Search

H2-Driven NADH regeneration has long suffered from low selectivity when non-enzymatic, particularly heterogeneous catalysts, are used. In addition to the unselective nature of the catalysts, the typically unmeasured NAD+ conversion has inevitably hindered catalyst development. Here we report Sn-doped Pt/SiO2 catalysts for the selective regeneration of NADH and show that doping Pt/SiO2 with 10 at% Sn can deliver a selectivity of 90% (at full conversion) using H2. We propose that this is a result of Sn disturbing the Pt ensemble, altering the mode of NAD+ adsorption and directing the reduction to the 1,4-position of the nicotinamide ring. [ABSTRACT FROM AUTHOR]

H2-Driven NADH regeneration has long suffered from low selectivity when non-enzymatic, particularly heterogeneous catalysts, are used. In addition to the unselective nature of the catalysts, the typically unmeasured NAD+ conversion has inevitably hindered catalyst development. Here we report Sn-doped Pt/SiO2 catalysts for the selective regeneration of NADH and show that doping Pt/SiO2 with 10 at% Sn can deliver a selectivity of 90% (at full conversion) using H2. We propose that this is a result of Sn disturbing the Pt ensemble, altering the mode of NAD+ adsorption and directing the reduction to the 1,4-position of the nicotinamide ring. [ABSTRACT FROM AUTHOR]

NAD(P)H is a key cofactor widely used in biocatalytic reductive transformations, facilitating a wide range of industrially significant reactions which ultimately result in the consumption of the costly cofactor. To make NAD(P)H dependent biotransformations sustainable and economically feasible, different catalytic routes have been investigated to regenerate NAD(P)H. Here we report a comprehensive life cycle assessment (LCA) of these catalytic regeneration methods. Midpoint characterisation and normalisation show that the synthesis of the catalyst, specifically the use of noble metals and energy consumption, dominate the environmental impacts and have the greatest contribution to all considered impact categories. This comparative LCA highlights the need for future investigation into noble metal based catalyst alternatives, to provide cleaner and more sustainable methods of regenerating the cofactor NAD(P)H. [ABSTRACT FROM AUTHOR]

This study demonstrates a novel method to quantify selective (1,4-NADH) and unselective products (1,2- and 1,6-NADH) in NADH regeneration using combined UV-Vis spectroscopy and biological assays. The validity of the proposed method was tested in the Pt/C promoted NAD+ hydrogenation using hydrogen as reducing agent. [ABSTRACT FROM AUTHOR]

We report that highly crystallized iron oxide nanoparticles (HCIONPs) made by thermal decomposition and further coating with a polysiloxane-containing copolymer can be used as effective mediators for photothermal therapy. Irradiation of a HCIONP solution containing 0.5 mg mL-1 Fe, for instance, with an 885 nm diode laser at a power of 2.5 W cm-2, induces a temperature increase of 33 °C from room temperature, while water produced only a ~3 °C increase as the control. In vivo studies are further evaluated for effective photothermal therapy using the as-prepared HCIONPs. Benefiting from the great antibiofouling property of the polymer coating and minimized hydrodynamic size (whole particle size: 24 nm), the nanoparticles intravenously administered to SUM-159 tumor-bearing mice can effectively accumulate within the tumor tissue (5.3% of injection dose) through the enhanced permeability and retention effect. After applying the same laser conditions to irradiate the tumors, complete tumor regression is observed within three weeks without disease relapse over the course of three months. Conversely, control mice exhibit continuous tumor growth leading to animal mortality within four weeks. To better understand the photothermal effect of HCIONPs and potentially improve their photothermal efficiency, we compare their photothermal effect and crystal structures with commercially available magnetic nanoparticles. Our data show that after applying the same laser to commercially available magnetic nanoparticles from FeREX at the same iron concentration, the temperature is only increased by 7.4 °C. We further use synchrotron-XRD and high-resolution TEM to compare the crystal structures of both magnetic nanoparticles. The data show that both magnetic nanoparticles are Fe3O4 but as-prepared HCIONPs are highly crystalline and have preferred lattice plane orientations, which may be the cause of their enhanced photothermal efficiency. Taken together, these data suggest that HCIONPs, with unique lattice orientations and small size as well as antifouling coating, can be used as promising mediators for photothermal cancer therapy. [ABSTRACT FROM AUTHOR]

We report that highly crystallized iron oxide nanoparticles (HCIONPs) made by thermal decomposition and further coating with a polysiloxane-containing copolymer can be used as effective mediators for photothermal therapy. Irradiation of a HCIONP solution containing 0.5 mg mL -1 Fe, for instance, with an 885 nm diode laser at a power of 2.5 W cm -2 , induces a temperature increase of 33 °C from room temperature, while water produced only a ∼3 °C increase as the control. In vivo studies are further evaluated for effective photothermal therapy using the as-prepared HCIONPs. Benefiting from the great antibiofouling property of the polymer coating and minimized hydrodynamic size (whole particle size: 24 nm), the nanoparticles intravenously administered to SUM-159 tumor-bearing mice can effectively accumulate within the tumor tissue (5.3% of injection dose) through the enhanced permeability and retention effect. After applying the same laser conditions to irradiate the tumors, complete tumor regression is observed within three weeks without disease relapse over the course of three months. Conversely, control mice exhibit continuous tumor growth leading to animal mortality within four weeks. To better understand the photothermal effect of HCIONPs and potentially improve their photothermal efficiency, we compare their photothermal effect and crystal structures with commercially available magnetic nanoparticles. Our data show that after applying the same laser to commercially available magnetic nanoparticles from FeREX at the same iron concentration, the temperature is only increased by 7.4 °C. We further use synchrotron-XRD and high-resolution TEM to compare the crystal structures of both magnetic nanoparticles. The data show that both magnetic nanoparticles are Fe 3 O 4 but as-prepared HCIONPs are highly crystalline and have preferred lattice plane orientations, which may be the cause of their enhanced photothermal efficiency. Taken together, these data suggest that HCIONPs, with unique lattice orientations and small size as well as antifouling coating, can be used as promising mediators for photothermal cancer therapy.