Dual-Emission Origins in Bi3+-Doped M2O3 Sesquioxides (M = Sc, Y, Gd and Lu): A First-Principles Study.

Bi3+-doped sesquioxides exhibit dual emissions, marked by distinct Stokes shift and bandwidth, meaning unraveling their underlying origins is particularly intriguing. In this study, we employ first-principles calculations to investigate the luminescence mechanisms within the M2O3:Bi3+ (M = Sc, Y, Gd, Lu) series, with the goal of addressing the posed inquiry. Our investigation commences with the analysis of the site occupancy and charge state of bismuth ions in the two cationic sites through formation energy calculations. Additionally, we examine the local coordination environments for various excited states of Bi3+ dopants, including the 3P0,1 state and two types of charge transfer states, by evaluating their equilibrium geometric structures. The utilization of the hybrid functional enables us to obtain results of electronic structures and optical properties comparable with experiments. Importantly, the calculated energies for the 6s-6p transitions of Bi3+ dopants in the M2O3 series align well with the observed dual-emission energies. This alignment challenges the conventional spectroscopic sense that emission bands with large Stokes shifts can be exclusively ascribed to charge transfer transitions. Consequently, the integration of experimental and theoretical approaches emerges as the optimal strategy for designing novel Bi3+-doped phosphors.

Chemodynamic PtMn Nanocubes for Effective Photothermal ROS Storm a Key Anti-Tumor Therapy in-vivo.

Background: Chemodynamic therapy (CDT) is a new treatment approach that is triggered by endogenous stimuli in specific intracellular conditions for generating hydroxyl radicals. However, the efficiency of CDT is severely limited by Fenton reaction agents and harsh reaction conditions. Methods: Bimetallic PtMn nanocubes were rationally designed and simply synthesized through a one-step high-temperature pyrolysis process by controlling both the nucleation process and the subsequent crystal growth stage. The polyethylene glycol was modified to enhance biocompatibility. Results: Benefiting from the alloying of Pt nanocubes with Mn doping, the structure of the electron cloud has changed, resulting in different degrees of the shift in electron binding energy, resulting in the increasing of Fenton reaction activity. The PtMn nanocubes could catalyze endogenous hydrogen peroxide to toxic hydroxyl radicals in mild acid. Meanwhile, the intrinsic glutathione (GSH) depletion activity of PtMn nanocubes consumed GSH with the assistance of Mn3+/Mn2+. Upon 808 nm laser irradiation, mild temperature due to the surface plasmon resonance effect of Pt metal can also enhance the Fenton reaction. Conclusion: PtMn nanocubes can not only destroy the antioxidant system via efficient reactive oxygen species generation and continuous GSH consumption but also propose the photothermal effect of noble metal for enhanced Fenton reaction activity.

V-doped MoS2 nanozymes providing reactive oxygen species and depleting glutathione for photothermally-enhanced nanocatalytic therapy.

Introduction: The tumor microenvironment and multidrug resistance of tumor cells seriously impair the activity of the nanozymes. Methods: Herein, a polyethylene glycol (PEG)-modified vanadium-doped molybdenum disulfide (V-MoS2@PEG) nanozymes were constructed to enhance anti-tumor activity through multi-enzymatic catalysis and photothermal effect with simultaneous reactive oxygen species replenishment and glutathione depletion. Results and discussion: V-MoS2@PEG nanosheets exerted peroxidase activity by causing molybdenum ion (Mo4+) to react with hydrogen peroxide to form toxic hydroxyl radicals (·OH). Meanwhile, the V-doping can deplete glutathione avoiding ·OH consumption. In addition, the high heat generated by V-MoS2@PEG nanozymes under near-infrared laser irradiation brought about a desirable local temperature gradient, which produced an enhanced catalytic effect by promoting band bending. Furthermore, the photothermally inspired polarized charge increased the permeability of the tumor cell membrane and promoted further aggregation of the nanozymes, which realized the combination of photothermal therapy with multi-enzymatic catalysis, solved the problem of multi-enzyme catalysis, and improved the anti-tumor efficiency.

Unraveling Broadband Near-Infrared Luminescence in Cr3+-Doped Ca3Y2Ge3O12 Garnets: Insights from First-Principles Analysis.

In this study, we conducted an extensive investigation into broadband near-infrared luminescence of Cr3+-doped Ca3Y2Ge3O12 garnet, employing first-principles calculations within the density functional theory framework. Our initial focus involved determining the site occupancy of Cr3+ activator ions, which revealed a pronounced preference for the Y3+ sites over the Ca2+ and Ge4+ sites, as evidenced by the formation energy calculations. Subsequently, the geometric structures of the excited states 2E and 4T2, along with their optical transition energies relative to the ground state 4A2 in Ca3Y2Ge3O12:Cr3+, were successfully modeled using the ΔSCF method. Calculation convergence challenges were effectively addressed through the proposed fractional particle occupancy schemes. The constructed host-referred binding energy diagram provided a clear description of the luminescence kinetics process in the garnet, which explained the high quantum efficiency of emission. Furthermore, the accurate prediction of thermal excitation energy yielded insights into the thermal stability of the compound, as illustrated in the calculated configuration coordinate diagram. More importantly, all calculated data were consistently aligned with the experimental results. This research not only advances our understanding of the intricate interplay between geometric and electronic structures, optical properties, and thermal behavior in Cr3+-doped garnets but also lays the groundwork for future breakthroughs in the high-throughput design and optimization of luminescent performance and thermal stability in Cr3+-doped phosphors.

Tailoring mSiO2-SmCox nanoplatforms for magnetic/photothermal effect-induced hyperthermia therapy.

Hyperthermia therapy is a hotspot because of its minimally invasive treatment process and strong targeting effect. Herein, a synergistic magnetic and photothermal therapeutic nanoplatform is rationally constructed. The well-dispersive mSiO2-SmCox nanoparticles (NPs) were synthesized through a one-step procedure with the regulated theoretical molar ratio of Sm/Co among 1:1, 1:2, and 1:4 for controlling the dispersion and magnetism properties of SmCox NPs in situ growth in the pore structure of mesoporous SiO2 (mSiO2), where mSiO2 with diverse porous structures and high specific surface areas serving for locating the permanent magnetic SmCox NPs. The mSiO2-SmCox (Sm/Co = 1:2) NPs with highly dispersed and uniform morphology has an average diameter of ∼73.08 nm. The photothermal conversion efficiency of mSiO2-SmCox (Sm/Co = 1:2) NPs was determined to be nearly 41%. The further in vitro and in vivo anti-tumor evaluation of mSiO2-SmCox (Sm/Co = 1:2) NPs present promising potentials for hyperthermia-induced tumor therapy due to magnetic and photothermal effects.

GSH-Triggered/Photothermal-Enhanced H2S Signaling Molecule Release for Gas Therapy.

Traditional treatment methods for tumors are inefficient and have severe side effects. At present, new therapeutic methods such as phototherapy, chemodynamic therapy, and gasodynamic therapy have been innovatively developed. High concentrations of hydrogen sulfide (H2S) gas exhibit cancer-suppressive effects. Herein, a Prussian blue-loaded tetra-sulfide modified dendritic mesoporous organosilica (PB@DMOS) was rationally constructed with glutathione (GSH)-triggered/photothermal-enhanced H2S signaling molecule release properties for gas therapy. The as-synthesized nanoplatform confined PB nanoparticles in the mesoporous structure of organosilica silica due to electrostatic adsorption. In the case of a GSH overexpressed tumor microenvironment, H2S gas was controllably released. And the temperature increases due to the photothermal effects of PB nanoparticles, further enhancing H2S release. At the same time, PB nanoparticles with excellent hydrogen peroxide catalytic performance also amplified the efficiency of tumor therapy. Thus, a collective nanoplatform with gas therapy/photothermal therapy/catalytic therapy functionalities shows potential promise in terms of efficient tumor therapy.

Corrigendum: Tailoring mSiO2-SmCox nanoplatforms for magnetic/photothermal effect-induced hyperthermia therapy.

[This corrects the article DOI: 10.3389/fbioe.2023.1249775.].

PdMo nanoflowers for endogenous/exogenous-stimulated nanocatalytic therapy.

The clinical application of reactive oxygen species (ROS)-mediated tumor treatment has been critically limited by inefficient ROS generation. Herein, we rationally synthesized and constructed the three-dimensional PdMo nanoflowers through a one-pot solvothermal reduction method for elaborately regulated peroxidase-like enzymatic activity and glutathione peroxidase-like enzymatic activity, to promote oxidation ROS evolvement and antioxidation glutathione depletion for achieving intensive ROS-mediated tumor therapy. The three-dimensional superstructure composed of two-dimensional nanosheet subunits can solve the issues by avoiding the appearance of tightly stacked crystalline nanostructures. Significantly, Mo is chosen as a second metal to alloy with Pd because of its more chemical valence and negative ionization energy than Pd for improved electron transfer efficiencies and enhanced enzyme-like activities. In addition, the photothermal effect generated by PdMo nanoflowers could also enhance its enzymatic activities. Thus, this work provides a promising paradigm for achieving highly ROS-mediated tumor therapeutic efficacy by regulating the multi-enzymatic activities of Pd-based nanoalloys.