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We report a facile method for assembly of a monolayer array of nitrogen-doped graphene (NG) and nanoparticles (NPs) and the subsequent transfer of two layers onto a solid substrate (S). Using 3 nm NiPd NPs as an example, we demonstrate that NiPd-NG-Si (Si=silicon wafer) can function as a catalyst and show maximum NiPd catalysis for the hydrolysis of ammonia borane (H3NBH3, AB) with a turnover frequency (TOF) of 4896.8 h−1 and an activation energy ( Ea) of 18.8 kJ mol−1. The NiPd-NG-S catalyst is also highly active for catalyzing the transfer hydrogenation from AB to nitro compounds, leading to the green synthesis of quinazolines in water. Our assembly method can be extended to other graphene and NP catalyst materials, providing a new 2D NP catalyst platform for catalyzing multiple reactions in one pot with maximum efficiency. [ABSTRACT FROM AUTHOR]

While dose dependencies in pharmacokinetics and clearance are often observed in clinically used small molecules, very few studies have been dedicated to the understandings of potential dose-dependent in vivo transport of nanomedicines. Here we report that the pharmacokinetics and clearance of renal clearable gold nanoparticles (GS-AuNPs) are strongly dose-dependent once injection doses are above 15 mg kg−1: high dose expedited the renal excretion and shortened the blood retention. As a result, the no-observed-adverse-effect-level (NOAEL) of GS-AuNPs was >1000 mg kg−1 in CD-1 mice. The efficient renal clearance and high compatibility can be translated to the non-human primates: no adverse effects were observed within 90 days after intravenous injection of 250 mg kg−1 GS-AuNPs. These fundamental understandings of dose effect on the in vivo transport of ultrasmall AuNPs open up a pathway to maximize their biomedical potentials and minimize their toxicity in the future clinical translation. [ABSTRACT FROM AUTHOR]

Soy protein isolate (SPI) is one of the base materials for edible film production in addition to polysaccharide and lipid, but it does not have antibacterial activities. Incorporation of antibacterial agents may increase the functional properties of the edible films. This research aimed to determine the effects of zinc oxide nanoparticles (ZnO-NPs) and turmeric extract addition into soy protein isolate-based films on the physical, mechanical and antibacterial characteristics of the films. The edible films were prepared by dissolving 5 grams of SPI into 100 mL of distilled water followed by the addition of ZnO-NPs (0, 1, and 2.5% of the SPI weight) and/or turmeric extracts (0 and 2.5% of the SPI weight). The results showed that addition of ZnO-NPs and turmeric extracts into the films significantly increased the thickness and values of tensile strength. Addition of turmeric extract decreased the percent of films elongation, while addition of ZnO-NPs had a significant effect in decreasing the water vapor transmission rate (WVTR) values. The combination of ZnO-NPs and turmeric extracst had a considerable effects in inhibiting E.coli growth in the range of 2.25 mm to 3.18 mm. Meanwhile, addition of ZnO-NPs resulted in inhibition against E.coli in the range of 2.54 mm to 4.29 mm. Furthermore, this research showed that addition of ZnO NPs and turmeric extracts could improve the physical and mechanical properties of SPI-based film. The best films was obtained by using ZnO NPs at 2.5% which can potentially be used as an antibacterial packaging. [ABSTRACT FROM AUTHOR]

The transition from molecular to plasmonic behaviour in metal nanoparticles with increasing size remains a central question in nanoscience. We report that the giant 246-gold-atom nanocluster (2.2 nm in gold core diameter) protected by 80 thiolate ligands is surprisingly non-metallic based on UV/Vis and femtosecond transient absorption spectroscopy as well as electrochemical measurements. Specifically, the Au246 nanocluster exhibits multiple excitonic peaks in transient absorption spectra and electron dynamics independent of the pump power, which are in contrast to the behaviour of metallic gold nanoparticles. Moreover, a prominent oscillatory feature with frequency of 0.5 THz can be observed in almost all the probe wavelengths. The phase and amplitude analysis of the oscillation suggests that it arises from the wavepacket motion on the ground state potential energy surface, which also indicates the presence of a small band-gap and thus non-metallic or molecular-like behaviour. [ABSTRACT FROM AUTHOR]

Nitrones are key intermediates in organic synthesis and the pharmaceutical industry. The heterogeneous synthesis of nitrones with multifunctional catalysts is extremely attractive but rarely explored. Herein, we report ultrasmall platinum nanoclusters (PtNCs) encapsulated in amine-functionalized Zr metal-organic framework (MOF), UiO-66-NH2 (Pt@UiO-66-NH2) as a multifunctional catalyst in the one-pot tandem synthesis of nitrones. By virtue of the cooperative interplay among the selective hydrogenation activity provided by the ultrasmall PtNCs and Lewis acidity/basicity/nanoconfinement endowed by UiO-66-NH2, Pt@UiO-66-NH2 exhibits remarkable activity and selectivity, in comparison to Pt/carbon, Pt@UiO-66, and Pd@UiO-66-NH2. Pt@UiO-66-NH2 also outperforms Pt nanoparticles supported on the external surface of the same MOF (Pt/UiO-66-NH2). To our knowledge, this work demonstrates the first examples of one-pot synthesis of nitrones using recyclable multifunctional heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

We report a facile approach to prepare an artificial enzyme system for tandem catalysis. NiPd hollow nanoparticles and glucose oxidase (GOx) were simultaneously immobilized on the zeolitic imidazolate framework 8 (ZIF-8) via a co-precipitation method. The as-prepared GOx@ZIF-8(NiPd) nanoflower not only exhibited the peroxidase-like activity of NiPd hollow nanoparticles but also maintained the enzymatic activity of GOx. A colorimetric sensor for rapid detection of glucose was realized through the GOx@ZIF-8(NiPd) based multi-enzyme system. Moreover, the GOx@ZIF-8(NiPd) modified electrode showed good bioactivity of GOx and high electrocatalytic activity for the oxygen reduction reaction (ORR), which could also be used for electrochemical detection of glucose. [ABSTRACT FROM AUTHOR]

Gold (Au) on ceria-zirconia is one of the most active catalysts for the low-temperature water-gas shift reaction (LTS), a key stage of upgrading H2 reformate streams for fuel cells. However, this catalyst rapidly deactivates on-stream and the deactivation mechanism remains unclear. Using stop-start scanning transmission electron microscopy to follow the exact same area of the sample at different stages of the LTS reaction, as well as complementary X-ray photoelectron spectroscopy, we observed the activation and deactivation of the catalyst at various stages. During the heating of the catalyst to reaction temperature, we observed the formation of small Au nanoparticles (NPs; 1-2 nm) from subnanometer Au species. These NPs were then seen to agglomerate further over 48 h on-stream, and most rapidly in the first 5 h when the highest rate of deactivation was observed. These findings suggest that the primary deactivation process consists of the loss of active sites through the agglomeration and possible dewetting of Au NPs. [ABSTRACT FROM AUTHOR]

The particle size effect of Pd nanoparticles supported on alumina with various crystalline phases on methane combustion was investigated. Pd/θ, α-Al2O3 with weak metal-support interaction showed a volcano-shaped dependence of the catalytic activity on the size of Pd particles, and the catalytic activity of the strongly interacted Pd/γ-Al2O3 increased with the particle size. Based on a structural analysis of Pd nanoparticles using CO adsorption IR spectroscopy and spherical aberration-corrected scanning/transmission electron microscopy, the dependence of catalytic activity on Pd particle size and the alumina crystalline phase was due to the fraction of step sites on Pd particle surface. The difference in fraction of the step site is derived from the particle shape, which varies not only with Pd particle size but also with the strength of metal-support interaction. Therefore, this interaction perturbs the particle size effect of Pd/Al2O3 for methane combustion. [ABSTRACT FROM AUTHOR]

Short interfering RNA (siRNA) is a promising molecular tool for cancer therapy, but its clinical success is limited by the lack of robust in vivo delivery systems. Rationally designed DNA nanoparticles (DNPs) have emerged as facile delivery vehicles because their physicochemical properties can be precisely controlled. Nonetheless, few studies have used DNPs to deliver siRNAs in vivo, and none has demonstrated therapeutic efficacy. Herein, we constructed a number of DNPs of rectangular and tubular shapes with varied dimensions using the modular DNA brick method for the systemic delivery of siRNA that targets anti-apoptotic protein Bcl2. The siRNA delivered by the DNPs inhibited cell growth both in vitro and in vivo, which suppressed tumor growth in a xenograft model that specifically correlated with Bcl2 depletion. This study suggests that DNPs are effective tools for the systemic delivery of therapeutic siRNA and have great potential for further clinical translation. [ABSTRACT FROM AUTHOR]

Despite high morbidity and mortality associated with lung diseases, addressing drugs towards lung tissue remains a pending task. Particle lung filtration has been proposed for passive lung targeting and drug delivery. However, toxicity issues derived from the long-term presence of the particles must be overcome. By exploiting some of the ignored properties of nanosized metal-organic frameworks it is possible to achieve impressive antitumoral effects on experimental lung tumors, even without the need to engineer the surface of the material. In fact, it was discovered that, based on unique pH-responsiveness and reversible aggregation behaviors, nanoMOF was capable of targeting lung tissue. At the neutral pH of the blood, the nanoMOFs form aggregates with the adequate size to be retained in lung capillaries. Within 24 h they then disaggregate and release their drug payload. This phenomenon was compatible with lung tissue physiology. [ABSTRACT FROM AUTHOR]

Nanokomposit adalah proses penggabungan dua atau lebih material antara matriks dengan reinforced pada skala nanostruktur untuk membentuk material baru yang lebih bermanfaat dalam industri manufaktur maupun rekayasa bahan. Nanokomposit memiliki keunggulan seperti dapat menghasilkan bahan komposit yang ringan, kuat, ramah lingkungan serta ekonomis. Pada penelitian ini, terdapat empat fraksi berat dan variasi waktu sonikasi untuk mengetahui fraksi berat terbaik dari hasil sintesis dan didapatkan nilai pengujian kekerasan dan thermal yang semakin meningkat seiring bertambahnya jumlah fraksi berat dari filler nanopartikel. Dua varian waktu sonikasi yang dilakukan untuk mengetahui waktu sonikasi terbaik dalam proses terdispersinya nanopartikel di dalam matriks epoksi resin yang berpengaruh pada sifat mekanik nanokomposit polimer yang dihasilkan dari proses sintesis dan hasil pengujian hardnesstertinggi didapatkan pada komposisi fraksi berat 10 %wt dan waktu sonikasi 30 menit dengan nilai kekerasan sebesar 80 shore D serta memiliki nilai temperatur Tg tertinggi dari hasil pengujian thermal sebesar 83°C. Pada pengamatan hasil foto struktur permukaan patahan yang dilakukan terlihat nanopartikel sudah terdispersi secara homogen pada waktu sonikasi 30 menit lebih baik daripada waktu sonikasi 60 menit karena tidak timbul sifat porous atau void pada hasil sintesis nanokomposit.

Daun Sirsak (Annona muricata Linn), Annonaceae telah diketahui memiliki kemampuan meredam radikal bebas yang kuat dan bisa dikembangkan menjadi sediaan farmasi antioksidan. Pembentukan nanopartikel dari ekstrak akan meningkatkan stabilitas, kemampuan mukoadhesif dan penetrasi ekstrak sehingga dapat meningkatkan efektifitasnya. Pembuatan nanopartikel dilakukan dengan melarutkan kitosan dalam larutan asam asetat glasial 1%, dan dicampurkan dengan infus daun sirsak. Suspensi nanopartikel ekstrak daun sirsak dikeringkan dengan menggunakan alat pengering semprot. Hasil evaluasi nanopartikel ekstrak diperoleh ukuran partikel 131,23 ± 1,81%, indeks polidispersitas 0,3 – 0,4; padatan total 0,47 %, warna coklat muda, bau khas ekstrak, rasa pahit, sifat serbuk halus, higroskopis, kadar air 6.86 ± 0,88%. Pemeriksaan aktivitas antioksidan pada nanopartikel ekstrak daun sirsak dengan menggunakan metode peredaman radikal bebas DPPH menunjukkan aktivitas antioksidan kuat dengan nilai 1C50 sebesar 80,98 bpj. Kata kunci : daun sirsak, Annona muricata Linn., DPPH, antioksidan, nanopartikel, kitosan

Ekstrak etanol Bawang dayak (Eleutherine americana (Aubl) Merr.) diketahui memiliki aktivitas antioksidan yang kuat sehingga berpotensi untuk dikembangkan menjadi sistem penghantaran nanopartikel. Penelitian ini bertujuan untuk mengetahui pengaruh variasi konsentrasi kitosan – tripolifosfat (TPP) terhadap karakteristik fisik dari nanopartikel. Ekstrak bawang dayak diformulasi dalam bentuk nanopartikel dengan metode gelasi ionik dengan variasi konsentrasi polimer kitosan : tripolifosfat yaitu 0,5% : 0,5% (F1), 0,75% : 0,5% (F2), dan 1% : 0,5% (F3). Parameter pengujian meliputi penentuan ukuran dan indeks polidispersitas nanopartikel menggunakan particle size analyzer, pengamatan morfologi menggunakan scanning electron microscopy, pengukuran efisiensi penjerapan, dan disolusi in vitro. Hasil penelitian menunjukkan bahwa nanopartikel F1, F2, dan F3 memiliki ukuran masing-masing sebesar 256,30 nm, 376,28 nm dan 419,18 nm dengan distribusi ukuran yang relatif homogen dan efisiensi penjerapan masing-masing sebesar 69,54%, 77,51% dan 79,79%. Pengamatan morfologi dari nanopartikel menunjukkan bentuk partikel yang mendekati spheris (bulat) dengan permukaan yang kasar. Profil pelepasan obat dari nanopartikel F1, F2, dan F3 pada jam ke-8 masing-masing sebesar 71,19 % (F1), 74,97% (F2) dan 80,55% (F3). Berdasarkan hasil penelitian yang telah dilakukan, dapat disimpulkan bahwa ekstrak bawang dayak dapat diformulasi dalam ukuran nanopartikel dengan karakteristik fisik yang bervariasi tergantung pada konsentrasi kitosan dan tripolifosfat yang digunakan. Kata Kunci: Bawang dayak (Eleutherine americana (Aubl) Merr.), antioksidan, nanopartikel, kitosan, tripolifosfat, gelasi ionik. ABSTRACT Bawang dayak (Eleutherine americana (Aubl) Merr.) ethanol extract had been known to have excellent antioxidant activity that has the potential to be developed into a nanoparticle delivery systems. This study aims to determine the effect of varying concentrations of chitosan - tripolyphosphate (TPP) to the physical characteristics of nanoparticles. Bawang dayak extract formulated in the form of nanoparticles with an ionic gelation method and and using polymers chitosan - tripolyphospate varying concentration as 0.5% : 0.5% (F1), 0.75% : 0.5% (F2), and 1% : 0.5% (F3). The measured parameters were determinating particle size and polydispersity index using particle size analyzer, observation of particle morph using scanning electron microscopy, measurement of entrapment efficiency and dissolution in vitro. The result showed that the average size of nanoparticle F1, F2, and F3 respectively is 256.30 nm, 376 nm and 419.18 nm with entrapment efficiency respectively is 69.54% (F1), 77.51% (F2) and 79.79% (F3) with a relatively homogenous size distribution and entrapment efficiencies respectively is 69.54%, 77.51% and 79.79%. Observation of morphology of the nanoparticles shows the particle shape is almost sphere (spherical) with a rough surface. The profile of drug release from the nanoparticles F1, F2, and F3 in 8 hours respectively is 71.19% (F1), 74.97% (F2) and 80.55% (F3). Based on this study, it was concluded that the etanol extract of bawang dayak can be formulated into nanoparticles with different physical characteristics based on the ratio of polymer chitosan and tripolyphosphate used. Keywords: Bawang dayak (Eleutherine americana (Aubl) Merr.), nanoparticles, chitosan, tripolyphosphate, ionic gelation.

An important challenge in molecular assembly and hierarchical molecular engineering is to control and program the directional self-assembly into chiral structures. Here, we present a versatile DNA surface adapter that can programmably self-assemble into various chiral supramolecular architectures, thereby regulating the chiral directional 'bonding' of gold nanorods decorated by the surface adapter. Distinct optical chirality relevant to the ensemble conformation is demonstrated from the assembled novel stair-like and coil-like gold nanorod chiral metastructures, which is strongly affected by the spatial arrangement of neighboring nanorod pair. Our strategy provides new avenues for fabrication of tunable optical metamaterials by manipulating the directional self-assembly of nanoparticles using programmable surface adapters. [ABSTRACT FROM AUTHOR]

A straightforward crack-patterning method is reported allowing the direct formation of periodic cracks in metal-organic framework (MOF) nanoparticle films during dip-coating deposition. The crack propagation and periodicity can be easily tailored by controlling the evaporation front and the withdrawal speed. Several MOF-patterned films can be fabricated on large surfaces and on several substrates (flat, curved or flexible) including the inner surface of a tube, not achievable by other lithographic techniques. We demonstrate that the periodic cracked arrays diffract light and, due to the MOF sorption properties, photonic vapor sensors are fabricated. A new concept of 'in-tube', MOF-based diffraction grating sensors is proposed with outstanding sensitivity that can be easily tuned 'on-demand' as function of the desired detection range. [ABSTRACT FROM AUTHOR]

In recent decades, extensive studies have been devoted to assembling nanoparticles (NPs) into various ordered structures to achieve novel optical properties. However, it still remains a challenging task to assemble NPs into cyclic one-dimensional (1D) shapes, such as rings and frames. Herein, we report a directed assembly method to precisely assemble NPs into well-defined, free-standing frames using polymer single crystals (PSCs) as the template. Preformed poly(ethylene oxide) (PEO) single crystals were used as the template to direct the crystallization of block copolymer (BCP) poly(ethylene oxide)-b-poly(4-vinylpyridine) (PEO-b-P4VP), which directs the gold NPs (AuNPs) to form AuNP frames. By controlling the PSC growth, we were able to, for the first time, precisely tune both the size and width of the AuNP frame. These novel AuNP frames topologically resemble NP nanorings and cyclic polymer chains, and show unique surface plasmon resonance (SPR) behaviors. [ABSTRACT FROM AUTHOR]

Single nanoparticle (NP) electrochemistry detection at a micro liquid|liquid interface (LLI) is exploited using the catalyzed oxygen reduction reaction (ORR). In this way, current spikes reminiscent of nanoimpacts were recorded, which corresponded to electrocatalytic enhancement of the ORR by Pt NPs. The nature of the LLI allows exploration of new phenomena in single NP electrochemistry. The recorded impacts result from a bipolar reaction occurring at the Pt NP straddling the LLI. O2 reduction takes place in the aqueous phase, while ferrocene hydride (Fc-H+; a complex generated upon facilitated interfacial proton transfer by Fc) is oxidized in the organic phase. Ultimately, the role of reactant partitioning, NP bouncing, or the ability of NPs to induce Marangoni effects, is demonstrated. [ABSTRACT FROM AUTHOR]

Synthetisch hergestellte und funktionalisierte nanoskopische Behälter werden in der Synthesebiologie eingesetzt, um räumlich abgegrenzte chemische Prozesse auszuführen. Systeme mit zunehmender Komplexität erfordern Methoden zur räumlichen und zeitlichen Kontrolle der eingeschlossenen Spezies. Hier wird diese Herausforderung durch ein DNA ‐ kodiertes Design für die aufeinanderfolgende Fusion mehrerer Liposompopulationen adressiert. Eine Liposomfusion in drei Stufen wurde durch orthogonal hybridisierende Paare membranverankerter Oligonukleotide kontrolliert. Jedes Fusionsereignis führte zu einer effizienten Vermischung der eingeschlossenen Volumen und zur Übertragung eines Oligonukleotides, das durch molekulare Erkennung die Einleitung der nachfolgenden Stufe ermöglicht. Im Unterschied zur proteingesteuerten Vesikelfusion in eukaryotischen Zellen und Synapsen nutzt die hier vorgestellte künstliche Fusionskaskade das vielseitige Kodierungspotenzial der DNA ‐ Hybridisierung. Heiße Fusion: Membranfusion kontrolliert durch Hybridisierung von lipidierten Oligonukleotiden (LiNAs) ermöglicht ein schnelles Vermischen der inneren Volumina von kleinen unilamellaren sowie großen Liposomen (GUVs) bei Temperaturen von 37 °C und 50 °C. Eine effiziente dreistufige Fusionssequenz mit orthogonal kodierten LiNA ‐ Paaren wurde bei 50 °C realisiert. [ABSTRACT FROM AUTHOR]

With more and more engineered nanoparticles (NPs) being designed renal clearable for clinical translation, fundamental understanding of their transport in the different compartments of kidneys becomes increasingly important. Here, we report noninvasive X-ray imaging of renal clearable gold NPs (AuNPs) in normal and nephropathic kidneys. By quantifying the transport kinetics of the AuNPs in cortex, medulla and pelvis of the normal and injured kidneys, we found that ureteral obstruction not just blocked the NP elimination through the ureter but also slowed down their transport from the medulla to pelvis and enhanced the cellular uptake. Moreover, the transport kinetics of the NPs and renal anatomic details can be precisely correlated with local pathological lesion. These findings not only advance our understandings of the nano-bio interactions in kidneys but also offer a new pathway to noninvasively image kidney dysfunction and local injuries at the anatomical level. [ABSTRACT FROM AUTHOR]

Der Begriff Aerogel beschreibt im Wesentlichen eine besondere geometrische Struktur der Materie, die materialunabhängig ist und keinem speziellen Syntheseverfahren unterliegt. Grundsätzlich können daher Aerogele aus unzähligen Materialien bestehen, wodurch die Anwendungsmöglichkeiten nahezu unbegrenzt sind. Dasselbe trifft auf Nanopartikel zu. Diese werden ebenso durch ihre geometrischen Eigenschaften definiert. In den letzten Jahrzehnten standen daher nanoskalige Materialien im Fokus der Forschung, und es entwickelten sich mögliche Anwendungen in vielen naturwissenschaftlichen Bereichen. Heute ist eine Vielzahl an Metall ‐ , Halbleiter ‐ , Oxid ‐ und anderen Nanopartikeln durch kolloidale Synthesen zugänglich. Dennoch ist es für eine Anwendung oft notwendig, dass diese Materialien zuvor in makroskopische Strukturen angeordnet werden. Dieser Aufsatz gibt eine ausführliche Übersicht über die Entwicklung, die die Welt der kolloidalen Nanopartikel und der Aerogele miteinander vereint. Ermöglicht wurde dies durch die kontrollierte Destabilisierung der vorab gebildeten Nanopartikel, die zu einer Anordnung der Nanopartikel zu einem dreidimensionalen, makroskopischen Netzwerk führt. Dieses revolutionäre Konzept verleiht die Möglichkeit, präzise kontrollierte Nanopartikel als Grundbausteine für makroskopische, poröse Strukturen mit einstellbaren Eigenschaften zu nutzen. Erschaffe etwas Großes! Die kontrollierte Destabilisierung kolloidaler Nanopartikel und die resultierende Anordnung in makroskopische 3D ‐ Strukturen ermöglicht die Fusion der Nano ‐ und der Makrowelt. Nanopartikel können verwendet werden, um Materialien mit neuartigen und einstellbaren Eigenschaften zu erschaffen. Der Aufsatz fasst diesen interessanten Teil der modernen Nanotechnologie zusammen. [ABSTRACT FROM AUTHOR]

Nanoparticles (NPs) are promising tools in biomedical research. In vitro testing is still the first method for initial evaluation; however, NP colloidal behavior and integrity, in particular inside cells (that is, in lysosomes), are largely unknown and difficult to evaluate because of the complexity of the environment. Furthermore, while the majority of NPs are usually labeled with fluorescent dyes for tracking purposes, the effect of the lysosomal environment on the fluorophore properties, as well as the ensuing effects on data interpretation, is often only sparsely addressed. In this work, we have employed several complementary analytical methods to better understand the fate of fluorescently encoded NPs and identify potential pitfalls that may arise from focusing primary analysis on a single attribute, for example, fluorophore detection. Our study shows that in a lysosomal environment NPs can undergo significant changes resulting in dye quenching and distorted fluorescence signals. [ABSTRACT FROM AUTHOR]

Development of Raman-active materials with enhanced and distinctive Raman vibrations in the Raman-silent region (1800-2800 cm−1) is highly required for specific molecular imaging of living cells with high spatial resolution. Herein, water-soluble cationic conjugated polymers (CCPs), poly(phenylene ethynylene) (PPE) derivatives, are explored for use as alkyne-state-dependent Raman probes for living cell imaging due to synergetic enhancement effect of alkyne vibrations in Raman-silent region compared to alkyne-containing small molecules. The enhanced alkyne signals result from the integration of alkyne groups into the rigid backbone and the delocalized π-conjugated structure. PPE-based conjugated polymer nanoparticles (CPNs) were also prepared as Raman-responsive nanomaterials for distinct imaging application. This work opens a new way into the development of conjugated polymer materials for enhanced Raman imaging. [ABSTRACT FROM AUTHOR]

Antibodies are important biopharmaceuticals, but almost all existing antibody-based drugs are limited to targeting antigens located at the cell exterior because of the inability of antibodies to enter the cell interior. Available methods for intracellular delivery of antibodies have major shortcomings. Herein, we report an approach to encapsulate native antibodies in a biodegradable silica nanoquencher (BS-qNP), which could undergo efficient cellular uptake and intracellular degradation to release antibodies only under hypoxic conditions. By coating the surface of BS-qNP with cell-penetrating poly(disulfide)s (CPD), the delivered antibodies (or other proteins) avoided endolysosomal trapping. Doping of the silica coating with a fluorescent dye and a dark hole quencher further endowed BS-qNP with hypoxia-responsive fluorescence turn-on property. Our antibody delivery system thus provides the first platform capable of stable encapsulation, efficient uptake, on-demand antibody release, and imaging of release/cell state. [ABSTRACT FROM AUTHOR]

Utilization of mangosteen fruit waste tends to be less practical, so nanoparticle based encapsulation is an effective approach. The objective if this research was to utilize the waste from the red mangosteen peel Garcinia forbesii (GF) and Garcinia mangostana (GM) to produce nanoparticle extract, its encapsulation products, and determine its functional properties. This research consists of three stages: extraction, synthesis of nanoparticle, and encapsulation. The parameters evaluated were the yield of extracts, antioxidant, total phenolic content (TPC), particle size, index of polydispersity, and surface morphology of the encapsulated product. Synthesis of nanoparticles was carried out by using ionic gelation method. The functional values was calculated based on 10% extracts in the nanoparticles solution. The results showed that extraction by reflux method gave better results than that with maceration. Formula of nanoparticles containing 0.2% of chitosan concentration and 0.1% STPP and products encapsulated with casein and maltodextrine gave the best result with increased functional values. [ABSTRACT FROM AUTHOR]

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Sensors based on responsive photonic hydrogels have recently attracted considerable attention for visual medical diagnostics, pharmaceutical bioassays, and environmental monitoring. However, the use of these promising materials for the detection of nanoparticles (NPs) has never been explored so far, although the sensing of nanoobjects is a rapidly evolving area of research. To address this issue, we have combined the concepts of inverse-opal hydrogels and nanoparticle-imprinted polymers. In this way, we could obtain a NP-imprinted photonic hydrogel consisting of a three-dimensional, highly ordered poly(methacrylic acid) macroporous array, in which nanocavities complementary to the target NPs, in this case colloidal quantum dots, are distributed. This novel type of NP-imprinted photonic hydrogel sensor was shown to display high sensitivity and selectivity, thus opening new prospects for the development of equipment-free and cost-efficient sensing devices for NPs. [ABSTRACT FROM AUTHOR]

Engineering nanoparticle (NP) functions at the molecular level requires a detailed understanding of the dynamic processes occurring at the NP surface. Herein we show that a combination of dark-state exchange saturation transfer (DEST) and relaxation dispersion (RD) NMR experiments on gel-stabilized NP samples enables the accurate determination of the kinetics and thermodynamics of adsorption. We used the former approach to describe the interaction of cholic acid (CA) and phenol (PhOH) with ceria NPs with a diameter of approximately 200 nm. Whereas CA formed weak interactions with the NPs, PhOH was tightly bound to the NP surface. Interestingly, we found that the adsorption of PhOH proceeds via an intermediate, weakly bound state in which the small molecule has residual degrees of rotational diffusion. We believe the use of aqueous gels for stabilizing NP samples will increase the applicability of solution NMR methods to the characterization of nanomaterials. [ABSTRACT FROM AUTHOR]

The amplification- and enzyme-free quantification of DNA at ultralow concentrations, on the order of 10-1000 targets, is highly beneficial but extremely challenging. To address this challenge, true detection signals must be reliably discriminated from false or noise signals. Herein, we describe the development of associating and dissociating nanodimer analysis (ADNA) as a method that enables a maximum number of detection signals to be collected from true target-binding events while keeping nonspecific signals at a minimum level. In the ADNA assay for ultralow target concentrations, Au nanoprobes on a lipid micropattern were monitored and analyzed in situ, and newly defined dissociating dimers, which are eventually decoupled into monomers again, were incorporated into the detection results. Tens to thousands of DNA copies can be reliably quantified with excellent single-base-mismatch differentiation capability by this non-enzymatic, amplification-free ADNA method. [ABSTRACT FROM AUTHOR]

In situ monitoring of biomolecular recognition, especially at surfaces, still presents a significant technical challenge. Electron paramagnetic resonance (EPR) of biomolecules spin-labeled with nitroxides can offer uniquely sensitive and selective insights into these processes, but new spin-labeling strategies are needed. The synthesis and study of a bromoacrylaldehyde spin label (BASL), which features two attachment points with orthogonal reactivity is reported. The first examples of mannose and biotin ligands coupled to aqueous carboxy-functionalized gold nanoparticles through a spin label are presented. EPR spectra were obtained for the spin-labeled ligands both free in solution and attached to nanoparticles. The labels were recognized by the mannose-binding lectin, Con A, and the biotin-binding protein avidin-peroxidase. Binding gave quantifiable changes in the EPR spectra from which binding profiles could be obtained that reflect the strength of binding in each case. [ABSTRACT FROM AUTHOR]

Regulation of transgene systems is needed to develop innovative medicines. However, noninvasive remote control of gene expression has been rarely developed and remains challenging. We herein synthesize a near-infrared (NIR) absorbing dendronized semiconducting polymer (DSP) and utilize it as a photothermal nanocarrier not only to efficiently deliver genes but also to spatiotemporally control gene expression in conjunction with heat-inducible promoter. DSP has a high photothermal conversion efficiency (44.2 %) at 808 nm, permitting fast transduction of NIR light into thermal signals for intracellular activation of transcription. Such a DSP-mediated remote activation can rapidly and safely result in 25- and 4.5-fold increases in the expression levels of proteins in living cells and mice, respectively. This study thus provides a promising approach to optically regulate transgene systems for on-demand therapeutic transgene dosing. [ABSTRACT FROM AUTHOR]

Cyclic polymers are an important class of macromolecules, but the structural diversity of the backbone is limited. Herein we report the use of the Piers-Rubinsztajn reaction for the one-step synthesis of cyclic polysiloxanes with novel structural features. Specifically, the B(C6F5)3-catalyzed coupling of various organic tris(dimethylsiloxy)silane and trialkoxysilane compounds generated a series of cyclic polysiloxanes with cyclotetrasiloxane subunits. The thiolated cyclic polymers were also shown to be effective in directing the circular assembly gold nanoparticles. The presence of constrained rings in the backbone is unprecedented and may offer opportunities for novel applications of these cyclic polymers. [ABSTRACT FROM AUTHOR]

Aqueous acrylamide gels can be used to provide dynamic nuclear polarization (DNP) NMR signal enhancements of around 200 at 9.4 T and 100 K. The enhancements are shown to increase with crosslinker concentration and low concentrations of the AMUPol biradical. This DNP matrix can be used in situations where conventional incipient wetness methods fail, such as to obtain DNP surface enhanced NMR spectra from inorganic nanoparticles. In particular, we obtain 113Cd spectra from CdTe-COOH NPs in minutes. The spectra clearly indicate a highly disordered cadmium-rich surface. [ABSTRACT FROM AUTHOR]

Catalyzing C−C bond-forming reactions with earth-abundant metals under mild conditions is at the heart of sustainable synthesis. The cyclotrimerization of alkynes is a valuable atom-efficient reaction in organic synthesis that is enabled by several metal catalysts, including iron. This study reports an effective iron-catalyzed cyclotrimerization for the regioselective synthesis of 1,2,4-substituted arenes (1 mol % catalyst, toluene, 20 °C, 5 min). A dual activation mechanism (substrate deprotonation, reductive elimination) renders the simple FeII precatalyst highly active in the absence of any reductant. [ABSTRACT FROM AUTHOR]

The effect of citrate-stabilized gold nanoparticles (AuNPs) on the secondary structure of an artificial β-sheet-forming cationic peptide has been studied. The AuNPs inhibited β-sheet formation and led to fragmented fibrils and spherical oligomers with assembled AuNPs on their surface. Besides this structural change, the functional properties of the peptide are also different. Whereas the peptide was unable to act as a vector for gene delivery, formation of a complex with AuNPs allowed successful gene delivery into cells. [ABSTRACT FROM AUTHOR]