Introduction:Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related mortality, particularly due to resistance induced by tumor-associated macrophages (TAMs)-exhibiting a M2-like phenotype-within the tumor microenvironment. The specific targeting of pro-tumoral M2 TAMs constitutes thus a major challenge in anticancer therapies but current strategies lack specificity. We produced and patented a monoclonal antibody, called mAb6-25, that specifically targets M2-like macrophages (M2M) but not M1-like macrophages (M1M) or monocytes. Here, we investigated the conjugation of this antibody on magnetic nanoparticles (MNPs) as a potential nanoplatform for specific M2 TAM targeting. Methods:Magnetic iron oxide multicore nanoflowers (NF) were functionalized with a fluorophore allowing their detection and the mAb6-25 for M2 TAM targeting. The M2M targeting by MNP-mAb6-25 was determined, comparatively to M1M, in 2D and 3D in vitro co-culture models with cancer cells by flow cytometry and confocal microscopy analysis, while MNP-mAb6-25 uptake was evaluated by NMR relaxometry. The in vivo M2 TAM targeting was analyzed in a xenograft mouse model of NSCLC by IVIS optical imaging. Results:We demonstrated that the MNP-mAb6-25 nanoplatform preferentially binds M2M compared to M1M (13-fold higher uptake in M2M) or cancer cells in monoculture as well as in 2D and 3D co-culture models mixing M2M or M1M with A549 NSCLC cells. Moreover, MNP-mAb6-25 internalized and accumulated in the lysosomes of M2M. The efficacy of intravenously injected MNP-mAb6-25 to target NSCLC sub-cutaneous xenografted models containing M2M was subsequently demonstrated. Conclusion:This study highlights the potential of MNP-mAb6-25 as a nanoplatform for selective targeting TAM-containing NSCLC tumors. This nanotechnology tool may lead to the development of new applications: one involving the imaging-based detection of pro-tumoral M2 TAMs by MRI, and the other involving their potential depletion through the application of localized magnetic fields, paving the way for imaging-guided diagnosis and further therapeutic evaluation.
Solid Oxide Fuel Cells (SOFCs) and Solid Oxide Electrolysis Cells (SOECs) are recognised for their potential energy efficiency inducing a reduction of greenhouse gas emissions 1 . However, the development of new, reliable and robust oxygen electrode materials remains a crucial challenge in improving overall performance. Based on the latest developments in research about electrodes materials and microstructures, 2,3 the present study is dedicated to new architectured oxygen electrodes as well as method for diagnosing electrodes. The study of the response of electrochemical systems in a three-electrode configuration has already been published in the literature using a single reference electrode (RE) 4 . It therefore becomes possible to separately determine the potential drop of the working electrode (WE), from that of the counter electrode (CE) 5 . Moreover, placing a RE on the oxygen side and hydrogen side enables a more comprehensive analysis of the electrochemical contribution of each electrode during operation. This technique will be helpful to diagnose the electrodes behaviour during operation but also to check the stability of materials or observe degradation during ageing tests. For this purpose, an electrolyte composed of gadolinium doped ceria (GDC) has been elaborated and its ion conductivity has been verified. Then, a porous GDC backbone has been deposited by screen printing on the electrolyte using optimised ink. This backbone was then infiltrated with a solution of praseodymium nitrate to obtain the architectured electrode GDC-Pr 6 O 11 . Finally, the Area Specific Resistance (ASR) has been measured on symmetrical half cells under air in the temperature range 800 °C to 500 °C. This work is first implemented in a three-electrode configuration. A symmetrical half-cell, composed of Pr₆O₁₁-GDC10/GDC10/GDC10-Pr₆O₁₁, is prepared according to the previously described protocol. The reference electrode is deposited around one of the two electrodes of the half-cell using a platinum lacquer. Electrochemical impedance spectroscopy measurements coupled to the application of a voltage varying from 0 to 1 V are then carried out over a temperature range from 800 °C to 600 °C, in order to characterise the polarizability of the structured electrode. Secondly, a four-electrode configuration was set up on a commercial cell which was made of NiO-8YSZ/8YSZ/GDC10/GDC-Pr 6 O 11 with the optimised oxygen electrode screen printed on it. Afterward, reference electrodes were placed on each side of the cell. This approach makes it possible not only to assess the performance of the electrode developed at the ICMCB, but also to dissociate the electrochemical contributions of each electrode. (1) Stambouli, A. B.; Traversa, E. Solid Oxide Fuel Cells (SOFCs): A Review of an Environmentally Clean and Efficient Source of Energy. Renewable & substainable energy reviews 2002 . (2) Tucker, M. C.; Cheng, L.; DeJonghe, L. C. Selection of Cathode Contact Materials for Solid Oxide Fuel Cells. Journal of Power Sources 2011 , 196 (20), 8313–8322. https://doi.org/10.1016/j.jpowsour.2011.06.044. (3) Nicollet, C.; Flura, A.; Vibhu, V.; Fourcade, S.; Rougier, A.; Bassat, J.-M.; Grenier, J.-C. Preparation and Characterization of Pr2NiO4+δ Infiltrated into Gd-Doped Ceria as SOFC Cathode. J Solid State Electrochem 2016 , 20 (7), 2071–2078. https://doi.org/10.1007/s10008-016-3211-x. (4) Cimenti, M.; Co, A. C.; Birss, V. I.; Hill, J. M. Distortions in Electrochemical Impedance Spectroscopy Measurements Using 3‐Electrode Methods in SOFC. I – Effect of Cell Geometry. Fuel Cells 2007 , 7 (5), 364–376. https://doi.org/10.1002/fuce.200700019. (5) Finklea, H.; Chen, X.; Gerdes, K.; Pakalapati, S.; Celik, I. Analysis of SOFCs Using Reference Electrodes. J. Electrochem. Soc. 2013 , 160 (9), F1055–F1066. https://doi.org/10.1149/2.093309jes. Figure 1
In this presentation 23 Na MAS NMR was used to probe the local structure, electronic structure and dynamics in several layered Na x MO 2 oxides for application in Na-ion batteries. Among them, P2-Na x CoO 2 appears to be a model material with a very specific phase diagram and unusual physical properties. 23 Na MAS NMR was used to characterize the changes in the electronic structure during Na deintercalation. 23 Na MAS was also used to characterize the local structure and dynamics versus temperature in several P2 or P3 Na x CoO 2 materials and P2-Na 1/2 VO 2 . In the latter, an increase of two orders of magnitude in its electronic conductivity has been observed at approximately 322 K and a structural transition has been found to occur simultaneously. At room temperature, high resolution powder diffraction and pair distribution function analysis reveal the triangular lattice formed by vanadium ions to be distorted by the formation of pseudo-trimers vanadium clusters. At 350 K, the mobility of the electronic charge carried by vanadium ions increases as evidenced by the increase in the electronic conductivity. The arrangement of sodium ordering in P2-Na 1/2 VO 2 , which maximizes sodium-sodium distances to lower electrostatic repulsions between alkali ions, is found to be unchanged across this transition, but the ionic mobility as observed by NMR, clearly change. Finally, the P2- Na 2+x Ni 2-x/2 TeO 6 (0 ≤ x ≤ 0.5) system provides a framework for investigating the effect of dual Na + substitution into the sodium layer and the transition-metal layer of the structure, and its effects on the electrochemical properties of the materials. The sodium substitution disrupts ordering within the transition-metal layer thereby disrupting Na + ordering in the adjacent sodium layers. Beyond a critical sodium concentration, the layer stacking shifts, and all voltage plateaus of the P2-Na 2 Ni 2 TeO 6 material are no longer observed. These results highlight how sodium ordering between the MO 2 layers and the electronic transport within the MO 2 layers are intimately correlated in Na x MO 2 type sodium layered oxides.
Rare-earth nickelates Ln 2 NiO 4+ δ (Ln = Pr, Nd) with perovskite-related structure are very promising cathodes materials for SOFCs ( Solid Oxide Fuel Cells ) due to their high ionic and electronic conductivities as well as their electrocatalytic properties. 1 Theses phases crystallize in the a Ruddlesden-Popper (RP) structure, with the intergrowth of n LnNiO 3 perovskite layers for one NaCl-type LnO layer. Electronic conductivity is provided by the NiO 6 octahedra in the perovskite layer, while anionic diffusion takes place mainly via interstitial oxygen sites in the NaCl layer. Neodymium nickelate (Nd 2 NiO 4+ ⸹ ) exhibits excellent chemical stability and a moderately good electrochemical performance. In contrast, praseodymium nickelate Pr 2 NiO 4+ ⸹ , presents a very low ASR ( Area Specific Resistance ) but shows a limited chemical stability especially during SOFC operation. Aiming to find a trade-off between the high electrochemical performance of Pr 2 NiO 4+ ⸹ and the excellent chemical stability of Nd 2 NiO 4+ ⸹ , the solid solution with the general formula Nd 2-x Pr x NiO 4+ ⸹ (x = 0.5, 1, and 1.5) has been studied. The different compositions were successfully synthesised via the citrate-nitrate route. The solid solution was characterised by XRD, and the lattice parameters exhibit intermediate values between those of Pr 2 NiO 4+ ⸹ and Nd 2 NiO 4+ ⸹ . Their crystallographic structure was studied and the oxygen content of each material was measured. The electrochemical performances measured on symmetrical cells showed lower ASR values for the NdPrNiO 4+ ⸹ compound. For further investigations, we aimed to introduce a limited cation vacancies amount into the lanthanide (Ln) sub-lattice, which could influence the oxygen non-stoichiometry, the electronic structure and conductivity as well as the electro-catalytic activity. Original compositions such as (NdPr) 2-x NiO 4+ ⸹ with x = 0, 0.05, 0.1 were successfully prepared. The electrochemical performance studies carried on the corresponding half symmetrical cells showed an ASR of 40 mΩ.cm 2 at 700 °C, i.e; among the best ones reported in the literature. Ageing measurements are currently in progress. Morales-Zapata, M. A., Larrea, A. & Laguna-Bercero, M. A. Lanthanide nickelates for their application on Solid Oxide Cells. Electrochimica Acta 444 , 141970 (2023).
Metal-ordered rock-salt oxides (e.g., AMO2, A2MO3, A3MO4) exhibit diverse functionalities arising from cation ordering, yet their structural evolution is difficult to predict due to the lack of systematic design principles. For A2MO3 compounds, although two-dimensional (2D) honeycomb structures have been widely explored, the three-dimensional (3D) hyperhoneycomb phase is still rare, despite its appeal as a battery cathode and as a Kitaev spin-liquid candidate. Here, we report pressure-induced phase transitions of Li2SnO3, from the ambient-pressure honeycomb phase to a hyperhoneycomb phase at 3 GPa, and subsequently to a Li2PbO3-type phase at 8 GPa. By integrating analyses of octahedral connectivity and Madelung energy, together with machine-learning-assisted molecular dynamics simulations, we established the thermodynamic landscape governing these transitions. Specifically, the hyperhoneycomb structure becomes competitive with the honeycomb structure under pressure and is stabilized by elevated temperatures, whereas the Li2PbO3-type structure stabilizes only at high pressures. This framework rationalizes the entire sequence of observed pressure-induced phase transitions. Furthermore, the hyperhoneycomb phase is accessible across the entire solid solution of Li2(Sn1-xRux)O3, although Ru-rich compositions require higher pressure. Remarkably, the phase-pure hyperhoneycomb x = 0.75 exhibits complete electrochemical lithium deintercalation. Given the prevalence of 2D oxides under ambient conditions, designing hyperhoneycomb phases via pressure highlights a hidden yet attractive chemical space of 3D polymorphs, offering new chemical landscapes and exotic functionalities.
