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Bioorthogonal metallocatalysis has opened up a xenobiotic route to perform nonenzymatic catalytic transformations in living settings. Despite their promising features, most metals are deactivated inside cells by a myriad of reactive biomolecules, including biogenic thiols, thereby limiting the catalytic functioning of these abiotic reagents. Here we report the development of cytocompatible alloyed AuPd nanoparticles with the capacity to elicit bioorthogonal depropargylations with high efficiency in biological media. We also show that the intracellular catalytic performance of these nanoalloys is significantly enhanced by protecting them following two different encapsulation methods. Encapsulation in mesoporous silica nanorods resulted in augmented catalyst reactivity, whereas the use of a biodegradable PLGA matrix increased nanoalloy delivery across the cell membrane. The functional potential of encapsulated AuPd was demonstrated by releasing the potent chemotherapy drug paclitaxel inside cancer cells. Nanoalloy encapsulation provides a novel methodology to develop nanoreactors capable of mediating new-to-life reactions in cells., UK Research & Innovation (UKRI), Engineering & Physical Sciences Research Council (EPSRC) EP/N021134/1, ERC (Advanced Grant CADENCE) ERC-2016-ADG-742684, European Commission European Commission Joint Research Centre H2020-MSCA-IF-2014-658833 H2020-MSCA-IF-2018-841990 H2020-MSCA-IF-2016-749299 H2020-MSCA-IF-2019-895664, Spanish Government RTI2018-099019-A-I00

Controlling the nano- and micropatterning of metal structures is an important requirement for various technological applications in photonics and biosensing. This work presents a method for controllably creating silver micropatterns by laser-induced photosculpting. Photosculpting is driven by plasmonic interactions between pulsed laser radiation and silver nanorods (AgNRs) in aqueous suspension; this process leads to optical binding forces transporting the AgNRs in the surroundings, while electronic thermalization results in photooxidation, melting, and ripening of the AgNRs into well-defined 3D structures. This work call these structures Airy castles due to their structural similarity with a diffraction-limited Airy disk. The photosculpted Airy castles contain emissive Ag nanoclusters, allowing for the visualization and examination of the aggregation process using luminescence microscopy. This work comprehensively examines the factors that define the photosculpting process, namely, the concentration and shape of the AgNRs, as well as the energy, power, and repetition rate of the laser. Finally, this work investigates the potential applications by measuring the metal-enhanced luminescence of a europium-based luminophore using Airy castles., MCIN/AEI/10.13039/501100011033 and the European Regional Development Fund (ERDF). Grant Number: CTQ2017-85658-R MCIN/AEI/10.13039/501100011033. Grant Number: PID2020-114256RB-I00 European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie. Grant Number: 101007934 Fundação para a Ciência e a Tecnologia, I.P. Grant Numbers: UIDB/00100/2020, 2022.04076.PTDC

Ethylene oxide is one of the most important raw materials in the chemical industry, with an annual production close to 35 million metric tons. Despite its importance, to date, no metal has been found that can compete with the original silver bulk material catalyst discovered in 1931. Recently, a few copper and copper–silver based nanostructures have demonstrated remarkable selectivity and activity, especially when coupled with an industrial chlorine promoter. The present work evaluates the mechanistic role of chlorine as an active promoter of the selective oxidation of ethylene to ethylene oxide in the presence of a silver–copper oxide hybrid nanocatalyst (AgCuO). Experimental kinetic studies combined with density functional theory (DFT) calculations provide insight into the influence that Ag/CuO-supported chlorine atoms have over the ethylene epoxidation reaction. Remarkably, the typically described indirect route via the formation of an oxametallacycle (OMC) is also accompanied by a direct route. Furthermore, the presence of chlorine seems to facilitate a more favorable adsorption energy for ethylene oxide (EO) than for acetaldehyde (AA), the main reaction by-product. As a result, complete oxidation of EO can be further prevented in the presence of this AgCuO hybrid heteronanostructure., We acknowledge financial support from the European Research Council ERC-Advanced Grant HECTOR (project number 267626) is gratefully acknowledged. The computations were performed on resources provided by the supercomputer “Caesaraugusta” (node of the Spanish Supercomputer Network) provided by BIFI (Universidad de Zaragoza). The TEM studies were conducted at the Laboratorio de Microscopias Avanzadas, Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Spain. S.H. acknowledges funding from the Agencia Estatal de Investigación and the Ministerio de Ciencia, Innovación y Universidades, of Spain (PID2019-110430G B-C22), and from the EU FEDER Framework 2014-2020 and Consejería de Conocimiento, Investigación y Universidad of the Andalusian Government (FEDER-UPO-1265695).

Cancer represents a major public health issue and a primary cause of death for the mankind and the search for alternative cancer treatments that assist or alleviate the drawbacks of current cancer therapies remains imperative. Nanocatalytic medicine represents a new discipline that aims at exploiting the unique response of heterogeneous catalysts exposed to unconventional conditions such as those encountered in the tumor microenvironment (TME). Photo-triggered cancer therapies using light-activable catalytic materiales can stimulate and activate multiple biological processes and represent a very promising field of study. Herein, we evaluate the use of carbon nanodots with different composition (CNDs) retrieved by laser pyrolysis as potential near-infrared (NIR) photosensitizers able to activate P25 semiconductor nanostructured photocatalysts. We describe the enhanced photocatalytic response towards glucose conversion and reactive oxygen species (ROS) generation upon irradiation with NIR-LEDs when CNDs doped with heteroatoms were tested. The most active photocatalysts were evaluated in the presence of cancer cells and revealed a promising photodynamic effect under NIR irradiation. This work represents one of the scarce examples of a conventional inorganic photocatalyst containing TiO2 that is translated into a biomedical application with a successful outcome.

Platinum nanoparticles (Pt NPs) have a well-established role as a classic heterogeneous catalyst. Also, Pt has traditionally been employed as a component of organometallic drug formulations for chemotherapy. However, a new role in cancer therapy is emerging thanks to its outstanding catalytic properties, enabling novel approaches that are surveyed in this review. Herein, we critically discuss results already obtained and attempt to ascertain future perspectives for Pt NPs as catalysts able to modify key processes taking place in the tumour microenvironment (TME). In addition, we explore relevant parameters affecting the cytotoxicity, biodistribution and clearance of Pt nanosystems. We also analyze pros and cons in terms of biocompatibility and potential synergies that emerge from combining the catalytic capabilities of Pt with other agents such as co-catalysts, external energy sources (near-infrared light, X-ray, electric currents) and conventional therapies., The authors gratefully acknowledge funding from the European Commission (ERC Advanced Grant-742684 CADENCE).

The semilocal convergence using recurrence relations of a family of iterations for solving nonlinear equations in Banach spaces is established. It is done under the assumption that the second order Fréchet derivative satisfies the Hölder continuity condition. This condition is more general than the usual Lipschitz continuity condition used for this purpose. Examples can be given for which the Lipschitz continuity condition fails but the Hölder continuity condition works on the second order Fréchet derivative. Recurrence relations based on three parameters are derived. A theorem for existence and uniqueness along with the error bounds for the solution is provided. The R-order of convergence is shown to be equal to 3 + q when θ = ±1; otherwise it is 2 + q, where q ∈ (0, 1]. Numerical examples involving nonlinear integral equations and boundary value problems are solved and improved convergence balls are found for them. Finally, the dynamical study of the family of iterations is also carried out.

The use of inorganic nanomaterials to tackle and exploit the intrinsic chemical nature of the tumor microenvironment (TME) has emerged as a promising strategy in cancer therapy. Manganese oxide nanoparticles (MnxOy) offer unique advantages in terms of redox properties and specificity towards the TME scenario: low O2 concentrations, mildly acidic pH and high oxidative stress; environmental conditions that often lead to a reduction in the efficacy of cancer treatments. MnxOy-based nanoplatforms have recently demonstrated exciting properties as inorganic nanocatalysts to operate under TME constraints. Alternatively, Mn-nanocatalysts have also displayed synergistic anticancer response in combination with other active co-adjuvant elements (drugs, enzymes or nanomaterials). The aim of this review is to provide new insights on the main functionalities of Mn-based nanomaterials applied to cancer therapy. We analyze its capacity as oxygen supplier in hypoxic scenarios, its role to induce the selective depletion of glutathione (GSH) to maximize cell stress or its capacity to promote starvation therapy via glucose oxidation. We aim at providing an insightful view of the operating mechanisms behind each of these critical processes and highlight the versatility and catalytic richness of Mn-based nanoparticles in this developing field. We also provide a general and comprehensive analysis of the Mn fate when trafficking through the intracellular levels., Financial support from the European Research Council (ERC Advanced Grant CADENCE number 742684) is gratefully acknowledged. J.B-A. thanks the Spanish Government for an FPU predoctoral contract.

Heterogeneous catalysis has emerged as a promising alternative for the development of new cancer therapies. In addition, regarding the tumor microenvironment as a reactor with very specific chemical features has provided a new perspective in the search for catalytic nanoarchitectures with specific action against chemical species playing a key role in tumor metabolism. One of these species is glutathione (GSH), whose depletion is the cornerstone of emerging strategies in oncology, since this metabolite plays a pivotal regulatory role as antioxidant agent, dampening the harmful effects of intracellular reactive oxidative species (ROS). Herein, we present copper-iron oxide spinel nanoparticles that exhibit a versatile and selective catalytic response to reduce GSH levels while generating ROS in a cascade reaction. We demonstrate a clear correlation between GSH depletion and apoptotic cell death in tumor cells in the presence of the copper-iron nanocatalyst. Furthermore, we also provide a novel analytical protocol, alternative to state-of-the-art commercial kits, to accurately monitoring the concentration of GSH intracellular levels in both tumor and healthy cells. We observe a selective action of the nanoparticles, with lower toxicity in healthy cell lines, whose intrinsic GSH levels are lower, and intense apoptosis in tumor cells accompanied by a fast reduction of GSH levels., Financial support from the European Research Council (ERC-Advanced Grant CADENCE number 742684) is gratefully acknowledged. The TEM measurements were conducted at the Laboratorio de Microscopias Avanzadas, Instituto de Nanociencia de Aragon, Universidad de Zaragoza, Spain. The synthesis of materials has been performed by the Platform of Production of Biomaterials and Nanoparticles of the NANBIOSIS ICTS, more specifically by the Nanoparticle Synthesis Unit of the CIBER in BioEngineering, Biomaterials & Nanomedicine (CIBER-BBN). J.B-A. acknowledges the Spanish Government for an FPU predoctoral contract. We would also like to thank to the Scientific Services of the Aragon Institute of Health Sciences (IACS), specifically to the Cell culture, Microscopy, and Citometry Services and their specialist and the ICTS ELECMI.

This article belongs to the Special Issue 10th Anniversary of Catalysts—Feature Papers in Photocatalysis., The present review aims at highlighting recent advances in the development of photocatalysts devoted to cancer therapy applications. We pay especial attention to the engineering aspects of different nanomaterials including inorganic semiconductors, organic-based nanostructures, noble metal-based systems or synergistic hybrid heterostructures. Furthermore, we also explore and correlate structural and optical properties with their photocatalytic capability to successfully performing in cancer-related therapies. We have made an especial emphasis to introduce current alternatives to organic photosensitizers (PSs) in photodynamic therapy (PDT), where the effective generation of reactive oxidative species (ROS) is pivotal to boost the efficacy of the treatment. We also overview current efforts in other photocatalytic strategies to tackle cancer based on photothermal treatment, starvation therapy, oxidative stress unbalance via glutathione (GSH) depletion, biorthogonal catalysis or local relief of hypoxic conditions in tumor microenvironments (TME)., This research was funded by the European Research Council (ERC) through an Advanced Research Grant (CADENCE, grant number 742684). J.B.-A. acknowledges the Spanish Government for a PhD predoctoral grant (FPU18/04618). J.I.G.-P. thanks the Regional Government of Aragon (DGA) for granting a PhD predoctoral contract.