Mechanism-Based Pharmacokinetic Modeling of Absorption and Disposition of a Deferoxamine-Based Nanochelator in Rats

Caffeic Acid-Biogenic Amine Complexes Outperform Standard Drugs in Reducing Toxicity: Insights from In Vivo Iron Chelation Studies

Iron homeostasis imbalance, caused by conditions such as thalassemia, sickle cell anemia, and myocardial infarction, often results in elevated free iron levels, leading to ferroptosis and severe organ damage. While current iron chelators like deferoxamine (DFO) and deferiprone are effective, they are associated with significant side effects, including nephrotoxicity, gastrointestinal bleeding, and liver fibrosis. This creates an urgent need for safer, natural-product-based alternatives for effective iron chelation therapy (ICT). This study investigates caffeic acid (CA)-based complexes with biogenic amines, specifically spermine (CA-Sp) and histidine (CA-His), as potential ICT candidates. Initial in vitro assays on HEK-293 cells under iron dextran (ID)-induced toxicity have demonstrated their protective effects, with CA-Sp exhibiting superior efficacy. The in vivo studies in mice have further validated their potential, showing remarkable iron chelation and toxicity mitigation compared to DFO. Inductively coupled plasma mass spectrometry (ICP-MS) reveals significant iron excretion in fecal matter in the treatment group along with reductions in serum ferritin levels. The markers of nephrotoxicity (creatinine) and liver function (ALT, AST) have also been shown to be normalized in treated groups, while immunological analyses have revealed restored levels of neutrophils, T cells, and B cells. Additionally, the inflammatory cytokines, TNF-α and IL-6, have exhibited significant reductions, with the CA-based formulations surpassing the effects of DFO. Histological analyses using Prussian blue staining have further confirmed reduced iron deposition in vital organs such as the liver, kidney, and spleen. These findings highlight CA-Sp as a particularly promising candidate for ICT, offering a safer and more effective strategy for managing iron overload and its associated complications.

Neuroinflammation and iron metabolism after intracerebral hemorrhage: a glial cell perspective

Intracerebral hemorrhage (ICH) is the most common subtype of hemorrhagic stroke causing significant morbidity and mortality. Previously clinical treatments for ICH have largely been based on a single pathophysiological perspective, and there remains a lack of curative interventions. Following the rupture of cerebral blood vessels, blood metabolites activate resident immune cells such as microglia and astrocytes, and infiltrate peripheral immune cells, leading to the release of a series of inflammatory mediators. Degradation of hemoglobin produces large amounts of iron ions, leading to an imbalance of iron homeostasis and the production of large quantities of harmful hydroxyl radicals. Neuroinflammation and dysregulation of brain iron metabolism are both important pathophysiological changes in ICH, and both can exacerbate secondary brain injury. There is an inseparable relationship between brain iron metabolism disorder and activated glial cells after ICH. Glial cells participate in brain iron metabolism through various mechanisms; meanwhile, iron accumulation exacerbates neuroinflammation by activating inflammatory signaling pathways modulating the functions of inflammatory cells, and so on. This review aims to explore neuroinflammation from the perspective of iron metabolism, linking the complex pathophysiological changes, delving into the exploration of treatment approaches for ICH, and offering insights that could enhance clinical management strategies.

Developing Iron Nanochelating Agents: Preliminary Investigation of Effectiveness and Safety for Central Nervous System Applications

Excessive iron levels are believed to contribute to the development of neurodegenerative disorders by promoting oxidative stress and harmful protein clustering. Novel chelation treatments that can effectively remove excess iron while minimizing negative effects on the nervous system are being explored. This study focuses on the creation and evaluation of innovative nanobubble (NB) formulations, shelled with various polymers such as glycol-chitosan (GC) and glycol-chitosan conjugated with deferoxamine (DFO), to enhance their ability to bind iron. Various methods were used to evaluate their physical and chemical properties, chelation capacity in diverse iron solutions and impact on reactive oxygen species (ROS). Notably, the GC-DFO NBs demonstrated the ability to decrease amyloid-β protein misfolding caused by iron. To assess potential toxicity, in vitro cytotoxicity testing was conducted using organotypic brain cultures from the substantia nigra, revealing no adverse effects at appropriate concentrations. Additionally, the impact of NBs on spontaneous electrical signaling in hippocampal neurons was examined. Our findings suggest a novel nanochelation approach utilizing DFO-conjugated NBs for the removal of excess iron in cerebral regions, potentially preventing neurotoxic effects.

Application of Allometric Scaling to Nanochelator Pharmacokinetics

Deferoxamine (DFO) is an effective FDA-approved iron chelator; however, its use is considerably limited by off-target toxicities and an extremely cumbersome dose regimen involving daily infusions. The recent development of a deferoxamine-based nanochelator (DFO-NP) with selective renal excretion has shown promise in ameliorating iron overload and associated physiological complications in rodent models with a substantially improved safety profile. While the dose- and administration route-dependent pharmacokinetics (PK) of DFO-NPs have been recently characterized, the optimized PK model was not validated, and the prior studies did not directly address the clinical translatability of DFO-NPs into humans. In the present work, these gaps were addressed by applying allometric scaling of DFO-NP PK in rats to predict those in mice and humans. First, this approach predicted serum concentration-time profiles of DFO-NPs, which were similar to those experimentally measured in mice, validating the nonlinear disposition and absorption models for DFO-NPs across the species. Subsequently, we explored the utility of allometric scaling by predicting the PK profile of DFO-NPs in humans under clinically relevant dosing schemes. These in silico efforts demonstrated that the novel nanochelator is expected to improve the PK of DFO when compared to standard infusion regimens of native DFO. Moreover, reasonable formulation strategies were identified and discussed for both early clinical development and more sophisticated formulation development.