Enhancing microbial superoxide generation and conversion to hydroxyl radicals for enhanced bioremediation using iron-binding ligands.

Harnessing bacteria for superoxide production in bioremediation holds immense promise, yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide. This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain, a prevalent soil bacterial genus. Our research reveals that introducing a carbon source along with specific iron-binding ligands, including deferoxamine (DFO), diethylenetriamine pentaacetate (DTPA), citrate, and oxalate, robustly augments microbial superoxide generation. Moreover, our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(III)/Fe(II) and superoxide. Remarkably, among the tested ligands, only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(III). We identify an optimal Fe(III) to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture. This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals, significantly elevating bioremediation performance. Furthermore, our study reveals that DTPA augments superoxide production in cultures of diverse soils, with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation. This emphasizes the universal applicability of DTPA across multiple bacterial genera. In conclusion, our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals. These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation, offering innovative solutions for addressing environmental contamination challenges.

Desferrioxamine-Laden Nanofibrous Scaffolds with Efficient Angiogenesis for Accelerating Diabetic Wound Healing.

Background: Delayed diabetic wound healing is one of the clinical difficulties, the main reason is the limited angiogenesis ability. Deferriamine (DFO) is an iron chelating agent that can induce angiogenesis, but its application is limited due to its short half-life. Increasing the load and slow release performance of desferriamine is beneficial to accelerate diabetic wound healing. Materials and Methods: In this study, we developed collagen (Col)-graphene oxide (GO) and (1% w/w) DFO-loaded nanofiber electrospinning scaffolds (DCG) using the electrospinning technique. We tested the physicochemical properties, drug release performance, and vascularization biological function of the scaffolds, and finally evaluated the promotion of full-thickness wound healing in the diabetic rat models. Results: The results showed that DCG scaffolds have good mechanical properties and water-holding capacity and can release DFO continuously for 14 days. In vitro, the novel DCG scaffold exhibited good biocompatibility, with the up-regulation at the gene level of VEGF and its regulator HIF-1α, promoters of angiogenesis. This was verified in vivo, as the scaffold enhanced granulation tissue formation and improved neovascularization, thereby accelerating wound healing when applied to full-thickness defects on the back of diabetic rats. Conclusion: The DCG nanofiber scaffold prepared in this study has good biocompatibility and vascularization ability, and improves the microenvironment in vivo, and has a good application prospect in diabetic wound repair.

Exenatide-Modified Deferoxamine-Based Nanoparticles Ameliorates Neurological Deficits in Parkinson's Disease Mice.

Purpose: To avoid the biotoxicity and poor bioavailability of deferoxamine mesylate (DFO), an iron chelation for the treatment of Parkinson's disease (PD), a self-oriented DFO nanoparticle functionalized with Exendin-4 was developed, which can be targeted delivered into the lesion brain area to achieve synergistic effects against PD by iron chelation and inflammatory suppression. Methods: The self-oriented DFO nanoparticles (Ex-4@DFO NPs) were synthesized by double emulsion technique, and characterized in terms of the particle size, morphology and DFO encapsulation efficiency. The cellular internalization, biocompatibility and cytoprotection of NPs were assessed on BV-2 and SH-SY5Y cells. The brain targeting and therapeutic effect of NPs were investigated in MPTP-induced PD mice by near-infrared II fluorescence imaging and immunofluorescence staining, as well as mobility behavioral tests. Results: Ex-4@DFO NPs with a particle size of about 100 nm, showed great biocompatibility and cytoprotection in vitro, which inhibited the decrease of mitochondrial membrane potential of SH-SY5Y cells and the release of inflammatory factors of BV-2 cells. In MPTP-induced PD mice, Ex-4@DFO NPs could penetrate the BBB into brain, and significantly mitigate the loss of dopaminergic neurons and inflammation in the substantia nigra, finally alleviate the mobility deficits. Conclusion: This self-oriented nanosystem not only improved the biocompatibility of DFO, but also enhanced therapeutic effects synergistically by ameliorating neuronal damage and neuroinflammation, showing a potential therapeutic strategy for PD.

89Zr-Labeled DFO@Durvalumab-HSA nanoparticles: In vitro potential for triple-negative breast cancer.

This study presents the development and evaluation of a DFO@mAb-NP (DFO@Durvalumab-HSA-DTX nanoparticle) nanoplatform for imaging in triple-negative breast cancer (TNBC). The nanoplatform demonstrated significant changes postconjugation with DFO, evidenced by increased particle size from 178.1 ± 5 nm to 311 ± 26 nm and zeta potential alteration from -31.9 ± 3 mV to -40.5 ± 0.8 mV. Fourier-transform infrared spectroscopy and ultraviolet spectral analyses confirmed successful DFO conjugation, with notable shifts in peak wavelengths. High labeling efficiency was achieved with 89Zr, as indicated by thin layer radio chromatography and high-performance liquid radio chromatography results, with labeling efficiencies of 98 ± 2% for 89Zr-DFO@mAb and 96 ± 3% for 89Zr-DFO@mAb-NP. The nanoplatforms maintained stability over 24 h, showing less than 5% degradation. Lipophilicity assays revealed logP values of 0.5 ± 0.03 for 89Zr-DFO@mAb-NP and 0.98 ± 0.2 for 89Zr-DFO@mAb, indicating a higher lipophilic tendency in the radiolabeled Durvalumab. Cell uptake experiments showed an initial high uptake in MDA-MB-468 cells (45.1 ± 3.2%), which decreased over time, highlighting receptor-specific interactions. These comprehensive findings suggest the promising potential of the DFO@mAb-NP nanoplatform for targeted imaging in TNBC, with implications for improved diagnostic accuracy and treatment strategies.

Deferoxamine alleviates ferroptosis in seawater immersion combined with traumatic brain injury.

Traumatic brain injury (TBI) is a major cause of death and disability worldwide, with its severity potentially exacerbated by seawater immersion. Ferroptosis, a form of regulated cell death driven by iron-dependent lipid peroxidation, has been implicated in TBI pathogenesis. However, the specific occurrence and underlying mechanisms of ferroptosis in the context of TBI compounded by seawater immersion remain unclear. Subsequently, we investigated the effects of seawater immersion on ferroptosis after the application of deferoxamine (DFO), an iron chelator and ferroptosis inhibitor, to explore its potential therapeutic value. We conducted RNA sequencing, protein expression analysis, oxidative stress assessment, histopathological examination, and behavioral testing to comprehensively evaluate the impact of DFO on ferroptosis and neurological outcomes. Our results demonstrated that seawater immersion significantly exacerbated ferroptosis in TBI. DFO treatment, however, attenuated ferroptosis, alleviated oxidative stress, reduced brain tissue damage, improved neuronal survival, and promoted motor function recovery. Despite these benefits, DFO exhibited limited effects on anxiety, novel object recognition, and spatial learning and memory. These findings suggest that ferroptosis represents a novel pathological mechanism in TBI under seawater immersion, and that DFO is a promising neuroprotective agent capable of modulating ferroptosis and enhancing neurological function. This study offers new insights into the complex injury conditions associated with TBI and seawater immersion, highlighting the potential of targeting ferroptosis for therapeutic intervention.

Iron Chelators Augment Large Osteochondral Allograft Osseointegration in a Preclinical Canine Model.

OBJECTIVES: Osteochondral allograft transplantation (OCAT) can be a successful joint restoration treatment option for large post-traumatic articular defects but is still associated with significant revision and failure rates. Despite recent advances that have improved OCAT success, insufficient osteochondral allograft (OCA) osseointegration remains a major cause of failure. Deferoxamine (DFO) is an effective angiogenic and osteo-anabolic iron chelator that consistently promotes bone neovascularization and regeneration. This study was designed to investigate local delivery of DFO for augmenting OCA osseointegration using a preclinical canine model for OCAT in the knee and hip as commonly affected joints. METHODS: On Institutional Animal Care and Use Committee (IACUC) approval, 12 purpose-bred dogs underwent OCAT of the femoral head or femoral condyles with DFO or DFO-free (controls) microspheres in recipient sites. OCA revascularization, cellular repopulation, and integration were evaluated based on functional, diagnostic imaging, microcomputed tomography, histology, and immunohistochemistry outcome measures. RESULTS: Local delivery of DFO into OCAT recipient sites was associated with maintained or improved joint function, superior radiographic appearance, significantly greater trabecular thickness, higher bone volume, and new bone ingrowth compared with DFO-free controls. CONCLUSION: OCA osseointegration is dependent on cellular repopulation and neovascularization, resulting in new bone ingrowth through creeping substitution, and insufficient osseointegration with resorption and subsidence of the OCA remains a major cause of failure after transplantation. The results of this study suggest that local delivery of DFO using a controlled microsphere release system may reduce resorption and improve revascularization and cellular repopulation to increase new bone ingrowth, potentially expediting OCA osseointegration after transplantation.

Preclinical Safety Assessment of Deferoxamine-preconditioned Canine Adipose Tissue-derived Mesenchymal Stem Cells.

BACKGROUND/AIM: In the pursuit of translating stem cell therapy technology into clinical practice, ensuring the safety and efficacy of treatments is paramount. Despite advancements, the effectiveness of stem cell applications often falls short of clinical requirements. This study aimed to address the challenge of limited efficacy by investigating the safety and effectiveness of canine adipose tissue-derived mesenchymal stem cells (cATMSCs) preconditioned with deferoxamine (DFO). MATERIALS AND METHODS: Different concentrations of DFO were used to evaluate its impact on cATMSC activity. The therapeutic potential of these preconditioned cells was validated using a mouse model of systemic inflammation. Comprehensive evaluations, including clinical hematological and radiological assessments before and after intravenous injection of preconditioned cells were conducted. RESULTS: The study showed a notable reduction in inflammatory markers and an overall decrease in the inflammatory response in the mouse model. The data collected from the clinical hematological and radiological assessments provided essential insights. CONCLUSION: This study lays the groundwork for the future clinical deployment of DFO-preconditioned cATMSCs, demonstrating their potential to improve the efficacy and safety of stem cell therapies.

Association of Microbleeds on Susceptibility-Weighted Imaging with Ferroptosis and Prognosis in Rabbits with Spinal Cord Injury.

BACKGROUND: Susceptibility-weighted imaging (SWI) is a common imaging technique used to identify cerebral microbleeds. Given that spinal cord injury (SCI) often creates an environment that favors ferroptosis, a type of cell death driven by iron, this study aimed to explore the relationship between microbleeds on SWI and ferroptosis, and explore the effect of deferoxamine on SCI. METHODS: Thirty-six rabbits were divided into three groups: sham, SCI, and SCI with deferoxamine (DFO, a ferroptosis inhibitor) treatment (SCI+DFO). Following 48 hours of SCI modeling, the rabbits underwent magnetic resonance imaging (MRI) and SWI examinations. Ferroptosis markers and spinal cord tissue morphology were examined, and the modified Tarlov's score was used to assess neurological function. RESULTS: SWI analysis revealed that rabbits in the SCI group exhibited lower signal intensities and larger microbleed areas compared to the those in the SCI+DFO group (p < 0.05). The SCI+DFO group demonstrated significantly decreased iron and malondialdehyde (MDA) levels, coupled with increased glutathione (GSH) and glutathione peroxidase 4 (GPX4) levels, along with attenuated ferroptosis (p < 0.05). This group also displayed greater Neuronal Nuclei (NeuN) expression, Tarlov's scores, and neurological recovery rates (all p < 0.05). A significant positive correlation was found between the microbleed area and iron content (r = 0.59, p = 0.04), MDA (r = 0.75, p = 0.01), and mitochondrial damage (r = 0.90, p < 0.01). Conversely, a negative correlation was established between the microbleed area and GPX4 levels (r = -0.87, p < 0.01), as well as neurological function recovery (r = -0.62, p = 0.03). CONCLUSION: The extent of microbleeds on SWI following SCI is closely correlated with ferroptosis, and the inhibition of ferroptosis could improve neurologic function. These findings suggest that the area of microbleeds on SWI could potentially serve as a predictive marker for ferroptosis in spinal cord injury.

Development of a Controllable Intelligent Drug Delivery System for Efficient Treatment of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a complex inflammatory disease of the joints, which is often accompanied by degeneration of articular cartilage and bone erosion, seriously affecting the quality of life and psychological state of patients. RA is difficult to be cured completely, and currently the main purpose of relief is through the use of anti-inflammatory and antirheumatic drugs, hormones, and biological agents. Tofacitib is a new type of small molecule inhibitor, which has a good effect in the treatment of RA. The current direct drug delivery method has serious side effects caused by the systemic distribution of the drug, so there is a need to develop an intelligent drug delivery system to realize precise treatment. In this work, tofacitib, gallic acid, targeted molecule folic acid, and Fe(III) were selected to assemble a novel type of artificial controllable nanodrug GF-TF. The self-photoacoustic/magnetic resonance imaging (self-PA/MRI) monitored the enrichment of GF-TF in the lesion in real-time, and artificially regulated the addition of deferoxamine (DFO) at the optimal enrichment. DFO strongly chelates Fe(III) in GF-TF and causes its structure to disintegrate gradually, and the self-PA/MRI signal of GF-TF became weaker while tofacitib began to be released, thus realizing the precise and artificially controlled release of the drug under the guidance of imaging. This nanodrug not only achieves efficient aggregation of drugs in inflamed joints, but also achieves real-time monitoring and precise control of drug release through self-PA/MRI, providing a new strategy for the precise treatment of RA.

Development of a Specifically Labeled 89Zr Antibody for the Noninvasive Imaging of Tumors Overexpressing B7-H3.

B7-H3 has emerged as a promising target and potential biomarker for diagnosing tumors, evaluating treatment efficacy, and determining patient prognosis. Hu4G4 is a recombinant humanized antibody that selectively targets the extracellular domain of human B7-H3. In this study, we describe the radiolabeling of hu4G4 with the positron emission tomography (PET) emitter radionuclide zirconium 89 (89Zr) and evaluate its potency as an immuno-PET tracer for B7-H3-targeted imaging by comparing it in vitro and in vivo to [89Zr]Zr-DFO-DS-5573a using various models. The radiolabeled compound, [89Zr]Zr-desferrioxamine-hu4G4 ([89Zr]Zr-DFO-hu4G4), demonstrated a high radiochemical purity (RCP) of greater than 99% and a specific activity of 74 MBq/mg following purification. Additionally, it maintained stability in human serum albumin (HSA) and acetate buffer, preserving over 90% of its RCP after 7 days. Three cell lines targeting human B7-H3(U87/CT26-CD276/GL261-CD276) were used. Flow cytometry analysis indicated that the B7-H3-positive cells (U87/CT26-CD276/GL261-CD276) had a higher B7-H3 protein level with no expression in the B7-H3-negative cells (CT26-wt/GL261-wt) (P < 0.001). Moreover, the cellular uptake was 45.71 ± 3.78% for [89Zr]Zr-DFO-hu4G4 in CT26-CD276 cells versus only 0.93 ± 0.47% in CT26-wt cells and 30.26 ± 0.70% when [89Zr]Zr-DFO-hu4G4 in CT26-CD276 cells were blocked with 100× 8H9. The cellular uptake of [89Zr]Zr-DFO-hu4G4 was akin to that observed with [89Zr]Zr-DFO-DS-5573a with no significant differences (45.71 ± 3.78 % vs 47.07 ± 0.86 %) in CT26-CD276 cells. Similarly, the CT26-CD276 mouse model demonstrated markedly low organ uptake and elevated tumor uptake 48 h after [89Zr]Zr-DFO-hu4G4 injection. PET/CT analysis showed that the tumor-to-muscle (T/M) ratios were substantially higher compared to other imaging groups: 27.65 ± 3.17 in CT26-CD276 mice versus 11.68 ± 4.19 in CT26-wt mice (P < 0.001) and 16.40 ± 0.78 when 100× 8H9 was used to block [89Zr]Zr-DFO-hu4G4 in CT26-CD276 mice (P < 0.01) at 48 h post-injection. Additionally, the tracer showed markedly high accumulation in the tumor region (22.57 ± 3.03% ID/g), comparable to the uptake of [89Zr]Zr-DFO-DS-5573a (24.76 ± 5.36% ID/g). A dosimetry estimation study revealed that the effective dose for [89Zr]Zr-DFO-hu4G4 was 2.96 × 10-01 mSv/MBq, which falls within the acceptable range for further research in nuclear medicine. Collectively, these results indicated that [89Zr]Zr-DFO-hu4G4 was successfully fabricated and applied in B7-H3-targeted tumor PET/CT imaging, which showed excellent imaging quality and tumor detection efficacy in tumor-bearing mice. It is a promising imaging agent for identifying tumors that overexpress B7-H3 for future clinical applications.

Unlocking the potential of deferoxamine: a systematic review on its efficacy and safety in alleviating myocardial ischemia-reperfusion injury in adult patients following cardiopulmonary bypass compared to standard care.

BACKGROUND: Reperfusion injury, characterized by oxidative stress and inflammation, poses a significant challenge in cardiac surgery with cardiopulmonary bypass (CPB). Deferoxamine, an iron-chelating compound, has shown promise in mitigating reperfusion injury by inhibiting iron-dependent lipid peroxidation and reactive oxygen species (ROS) production. OBJECTIVES: The objective of our study was to analyze and evaluate both the efficacy and safety of a new and promising intervention, that is, deferoxamine for ischemia-reperfusion injury (I/R). DESIGN: Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines are used to perform the study. DATA SOURCES AND METHODS: We conducted a systematic review following PRISMA guidelines to assess the efficacy and safety of deferoxamine in reducing I/R injury following CPB. A comprehensive search of electronic databases, namely, PubMed, Scopus, and Embase, yielded relevant studies published until August 18, 2023. Included studies evaluated ROS production, lipid peroxidation, cardiac performance, and morbidity outcomes. RESULTS: (a) ROS production: Multiple studies demonstrated a statistically significant decrease in ROS production in patients treated with deferoxamine, highlighting its potential to reduce oxidative stress. (b) Lipid peroxidation: Deferoxamine was associated with decreased lipid peroxidation levels, indicating its ability to protect cardiac tissue from oxidative damage during CPB. (c) Cardiac performance: Some studies reported improvements in left ventricular ejection fraction and wall motion score index with deferoxamine. CONCLUSION: Our review shows that deferoxamine is an efficacious and safe drug that can be used to prevent myocardial I/R injury following CPB. It also highlights the need for trials on a larger scale to develop potential strategies and guidelines on the use of deferoxamine for I/R injury.

Combination of Deferoxamine With Cyclosporine Synergistically Blunt Renal Cold Ischemia-Reperfusion Injury in Rat Transplantation Model.

OBJECTIVES: Ferroptosis plays a pivotal role in the pathogenesis of renal ischemia-reperfusion injury, where the processes are mediated by free ferrous ions and mitochondrial-released reactive oxygen species. However, the administration of high doses of cyclosporine A (CsA) or deferoxamine (DFO) poses a significant risk of renotoxicity. In contrast, low doses of DFO act as a ferrous iron chelator, and CsA functions as a mitochondrial reactive oxygen species blocker. This study aims to explore the potential protective effects of donor treatment with low-dose CsA, DFO, or their combination against ischemia-reperfusion injury during renal transplantation in a rat model. MATERIALS AND METHODS: In an ex vivo cold storage (CS) model utilizing renal slices, the impact of incorporating DFO, CsA, and a combination of both into the University of Wisconsin solution was assessed through the measurement of lactate dehydrogenase leakage. Additionally, their potential benefits were investigated in a rat donation after circulatory death (DCD) kidney transplant model, where the extent of damage was evaluated based on graft function, tubular necrosis, and inflammation. RESULTS: The co-administration of DFO and CsA effectively decreased the release of lactate dehydrogenase induced by CS ( P ≥ .05). In the in vivo model, this combined supplementation demonstrated a mitigating effect on reperfusion injury, evidenced by lower blood urea nitrogen levels and acute tubular necrosis scores compared to the control group (allP ≤ .05). Furthermore, the combined treatment significantly reduced apoptotic levels compared to the control group (P ≥ .05). CONCLUSIONS: The combined treatment with DFO and CsA mitigated the cold ischemia-reperfusion injury in the DCD kidney. Hence, this presents a new strategy for the CS of DCD kidney in clinical transplants.

αvß3 integrin-targeted magnetic resonance imaging in a pancreatic cancer mouse model using RGD-modified liposomes encapsulated with Fe-deferoxamine.

Magnetic resonance (MR) imaging is a powerful imaging modality for obtaining anatomical information with high spatial and temporal resolution. In the drug delivery system (DDS) framework, nanoparticles such as liposomes are potential candidates for MR imaging. We validated that RGD peptides are possible targeting molecules for pancreatic cancer with αvß3 integrin expression. This study aimed to evaluate RGD-modified liposomes loaded with ferrioxamine B for pancreatic cancer imaging. We synthesized four types of RGD-modified liposomes encapsulated with ferrioxamine B (SH-, H-, M-, and L-RGD-liposomes). The binding affinity of RGD-modified liposomes was evaluated in a competitive inhibition study using 125I-echistatin. To investigate the pharmacokinetics of RGD-modified liposomes, a biodistribution study using RGD-liposomes labeled with 111In was carried out in a human pancreatic cancer PANC-1 xenograft mouse model. Finally, MR was performed using ferrioxamine-B-loaded liposomes. RGD-liposomes inhibited the binding of 125I-echistatin to RGD. The biodistribution study revealed that 111In-RGD-liposomes accumulated significantly in the liver and spleen. Among the 111In-RGD-liposomes, 111In-H-RGD-liposomes showed the highest tumor-to-normal tissue ratio. In the MR study, H-RGD-liposomes loaded with ferrioxamine B showed higher tumor-to-muscle signal ratios than RKG-liposomes loaded with ferrioxamine B (control). We successfully synthesized RGD-liposomes that can target αvß3 integrin.

Targeting the Labile Iron Pool with Engineered DFO Nanosheets to Inhibit Ferroptosis for Parkinson's Disease Therapy.

Ferroptosis in neurons is considered one of the key factors that induces Parkinson's disease (PD), which is caused by excessive iron accumulation in the intracellular labile iron pool (LIP). The iron ions released from the LIP lead to the aberrant generation of reactive oxygen species (ROS) to trigger ferroptosis and exacerbate PD progression. Herein, a pioneering design of multifunctional nanoregulator deferoxamine (DFO)-integrated nanosheets (BDPR NSs) is presented that target the LIP to restrict ferroptosis and protect against PD. The BDPR NSs are constructed by incorporating a brain-targeting peptide and DFO into polydopamine-modified black phosphorus nanosheets. These BDPR NSs can sequester free iron ions, thereby ameliorating LIP overload and regulating iron metabolism. Furthermore, the BDPR NSs can decrease lipid peroxidation generation by mitigating ROS accumulation. More importantly, BDPR NSs can specifically accumulate in the mitochondria to suppress ROS generation and decrease mitochondrial iron accumulation. In vivo experiments demonstrated that the BDPR NSs highly efficiently mitigated dopaminergic neuronloss and its associated behavioral disorders by modulating the LIP and inhibiting ferroptosis. Thus, the BDPR-based nanovectors holds promise as a potential avenue for advancing PD therapy.

Zirconium- 89 Labeled Antibody K1-70 for PET Imaging of Thyroid-stimulating Hormone Receptor Expression in Thyroid Cancer.

PURPOSE: Thyroid-stimulating hormone receptor (TSHR) is a G-protein coupled receptor that is highly expressed on benign and malignant thyroid tissues. TSHR binding and activation has long been a component of thyroid cancer molecular imaging and radiotherapy, by promoting expression of the sodium-iodide symporter (NIS) and incorporation of I-131 into thyroid hormones. Here, we report the radiosynthesis and preclinical evaluation of a Zirconium-89 (89Zr) labeled TSHR antibody to serve as a positron emission tomography (PET) diagnostic correlate for therapeutic agents targeting TSHR without reliance on NIS. PROCEDURES: TSHR human monoclonal antibody K1-70 was conjugated to chelator desferrioxamine-p-benzyl-isothiocyanate, followed by labeling with Zr-89, yielding the radiotracer 89Zr-DFO-TSHR-Ab. The in vitro cellar uptake and binding affinity of 89Zr-DFO-TSHR-Ab were analyzed in three new TSHR stable overexpressing tumor cell lines and their corresponding wild types (WT) with low or no TSHR expression. 89Zr-DFO-TSHR-Ab PET/CT imaging of TSHR expression was evaluated in tumor mouse models bearing one TSHR-positive tumor and other negative control with or without the coinjection of antibody K1-70, and then verified by radiotracer biodistribution study and tumor immunohistochemistry (IHC). RESULTS: The conjugate DFO-TSHR-Ab was labeled with Zr-89 at 37 °C for 60 min and purified by PD-10 column in radiochemical yields of 68.8 ± 9.9%, radiochemical purities of 98.7 ± 0.8%, and specific activities of 19.1 ± 2.7 mCi/mg (n = 5). In vitro cell studies showed 89Zr-DFO-TSHR-Ab had significantly high uptake on TSHR expressing tumor cells with nanomolar affinity and high potency. Preclinical PET/CT imaging revealed that 89Zr-DFO-TSHR-Ab selectively detected TSHR expressing thyroid tumors and displayed improved in vivo performance with the coinjection of unlabeled TSHR antibody K1-70 leading to higher uptake in TSHR expressing tumors than parental WT tumors and physiologic tissues; this observation was confirmed by the biodistribution and immunostaining analyses. CONCLUSIONS: We synthesized 89Zr-labeled antibody K1-70 as a new radiopharmaceutical for PET imaging of TSHR. 89Zr-DFO-TSHR-Ab has high radioactive uptake and retention in TSHR expressing tumors and cleared quickly from most background tissues in mouse models. Our study demonstrated that 89Zr-DFO-TSHR-Ab has the potential for PET imaging of TSHR-positive thyroid cancer and monitoring TSHR-targeted therapy.

Ultrasmall Nanodots with Dual Anti-Ferropototic Effect for Acute Kidney Injury Therapy.

Ferroptosis is known to mediate the pathogenesis of chemotherapeutic drug-induced acute kidney injury (AKI); however, leveraging the benefits of ferroptosis-based treatments for nephroprotection remains challenging. Here, ultrasmall nanodots, denoted as FerroD, comprising the amphiphilic conjugate (tetraphenylethylene-L-serine-deferoxamine, TPE-lys-Ser-DFO (TSD)) and entrapped ferrostatin-1 are designed. After being internalized through kidney injury molecule-1-mediated endocytosis, FerroD can simultaneously remove the overloaded iron ions and eliminate the overproduction of lipid peroxides by the coordination-disassembly mechanisms, which collectively confer prominent inhibition efficiency of ferroptosis. In cisplatin (CDDP)-induced AKI mice, FerroD equipped with dual anti-ferroptotic ability can provide long-term nephroprotective effects. This study may shed new light on the design and clinical translation of therapeutics targeting ferroptosis for various ferroptosis-related kidney diseases.

Hypoxic microenvironment promotes diabetic wound healing by polarizing macrophages to the M2 phenotype in vivo.

BACKGROUND: In diabetic wounds, M2 polarization of macrophages regulates the transition from an inflammatory phase to a proliferative phase. Prior investigations have demonstrated the potential of deferoxamine (DFO) in creating a localized hypoxic microenvironment, which could stimulate angiogenesis by promoting vascular endothelial growth factor (VEGF) secretion in diabetic wound healing. Nevertheless, there is still no clear information on whether this chemically induced hypoxic microenvironment modulates macrophage polarization to promote diabetic wound healing. METHODS: The 18 diabetic mice were randomly divided into three groups: a control group (n = 6), a 100µM DFO group (n = 6), and a 200µM DFO group (n = 6). Subsequently, a full-thickness wound with a diameter of 1.00 cm was created on the dorsal region of the diabetic mice. Observe wound closure regularly during treatment. At the end of the observation, tissue specimens were collected for a series of experiments and analyses, including hematoxylin and eosin (H&E), Masson, immunofluorescent, and immunohistochemical staining. The role and mechanism of DFO in regulating macrophage polarization were studied using RAW264.7 cells. RESULTS: In comparison to the control group, the administration of DFO notably facilitates wound healing in diabetic mice. In diabetic wounds, DFO increases blood supply by upregulating VEGF, which promotes angiogenesis. Additionally, The expression of HSP70 and CD206 were also upregulated by DFO in both vivo and in vitro, while iNOS expression was downregulated. Additionally, knk437 inhibited the expression of HSP70 in RAW264.7 cells, resulting in a reduction of M2 polarization and an increase in M1 polarization. CONCLUSION: The induction of a hypoxic microenvironment by DFO has been found to exert a substantial influence on the process of diabetic wound healing. DFO treatment enhances the capacity of diabetic wounds to stimulate angiogenesis and modulate macrophage polarization that may be associated with HSP70 expression, thereby expediting the transition of these wounds from an inflammatory to a proliferative state.

[Effect of accordion technique and deferoxamine on promoting bone regeneration in distraction osteogenesis].

Objective: To compare the effects of hypoxia-inducible drugs using deferoxamine (DFO) and accordion technique (AT) on activating the hypoxia-inducible factor 1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway to promote bone regeneration and remodelling during consolidation phase of distraction osteogenesis (DO). Methods: Forty-five specific-pathogen-free adult male Sprague-Dawley (SD) rats were randomly divided into the control group, DFO group, and AT group, with 15 rats in each group. All rats underwent osteotomy to establish a right femur DO model. Then, continuous distraction was started for 10 days after 5 days of latency in each group. During the consolidation phase after distraction, no intervention was performed in the control group; DFO was locally perfused into the distraction area in the DFO group starting at the 3rd week of consolidation phase; cyclic stress stimulation was given in the AT group starting at the 3rd week of consolidation phase. The general condition of rats in each group was observed. X-ray films were conducted at the end of the distraction phase and at the 2nd, 4th, and 6th weeks of the consolidation phase to observe the calcification in the distraction area. At the 4th and 6th weeks of the consolidation phase, peripheral blood was taken for ELISA detection (HIF-1α, VEGF, CD31, and Osterix), femoral specimens were harvested for gross observation, histological staining (HE staining), and immunohistochemical staining [HIF-1α, VEGF, osteopontin (OPN), osteocalcin (OCN)]. At the 6th week of the consolidation phase, Micro-CT was used to observe the new bone mineral density (BMD), bone volume/tissue volume (BV/TV), trabecular separation (Tb.Sp), trabecular number (Tb.N), and trabecular thickness (Tb.Th) in the distraction area, and biomechanical test (ultimate load, elastic modulus, energy to failure, and stiffness) to detect bone regeneration in the distraction area. Results: The rats in all groups survived until the termination of the experiment. ELISA showed that the contents of HIF-1α, VEGF, CD31, and Osterix in the serum of the AT group were significantly higher than those of the DFO group and control group at the 4th and 6th weeks of the consolidation phase ( P<0.05). General observation, X-ray films, Micro-CT, and biomechanical test showed that bone formation in the femoral distraction area was significantly better in the DFO group and AT group than in the control group, and complete recanalization of the medullary cavity was achieved in the AT group, and BMD, BV/TV, Tb.Sp, Tb.N, and Tb.Th, as well as ultimate load, elastic modulus, energy to failure, and stiffness in the distraction area, were better in the AT group than in the DFO group and control group, and the differences were significant ( P<0.05). HE staining showed that trabecular bone formation and maturation in the distraction area were better in the AT group than in the DFO group and control group. Immunohistochemical staining showed that at the 4th week of consolidation phase, the expression levels of HIF-1α, VEGF, OCN, and OPN in the distraction area of the AT group were significantly higher than those of the DFO group and control group ( P<0.05); however, at 6th week of consolidation phase, the above indicators were lower in the AT group than in the DFO group and control group, but there was no significant difference between groups ( P>0.05). Conclusion: Both continuous local perfusion of DFO in the distraction area and AT during the consolidation phase can activate the HIF-1α/VEGF signaling pathway. However, AT is more effective than local perfusion of DFO in promoting the process of angiogenesis, osteogenesis, and bone remodelling.

Quaternary ammonium grafted chitosan hydrogel with enhanced antibacterial performance as tannin acid and deferoxamine carrier to promote diabetic wound healing.

The delay of diabetic wound healing puts a huge burden on the society. The key factors hindering wound healing include bacterial infection, unresolved inflammation and poorly generated blood vessels. In this paper, glycidyl trimethyl ammonium chloride (GTA) was grafted to chitosan (CS) to obtain quaternary ammonium grafted chitosan (QCS) with enhanced antibacterial performance, and then cross-linked by dialdehyde terminated poly(ethylene oxide) (PEO DA) to construct QCS/PEO DA hydrogel with tissue adhesion, biodegradation and self-healing properties. The QCS/PEO DA hydrogel is loaded with tannin acid (TA) and deferoxamine (DFO) to enhance antioxidant property and angiogenesis. At the same time, the TA and DFO loaded TA@DFO/hydrogel preserved the biocompatibility and biodegradability of chitosan. Moreover, the multifunctional hydrogel behaved excellent hemostatic properties in mice model and significantly promoted the healing efficacy of diabetic wounds. Overall, the TA@DFO/hydrogel is promising anti-infection dressing material for diabetic wound healing.

Coke oven emissions exacerbate allergic asthma by promoting ferroptosis in airway epithelial cells.

Epidemiological studies have shown that coke oven emissions (COEs) affect the deterioration of asthma, but has not been proven by experimental results. In this study, we found for the first time that COEs exacerbate allergen house dust mite (HDM)-induced allergic asthma in the mouse model. The findings reveal that airway inflammation, airway remodeling and allergic reaction were aggravated in the COE + HDM combined exposure group compared with the individual exposure group. Mechanism studies indicated higher levels of iron and MDA in the COE + HDM combined exposure group, along with increased expression of Ptgs2 and reduced GPX4 expression. Iron chelator deferoxamine (DFO) effectively inhibited ferroptosis induced by COE synergistically with HDM in vitro. Further studies highlighted the role of ferritinophagy in the COE + HDM-induced ferroptosis. 3-methyladenine (3-MA) could inhibit ferroptosis in the COE + HDM exposure group. Interestingly, we injected DFO intraperitoneally into mice in the combined exposure group and found DFO could significantly inhibit the COE-exacerbated ferroptosis and allergic asthma. Our findings link ferroptosis with COE-exacerbated allergic asthma, implying that ferroptosis may have important therapeutic potential for asthma in patients with occupational exposure of COE.