Enhancing radioprotection: A chitosan-based chelating polymer is a versatile radioprotective agent for prophylactic and therapeutic interventions against radionuclide contamination.

To mitigate the risk of radioactive isotope dissemination, the development of preventative and curative measures is of particular interest. For mass treatment, the developed solution must be easily administered, preferably orally, with effective, nontoxic decorporating properties against a wide range of radioactive isotopes. Currently, most orally administered chelation therapy products are quickly absorbed into the blood circulation, where chelation of the radioactive isotope is a race against time due to the short circulation half-life of the therapeutic. This report presents an alternative therapeutic approach by using a functionalized chitosan (chitosan@DOTAGA) with chelating properties that remains within the gastrointestinal tract and is eliminated in feces, that can protect against ingested radioactive isotopes. The polymer shows important in vitro chelation properties towards different metallic cations of importance, including (Cs(I), Ir(III), Th(IV), Tl(I), Sr(II), U(VI) and Co(II)), at different pH (from 1 to 7) representing the different environments in the gastrointestinal tract. An in vivo proof of concept is presented on a rodent model of uranium contamination following an oral administration of Chitosan@DOTAGA. The polymer partially prevents the accumulation of uranium within the kidneys (providing a protective effect) and completely prevents its uptake by the spleen.

Iron as an emerging therapeutic target in critically ill patients.

The multiple roles of iron in the body have been known for decades, particularly its involvement in iron overload diseases such as hemochromatosis. More recently, compelling evidence has emerged regarding the critical role of non-transferrin bound iron (NTBI), also known as catalytic iron, in the care of critically ill patients in intensive care units (ICUs). These trace amounts of iron constitute a small percentage of the serum iron, yet they are heavily implicated in the exacerbation of diseases, primarily by catalyzing the formation of reactive oxygen species, which promote oxidative stress. Additionally, catalytic iron activates macrophages and facilitates the growth of pathogens. This review aims to shed light on this underappreciated phenomenon and explore the various common sources of NTBI in ICU patients, which lead to transient iron dysregulation during acute phases of disease. Iron serves as the linchpin of a vicious cycle in many ICU pathologies that are often multifactorial. The clinical evidence showing its detrimental impact on patient outcomes will be outlined in the major ICU pathologies. Finally, different therapeutic strategies will be reviewed, including the targeting of proteins involved in iron metabolism, conventional chelation therapy, and the combination of renal replacement therapy with chelation therapy.

Gene/environment interaction in the susceptibility of Crohn's disease patients to aluminum.

BACKGROUND & AIM: The key role of environmental factors in the pathogenesis of Inflammatory Bowel Diseases (IBD) is recognized. Aluminum is suspected to be a risk factor for IBD. However, mechanisms linking aluminum exposure to disease development are unknown. We examined the role of aluminum transport and subcellular localisation on human colon susceptibility to aluminum-induced inflammation. METHODS: Human colon biopsies isolated from Crohn's disease (CD) or control patients and Caco-2 cells were incubated with aluminum. The effects of aluminum were evaluated on cytokine secretion and transporter expression. The role of aluminum kinetics parameters was studied in Caco-2 using transport inhibitors and in human colon biopsies by assessing genetic polymorphisms of transporters. RESULTS: Aluminum exposure was shown to induce cytokine secretion in colon of CD but not healthy patients. In Caco-2 cells, aluminum internalisation was correlated with inflammatory status. In human colon, analysis of genetic polymorphisms and expression of ABCB1 and SLC26A3 transporters showed that their decreased activity was involved in aluminum-induced inflammation. CONCLUSIONS: We hypothesize that alteration in detoxifying response would lead to a deregulation of intestinal homeostasis and to the expression of IBD. Our study emphasizes the complexity of gene/environment interaction for aluminum adverse health effect, highlighting at risk populations or subtypes of patients. A better understanding of correlations between gene expression or SNP and xenobiotic kinetics parameters would shift the medical paradigm to more personalized disease management and treatment.

Roadmap for metal nanoparticles in radiation therapy: current status, translational challenges, and future directions.

This roadmap outlines the potential roles of metallic nanoparticles (MNPs) in the field of radiation therapy. MNPs made up of a wide range of materials (from Titanium, Z = 22, to Bismuth, Z = 83) and a similarly wide spectrum of potential clinical applications, including diagnostic, therapeutic (radiation dose enhancers, hyperthermia inducers, drug delivery vehicles, vaccine adjuvants, photosensitizers, enhancers of immunotherapy) and theranostic (combining both diagnostic and therapeutic), are being fabricated and evaluated. This roadmap covers contributions from experts in these topics summarizing their view of the current status and challenges, as well as expected advancements in technology to address these challenges.

Proton MR Spectroscopy and Diffusion MR Imaging Monitoring to Predict Tumor Response to Interstitial Photodynamic Therapy for Glioblastoma.

Despite recent progress in conventional therapeutic approaches, the vast majority of glioblastoma recur locally, indicating that a more aggressive local therapy is required. Interstitial photodynamic therapy (iPDT) appears as a very promising and complementary approach to conventional therapies. However, an optimal fractionation scheme for iPDT remains the indispensable requirement. To achieve that major goal, we suggested following iPDT tumor response by a non-invasive imaging monitoring. Nude rats bearing intracranial glioblastoma U87MG xenografts were treated by iPDT, just after intravenous injection of AGuIX® nanoparticles, encapsulating PDT and imaging agents. Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spectroscopy (MRS) allowed us an original longitudinal follow-up of post-treatment effects to discriminate early predictive markers. We successfully used conventional MRI, T2 star (T2*), Diffusion Weighted Imaging (DWI) and MRS to extract relevant profiles on tissue cytoarchitectural alterations, local vascular disruption and metabolic information on brain tumor biology, achieving earlier assessment of tumor response. From one day post-iPDT, DWI and MRS allowed us to identify promising markers such as the Apparent Diffusion Coefficient (ADC) values, lipids, choline and myoInositol levels that led us to distinguish iPDT responders from non-responders. All these responses give us warning signs well before the tumor escapes and that the growth would be appreciated.

Stereotactic modulation of blood-brain barrier permeability to enhance drug delivery.

Drug delivery in the CNS is limited by endothelial tight junctions forming the impermeable blood-brain barrier. The development of new treatment paradigms has previously been hampered by the restrictiveness of the blood-brain barrier to systemically administered therapeutics. With recent advances in stereotactic localization and noninvasive imaging, we have honed the ability to modulate, ablate, and rewire millimetric brain structures to precisely permeate the impregnable barrier. The wide range of focused radiations offers endless possibilities to disrupt endothelial permeability with different patterns and intensity following 3-dimensional coordinates offering a new world of possibilities to access the CNS, as well as to target therapies. We propose a review of the current state of knowledge in targeted drug delivery using noninvasive image-guided approaches. To this end, we focus on strategies currently used in clinics or in clinical trials such as targeted radiotherapy and magnetic resonance guided focused ultrasound, but also on more experimental approaches such as magnetically heated nanoparticles, electric fields, and lasers, techniques which demonstrated remarkable results both in vitro and in vivo. We envision that biodistribution and efficacy of systemically administered drugs will be enhanced with further developments of these promising strategies. Besides therapeutic applications, stereotactic platforms can be highly valuable in clinical applications for interventional strategies that can improve the targetability and efficacy of drugs and macromolecules. It is our hope that by showcasing and reviewing the current state of this field, we can lay the groundwork to guide future research in this realm.

Coupling of HPLC with electrospray ionization mass spectrometry for studying the aging of ultrasmall multifunctional gadolinium-based silica nanoparticles.

Sub-5 nm multimodal nanoparticles have great potential for theranostic applications due to their easy renal elimination combined with complementary imaging properties and therapeutic facilities. Their potential clinical use requires the full characterization of not only the nanoparticle but also all its possible degradation products. We have recently proposed new ultrasmall gadolinium-based nanoparticles for multimodal imaging and radiosensitization. The aim of this article is to describe an analytical tool to characterize degradation products in a highly diluted medium. We demonstrate that HPLC coupled to electrospray ionization mass spectrometry (ESI-MS) can be used in order to determine precisely the composition of nanoparticles and their degradation fragments during aging.