In this work, we report the multifunctional character of neodymium-doped LaF3 core/shell nanoparticles. Because of the spectral overlap of the neodymium emission bands with the transparency windows ...of human tissues, these nanoparticles emerge as relevant subtissue optical probes. For neodymium contents optimizing the luminescence brightness of Nd3+:LaF3 nanoparticles, subtissue penetration depths of several millimeters have been demonstrated. At the same time, it has been found that the infrared emission bands of Nd3+:LaF3 nanoparticles show a remarkable thermal sensitivity, so that they can be advantageously used as luminescent nanothermometers for subtissue thermal sensing. This possibility has been demonstrated in this work: Nd3+:LaF3 nanoparticles have been used to provide optical control over subtissue temperature in a single-beam plasmonic-mediated heating experiment. In this experiment, gold nanorods are used as nanoheaters while thermal reading is performed by the Nd3+:LaF3 nanoparticles. The possibility of a real single-beam-controlled subtissue hyperthermia process is, therefore, pointed out.
Nanoparticles promise to revolutionize the way we think of ordinary materials thanks to the new features such small structures exhibit which include strength, durability, optical and magnetics ...properties. Magnetic iron oxide nanoparticles (IONPs) are a prominent class of NMs because of their potential application in magnetic separation, hyperthermia, targeted drug delivery, and catalysis. Most synthetic nanoparticulate platforms rely on the use of tough chemical procedures associated with unfriendly, harmful and costly reactants. For this reason, bio-inspired approaches have become the most successful alternatives to fabricate nanomaterials in an “eco-friendly” manner, and many bio-protocols that make use of substrates from plants and microorganisms have been successfully applied in the synthesis of magnetic IONPs. In this review, the main biosynthesis protocols applied in the synthesis of iron oxide nanoparticles are discussed. A discussion on the challenges for a second stage perspective which would be a large scale production is also given.
Photocatalysts have been widely applied in the degradation of organic compounds using visible and ultraviolet radiation. Different synthesis approaches have been developed and optimized to produce ...efficient, eco-friendly, and inexpensive materials to photo-treat water samples contaminated with dyes, pigments, pesticides, and other organic pollutants. Over the last two decades magnetic materials have emerged as a potential alternative to facilitate catalyst isolation in heterogeneously catalyzed liquid-phase reactions. In this review, we focus on the discussion of several studies including the main synthesis processes and new protocol modifications for the fabrication of magnetic photocatalysts, and their impact on the catalyst morphology, efficiency, and recycling. Emphasis is given on the discussion of the synthesis strategies over last decade to produce photoactive catalysts including single-phase catalysts, composites, Multifunctional metal–organic framework materials, binary and ternary core–shell materials, and yolk–shell photocatalysts.
Highlights
A review on magnetic materials for photocatalysis is given.
Emphasis is given on sol–gel preparation methods utilized for the fabrication of magnetic photocatalysts.
Discussion on different material types of magnetic photocatalysts is presented.
Magnetic separation properties and efficiency are discussed based on the material structures.
•ATPS conditions for the extraction of HIV VLPs were optimized in batch mL scale.•Polymer–salt and polymer–polymer systems were investigated.•PEG–ammonium sulfate system demonstrated the higher ...partition coefficient (K=4.4).•The extraction was also tested in a continuous microfluidic setting.•Batch and continuous extractions provided similar K values and protein purities.
Virus-like particles (VLPs) are promising candidates for a new generation of biopharmaceuticals, with a high impact in gene therapy, vaccination and also in the construction of delivery vehicles. Despite the growing interest in these particles, their production is currently limited by the low capacities and throughputs of classical downstream processing technologies.
Aqueous two-phase extraction (ATPE) is a promising bioprocessing technique allowing clarification, concentration and purification to be accomplished in a single step. ATPE also combines a high biocompatibility with a simple and reliable scale-up and can also be performed in a continuous mode of operation.
In this work, ATPE conditions for the purification of a Human Immunodeficiency Virus (HIV) VLP were screened and optimized in mL scale batch conditions. Polyethylene glycol (PEG)–salt (potassium phosphate, ammonium sulfate and trisodium citrate) and polymer–polymer (PEG–dextran) systems were investigated, among which the PEG–ammonium sulfate system demonstrated the higher partition coefficient (K=4.4). This parameter was then compared with the obtained in a continuous microfluidic setting, performed by flowing both immiscible phases through a 100 width×20μm wide microchannel. The batch optimization results showed good agreement with the continuous miniaturized extraction, both in terms of K (K=3.9 in microfluidic scale) and protein purity. These novel findings show that PEG–ammonium sulfate ATPE is a promising system for primary HIV-VLP recovery and demonstrate the potential of a miniaturized ATPE for massive parallelization (scale-out) at the preparative scale or integrated in analytical miniaturized systems.
The future perspective of fluorescence imaging for real in vivo application are based on novel efficient nanoparticles which is able to emit in the second biological window (1000–1400 nm). In this ...work, the potential application of Nd3+‐doped LaF3 (Nd3+:LaF3) nanoparticles is reported for fluorescence bioimaging in both the first and second biological windows based on their three main emission channels of Nd3+ ions: 4F3/2→4I9/2, 4F3/2→4I11/2 and 4F3/2→4I13/2 that lead to emissions at around 910, 1050, and 1330 nm, respectively. By systematically comparing the relative emission intensities, penetration depths and subtissue optical dispersion of each transition we propose that optimum subtissue images based on Nd3+:LaF3 nanoparticles are obtained by using the 4F3/2→4I11/2 (1050 nm) emission band (lying in the second biological window) instead of the traditionally used 4F3/2→4I9/2 (910 nm, in the first biological window). After determining the optimum emission channel, it is used to obtain both in vitro and in vivo images by the controlled incorporation of Nd3+:LaF3 nanoparticles in cancer cells and mice. Nd3+:LaF3 nanoparticles thus emerge as very promising fluorescent nanoprobes for bioimaging in the second biological window.
The future achievement of depth tissue real in vivo imaging requires the development of novel efficient infrared fluorescence nanoparticles. In this work, the potential application of Nd3+‐doped LaF3 nanoparticles is reported for fluorescence bioimaging based on their three main emission channels of Nd3+ ions (first and second biological windows). High contrast and low toxicity are obtained, both in vivo and in vitro, using 1.06 μm.
The AML1-ETO fusion protein, which is present in 10-15% of cases of acute myeloid leukemia, is known to repress myeloid differentiation genes through DNA binding and recruitment of ...chromatin-modifying proteins and transcription factors in target genes. ChIP-chip analysis of human hematopoietic stem/progenitor cells transduced with the AML1-ETO fusion gene enabled us to identify 1168 AML1-ETO target genes, 103 of which were co-occupied by histone deacetylase 1 (HDAC1) and had lost the hyperacetylation mark at histone H4, and 264 showed a K9 trimethylation at histone H3. Enrichment of genes involved in hematopoietic differentiation and in specific signaling pathways was observed in the presence of these epigenetic modifications associated with an 'inactive' chromatin status. Furthermore, AML1-ETO target genes had a significant correlation between the chromatin marks studied and transcriptional silencing. Interestingly, AML1 binding sites were absent on a large number of selected AML1-ETO promoters and an Sp1 binding site was found in over 50% of them. Reversible silencing induced by the fusion protein in the presence of AML1 and/or Sp1 transcription factor binding site was confirmed. Therefore, this study provides a global analysis of AML1-ETO functional chromatin modifications and identifies the important role of Sp1 in the DNA binding pattern of AML1-ETO, suggesting a role for Sp1-targeted therapy in this leukemia subtype.
This roadmap on Nanotechnology for Catalysis and Solar Energy Conversion focuses on the application of nanotechnology in addressing the current challenges of energy conversion: 'high efficiency, ...stability, safety, and the potential for low-cost/scalable manufacturing' to quote from the contributed article by Nathan Lewis. This roadmap focuses on solar-to-fuel conversion, solar water splitting, solar photovoltaics and bio-catalysis. It includes dye-sensitized solar cells (DSSCs), perovskite solar cells, and organic photovoltaics. Smart engineering of colloidal quantum materials and nanostructured electrodes will improve solar-to-fuel conversion efficiency, as described in the articles by Waiskopf and Banin and Meyer. Semiconductor nanoparticles will also improve solar energy conversion efficiency, as discussed by Boschloo et al in their article on DSSCs. Perovskite solar cells have advanced rapidly in recent years, including new ideas on 2D and 3D hybrid halide perovskites, as described by Spanopoulos et al 'Next generation' solar cells using multiple exciton generation (MEG) from hot carriers, described in the article by Nozik and Beard, could lead to remarkable improvement in photovoltaic efficiency by using quantization effects in semiconductor nanostructures (quantum dots, wires or wells). These challenges will not be met without simultaneous improvement in nanoscale characterization methods. Terahertz spectroscopy, discussed in the article by Milot et al is one example of a method that is overcoming the difficulties associated with nanoscale materials characterization by avoiding electrical contacts to nanoparticles, allowing characterization during device operation, and enabling characterization of a single nanoparticle. Besides experimental advances, computational science is also meeting the challenges of nanomaterials synthesis. The article by Kohlstedt and Schatz discusses the computational frameworks being used to predict structure-property relationships in materials and devices, including machine learning methods, with an emphasis on organic photovoltaics. The contribution by Megarity and Armstrong presents the 'electrochemical leaf' for improvements in electrochemistry and beyond. In addition, biohybrid approaches can take advantage of efficient and specific enzyme catalysts. These articles present the nanoscience and technology at the forefront of renewable energy development that will have significant benefits to society.
Aa robust inflammatory response to tissue damage and infection is conserved across almost all animal phyla. Neutrophils and macrophages, or their equivalents, are drawn to the wound site where they ...engulf cell and matrix debris and release signals that direct components of the repair process. This orchestrated cell migration is clinically important, and yet, to date, leukocyte chemotaxis has largely been studied in vitro. Here, we describe a genetically tractable in vivo wound model of inflammation in the Drosophila melanogaster embryo that is amenable to cinemicroscopy. For the first time, we are able to examine the roles of Rho-family small GTPases during inflammation in vivo and show that Rac-mediated lamellae are essential for hemocyte motility and Rho signaling is necessary for cells to retract from sites of matrix- and cell-cell contacts. Cdc42 is necessary for maintaining cellular polarity and yet, despite in vitro evidence, is dispensable for sensing and crawling toward wound cues.
Aim
To evaluate the biocompatibility, induction of mineralization and antimicrobial activity of experimental intracanal pastes based on two glass and glass‐ceramic materials. Calcium hydroxide ...(Ca(OH)2) paste was used as the positive control.
Methodology
The glass‐ceramic powder two‐phased Biosilicate (BS‐2P) and F18 bioactive glass were mixed with distilled water (ratio 2 : 1), inserted in polyethylene tubes and implanted in the subcutaneous tissues of 16 rats. Empty tubes were used as negative control. After 7 and 30 days (n = 8), the rats were euthanized for haematoxylin–eosin, von Kossa, polarized light and osteopontin (OPN) immunolabeling analysis. Direct contact tests using a suspension of each paste were performed with Enterococcus faecalis planktonic cells to evaluate antimicrobial activity (24 h of contact), in a pilot study. The number of CFU mL−1 was calculated for each group. The antimicrobial analysis data were submitted to one‐way anova and Tukey tests, whilst biocompatibility and immunohistochemical data were submitted to the Kruskal–Wallis and Dunn tests (P < 0.05).
Results
Most specimens of the control, BS‐2P and Ca(OH)2 groups were associated with moderate inflammation seven days following implantation, whilst F18 was associated with moderate to severe inflammation, without differences amongst the groups (P > 0.05). At 30 days, most specimens of control, F18 and BS‐2P groups had mild inflammation, whilst Ca(OH)2 had mild to moderate inflammation; however, no differences were determined amongst the groups (P > 0.05). The fibrous capsule was thick at 7 days, becoming thin at 30 days. All pastes induced von Kossa‐positive structures and were birefringent to polarized light. At seven days, the BS‐2P group had significantly more OPN immunolabeling compared to the control and Ca(OH)2 groups (P < 0.05). At 30 days, the F18 group had significantly more OPN immunolabeling compared to the control and Ca(OH)2 groups (P < 0.05). All pastes reduced the total number of E. faecalis; however, the reduction was only significant when comparing BS‐2P and Ca(OH)2 groups to the control (P < 0.05). Only calcium hydroxide eliminated E. faecalis.
Conclusions
Experimental BS‐2P and F18 pastes were biocompatible, stimulated biomineralization and induced significant OPN immunolabeling compared to Ca(OH)2. Only the BS‐2P paste demonstrated antimicrobial activity comparable to Ca(OH)2.
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