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As a typical tumor microenvironment-responsive therapy, chemodynamic therapy (CDT), producing hydroxyl radicals ( • OH) to eliminate tumor cells, has demonstrated great promise. Nevertheless, there are still major challenges: • OH generated from endogenous H 2 O 2 is usually insufficient; the CDT effect is strongly dependent on the pre-reaction with glutathione. Addressing the challenges, Au@MnSe 2 core-shell nanoagent for synergetic chemodynamic-photothermo-photocatalytic therapy combined with tetramodal imaging, including magnetic resonance imaging, computed tomography, photoacoustic, and infrared thermal imaging is reported. Distinct from the reported glutathione-depleting agents, Mn 2+ in MnSe 2 allows immediate generation of • OH, independent of pre-reaction. Meanwhile, Mn 3+ consumes glutathione by its conversion to Mn 2+ . The Au-MnSe 2 combination promotes photothermal conversion and photocatalytic reaction, resulting in largely enhanced • OH generation from endogenous H 2 O 2 and significant hyperthermia. Meanwhile, immune response is effectively activated: the intratumoral expression of programmed cell death-1 and proinflammatory cytokines increase to 4-7 folds; the cytotoxic and helper T lymphocytes cells in the tumor area increase to more than 2.5-folds; an evident, temporary systemic immunostimulatory effect is demonstrated. High tumor inhibition rate (≈97.3%) and greatly prolonged survival are obtained. This highly-integrated design coordinating three different therapies with four different imaging modals provide new possibilities for high-performance theranostic nanoagents., (© 2022 Wiley-VCH GmbH.)

Biocompatible single-component theranostic agents integrating multimodal imaging and therapeutic functions (namely, "all-in one" agents) are highly desired for clinical cancer treatments. Herein, PEGylated pure metallic bismuth nanocrystals (Bi-PEG NCs) have been developed to be a competent theranostic agent for in vivo high-performance multimodal bio-imaging and photothermal ablation of tumors. The resultant Bi-PEG NCs show excellent physiological stability, biocompatibility, prolonged blood circulation half-life and preferential tumor accumulation. Thanking to the strong near-infrared (NIR) absorbance as well as the high photothermal conversion efficiency and conversion stability, highly effective in vivo photothermal ablation on tumors has been realized upon NIR irradiation, without noticeable toxicity. Impressively, the Bi-PEG NCs show ultrahigh X-ray computed topography (CT) enhancement efficiency (∼60.3 HU mL mg -1 ), overwhelming all CT contrast agents reported so far. Combining the strong CT contrast ability and photoacoustic/photothermal effect, high-contrast CT, photoacoustic (PA) and infrared thermal (IRT) triple-modal imaging have been demonstrated both in vitro and in vivo. This work highlights the potentials of such NCs as a powerful "all-in-one" theranostic nanoplatform for bioimaging and antitumor therapy, and may have provided a rather promising candidate for clinically-applied antitumor treatments based on single-component agents., (Copyright © 2017. Published by Elsevier Ltd.)

Biocompatible single-component nanoplatforms simultaneously integrating multiple therapeutic functions with multiple imaging modes are desirable for anticancer treatments. Herein, elaborately-designed highly porous PEGylated bismuth sulfide nano-urchins (Bi2S3-PEG NUs) have been successfully synthesized by using Bi2O3 nanospheres as the sacrificial template via the hydrothermal process. It is demonstrated that the Bi2S3-PEG NUs possess high compatibility, stability, X-ray attenuation ability, near-infrared (NIR) absorbance and photothermal conversion capability, without noticeable toxicity. Based on both in vitro and in vivo results, the product shows excellent performance in highly effective photothermal therapy (PTT) guided by triple-modal imaging, including X-ray computed tomography (CT), and photoacoustic (PA) and infrared thermal (IRT) imaging, without noticeable toxicity in vivo. Importantly, the NUs are highly porous with a high specific surface area and copious mesopores, providing high loading capacity to accommodate drugs (or guest biomolecules) for further applications in chemotherapy and other additional functions. Doxorubicin is loaded as an example, showing a rather high loading capacity (∼37.9%) together with a bimodal on-demand pH/photothermal-sensitive drug release property. Such fascinating multifunctional nanoagents may have considerable applications in antitumor diagnosis and therapy in the clinic.

The limitations of graphene as an effective corrosion-inhibiting coating on metal surfaces, here exemplified by the hex-reconstructed Pt(100) surface, are probed by scanning tunneling microscopy measurements and density functional theory calculations. While exposure of small molecules directly onto the Pt(100) surface will lift the reconstruction, a single graphene layer is observed to act as an effective coating, protecting the reactive surface from O(2) exposure and thus preserving the reconstruction underneath the graphene layer in O(2) pressures as high as 10(-4) mbar. A similar protective effect against CO is observed at CO pressures below 10(-6) mbar. However, at higher pressures CO is observed to intercalate under the graphene coating layer, thus lifting the reconstruction. The limitations of the coating effect are further tested by exposure to hot atomic hydrogen. While the coating can withstand these extreme conditions for a limited amount of time, after substantial exposure, the Pt(100) reconstruction is lifted. Annealing experiments and density functional theory calculations demonstrate that the basal plane of the graphene stays intact and point to a graphene-mediated mechanism for the H-induced lifting of the reconstruction.

We report a study of nanoribbons of quercetin, a phase I clinical trial anticancer drug, and their inhibitory effects on cancer cell proliferation. Novel quercetin nanoribbons have been prepared by atmospheric pressure physical vapor deposition (PVD). The nanostructures have been characterized by optical microscopy, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy, etc. Significantly enhanced solubility in PBS solution and increased drug release rate have been observed for quercetin nanoribbons in comparison to those of quercetin powder. The observed increase of inhibitory effects of quercetin nanoribbons on 4T1 cancel cell growth is correlated with an improvement in their solubility and drug release behavior., (This journal is © The Royal Society of Chemistry 2012)

We studied the osteoconductive tissue response of hydroxyapatite (HA) nanoparticles functionalized with osteopontin (OPN) in a matrix of poly-D,L-lactic-acid (PDLLA). In a canine endosseus 0.75-mm gap implant model, we tested the osteointegrative impact of the OPN functionalized composite as an implant coating, and a non-functionalized composite was used as reference control. During the four weeks of observation, the OPN functionalized composite coating significantly increased the formation of new bone in the porosities of the implant, but no differences were observed in the gap. The study provides evidence of its potential use either alone or in combination with other osteoconductive compounds., (Copyright © 2011 Wiley Periodicals, Inc.)

The world in the 21(st) century is facing increasing challenges within the development of more environmentally friendly energy systems, sustainable and 'green chemistry' solutions for a variety of chemical and catalytic processes. Nanomaterials science is expected to contribute strongly by the development of new nanotools, e.g. for improving the performance of chemical reactions. Nanoconfinement is of increasing interest and may lead to significantly enhanced kinetics, higher degree of stability and/or more favourable thermodynamic properties. Nanoconfined chemical reactions may have a wide range of important applications in the near future, e.g. within the merging area of chemical storage of renewable energy. This review provides selected examples within nanoconfinement of hydrogen storage materials, which may serve as an inspiration for other research fields as well. Selected nanoporous materials, methods for preparation of nanoconfined systems and their hydrogen storage properties are reviewed., (© The Royal Society of Chemistry 2011)

It is well established in the field of biomaterials that hydroxyapatite (HA) may provide interesting osteoconductive properties. In this study, we investigated the osseointegrational effect of a 50/50 vol % composite of HA nanoparticles and poly-D,L-lactic acid (PDLLA) coated on model titanium bone implants in an in vivo animal model. The aim is to evaluate how the addition of HA to PDLLA may improve the bone formation and initial fixation of the implant. Two titanium implants coated with the PDLLA/HA composite and pure PDLLA, respectively, were implanted bilaterally in proximal part of humeri with a 2-mm peri-implant gap in 10 sheep. After 12 weeks, the remains of the coatings were present on 20.3 and 19.8% of PDLLA/HA composite- and PDLLA-coated implants, respectively. It was observed that newly formed bone (39.3%) and fibrous tissue (58.3%) had replaced the PDLLA/HA composite, whereas pure PDLLA was replaced almost completely by fibrous tissue (96.2%). Consequently, the PDLLA/HA composite-coated implants were better fixated as confirmed by push-out tests. Using quantification of peri-implant tissue and implant fixation as parameters, the present findings, therefore, clearly reveal that the addition of nanoparticulate HA to a PDLLA coating on titanium implants increases osseointegration., (© 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.)

Background and Purpose: One of the most common and dose-limiting long-term adverse effects of radiation therapy is radiation-induced fibrosis (RIF), which is characterized by restricted tissue flexibility, reduced compliance or strictures, pain and in severe cases, ulceration and necrosis. Several strategies have been proposed to ameliorate RIF but presently no effective one is available. Recent studies have reported that tumor necrosis factor-α (TNFα) plays a role in fibrogenesis., Material and Methods: Male CDF1 mice were radiated with a single dose of 45 Gy. Chitosan/DsiRNA nanoparticles targeting TNFα were intraperitoneal injected and late radiation-induced fibrosis (RIF) was assessed using a modification of the leg contracture model. Additionally, the effect of these nanoparticles on tumor growth and tumor control probability in the absence of radiation was examined in a C3H mammary carcinoma model., Results: We show in this work, that targeting TNFα in macrophages by intraperitoneal administration of chitosan/DsiRNA nanoparticles completely prevented radiation-induced fibrosis in CDF1 mice without revealing any cytotoxic side-effects after a long-term administration. Furthermore, such TNFα targeting was selective without any significant influence on tumor growth or irradiation-related tumor control probability., Conclusion: This nanoparticle-based RNAi approach represents a novel approach to prevent RIF with potential application to improve clinical radiation therapeutic strategies., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

This work presents a method for decorating the surface of poly (lactide-co-glycolide) (PLGA) nanoparticles with polyethyleneimine (PEI) utilising a cetyl derivative to improve surface functionalisation and siRNA delivery. Sub-micron particles were produced by an emulsion-diffusion method using benzyl alcohol. We demonstrate by x-ray photoelectron spectroscopy (XPS), 2.6 times higher surface presentation of amines using the cetyl derivative compared to non-cetylated-PEI formulations (6.5 and 2.5% surface nitrogen, respectively). The modified particles were shown by spectroscopy, fluorescent microscopy and flow cytometry to bind and mediate siRNA delivery into the human osteosarcoma cell line U2OS and the murine macrophage cell line J774.1. Specific reduction in the anti-apoptotic oncogene BCL-w in U2OS cells was achieved with particles containing cetylated-PEI (53%) with no cellular toxicity. In addition, particles containing cetylated-PEI achieved 64% silencing of TNFalpha in J774.1 cells. This rapid method for surface modification of PLGA nanoparticles promotes its application for alternative cetylated functional derivatives as a strategy to control specific biological properties of nanoparticles., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)

Instability and inadequate biodistribution of double-stranded RNA are major drawbacks to the clinical use of RNA interference. This work compares chemical modification and nanoparticle formulation as strategies to improve the systemic delivery of small interfering RNA (siRNA). Variable levels of chemical modified siRNA, either naked or within nanoparticle, were intravenously injected into mice to study temporal stability and biodistribution detected by direct radioactive labeling or by northern blotting. Naked siRNA showed rapid renal clearance, with circulatory half-life of <5 minutes that could be extended to >30 minutes by cholesterol conjugation. The integrity of the chemically stabilized siRNA was maintained in blood for at least 30 minutes, whereas, unmodified siRNA duplex was degraded within 1 minute. Intact chemically modified siRNA could also be detected in all analyzed organs at 30 minutes but disappeared at 24 hours, except for heavy locked nucleic acid (LNA)-modified and cholesterol-conjugated siRNA in the lungs. Chitosan, liposomal, or JetPEI formulation greatly improved the stability and biodistribution of siRNA. Interestingly, high siRNA accumulation of the chitosan/siRNA formulation within the kidney was observed 24 hours postadministration. This comparative study highlights improvements to siRNA stability and pharmacokinetics, key determinants for development of clinically relevant RNAi therapeutics.

Electrospinning of nanofibers with cyclodextrin inclusion complexes (CD-ICs) is particularly attractive since distinct properties can be obtained by combining the nanofibers with specific functions of the CD-ICs. Here we report on the electrospinning of poly(methyl methacrylate) (PMMA) nanofibers containing cyclodextrin-menthol inclusion complexes (CD-menthol-ICs). These CD-menthol-IC functionalized nanofibers were developed with the purpose of producing functional nanofibers that contain fragrances/flavors with high temperature stability, and menthol was used as a model fragrance/flavor material. The PMMA nanofibers were electrospun with CD-menthol-ICs using three type of CD: alpha-CD, beta-CD, and gamma-CD. Direct pyrolysis mass spectrometry (DP-MS) studies showed that the thermal evaporation of menthol occurred over a very high and a broad temperature range (100-355 degrees C) for PMMA/CDmenthol-IC nanowebs, demonstrating the complexation of menthol with the CD cavity and its high temperature stability. Furthermore, as the size of CD cavity increased in the order alpha-CDbeta-CD>alpha-CD.

Polymer-based nanopatterning on metal surfaces is of increasing importance to a number of applications, including biosensors, bioelectronic devices and medical implants. Here we show that polycrystalline gold surfaces can be functionalized with monocomponent nanoparticle (NP) assemblies by a simple drop deposition method. Ordered 3D hexagonal close-packed structures consisting of 350 nm polystyrene (PS) NPs on hydrophobically modified gold surfaces from solutions of very low volume fraction (varphi = 0.0006) were obtained as a result of capillary force induced self-assembly, whilst 2D self-assembly of PS NPs was generated over large area on hydrophilic gold and TiO(2) surfaces by spin coating. Furthermore, we show that when Triton X-100 is added to the PS NP suspending medium longer range ordering is obtained. Our observations may initiate interesting applications in the areas of nanoengineering of metal-based sensors and as a means to design new nanostructures for biocompatible implant surfaces.

We have previously introduced the use of the biomaterial chitosan to form chitosan/siRNA nanoparticles for gene silencing protocols. This present study shows that the physicochemical properties (size, zeta potential, morphology and complex stability) and in vitro gene silencing of chitosan/siRNA nanoparticles are strongly dependent on chitosan molecular weight (Mw) and degree of deacetylation (DD). High Mw and DD chitosan resulted in the formation of discrete stable nanoparticles approximately 200 nm in size. Chitosan/siRNA formulations (N:P 50) prepared with low Mw (approximately 10 kDa) showed almost no knockdown of endogenous enhanced green fluorescent protein (EGFP) in H1299 human lung carcinoma cells, whereas those prepared from higher Mw (64.8-170 kDa) and DD (approximately 80%) showed greater gene silencing ranging between 45% and 65%. The highest gene silencing efficiency (80%) was achieved using chitosan/siRNA nanoparticles at N:P 150 using higher Mw (114 and 170 kDa) and DD (84%) that correlated with formation of stable nanoparticles of approximately 200 nm. In conclusion, this work confirms the application of chitosan as a non-viral carrier for siRNA and the importance of polymeric properties for the optimisation of gene silencing using chitosan/siRNA nanoparticles.

Highlights: [•] Scanning tunneling microscopy studies of MoS2 and CoMoS nanoparticle morphologies in hydrotreating. [•] Morphology effect of sulfo-reductive conditions. [•] Morphology effect of promoter atoms (Co, Ni, Fe, Cu). [•] Morphology effect of supports (TiO2, graphite). [Copyright &y& Elsevier]

Single-layer MoS2 nanoclusters were synthesized on a Au substrate as a model system for the hydrotreating catalyst and studied by atomically resolved scanning tunneling microscopy (STM) in order to achieve atomic-scale insight into the interactions with hydrogen and thiophene (C4H4S). Surprisingly, STM images show that thiophene molecules can adsorb and react on the fully sulfided edges of triangular single-layer MoS2 nanoclusters. We associate this unusual behavior with the presence of special brim sites exhibiting a metallic character. The STM images reveal that these sites exist only at the regions immediately adjacent to the edges of the MoS2 nanoclusters, and from density-functional theory such sites are found to be associated with one-dimensional electronic edge states. The fully sulfur-saturated sites are from STM images found to be capable of adsorbing thiophene, and when thiophene and hydrogen reactants are coadsorbed here, a reaction path is revealed which leads to partial hydrogenation of the thiophene followed by C&z.sbnd;S bond activation and ring opening of thiophene molecules. This may be regarded as important first steps in the hydrodesulfurization of thiophene. The metallic brim sites are suggested to be important for other hydrotreating reactions over MoS2-based catalysts, and the properties of the brim sites directly explain why hydrogenation reactions of aromatics are not severely inhibited by H2S. The presence of brim sites in MoS2 nanoclusters also explains previous structure–activity relations and observations regarding steric effects and the influence of stacking of MoS2 on the reactivity and selectivity. [Copyright &y& Elsevier]