Iron(III)-Quercetin Complexes' Safety for MRI Cell Tracking in Cell Therapy Applications: Cytotoxic and Genotoxic Assessment

Tracking the healing effect of human Wharton's jelly stem cells labeled with superparamagnetic iron oxide nanoparticles seeded onto polyvinyl alcohol/chitosan/carbon nanotubes in burn wounds by MRI and Prussian blue staining

Regenerative medicine through the application of tissue engineering and cell transplantation has provided a new door for wound healing. In this study, the healing effect of human Wharton's jelly stem cells (WJSCs) labeled with superparamagnetic iron oxide nanoparticles (SPIONs) seeded onto polyvinyl alcohol/chitosan/carbon nanotubes (PVA/CS/CNTs) in burn wounds was investigated by performing magnetic resonance imaging (MRI) and Prussian blue staining. Human WJSCs were prepared from umbilical cord and characterized. PVA/CS/CNTs were fabricated via electrospinning. Forty-eight rats were divided into four groups. The control group underwent a third-degree burn injury and was left untreated. The second group received silver sulfadiazine after burn induction, the third group was treated with PVA/CS/CNTs after burn wounds, and the fourth group received WJSCs labeled with SPIONs seeded onto PVA/CS/CNTs following burn injury. Tensile strength was investigated, real-time polymerase chain reaction was used to evaluate apoptosis, and Prussian blue staining and MRI were performed to trace labeled cells. The mesenchymal properties of WJSCs were characterized. Histologically, healing was observed as complete granulation occurred and epithelial tissues were formed in the absence of inflammatory cells, with increased expression of Bcl-2 and a decrease in Bax genes in the fourth group. Internalization of SPIONs within WJSCs was confirmed by Prussian blue staining and MRI on day 14. WJSCs labeled with SPIONs seeded onto PVA/CS/CNTs could successfully participate in the healing of burn wounds and could be easily tracked by MRI as a noninvasive method, providing a new door in regenerative medicine for burn wounds.

Iron-Quercetin complex enhances mesenchymal stem cell-mediated HGF secretion and c-Met activation to ameliorate acute kidney injury through the prevention of tubular cell apoptosis

Background

Acute kidney injury (AKI) is a life-threatening clinical syndrome with no effective treatment currently available. This study aims to investigate whether Iron-Quercetin complex (IronQ) pretreatment can enhance the therapeutic efficacy of Mesenchymal stem cells (MSCs) in AKI and explore the underlying mechanisms.

Methods

A cisplatin-induced AKI model was established in male C57BL/6 mice, followed by the intravenous administration of 1x10ˆ6 MSCs or IronQ-pretreated MSCs (MSCIronQ). Renal function, histology, and tubular cell apoptosis were analyzed three days post-treatment. In vitro, apoptosis was induced in mouse tubular epithelial cells (mTECs) using cisplatin, followed by treatment with MSCs or MSCIronQ conditioned medium (CM). Apoptosis was evaluated using TUNEL assay, RT-PCR, and western blotting. Furthermore, RNA sequencing (RNA-seq) was performed on MSCIronQ to explore the underlying mechanisms.

Results

Compared to MSC-treated AKI mice, those treated with MSCIronQ showed significantly improved renal function and histological outcomes, with reduced tubular cell apoptosis. A similar effect was observed in cisplatin-treated mTECs exposed to MSCIronQ-CM. Mechanistically, RNA-seq and subsequent validation revealed that IronQ treatment markedly upregulated the expression and secretion of hepatocyte growth factor (HGF) in MSCs. Furthermore, RNA interference or antibody-mediated neutralization of HGF effectively abolished the anti-apoptotic effects of MSCIronQ on mTECs. This mechanistic insight was reinforced by pharmacological inhibition of c-Met, the specific receptor of HGF, in both in vitro and in vivo models.

Conclusions

IronQ pretreatment enhances MSCs efficacy in AKI by promoting HGF expression and secretion, activating the HGF/c-Met pathway to suppress tubular cell apoptosis. These findings indicate that IronQ improves MSC-based therapies and offers insights into molecular mechanisms, supporting the development of better AKI treatments.

Iron(III)-Quercetin Complex: In Vivo Acute Toxicity and Biodistribution of Novel MRI Agent

Background

The iron(III)-quercetin complex, known as "IronQ", is an innovative MRI contrast agent composed of one Fe(III) ion and two quercetin molecules. IronQ is efficiently internalized by cells, enabling T1-weighted MRI tracking. It has demonstrated therapeutic benefits in reducing inflammation in an intracerebral hemorrhage (ICH) mouse model and offers a safer alternative to gadolinium-based agents by avoiding cytotoxicity and genotoxicity. These properties make IronQ a promising candidate for safe and effective MRI contrast enhancement.

Purpose

This study aims to further the development of IronQ as an MRI contrast agent by investigating its biodistribution, pharmacokinetics, and acute toxicity in a preclinical animal model.

Methods

The relaxivity of IronQ was measured in water and whole blood phantoms. Acute toxicity was evaluated in Sprague Dawley rats administered single intraperitoneal doses of IronQ (75, 150, and 225 µmol Fe/kg BW) over a 14-day period. Pharmacokinetic studies were performed at a dose of 150 µmol Fe/kg BW, with blood iron content analyzed using ICP-OES. For in vivo biodistribution, SD rats were administered an intravenous dose of IronQ (225 µmol Fe/kg BW), followed by MR imaging using a 1.5 T scanner and subsequent tissue-ICP analysis.

Results

The longitudinal relaxivity (r1) of IronQ was measured to be 2.17 mm⁻¹s⁻¹ in ultrapure water and 3.56 mm⁻¹s⁻¹ in whole blood. Acute toxicity studies showed no mortality, morbidity, or significant biochemical changes, with histopathology confirming no irreversible organ damage. Pharmacokinetics revealed peak blood iron content at 1.1 hours post-administration and clearance within 24 hours. MRI demonstrated enhanced T1 signal intensity, particularly in the liver and kidney.

Conclusion

These findings provide valuable insights into the safety, pharmacokinetics, and imaging efficacy of IronQ, highlighting its potential as a robust and biocompatible MRI contrast agent.

Mincle as a potential intervention target for the prevention of inflammation and fibrosis (Review)

Macrophage‑inducible C‑type lectin receptor (Mincle) is predominantly found on antigen‑presenting cells. It can recognize specific ligands when stimulated by certain pathogens such as fungi and Mycobacterium tuberculosis. This recognition triggers the activation of the nuclear factor‑κB pathway, leading to the production of inflammatory factors and contributing to the innate immune response of the host. Moreover, Mincle identifies lipid damage‑related molecules discharged by injured cells, such as Sin3‑associated protein 130, which triggers aseptic inflammation and ultimately hastens the advancement of renal damage, autoimmune disorders and malignancies by fostering tissue inflammation. Presently, research on the functioning of the Mincle receptor in different inflammatory and fibrosis‑associated conditions has emerged as a popular topic. Nevertheless, there remains a lack of research on the impact of Mincle in promoting long‑lasting inflammatory reactions and fibrosis. Additional investigation is required into the function of Mincle receptors in chronological inflammatory reactions and fibrosis of organ systems, including the progression from inflammation to fibrosis. Hence, the present study showed an overview of the primary roles and potential mechanism of Mincle in inflammation, fibrosis, as well as the progression of inflammation to fibrosis. The aim of the present study was to clarify the potential mechanism of Mincle in inflammation and fibrosis and to offer perspectives for the development of drugs that target Mincle.

Identifying transcriptomic profiles of iron-quercetin complex treated peripheral blood mononuclear cells from healthy volunteers and diabetic patients

Peripheral blood is an alternative source of stem/progenitor cells for regenerative medicine owing to its ease of retrieval and blood bank storage. Previous in vitro studies indicated that the conditioned medium derived from peripheral blood mononuclear cells (PBMCs) treated with the iron-quercetin complex (IronQ) contains potent angiogenesis and wound-healing properties. This study aims to unveil the intricate regulatory mechanisms governing the effects of IronQ on the transcriptome profiles of human PBMCs from healthy volunteers and those with diabetes mellitus (DM) using RNA sequencing analysis. Our findings revealed 3741 and 2204 differentially expressed genes (DEGs) when treating healthy and DM PBMCs with IronQ, respectively. Functional enrichment analyses underscored the biological processes shared by the DEGs in both conditions, including inflammatory responses, cell migration, cellular stress responses, and angiogenesis. A comprehensive exploration of these molecular alterations exposed a network of 20 hub genes essential in response to stimuli, cell migration, immune processes, and the mitogen-activated protein kinase (MAPK) pathway. The activation of these pathways enabled PBMCs to potentiate angiogenesis and tissue repair. Corroborating this, quantitative real-time polymerase chain reaction (qRT-PCR) and cell phenotyping confirmed the upregulation of candidate genes associated with anti-inflammatory, pro-angiogenesis, and tissue repair processes in IronQ-treated PBMCs. In summary, combining IronQ and PBMCs brings about substantial shifts in gene expression profiles and activates pathways that are crucial for tissue repair and immune response, which is promising for the enhancement of the therapeutic potential of PBMCs, especially in diabetic wound healing.

Recent Advances in Nanoformulations for Quercetin Delivery

Quercetin (QUE) is a flavonol that has recently received great attention from the research community due to its important pharmacological properties. However, QUE's low solubility and extended first-pass metabolism limit its oral administration. This review aims to present the potential of various nanoformulations in the development of QUE dosage forms for bioavailability enhancement. Advanced drug delivery nanosystems can be used for more efficient encapsulation, targeting, and controlled release of QUE. An overview of the primary nanosystem categories, formulation processes, and characterization techniques are described. In particular, lipid-based nanocarriers, such as liposomes, nanostructured-lipid carries, and solid-lipid nanoparticles, are widely used to improve QUE's oral absorption and targeting, increase its antioxidant activity, and ensure sustained release. Moreover, polymer-based nanocarriers exhibit unique properties for the improvement of the Absorption, Distribution, Metabolism, Excretion, and Toxicology (ADME(T)) profile. Namely, micelles and hydrogels composed of natural or synthetic polymers have been applied in QUE formulations. Furthermore, cyclodextrin, niosomes, and nanoemulsions are proposed as formulation alternatives for administration via different routes. This comprehensive review provides insight into the role of advanced drug delivery nanosystems for the formulation and delivery of QUE.