Benjamin Chacon

Niobium‐based MXenes exhibitefficient near‐infrared (NIR) absorption but remain underexplored for in vivo cancer therapy. In this study, we investigated Nb ₄ C ₃ T _x MXene as an NIR‐II photothermal therapy (PTT) sensitizer for melanoma. Both in vitro and in vivo experiments were performed using Nb ₄ C ₃ T _x in combination with pulsed 1064 nm laser irradiation. Tumor growth, histological changes, and spatial localization of MXene were assessed to evaluate therapeutic efficacy and safety. Nb ₄ C ₃ T _x significantly enhanced tumor suppression under pulsed NIR‐II irradiation, inducing extensive destruction of melanoma cells while sparing surrounding tissue. Histological analysis revealed macrophage‐mediated uptake and clearance of MXene, with no evidence of persistent accumulation in tumor remnants or visceral organs. Pulsed laser irradiation provided precise and rapid heating, improving treatment accuracy and minimizing collateral damage. However, complete tumor eradication was not achieved, likely owing to limited light penetration in bulky tumors and the nontargeted distribution of pristine MXene. Our study demonstrates the feasibility and safety of Nb ₄ C ₃ T _x MXene‐assisted PTT in vivo, providing the first experimental evidence of its therapeutic potential in melanoma treatment. These findings establish Nb ₄ C ₃ T _x as a promising platform for pulsed laser–mediated PTT, while highlighting the need for targeted functionalization and treatment optimization to achieve selective tumor ablation.

Since their discovery in 2011, MXenes have emerged as versatile 2D materials for energy storage, biomedicine, and electromagnetic interference shielding. While Ti₃C₂T_x remains the most studied, this research investigates heavy metal MXenes, specifically focusing on tantalum carbide Ta₄C₃T_x By optimizing precursor stoichiometry and sintering parameters, we achieved highly stoichiometric Ta₄AlC₃ MAX phase, resulting in Ta₄C₃T_x MXene with a record 50% yield and defect-free surfaces. The study further evaluates the biocompatibility of heavy metal MXenes (Ta₄C₃T_x, Nb₄C₃T_x, and Mo₂Ti₂C₃T_x following degradation in biological environments. All compositions maintained a non-toxic profile toward peripheral blood mononuclear cells (PBMCs) at concentrations up to 100 [mu]g/mL. Proteomic and lipidomic analyses revealed that the protein corona and lipid binding are composition-dependent, directly influencing immune recognition. Additionally, investigations into microgravity's effect on cellular uptake provide critical insights for applications in space medicine. Finally, this work presents the first experimental measurements of [gamma]-ray attenuation in MXenes. Ta₄C₃T_x significantly outperforms the archetypal Ti₃C₂T_x across all energy levels, demonstrating attenuation properties comparable to bulk tantalum carbide (TaC). X-ray CT scans of Ta₄C₃T_x-coated cotton fabrics confirm enhanced radiation shielding without compromising fabric texture or wearability. These findings establish a robust synthesis for high-yield Ta₄C₃T_x MXene, validate the long-term biocompatibility of heavy metal MXenes, and pioneer their use in lightweight, flexible radiation shielding. This research positions MXenes as a multifunctional solution for next-generation personal protection and space exploration technologies.

Understanding the communication of individual neurons necessitates precise control of neural activity. Photothermal modulation is a remote and non‐genetic technique to control neural activity with high spatiotemporal resolution. The local heat release by photothermally active nanomaterial will change the membrane properties of the interfaced neurons during light illumination. Recently, it is demonstrated that the two‐dimensional Ti₃C₂T_x MXene is an outstanding candidate to photothermally excite neurons with low incident energy. However, the safety of using Ti₃C₂T_x for neural modulation is unknown. Here, the biosafety of Ti₃C₂T_x‐based photothermal modulation is thoroughly investigated, including assessments of plasma membrane integrity, mitochondrial stress, and oxidative stress. It is demonstrated that culturing neurons on 25 µg cm⁻² Ti₃C₂T_x films and illuminating them with laser pulses (635 nm) with different incident energies (2–10 µJ per pulse) and different pulse frequencies (1 pulse, 1 Hz, and 10 Hz) neither damage the cell membrane, induce cellular stress, nor generate oxidative stress. The threshold energy to cause damage (i.e., 14 µJ per pulse) exceeded the incident energy for neural excitation (<10 µJ per pulse). This multi‐assay safety evaluation provides crucial insights for guiding the establishment of light conditions and protocols in the clinical translation of photothermal modulation.