Deferoxamine preconditioning enhances the protective effects of stem cells in streptozotocin-induced Alzheimer's disease.

AIMS: Stem cell-based therapy is one of the promising strategies in the treatment of Alzheimer's disease (AD), but the short lifespan and low homing of transplanted cells continue to be a major obstacle in this method. Preconditioning of stem cells before transplantation could increase cell therapy efficiency. Herein, we examined whether the treatment of stem cells with deferoxamine (DEF) prior to graft could enhance the neuroprotective effects of stem cells in the streptozotocin (STZ)-treated male rats. MATERIALS AND METHODS: After induction of the AD model, the rats were transplanted with DEF-preconditioned Adipose-derived mesenchymal stem cells (AMSCs) or untreated cells. Memory function, antioxidant capacity, cell density, and homing of transplanted cells were assessed using Morris water maze and shuttle box tasks as well as biochemical and histochemical methods. KEY FINDINGS: Transplantation of AMSCs caused a memory improvement when compared to the AD model. The injection of DEF-preconditioned AMSCs was more effective in improving learning and memory than the untreated cells through an increase in the antioxidant capacity. Moreover, the homing of transplanted cells was higher in the rats that received the preconditioned cells than that of the naïve cell-injected group. SIGNIFICANCE: It seems that the transplantation of DEF-treated cells may increase the efficiency of stem cells via an increase in the antioxidant capacity.

Targeting Mitochondrial Iron Metabolism Suppresses Tumor Growth and Metastasis by Inducing Mitochondrial Dysfunction and Mitophagy.

Deferoxamine (DFO) represents a widely used iron chelator for the treatment of iron overload. Here we describe the use of mitochondrially targeted deferoxamine (mitoDFO) as a novel approach to preferentially target cancer cells. The agent showed marked cytostatic, cytotoxic, and migrastatic properties in vitro, and it significantly suppressed tumor growth and metastasis in vivo. The underlying molecular mechanisms included (i) impairment of iron-sulfur [Fe-S] cluster/heme biogenesis, leading to destabilization and loss of activity of [Fe-S] cluster/heme containing enzymes, (ii) inhibition of mitochondrial respiration leading to mitochondrial reactive oxygen species production, resulting in dysfunctional mitochondria with markedly reduced supercomplexes, and (iii) fragmentation of the mitochondrial network and induction of mitophagy. Mitochondrial targeting of deferoxamine represents a way to deprive cancer cells of biologically active iron, which is incompatible with their proliferation and invasion, without disrupting systemic iron metabolism. Our findings highlight the importance of mitochondrial iron metabolism for cancer cells and demonstrate repurposing deferoxamine into an effective anticancer drug via mitochondrial targeting. SIGNIFICANCE: These findings show that targeting the iron chelator deferoxamine to mitochondria impairs mitochondrial respiration and biogenesis of [Fe-S] clusters/heme in cancer cells, which suppresses proliferation and migration and induces cell death. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/9/2289/F1.large.jpg.

Challenges and Opportunities of Deferoxamine Delivery for Treatment of Alzheimer's Disease, Parkinson's Disease, and Intracerebral Hemorrhage.

Deferoxamine mesylate (DFO) is an FDA-approved, hexadentate iron chelator routinely used to alleviate systemic iron burden in thalassemia major and sickle cell patients. Iron accumulation in these disease states results from the repeated blood transfusions required to manage these conditions. Iron accumulation has also been implicated in the pathogenesis of Alzheimer's disease (AD), Parkinson's disease (PD), and secondary injury following intracerebral hemorrhage (ICH). Chelation of brain iron is thus a promising therapeutic strategy for improving behavioral outcomes and slowing neurodegeneration in the aforementioned disease states, though the effectiveness of DFO treatment is limited on several accounts. Systemically administered DFO results in nonspecific toxicity at high doses, and the drug's short half-life leads to low patient compliance. Mixed reports of DFO's ability to cross the blood-brain barrier (BBB) also appear in literature. These limitations necessitate novel DFO formulations prior to the drug's widespread use in managing neurodegeneration. Herein, we discuss the various dosing regimens and formulations employed in intranasal (IN) or systemic DFO treatment, as well as the physiological and behavioral outcomes observed in animal models of AD, PD, and ICH. The clinical progress of chelation therapy with DFO in managing neurodegeneration is also evaluated. Finally, the elimination of intranasally administered particles via the glymphatic system and efflux transporters is discussed. Abundant preclinical evidence suggests that intranasal DFO treatment improves memory retention and behavioral outcome in rodent models of AD, PD, and ICH. Several other biochemical and physiological metrics, such as tau phosphorylation, the survival of tyrosine hydroxylase-positive neurons, and infarct volume, are also positively affected by intranasal DFO treatment. However, dosing regimens are inconsistent across studies, and little is known about brain DFO concentration following treatment. Systemic DFO treatment yields similar results, and some complex formulations have been developed to improve permeability across the BBB. However, despite the success in preclinical models, clinical translation is limited with most clinical evidence investigating DFO treatment in ICH patients, where high-dose treatment has proven dangerous and dosing regimens are not consistent across studies. DFO is a strong drug candidate for managing neurodegeneration in the aging population, but before it can be routinely implemented as a therapeutic agent, dosing regimens must be standardized, and brain DFO content following drug administration must be understood and controlled via novel formulations.

Management of Iron Overload in Beta-Thalassemia Patients: Clinical Practice Update Based on Case Series.

Thalassemia syndromes are characterized by the inability to produce normal hemoglobin. Ineffective erythropoiesis and red cell transfusions are sources of excess iron that the human organism is unable to remove. Iron that is not saturated by transferrin is a toxic agent that, in transfusion-dependent patients, leads to death from iron-induced cardiomyopathy in the second decade of life. The availability of effective iron chelators, advances in the understanding of the mechanism of iron toxicity and overloading, and the availability of noninvasive methods to monitor iron loading and unloading in the liver, heart, and pancreas have all significantly increased the survival of patients with thalassemia. Prolonged exposure to iron toxicity is involved in the development of endocrinopathy, osteoporosis, cirrhosis, renal failure, and malignant transformation. Now that survival has been dramatically improved, the challenge of iron chelation therapy is to prevent complications. The time has come to consider that the primary goal of chelation therapy is to avoid 24-h exposure to toxic iron and maintain body iron levels within the normal range, avoiding possible chelation-related damage. It is very important to minimize irreversible organ damage to prevent malignant transformation before complications set in and make patients ineligible for current and future curative therapies. In this clinical case-based review, we highlight particular aspects of the management of iron overload in patients with beta-thalassemia syndromes, focusing on our own experience in treating such patients. We review the pathophysiology of iron overload and the different ways to assess, quantify, and monitor it. We also discuss chelation strategies that can be used with currently available chelators, balancing the need to keep non-transferrin-bound iron levels to a minimum (zero) 24 h a day, 7 days a week and the risk of over-chelation.

Combined chelation with high-dose deferiprone and deferoxamine to improve survival and restore cardiac function effectively in patients with transfusion-dependent thalassemia presenting severe cardiac complications.

Iron overload-induced cardiomyopathy is the leading cause of death in patients with transfusion-dependent thalassemia (TDT). The mortality is extremely high in these patients with severe cardiac complications, and how to rescue them remains a challenge. It is reasonable to use combined chelation with deferiprone (L1) and deferoxamine (DFO) because of their shuttle and synergistic effects on iron chelation. Here, seven consecutive patients with TDT who had severe cardiac complications between 2002 and 2019 and received combined chelation therapy with oral high-dose L1 (100 mg/kg/day) and continuous 24-h DFO infusion (50 mg/kg/day) in our hospital were reported. Survival for eight consecutive patients receiving DFO monotherapy for their severe cardiac complications between 1984 and 2001 was compared. We found that combined chelation therapy with high-dose L1 and DFO was efficient to improve survival and cardiac function in patients with TDT presenting severe cardiac complications. Reversal of arrhythmia to sinus rhythm was noted in all patients. Their 1-month follow-up left ventricular ejection fraction increased significantly (P < 0.001). There were no deaths, and all patients were discharged from hospital with good quality of life. In contrast, all the eight patients receiving DFO monotherapy died (P < 0.001). Accordingly, combined chelation therapy with high-dose L1 and DFO should be considered in patients with TDT presenting cardiac complications.

Brief topical and intraluminal use of Carolina rinse solution does not attenuate experimental ischemia and reperfusion injury in rabbit jejunum / [O uso tópico breve e intraluminal da solução de Carolina rinse não atenua a injúria de isquemia e reperfusão experimental no jejuno de coelhos ]

Fifteen New Zealand adult rabbits were randomly allocated into three groups: Sham-operated (group A), Ischemia and Reperfusion (group B) and Carolina Rinse Solution (CRS) (group C). Groups B and C were subjected to one hour of ischemia and two hours of reperfusion. In group C, ten minutes before reperfusion, the bowel lumen was filled with CRS, and the segment immersed in CRS. Necrosis and loss of integrity of the villi were visible in groups B and C. Edema of the submucosa and circular muscle was observed in all groups. Hemorrhage was observed in different layers for groups B and C, but group C showed more severe hemorrhage in different layers during reperfusion. All groups showed polymorphonuclear leukocyte infiltration on the base of the mucosa, submucosa, and longitudinal muscle, in addition to polymorphonuclear leukocytes margination in the mucosal and submucosal vessels. Necrosis of enterocytes, muscles, crypts of Lieberkühn and myenteric plexus was observed in groups B and C during reperfusion. Topical and intraluminal Carolina Rinse Solution did not attenuate the effects of ischemia and reperfusion in the small intestine of rabbits.(AU)

Quinze coelhos da raça Nova Zelândia foram alocados em três grupos: instrumentado (grupo A), isquemia e reperfusão (grupo B) e solução de Carolina rinse (CRS) (grupo C). Os grupos B e C foram submetidos a uma hora de isquemia e a duas horas de reperfusão. No grupo C, 10 minutos antes da reperfusão, o segmento isolado foi imerso e teve seu lúmen preenchido com CRS. Os grupos B e C apresentaram necrose e perda progressiva da integridade das vilosidades. Foi observado edema na submucosa e na camada muscular circular em todos os grupos. Nos grupos B e C, foi observada hemorragia em diferentes camadas, mas, no grupo C, a hemorragia foi mais intensa durante a reperfusão. Todos os grupos apresentaram infiltrado de PMN na base da mucosa, na submucosa e na camada muscular longitudinal e marginação de PMN nos vasos da mucosa e da submucosa. Durante a reperfusão, foi observada necrose dos enterócitos, das camadas musculares, das criptas de Lieberkühn e do plexo mioentérico nos grupos B e C. O uso tópico e intraluminal de CRS não atenuou os efeitos da isquemia e da reperfusão no intestino delgado de coelhos.(AU)

Cost-utility of new film-coated tablet formulation of deferasirox vs deferoxamine among major beta-thalassemia patients in Iran.

OBJECTIVES: Thalassemia is a hereditary disease, which caused economic burden in developing countries. This study evaluated the cost utility of new formulation of deferasirox (Jadenu) vs deferoxamine (Desferal) among B-Thalassemia-major patients from payer perspective in Iran. METHODS: An economic-evaluation through Markov model was performed. A systematic review was conducted in order to evaluate the clinical effectiveness of comparators. Because of chelating therapy is weight-dependent, patients were assumed to be 2 years-old at initiation in first and 18 years-old in second scenario, and model was estimated lifetime costs and utilities. Costs were calculated to the Iran healthcare system through payer perspective and measured effectiveness using quality-adjusted life years (QALYs). One-way sensitivity analysis and budget impact analysis was also employed. RESULTS: The 381 studies were retrieved from systematic searching through databases. After eliminating duplicate and irrelevant studies, 2 studies selected for evaluating the effectiveness. Jadenu was associated with an incremental cost-effectiveness ratio (ICER) of 1470.6 and 2544.7 US$ vs Desferal in first and second scenario respectively. The estimated ICER for Jadenu compared to generic deferoxamine was 2837.0 and 6924.1 US$ for first and second scenario respectively. For all scenarios Jadenu is presumed as cost-effective option based on calculated ICER which was lower than 1 gross domestic product per capita in Iran. Sensitivity analysis showed that different parameters except discount rate and indirect cost did not have impact on results. Based on budget impact analysis the estimated cost for patients using Desferal (based on the market share of brand) was 44,021,478 US$ in 3 years vs 42,452,606 US$ in replacing 33% of brand market share with Jadenu. This replacement corresponded to the cost saving of almost 1,568,872 US$ for the payers in 3 years. The calculated cost of using generic deferoxamine in all patients was 68,948,392 US$. The increase in the cost of using Jadenu for 10% of all patients in this scenario would be 934,427 US$ (1.36%) US$ at the first year. CONCLUSIONS: Based on this analysis, film-coated deferasirox appeared to be cost-effective treatment in comparison with Desferal for managing child and adult chronic iron overload in B-thalassemia major patients of Iran.

Deferoxamine Ameliorates Compressed Spinal Cord Injury by Promoting Neovascularization in Rats.

The therapeutic effect of deferoxamine (DFO) for spinal cord injury (SCI) has been demonstrated in previous studies; however, the exact mechanism of action is still unclear. Here, we hypothesized that DFO ameliorates spinal cord compression by promoting neovascularization. Using an SCI model of moderate compression, rats were intraperitoneally injected with 30 mg/kg or 100 mg/kg DFO for 1-2 weeks, and significant neovascularization was found in the injured spinal cord, showing overexpression of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF), and an increase in the number of new blood vessels. In addition, SCI in rats was significantly ameliorated after treatment with DFO, with less motor dysfunction, increased spared neural tissue, and improved electrophysiological conduction. By contrast, the ameliorative effect of DFO on SCI was suppressed when DFO-induced neovascularization was blocked by lenvatinib, a vascular endothelial growth factor receptor inhibitor, further suggesting that the primary pharmacological effect of DFO in SCI is the promotion of neovascularization. Therefore, we concluded that DFO effectively alleviated SCI by promoting neovascularization in the injured spinal cord. Considering that DFO is an FDA-approved free radical scavenger and iron chelator, it may represent a promising alternative strategy for SCI therapy in the future.

Injectable hydrogel systems with multiple biophysical and biochemical cues for bone regeneration.

Bone regeneration is a complex process in which angiogenesis and osteogenesis are crucial. Introducing multiple angiogenic and osteogenic cues simultaneously into a single system and tuning these cues to optimize the niche remains a challenge for bone tissue engineering. Herein, based on our injectable biomimetic hydrogels composed of silk nanofibers (SNF) and hydroxyapatite nanoparticles (HA), deferoxamine (DFO) and bone morphogenetic protein-2 (BMP-2) were loaded on SNF and HA to introduce more angiogenic and osteogenic cues. The angiogenesis and osteogenesis capacity of injectable hydrogels could be regulated by tuning the delivery of DFO and BMP-2 independently, resulting in vascularization and bone regeneration in cranial defects. The angiogenesis and osteogenesis outcomes accelerated the regeneration of vascularized bones toward similar composition and structure to natural bones. Therefore, the multiple biophysical and chemical cues provided by the nanofibrous structures, organic-inorganic compositions, and chemical and biochemical angiogenic and osteogenic inducing cues suggest the potential for clinical applicability of these hydrogels in bone tissue engineering.

Use of deferoxamine (DFO) in transfusion-dependent ß-thalassemia during pregnancy: A retrospective study.

OBJECTIVE: To report cases of use of chelation therapy during pregnancy which resulted in favorable outcomes for the babies. MATERIALS AND METHODS: In this retrospective cohort study, we described the evolution and outcome of 9 pregnancies in Italian thalassemic women who received deferoxamine (DFO) inadvertently during early pregnancy. RESULTS: The use of deferoxamine during first trimester did not lead to adverse effects on the fetus or cause major complications for the gestation, although an increase in iron burden was observed after suspending chelation therapy. CONCLUSION: In our experience, iron-chelation therapy might be administrated in pregnancy where the benefits to the mother outweigh the potential risks to the baby.

Intranasal deferoxamine can improve memory in healthy C57 mice, suggesting a partially non-disease-specific pathway of functional neurologic improvement.

INTRODUCTION: Intranasal deferoxamine (IN DFO) has been shown to decrease memory loss and have beneficial impacts across several models of neurologic disease and injury, including rodent models of Alzheimer's and Parkinson's disease. METHODS: In order to assess the mechanism of DFO, determine its ability to improve memory from baseline in the absence of a diseased state, and assess targeting ability of intranasal delivery, we treated healthy mice with IN DFO (2.4 mg) or intraperitoneal (IP) DFO and compared behavioral and biochemical changes with saline-treated controls. Mice were treated 5 days/week for 4 weeks and subjected to behavioral tests 30 min after dosing. RESULTS: We found that IN DFO, but not IP DFO, significantly enhanced working memory in the radial arm water maze, suggesting that IN administration is more efficacious as a targeted delivery route to the brain. Moreover, the ability of DFO to improve memory from baseline in healthy mice suggests a non-disease-specific mechanism of memory improvement. IN DFO treatment was accompanied by decreased GSK-3ß activity and increased HIF-1α activity. CONCLUSIONS: These pathways are suspected in DFO's ability to improve memory and perhaps represent a component of the common mechanism through which DFO enacts beneficial change in models of neurologic disease and injury.

Deferoxamine and Curcumin Loaded Nanocarriers Protect Against Rotenone-Induced Neurotoxicity.

BACKGROUND: Reduced glutathione and excess free iron within dopaminergic, substantia nigra neurons in Parkinson's disease (PD) can drive accumulation of toxic hydroxyl radicals resulting in sustained oxidative stress and cellular damage. Factors such as brain penetrance and bioavailability have limited the advancement of potential antioxidant and iron chelator therapies for PD. OBJECTIVE: This study aimed to develop novel nanocarrier delivery systems for the antioxidant curcumin and/or iron chelator deferoxamine (DFO) to protect against rotenone-induced changes in cell viability and oxidative stress in SH-SY5Y cells. METHODS: Nanocarriers of curcumin and/or DFO were prepared using Pluronic F68 (P68) with or without dequilinium (DQA) by modified thin-film hydration. Cell viability was assessed using an MTT assay and oxidative stress was measured using thiobarbituric acid reactive substances and cellular antioxidant activity assays. RESULTS: All formulations demonstrated high encapsulation efficiency (65-96%) and nanocarrier size was <200 nm. 3-h pretreatment with P68 or P68+DQA nanocarriers containing various concentrations of curcumin and/or DFO significantly protected against rotenone-reduced cell viability. The addition of DFO to curcumin-loaded P68+DQA nanocarriers resulted in increased protection by at least 10%. All nanoformulations significantly protected against rotenone-induced lipid peroxidation (p < 0.0001). The addition of DQA, which targets mitochondria, resulted in up to 65% increase in cellular antioxidant activity. In nearly all preparations, the combination of 10 µM curcumin and 100 µM DFO had the most antioxidant activity. CONCLUSION: This study demonstrates for the first time the formulation and delivery using P68 and P68+DQA curcumin and/or DFO nanocarriers to protect against oxidative stress induced by a rotenone PD model. This strategy to combine antioxidants with iron chelators may provide a novel approach to fully utilise their therapeutic benefit for PD.

Quantifying Intranasally Administered Deferoxamine in Rat Brain Tissue with Mass Spectrometry.

Deferoxamine, a metal chelator, has been shown to be neuroprotective in animal models of ischemic stroke, traumatic brain injury and both subarachnoid and intracerebral hemorrhage. Intranasal deferoxamine (IN DFO) has also shown promise as a potential treatment for multiple neurodegenerative diseases, including Parkinson's and Alzheimer's. However, there have been no attempts to thoroughly understand the dynamics and pharmacokinetics of IN DFO. We developed a new high-performance liquid-chromatography electrospray-tandem mass spectrometry (HPLC/ESI-MS2) method to quantify the combined total levels of DFO, ferrioxamine (FO; DFO bound to iron), and aluminoxamine (AO; aluminum-bound DFO) in brain tissue using a custom-synthesized deuterated analogue (DFO-d7, Medical Isotopes Inc., Pelham NH) as an internal standard. We applied our method toward understanding the pharmacokinetics of IN DFO delivery to the brain and blood of rats from 15 min to 4 h after delivery. We found that IN delivery successfully targets DFO to the brain to achieve concentrations of 0.5-15 µM in various brain regions within 15 min, and decreasing though still detectable after 4 h. Systemic exposure was minimized as assessed by concentration in blood serum. Serum concentrations were 0.02 µM at 15 min and no more than 0.1 µM at later time points. Compared to blood serum, brain region-specific drug exposure (as measured by area under the curve) ranged from slightly under 10 times exposure in the hippocampus to almost 200 times exposure in the olfactory bulb with IN DFO delivery. These findings represent a major step toward future method development, pharmacokinetic studies, and clinical trials for this promising therapeutic.

A Pilot Optical Coherence Tomography Angiography Study on Superficial and Deep Capillary Plexus Foveal Avascular Zone in Patients With Beta-Thalassemia Major.

Purpose: To investigate foveal avascular zone (FAZ) changes in the superficial (SCP) and deep (DCP) capillary plexuses in beta-thalassemia major (BTM) patients, as shown in optical coherence tomography angiography. Methods: Nonrandomized, comparative case series of 54 eyes of 27 BTM patients and 46 eyes of 23 healthy controls, utilizing an automated FAZ detection algorithm. Measurements included FAZ area and FAZ shape descriptors (convexity, circularity, and contour temperature). Results were compared between the two groups, and correlated to iron load and chelation therapy parameters. Results: SCP and DCP FAZ area were not significantly different between the control and BTM groups (P = 0.778 and P = 0.408, respectively). The same was true regarding SCP FAZ convexity (P = 0.946), circularity (P = 0.838), and contour temperature (P = 0.907). In contrast, a statistically significant difference was detected between controls and BTM group regarding DCP FAZ convexity (P = 0.013), circularity (P = 0.010), and contour temperature (P = 0.014). Desferrioxamine dosage was strongly correlated to the DCP area (r = 0.650, P = 0.05) and liver magnetic resonance imaging/T2-star to DCP circularity (r = -0.492, P = 0.038). Correlations were also revealed between urine Fe excretion and DCP convexity (r = 0.531, P = 0.019), circularity (r = 0.661, P = 0.002), and contour temperature (r = -0.591, P = 0.008). Conclusions: Retinal capillary plexuses and especially DCP seem to present unique morphologic changes in BTM patients, not in the FAZ area, but in specific shape descriptors, indicating minor but detectable FAZ changes. These changes correlate well with iron load and chelation therapy parameters. Their clinical importance and pathophysiologic implications remain to be elucidated through further studies.

Optimization of transdermal deferoxamine leads to enhanced efficacy in healing skin wounds.

Chronic wounds remain a significant burden to both the healthcare system and individual patients, indicating an urgent need for new interventions. Deferoxamine (DFO), an iron-chelating agent clinically used to treat iron toxicity, has been shown to reduce oxidative stress and increase hypoxia-inducible factor-1 alpha (HIF-1α) activation, thereby promoting neovascularization and enhancing regeneration in chronic wounds. However due to its short half-life and adverse side effects associated with systemic absorption, there is a pressing need for targeted DFO delivery. We recently published a preclinical proof of concept drug delivery system (TDDS) which showed that transdermally applied DFO is effective in improving chronic wound healing. Here we present an enhanced TDDS (eTDDS) comprised exclusively of FDA-compliant constituents to optimize drug release and expedite clinical translation. We evaluate the eTDDS to the original TDDS and compare this with other commonly used delivery methods including DFO drip-on and polymer spray applications. The eTDDS displayed excellent physicochemical characteristics and markedly improved DFO delivery into human skin when compared to other topical application techniques. We demonstrate an accelerated wound healing response with the eTDDS treatment resulting in significantly increased wound vascularity, dermal thickness, collagen deposition and tensile strength. Together, these findings highlight the immediate clinical potential of DFO eTDDS to treating diabetic wounds. Further, the topical drug delivery platform has important implications for targeted pharmacologic therapy of a wide range of cutaneous diseases.

Thermo-sensitive keratin hydrogel against iron-induced brain injury after experimental intracerebral hemorrhage.

In situ keratin hydrogel offer a promising strategy to relieve the brain injury after intracerebral hemorrhage (ICH) by delivering the iron chelator directly to the stroke site. However, the injectable property of traditional keratin hydrogel is unsatisfactory, which can't provide adaptable filling of lesion defects with irregular shapes. Herein, the thermo sensitive keratin-g-PNIPAM polymers with different graft ratios were synthesized, and deferoxamine mesylate (DFO) loaded thermo sensitive keratin hydrogels (TKGs) were prepared using the oxidative crosslinking method. The lower critical solution temperature of TKGs can be tailored from 28.5 to 31.8 °C by varying the graft ratios of keratin to NIPAM, and TKG can fill up the complex shapes of lesion cavities easily due to the characteristic of sol-gel transition. In addition, TKGs exhibit stronger adsorption and clearance capacities for the Fe2+ than keratin gel. Meanwhile, in situ injection of TKG with different DFO loadings (0.1, 1.0, and 10 mg/mL) into the hematoma region after ICH surgery showed a stronger effect on the reduction of ICH-induced iron deposits, brain non-heme iron content, brain edema and ROS level compared to the DFO treatment by intraperitoneal administration. Thus, the developed TKG can be potentially exploited for iron-induced brain injury after ICH.

A 1-year randomized trial of deferasirox alone versus deferasirox and deferoxamine combination for the treatment of iron overload in thalassemia major.

AIM: Iron chelators are extensively used to reduce iron overload. Our purpose was to compare effects of deferasirox versus deferasirox and deferoxamine in patients with thalassemia major. METHODS: This randomized and double blind trial was performed on 62 patients. Patients were assigned 1:1 to oral 30 mg/kg deferasirox daily or oral 30 mg/kg deferasirox daily plus SC 50 mg/kg deferoxamine for 5 days a week. Treatment continued for 12 months in both groups. RESULTS: Fifty-five patients completed the 1 year of treatment. Mean age was 24.5 years with an excess of females. Combined therapy caused a significant increase in myocardial T2* from 23.1 ± 7.5 ms at baseline to 27.1 ± 7.0 ms at 12 months (P < 0.05). This difference was statistically significant between 2 groups at 12 months (P = 0.01). Combined therapy and monotherapy had no significant effect on liver T2*. At 12 months, serum ferritin levels were reduced in two groups; however, the difference was significant (737 ± 459 µg/ml vs 1085 ± 919 µg/ml, P < 0.01). CONCLUSION: Our study indicates that combined treatment with deferasirox and deferoxmaine is more effective than deferasirox for reduction of iron over load in patients with thalassemia major.

Deferoxamine: An Angiogenic and Antioxidant Molecule for Tissue Regeneration.

Deferoxamine (DFO) has been in use for half a century as a Food and Drug Administration-approved iron chelator, but recent studies indicate a variety of properties that could expand this drug's application into the fields of tissue and regenerative engineering. DFO has been implicated as an angiogenic agent in studies on ischemia, wound healing, and bone regeneration because of its ability to upregulate hypoxia-inducible factor-1 alpha (HIF-1α) and other key downstream angiogenic factors. DFO has also demonstrated antioxidant capabilities unrelated to its iron-chelating properties, making it a potential modulator of the oxidative stress involved in the inflammation response. Together, these properties make DFO a potential bioactive molecule to promote wound healing and enhance tissue integration of biomaterials in vivo. Impact Statement Deferoxamine (DFO) is approved by the Food and Drug Administration as an iron chelator and is been used to treat iron overload. Recent studies indicate that DFO may have important applications in the growing field of tissue regeneration because of its unique properties of downregulating inflammation while promoting vascularization, thereby enhancing wound healing in vivo.

Therapeutic mechanism of combined oral chelation therapy to maximize efficacy of iron removal in transfusion-dependent thalassemia major - a pilot study.

OBJECTIVES: Three iron chelators are used to treat transfusion-dependent beta-thalassemia: desferrioxamine (DFO), deferasirox (DFX), and deferiprone (DFP). Compliance is low for DFO as it cannot be administered orally. Combined administration of DFP and DFX is orally available, however, the therapeutic mechanism is unknown. This pilot study investigated the iron removal mechanisms of DFX and DFP treatment in patients with transfusion-dependent thalassemia major. METHODS: Each patient received three treatments sequentially: (1) DFX monotherapy, (2) DFP monotherapy, and (3) DFX/DFP combination therapy with a four-day washout period between each treatment. Urine and stool specimens were collected to determine the primary outcome of iron excretion volumes. RESULTS: The mean iron excretion was seven times higher after combination therapy with DFX and DFP. Monotherapies also increased excretions volumes, though to a significantly lesser degree. Combined administration of DFX and DFP achieves maximum iron removal in transfusion-dependent thalassemia major compared to monotherapy with either drug. CONCLUSIONS: We suggest combination therapy in chronic severe iron overload cases, especially for patients in poor compliance with DFO/DFP combination therapy or those exhibiting poor iron removal from DFX or DFP monotherapy.

The impact of clay-based hypoxia mimetic hydrogel on human fibroblasts of the periodontal soft tissue.

Thixotropic clays have favorable properties for tissue regeneration. Hypoxia mimetic agents showed promising results in pre-clinical models for hard and soft tissue regeneration. It is unclear if clays can be used as carrier for hypoxia mimetic agent in a periodontal regenerative setting. Here, we tested the response of human fibroblasts of the periodontal soft tissue to synthetic clay hydrogels and assessed hypoxia mimetic agent release. Cells were cultured on synthetic clay hydrogels (5.00%-0.15%). We assessed viability and differentiation capacity with resazurin-based toxicity assays, MTT staining, Live-Dead staining, and alkaline phosphatase staining. To reveal the response of fibroblasts to hypoxia mimetic agent-loaded clay hydrogels, cells were exposed to clay supplemented with dimethyloxalylglycine, deferoxamine, l-mimosine, and CoCl2. Supernatants from hypoxia mimetic agent-loaded clay hydrogels were harvested and replaced with medium at hour 1, 3, 6, 24, 48, and 72. To reveal the hypoxia mimetic capacity of supernatants, vascular endothelial growth factor production in the fibroblasts was assessed in the culture medium. Our data show that clay did not induce relevant toxic effects in the fibroblasts which remained capable to differentiate into alkaline phosphatase-positive cells at the relevant concentrations. Fibroblasts cultured on clay hydrogel loaded with dimethyloxalylglycine, deferoxamine, l-mimosine, and CoCl2 remained vital, however, no significant increase in vascular endothelial growth factor levels was found in the culture medium. Only dimethyloxalylglycine-loaded clay supernatants taken in the first hours stimulated vascular endothelial growth factor production in fibroblasts. In conclusion no pronounced toxic effects of synthetic clay were observed. Supplementation with dimethyloxalylglycine leads to hypoxia mimetic activity. This pilot study provides first insights into the impact of synthetic clay on periodontal tissue.