippocampal neurons, symbolic changes of ferroptosis, and levels of pro-inflammatory cytokines were assessed using TUNEL staining, Western blotting, colorimetry, and ELISA. The localization and expression of nuclear factor-erythroid 2-related factor 2 (Nrf2) were detected. HT22 cells were exposed to Hemin as in vitro SAH models and treated with FIN56 to induce ferroptosis, followed by evaluation of the effects of DFO on FIN56-treated HT22 cells. The regulation of Nrf2 in thioredoxin reductase 1 (TXNRD1) was analyzed by co-immunoprecipitation and Western blotting. Moreover, HT22 cells were treated with DFO and ML385 to identify the role of DFO in the Nrf2/TXNRD1 axis. DFO extenuated brain injury, and ferroptosis and inflammation in hippocampal neurons of SAH mice. Nrf2 localized at the CA1 region of hippocampal neurons, and DFO stimulated nuclear translocation of Nrf2 protein in hippocampal neurons of SAH mice. Additionally, DFO inhibited ferroptosis and inflammatory responses in FIN56-induced HT22 cells. Nrf2 positively regulated TXNRD1 protein expression. Indeed, DFO alleviated FIN56-induced ferroptosis and inflammation via activation of the Nrf2/TXNRD1 axis. DFO alleviated neurological deficits, BBB disruption, brain edema, and brain injury in mice after SAH by inhibiting hippocampal neuron ferroptosis via the Nrf2/TXNRD1 axis. DFO ameliorates SAH-induced ferroptosis and inflammatory responses in hippocampal neurons by activating the Nrf2/TXNRD1 axis.

Vanillin serves as a potential substitute for chemical chelator desferal in iron-overloaded mice.

PURPOSE: Iron toxicity occurs under iron-overloaded settings, such as a high iron diet and blood transfusion, and damages important organs. Vanillin has been proven to have potential iron chelation capability. Given the negative effects of commonly used iron chelators like deferoxamine (DFO), we sought to examine the iron chelation potency of vanillin and evaluate its potential effect in the treatment of iron overload-related disorders. METHODS: 42 male NMRI mice were prepared for this purpose, and except for the negative control group, iron overload conditions were generated in them by injecting iron. Then normal saline (as a control), vanillin, and DFO (n = 7) were subsequently given to iron-overloaded mice. In the following, the activity of antioxidant enzymes catalase and superoxide dismutase were measured in the blood serum, brain, kidney, spleen, lung, and liver tissues of mice. Furthermore, the level of lipid peroxidation was determined by measuring the amount of malondialdehyde. Also, Perl's and H&E staining were used to examine the physiopathology changes of tissues. FINDINGS: Vanillin, a natural antioxidant compound, outperformed deferoxamine, a chemical iron chelator. Along with a decrease in iron content, the activity of catalase and superoxide dismutase enhanced in the iron-overloaded groups that were treated with vanillin. The level of lipid peroxidation was also declined in the iron-overloaded mice receiving vanillin. CONCLUSION: Vanillin can be used as a suitable substitute for chemical chelators with fewer side effects and equivalent efficiency. We encourage the use of this compound as a natural iron chelator following performing additional safety and efficacy studies.