Full camouflage for stealth nanoparticles

‘Marker-of-self’ functionalization of nanoscale particles through a top-down cellular membrane coating approachCamouflaging nanoparticles so that they are not attacked by the immune system is a major challenge in developing long-circulating, effective drug-delivery vehicles. Attaching CD47, a transmembrane protein that serves as a universal molecular ‘marker-of-self’, to the surface of nanoparticles is one way to enable active immune evasion. However, functionalising the particle surface evenly and with uniformly oriented protein is very difficult.

Liangfang Zhang et al. show that their membrane translocation approach is very effective for functionalizing nanoparticles with molecules of CD47 in their recent Nanoscale Communication. They were able to coat nanoparticles with immunomodulatory proteins at an equivalent density to those on red blood cells, and in the correct orientation.

Read this HOT article today:

‘Marker-of-self’ functionalization of nanoscale particles through a top-down cellular membrane coating approach
Che-Ming J. Hu, Ronnie H. Fang, Brian T. Luk, Kevin N. H. Chen, Cody Carpenter, Weiwei Gao, Kang Zhang and Liangfang Zhang
DOI: 10.1039/C3NR00015J

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An exciting new anode material with impressive properties for high-performance lithium-ion batteries

Lixia Yuan, Yunhui Huang and co-workers report a simple one-pot method to synthesize a nanocluster composite assembled by interconnected ultrafine  SnO2@C nanospheres in their recent Nanoscale paper. They found that with a mixture of sodium carboxyl methyl cellulose and styrene butadiene rubber as a binder, the SnO2@C nanocluster anode exhibits superior cycling stability and rate capability.

A SnO2@carbon nanocluster anode material with superior cyclability and rate capability for lithium-ion batteries

Electrode materials are crucial for the overall performance of lithium ion batteries. Graphite is a traditionally used anode material, and tin dioxide is one promising alternative with a higher theoretical lithium storage capacity. However, the practical use of tin dioxide is limited by its rapid capacity fading, low initial coulombic efficiency and poor rate performance. Scientists from China have recently come up with a clever solution to these problems by skilfully combining SnO2@C nanoclusters with a suitable binder.

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A SnO2@carbon nanocluster anode material with superior cyclability and rate capability for lithium-ion batteries
Min He, Lixia Yuan, Xianluo Hu, Wuxing Zhang, Jie Shu and Yunhui Huang
DOI: 10.1039/C3NR34133J

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Nanoparticle system for simultaneous drug delivery and biomedical imaging

Lee Barrett is a guest web-writer for Nanoscale. He is currently a post-doctoral researcher at the University of Strathclyde, UK.

Huanxin Cai and Ping Yao, from Fudan University, have developed a facile and green approach for the synthesis of gold nanoparticle conjugates prepared from a lys-dex nangel, comprising a lysozyme core with a dextran shell. The Au@lys-dex nangels loaded with doxorubicin show the same antitumour activity as free doxorubicin, showing the potential of the nanogels for drug delivery applications.

Table of contents imageThe lys-dex conjugates were spherical in shape with a hydrodynamic radius of 200 nm.  Due to the stability of the lys-dex nanogels against changes in pH and ionic strength, in addition to the net positive charge of the lys core produced at pH < 10.7, the nanogels are a suitable substrate for the synthesis of gold nanoparticles.

By mixing the lys-dex nanogel and chloroauric acid at pH 4, gold nanoparticles can be synthesized by inducing the reduction of Au3+ using UV photo-irradiation.  The synthesis process was monitored by UV-Vis spectroscopy indicating that 2 hours of UV-irradiation is sufficient to produce gold nanoparticles with a surface plasmon band centered at 536 nm.   The authors report that the gold nanoparticle morphology can be controlled by altering the pH of the reaction, thereby leading to nanoparticles with sizes of 11, 8 and 4 nm at pH 2, 4 and 6, respectively.

Due to the plasmonic properties of the nanoparticles, the Au@lys-dex nanogels can also be used as contrast agents for optical microscopy imaging.  The authors have therefore devised a nanoparticle system for simultaneous drug delivery and biomedical imaging applications.

by Dr Lee Barrett

Read the full details of this HOT Nanoscale paper today:

In situ preparation of gold nanoparticle-loaded lysozyme–dextran nanogels and applications for cell imaging and drug delivery
Huanxin Cai and Ping Yao
DOI: 10.1039/C3NR00178D

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Top 10 most-read Nanoscale articles in January

This month sees the following articles in Nanoscale that are in the top ten most accessed for January:

Nanostructured carbon–metal oxide composite electrodes for supercapacitors: a review 
Mingjia Zhi ,  Chengcheng Xiang ,  Jiangtian Li ,  Ming Li and Nianqiang Wu  
Nanoscale, 2013,5, 72-88 
DOI: 10.1039/C2NR32040A 

Graphene transfer: key for applications 
Junmo Kang ,  Dolly Shin ,  Sukang Bae and Byung Hee Hong 
Nanoscale, 2012,4, 5527-5537 
DOI: 10.1039/C2NR31317K 

Recent advances in the efficient reduction of graphene oxide and its application as energy storage electrode materials 
Tapas Kuila ,  Ananta Kumar Mishra ,  Partha Khanra ,  Nam Hoon Kim and Joong Hee Lee  
Nanoscale, 2013,5, 52-71 
DOI: 10.1039/C2NR32703A 

Graphene synthesis: relationship to applications 
Rebecca S. Edwards and Karl S. Coleman  
Nanoscale, 2013,5, 38-51 
DOI: 10.1039/C2NR32629A 

Upconversion nanoparticles and their composite nanostructures for biomedical imaging and cancer therapy 
Liang Cheng ,  Chao Wang and Zhuang Liu  
Nanoscale, 2013,5, 23-37 
DOI: 10.1039/C2NR32311G 

Core–shell sulfur@polypyrrole composites as high-capacity materials for aqueous rechargeable batteries 
Jie Shao ,  Xinyong Li ,  Li Zhang ,  Qunting Qu and Honghe Zheng  
Nanoscale, 2013,5, 1460-1464 
DOI: 10.1039/C2NR33590E 

Advances in 2D boron nitride nanostructures: nanosheets, nanoribbons, nanomeshes, and hybrids with graphene 
Yi Lin and John W. Connell  
Nanoscale, 2012,4, 6908-6939 
DOI: 10.1039/C2NR32201C 

Magnetic Fe3O4–graphene composites as targeted drug nanocarriers for pH-activated release 
Xiujuan Fan ,  Guozheng Jiao ,  Wei Zhao ,  Pengfei Jin and Xin Li  
Nanoscale, 2013,5, 1143-1152 
DOI: 10.1039/C2NR33158F 

Dopamine as the coating agent and carbon precursor for the fabrication of N-doped carbon coated Fe3O4 composites as superior lithium ion anodes 
Cheng Lei ,  Fei Han ,  Duo Li ,  Wen-Cui Li ,  Qiang Sun ,  Xiang-Qian Zhang and An-Hui Lu  
Nanoscale, 2013,5, 1168-1175 
DOI: 10.1039/C2NR33043A 

Self-assembly of hierarchical star-like Co3O4 micro/nanostructures and their application in lithium ion batteries 
Li Li ,  Kuok Hau Seng ,  Zhixin Chen ,  Zaiping Guo and Hua Kun Liu  
Nanoscale, 2013,5, 1922-1928 
DOI: 10.1039/C2NR33223J 

Why not take a look at the articles today and blog your thoughts and comments below.

Fancy submitting an article to Nanoscale? Then why not submit to us today!

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Making temperature sensitive porous nanolayers

A method of manufacturing porous nanolayers using temperature sensitive substrates has been developed by scientists working in Germany.

Traditionally such materials are made using flame spray pyrolysis (FSP), but this process is limited by the thermal sensitivity of the substrate onto which the nanoparticles are coated. Furthermore the mechanical stability of the layers is often weak in liquid environments.

The new process involves separating the pyrolysis step from the introduction of the final substrate material. In stage one the nanoparticles (eg titanium dioxide) are coated onto an initial substrate, using FSP, to create an intermediate porous nanolayer material. In stage two a new substrate is applied to the intermediate material to create a ‘nanoparticle sandwich’, which is passed through rollers under pressure and at low temperature. The nanoparticle layer transfers to the new substrate to yield the final material.

The technique produces materials that have superior mechanical stability, and opens up the possibility of using different substrates, such as polypropylene foil.

Read this HOT Nanoscale article today:

Transfer of highly porous nanoparticle layers to various substrates through mechanical compression
Sven Oliver Schopf, Samir Salameh and Lutz Mädler
DOI: 10.1039/C3NR34235B

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Nanoscale Issue 7 of 2013 out now!

The latest issue of Nanoscale is now online. You can read the full issue here.

The outside front cover features an article on Encapsuled nanoreactors (Au@SnO2): a new sensing material for chemical sensors by Lili Wang, Huimin Dou, Zheng Lou and Tong Zhang

Three-dimensional quantitative force maps in liquid with 10 piconewton, angstrom and sub-minute resolutions is the article highlighted on the inside front cover by Elena T. Herruzo, Hitoshi Asakawa, Takeshi Fukuma and Ricardo Garcia 

Issue 7 contains the following Review and Feature articles: 

Fancy submitting an article to Nanoscale? Then why not submit to us today!

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Exfoliating graphene with organic dyes

Scientists from Italy, the UK, Belgium and France provide insights into the efficiency of pyrene sulfonic sodium salts for the preparation of graphene in their recent Nanoscale paper, and clarify the role of different molecular properties on graphene exfoliation.

Nanoscale insight into the exfoliation mechanism of graphene with organic dyes: effect of charge, dipole and molecular structure

They compared pyrene derivatives with increasing number of sulfonic groups for their efficiency as exfoliating agents in the preparation of graphene. They combined different experimental and modelling techniques to find a correlation between the graphene-pyrene dye interaction, the molecular structure and the amount of graphene flakes solubilised. They found that a large dipole and molecular asymmetry are important for adsorption of the dye molecule on graphene. The dipole allows the molecule to “slide” into the solvent layer between the graphene surface and the aromatic core of the dye, and displace the water molecules.

The efficiency of pyrene derivatives in exfoliating graphene is well known, but the details of their interactions with graphene have been somewhat unclear so far. An understanding of these interactions is important for developing the processability of graphene, which holds great potential for technological applications in numerous fields.

Read this HOT article today:

Nanoscale insight into the exfoliation mechanism of graphene with organic dyes: effect of charge, dipole and molecular structure
Andrea Schlierf, Huafeng Yang, Elias Gebremedhn, Emanuele Treossi, Luca Ortolani, Liping Chen, Andrea Minoia, Vittorio Morandi, Paolo Samorì, Cinzia Casiraghi, David Beljonne and Vincenzo Palermo
DOI: 10.1039/C3NR00258F

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Clever control of nanoscale cylinder orientation in sugar-based block copolymer thin films

In their recent Nanoscale Communication, Borsali et al. varied the composition of the annealing co-solvent in order to control the orientation of nanocylinders in sugar-based block copolymer thin films. Their method, which achieves nanopatterning in three dimensions, could have important applications in next-generation nanoelectronics.

Control of 10 nm scale cylinder orientation in self-organized sugar-based block copolymer thin films

The group have developed a novel class of natural-synthetic “hybrid” block copolymer, where one of the blocks consists of poly- or oligosaccharides. The rod-like structures formed by the saccharide blocks further sterically increase the incompatibility of the hydrophobicity-hydrophilicity imbalance of the saccharide and synthetic polymer blocks.  The authors used H2O -THF mixtures as the annealing solvent system, since the saccharide component of the polymer is soluble in H2O, but not in THF, and vice versa for the other block polymer component. By changing the composition of the H2O-THF mixture, the orientation of the cylinder domain in the block copolymer thin film on a silicon substrate was successfully controlled from horizontal to perpendicular.

Read this HOT Nanoscale communication today:

Control of 10 nm scale cylinder orientation in self-organized sugar-based block copolymer thin films
Issei Otsuka, Salomé Tallegas, Yoko Sakai, Cyrille Rochas, Sami Halila, Sébastien Fort, Ahmad Bsiesy, Thierry Baron and Redouane Borsali
DOI: 10.1039/C3NR00332A

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Understanding the hydrophobic assembly of nanomaterials

The interfacial-organized monolayer water film (MWF) induced “two-step” aggregation of nanographene: both in stacking and sliding assembly pathwaysWenping Lv and Ren’an Wu from the Dalian Institute of Chemical Physics have investigated the aggregation of two graphene nanosheets in water and the role of the interfacial water monolayer in the aggregation mechanism.

They found that the interfacial water monolayers hinder the aggregation of graphene nanosheets, attributed to the many  structurally ordered H-bonds of the water monolayer. Their findings advance understanding of the hydrophobic assembly of nanomaterials, such as proteins in aqueous solution.

Read this Nanoscale paper in full:

The interfacial-organized monolayer water film (MWF) induced “two-step” aggregation of nanographene: both in stacking and sliding assembly pathways
Wenping Lv and Ren’an Wu
DOI: 10.1039/C3NR33447C

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Gold nanoparticles target HIV

Table of contents imageGold nanoparticles functionalised with aptamers have been found to be highly effective inhibitors for human immunodeficiency virus type 1 reverse transcriptase. The nanoparticles particles have been shown to reduce the ability of the HIV virus to reproduce and infect new cells.

The scientists behind the work describe how inhibition is enhanced further by using combinations of different aptamers that each target different parts of the virus.

Find out more about this exciting work – read the Nanoscale article today:

Highly efficient inhibition of human immunodeficiency virus type 1 reverse transcriptase by aptamers functionalized gold nanoparticles
Yen-Chun Shiang, Chung-Mao Ou, Shih-Ju Chen, Ting-Yu Ou, Han-Jia Lin, Chih-Ching Huang and Huan-Tsung Chang
DOI: 10.1039/C3NR33403A

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