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HOT article: Ultra-small lipid–polymer hybrid nanoparticles for tumor-penetrating drug delivery

27 Jul 2016

When it comes to cancer treatment, smaller can sometimes be better, as a new HOT article published in Nanoscale has shown. New ultra-small hybrid nanoparticles, developed by Jiangfang Zhang and a team based at the University of California, have proven highly effective at delivering anti-cancer drugs in mice – the nanoparticles, which are under 25nm in size, could penetrate deep into the tumours of the mice to release the drug where it would be most effective.

The size of drug delivery nanocarriers has a crucial role in how effective they are at moving through the body: too large, and they will be cleared by the liver; too small, and they will be filtered by the kidneys. Cancer drug carriers work best at sizes below 50nm, where they can more easily infiltrate tumours, but preventing such small particles from aggregating once synthesised can be a challenge. Zhang’s team used both lipids and polymers to make their nanoparticles highly stable, even in physiological conditions – the polymer cores took up the hydrophobic drug, while the lipid coating provided stability and protection from the aqueous environment of the body.

The nanoparticles were targeted to tumour cells by conjugating them to folate ligands – when injected into mice with induced tumours, the number of target nanoparticles present within the tumours was three times that of non-targeted carriers. What’s more, the anti-cancer drug docetaxel could be loaded into the nanoparticles and used to treat the mice, with highly promising results. Over half of the mice treated with the hybrid nanocarriers were still alive 64 days after having tumours induced, a significant extension compared to a clinically used drug treatment.

Read the full article here:

Ultra-small lipid–polymer hybrid nanoparticles for tumor-penetrating drug delivery

Diana Dehaini, Ronnie H. Fang, Brian T. Luk, Zhiqing Pang, Che-Ming J. Hu, Ashley V. Kroll, Chun Lai Yu, Weiwei Gao and Liangfang Zhang*
Nanoscale, 2016, Advance Article

Susannah May is a guest web writer for the RSC Journal blogs. She currently works in the Publishing Department of the Royal Society of Chemistry, and has a keen interest in biology and biomedicine, and the frontiers of their intersection with chemistry. She can be found on Twitter using @SusannahCIMay.

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The role of advanced nanomaterials in tackling key global challenges

13 May 2016

Duncan Graham, University of Strathclyde

Kian Ping Loh, National University of Singapore

As human demand on earth’s limited resources continues to grow and evolve, global challenges are emerging that require solutions to sustain the quality of life and improve communities where socio-economic disparities remain. The chemical sciences, and in particular advanced nanomaterials, can play a leading role in providing solutions to some of these global challenges. Top of the list in terms of the most pressing global challenges is the change in our environment. For instance, the quality of air that we breathe is being affected by industrialization and other human activities. Can more efficient chemical processes be devised to reduce the release of pollutants into the atmosphere? Or can new materials be produced which sequester and maintain the quality of the air which we are used to breathing?

Climate change has been discussed since the 1830s and it is clear that human activities are having a highly detrimental effect on our climate. Can nanoscience provide solutions to reduce the rising temperatures experienced globally? Can chemistry have a role in understanding some of the mechanisms that are resulting in climate change and as a result provide effective mediation measures?

Water is the major component of the surface of our planet – however an alarmingly large number of countries struggle to have access to this most basic necessity for drinking, agriculture and sanitation. Can chemistry and advanced nanomaterials provide solutions to new desalination processes? Or be used to harness solar energy to provide sanitation in remote parts of the globe?

In addition to our environmental concerns, the human population is increasing in some parts of the world which results in a greater demand for food, energy and agricultural lands; this all contributes to increasing food prices. Can we find chemical solutions to enhance the ability to feed our growing population and can these be effective solutions in the areas that need it most?

With a rapidly aging population in many developed countries, health is also a concern across the globe. People are living longer – health monitoring and diagnostics create the need for wearable, portable sensors. With the boundaries between countries becoming increasingly transparent, infectious diseases, caused by rapidly mutating biological agents, are potentially worrying. Anti-microbial resistance features prominently in the national research agenda of many countries. Drug discovery is taking longer and costing more than it should. Can chemistry, and in particular advanced nanomaterials, play a role in addressing some of these health challenges which are common to all countries across the globe? Can we produce new materials for sensing, diagnosis of disease or produce a therapeutic effect using different mechanisms to traditional small molecule drugs?

Finally, all of the earth’s activities require energy and we have to move towards a sustainable energy future. Can chemistry play a role in providing new materials which can harvest solar energy efficiently? Furthermore, can we safely harness the potential cleanliness of nuclear fuel? How can bioenergy be used to create a sustainable future based on renewables? These global challenges affect everyone on the planet and unless steps are taken now, with a strong scientific basis for the solutions, the future health and wellbeing of the global civilisation is at risk.

(more…)

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iPAINT: brushing-up on super resolution microscopy

05 May 2016

In recent years, super-resolution microscopy has enabled researchers to explore biological interfaces at the nanoscale. Single-molecule localization methods, such as point accumulation for imaging in nanoscale topography (PAINT), are fundamental techniques for studying the morphology and architecture of living matter. While super-resolution microscopy techniques like PAINT have acquired the interest of researchers in biology, it remains elusive to applications in soft matter and materials science.

In issue 16 of Nanoscale, researchers from the Netherlands have endeavoured to overcome the limitations of PAINT, such as a pre-requisite for hydrophobic domains or specific ligand/receptor pairs, by introducing interface point accumulation for imaging in nanoscale topography (iPAINT). In short, this new technique enables nanometre resolution imaging of interfaces by non-covalent, continuous labelling during imaging. This was achieved by labelling silica nanoparticles with polyethylene glycol (PEG) end-functionalized with a photoactivatable rhodamine analogue (PEG552) that is able to continuously adsorb and desorb from the interface. This method of labelling is essential for interfaces such as emulsions, foams and crystals like ice.

By employing iPAINT as a generic imaging method, the authors are able to obtain super-solution images at different interfaces in 3D. This innovation allows users to develop PAINT in other fields, such as colloid and interface science, food science, soft matter physics and nanotechnology.

iPAINT: a general approach tailored to image the topology of interfaces with nanometer resolution
A. Aloi, N. Vilanova, L. Albertazzi and I. K. Voets
Nanoscale, 2016, DOI: 10.1039/C6NR00445H

Dr Lee Barrett is a guest web writer for the Nanoscale blog. Lee is currently a postdoctoral researcher in the Centre for Molecular Nanometrology at the University of Strathclyde. His research is currently focused on the development of nanoparticle-based sensors and surface enhanced Raman scattering (SERS). Follow him on twitter @L_Bargie

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Siligraphene gets serious about solar cells: Nanoscale article featured in Chemistry World

31 Mar 2016

Theoretical scientists have predicted SiC₇ – a new phase of the graphene–silicene hybrid siligraphene, which if synthesisable, could revolutionise flexible optoelectronic devices such as solar cells.

A charge density map reveals delocalised π bonds in SiC7 siligraphene's irregular hexagonal rings

SiC₇ siligraphene has an interesting structure with a graphene-like honeycomb lattice, but unlike graphene, its hexagonal rings are irregular. The scientists expect SiC₇ siligraphene to be much better than SiC₂ siligraphene and single-layer black phosphorus at absorbing sunlight. Additionally, broken symmetry caused by silicon doping would create band gaps that boost its optoelectronic properties.

Interested to know more? Read the full article by Suzanne Howson in Chemistry World.

The original article is free to access and can be read at:

SiC₇ siligraphene: a novel donor material with extraordinary sunlight absorption
Huilong Dong, Liujiang Zhou, Thomas Frauenheim, Tingjun Hou, Shuit-Tong Lee and Youyong Li
Nanoscale, 2016,8, 6994-6999.

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Go with the (lateral) flow

25 Jan 2016

Lateral flow assays (LFA) have become a promising tool in the diagnostics market in recent years due to their low cost, ease of use and short assay times. The simplicity of their use extends to the inclusion of, typically, gold nanoparticle labels that provide a visual confirmation, due to their distinctive red colour, of a particular target analyte. However, limitations, such as quantitative analysis and assay sensitivity, can hinder their broader use in diagnostics.

To overcome these limitations, researchers from South Korea have utilised surface enhanced Raman scattering (SERS) to detect staphylococcal enterotoxin B (SEB) on a LFA strip. The authors have opted to use Raman reporter-labelled hollow gold nanospheres (HGNs) instead of the conventional gold nanoparticle labels. Using HGNs, the authors were able to detect as low as 0.001 ng/mL of SEB, which is about three orders of magnitude more sensitive than the conventional ELISA-based method for SEB.

These researchers demonstrates that SERS can be utilised to overcome the limitations of conventional LFAs in order to achieve greater assay sensitivity without deviating from the original LFA design.

Application of a SERS-based lateral flow immunoassay strip for the rapid and sensitive detection of staphylococcal enterotoxin B
Joonki Hwang, Sangyeop Lee and Jaebum Choo
Nanoscale, 2016, DOI: 10.1039/C5NR07243C

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Emerging topic: Two-dimensional materials

14 Dec 2015

Two-dimensional materials research is an emerging topic area, in particular their application in electronic devices. To help our readers stay up to date we have collected papers published in Nanoscale into one online web collection entitled 2D materials for electronic devices.

Editor’s Choice selection from Associate Editor, Professor Andrea Ferarri

A highly conducting graphene film with dual-side molecular n-doping
Youngsoo Kim, Jaesung Park, Junmo Kang, Je Min Yoo, Kyoungjun Choi, Eun Sun Kim, Jae-Boong Choi, Chanyong Hwang, K. S. Novoselov and Byung Hee Hong
Nanoscale, 2014,6, 9545-9549

“Graphene has many record properties. It is transparent like (or better than) plastic, but conducts heat and electricity better than any metal, it is an elastic film, behaves as an impermeable membrane, and it is chemically inert and stable. Thus it seems ideal as the next generation transparent conductor. There is a need to find a substitute for indium tin oxide (ITO) in the manufacturing of various types of displays and touch screens, due to the brittleness of indium that makes it difficult to use them when flexibility is a requirement. Graphene is an ideal candidate for such a task. Thus, coupled with carbon’s abundance, this presents a more sustainable alternative to ITO. Prototypes of graphene-based displays have been produced and commercial products seem imminent.

One drawback is that, in order to beat ITO’s conductivity, graphene needs to be doped. Kim et al. report a dual-side molecular doping method, demonstrating effective work function modulation, high carrier density and significant reduction of sheet resistance in large area graphene samples grown by chemical vapour deposition. With further optimization, their approach may enable a variety of practical applications of graphene films requiring low sheet resistance comparable to indium tin oxide (ITO), as well as high transparency and flexibility.”

Here are some popular articles from the collection:

Graphene-analogue carbon nitride: novel exfoliation synthesis and its application in photocatalysis and photoelectrochemical selective detection of trace amount of Cu²⁺
Hui Xu, Jia Yan, Xiaojie She, Li Xu, Jiexiang Xia, Yuanguo Xu, Yanhua Song, Liying Huang and Huaming Li
Nanoscale, 2014, 6, 1406-1415

Electrochemical properties of CVD grown pristine graphene: monolayer- vs. quasi-graphene
Dale A. C. Brownson, Sarah A. Varey, Fiazal Hussain, Sarah J. Haigh and Craig E. Banks
Nanoscale, 2014,6, 1607-1621

Transparent conductors composed of nanomaterials
Michael Layani, Alexander Kamyshny and Shlomo Magdassi
Nanoscale, 2014, 6, 5581-5591

Access the full collection here!

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HOT article: Ionizing radiation improves glioma-specific targeting of superparamagnetic iron oxide nanoparticles conjugated with cmHsp70.1 monoclonal antibodies (SPION–cmHsp70.1)

09 Dec 2015

In this HOT article, tumour-specific targeting using superparamagnetic iron oxide nanoparticles (SPIONs) combined with ionising radiation is investigated. Heat shock protein Hsp70 is known to be expressed by cells exposed to stressful conditions or specifically on the membrane of highly aggressive tumour cells. SPIONs, which are negative contrast agents for magnetic resonance imaging (MRI), were synthesised to contain the Hsp70 specific antibody (cmHsp70.1) to increase uptake into various tumour cells.

Conjugation of the cmHsp70.1 was accomplished by introducing amine groups to the dextran polymer coating of SPIONs, allowing covalent attachment to the carboxylic acid functional groups of the antibody through carbodiimide coupling. This was shown to dramatically increase loading of iron oxide into various tumour cells, compared to unconjugated SPIONs. By exposing cells to a non-lethal dose of ionising radiation, additional uptake could be achieved as cells express more of the heat shock mHsp70.

The differences in uptake can be seen in the figure below in both in vivo and in vitro environments using MRI and fluorescence microscopy, respectively. This approach has the potential to be clinically relevant for both diagnosis and therapy of tumours.

Figure 1 Targeting of the orthotopic C6 glioma by SPION–cmHsp70.1 conjugates. (A) Magnetic resonance images for the control, non-irradiated animals treated with SPIONs, SPION–cmHsp70.1 particles and irradiated rats (10 Gy) treated with SPION–cmHsp70.1. Images were obtained in RARE-T1, TurboRARE-T2 and FLASH regimens. Retention of the nanoparticles in the tumor presented as hypotensive zones on T2-weighted and gradient echo images (red arrows). (B) Immunofluorescent images of the brain tumor stained with anti-Hsp70 antibodies (green). Nuclei stained with DAPI (blue). Nanoparticles detected using reflective laser scanning at 488 nm (red). Scale bar, 40 μm.

Ionizing radiation improves glioma-specific targeting of superparamagnetic iron oxide nanoparticles conjugated with cmHsp70.1 monoclonal antibodies (SPION–cmHsp70.1)
Maxim A. Shevtsov, Boris P. Nikolaev, Vyacheslav A. Ryzhov, Ludmila Y. Yakovleva, Yaroslav Y. Marchenko, Marina A. Parr, Valerij I. Rolich, Anastasiya L. Mikhrina, Anatolii V. Dobrodumov, Emil Pitkin and Gabriele Multhoff
Nanoscale, 2015,7, 20652-20664, DOI: 10.1039/C5NR06521F, Paper

Dr Mike Barrow is a guest web writer for the Nanoscale blog, he currently works as a Postdoctoral Researcher at the University of Liverpool. Twitter: @mikesyb

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HOT article: Responsive polymer brushes for controlled nanoparticle exposure

19 Nov 2015

In this article, Scheutjens-Fleer self-consistent field (SF-SCF) theory simulations were used to accurately predict the position of a nanoparticle attached to the end-group of a responsive polymer chain surrounded by a majority of non-responsive polymer chains in a mixed brush system.

Certain stimuli such as pH or temperature can be used to create a defined ‘on-off’ switch between a protected ‘off’ state, where the responsive polymer chain is contracted thus burying the nanoparticles well within the non-responsive components, or an ‘on’ state where the nanoparticle is exposed to the medium through swelling of the responsive polymer chains.

The solvent quality was parameterised by the Flory-Huggins interaction parameter (χ) and for nearly all investigated systems there was a sharp transition at the so-called critical χ value between the on-off state. Design variables for mixed polymer brushes such as grafting density, chain length and nanoparticle size were investigated and all had an effect on the critical χ value, with a larger particle size and grafting density leading to an increase in χ. Fixing the polymer chain length for both responsive and non-responsive polymer chains led to the most optimal switching.

The authors are planning to develop materials from these findings and use the mixed polymer brush-nanoparticle systems as rapidly responsive (bio)sensors with single molecule sensitivity.

Responsive polymer brushes for controlled nanoparticle exposure
Namik Akkilic, Frans A. M. Leermakers and Wiebe M. de Vos
Nanoscale, 2015,7, 17871-17878, DOI: 10.1039/C5NR05150A

Dr Mike Barrow is a guest web writer for the Nanoscale blog, he currently works as a Postdoctoral Researcher at the University of Liverpool. Twitter: @mikesyb

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Highlights from ChinaNANO

05 Nov 2015

The Nanoscale Editorial Office is delighted at the success of the Nanoscience Symposium which occurred at the ChinaNANO 2015 conference in Beijing from 3rd-5th September. This one-day symposium included talks from the Nanoscale Associate Editors about their latest research covering topics such as carbon nanomaterials, nanoelectronics, bionanomaterials, nanophotonics, nanoclusters and nanocrystals.

Some articles submitted to Nanoscale from delegates of the ChinaNANO 2015 conference can be found below.

Surface coating of siRNA-peptidomimetic nano-self-assemblies with anionic lipid bilayers: Enhanced gene silencing and reduced adverse effects in vitro
Xianghui Zeng, Anne Marit de Groot, Alice Sijts, Femke Broere, Erik Oude Blenke, Stefano Colombo, Willem van Eden, Henrik Franzyk, Hanne M Nielsen and Camilla Foged
Nanoscale, 2015, DOI: 10.1039/C5NR04807A

Strong metal-support interaction in novel core-shell Au-CeO₂ nanostructures induced by different pretreatment atmospheres and its influence on CO oxidation
Zhihua Wang, Huifen Fu, Ziwei Tian, Dongmei Han and Fubo Gu
Nanoscale, 2015, DOI: 10.1039/C5NR06929G

Fabrication of ultra-thin silicon nanowire arrays using ion beam assisted chemical etching
Zhiyuan Tan, Wenjia Shi, Chungang Guo, Quan Zhang, Liang Yang, Xiaoling Wu, Guo-an Cheng and Ruiting Zheng
Nanoscale, 2015,7, 17268-17273, DOI: 10.1039/C5NR02876K

Ethanol-assisted gel chromatography for single-chirality separation of carbon nanotubes
Xiang Zeng, Jinwen Hu, Xiao Zhang, Naigen Zhou, Weiya Zhou, Huaping Liu and Sishen Xie
Nanoscale, 2015,7, 16273-16281, DOI: 10.1039/C5NR04116C

There was a great turn-out and we received a lot of useful feedback from the attendees.

A prominent highlight of the event was the reception organised by the Royal Society of Chemistry to celebrate the launch of Nanoscale Horizons as well as the Nanoscale and Nanoscale Horizons partnership with the National Center for Nanoscience and Technology (NCNST) in Beijing which included cutting an enormous cake!

Left to right: Xiaodong Chen, Fiona McKenzie, Chunli Bai and Xingyu Jiang

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Micro meets nano: Multicolour gold nanoprobes detect micoRNA biomarkers in serum

04 Nov 2015

Researchers from Chinese Academy of Sciences have investigated the use of molecular beacons (MBs) for the simultaneous detection of multiple microRNA (miRNA) biomarkers.

The MBs were immobilized onto gold nanoparticles (AuNPs) via poly-adenine (poly-A) spacer. In addition, the authors used short oligonucleotides (oligos) consisting of 5 As in order to fill the gaps between MBs on the AuNP surface to ensure stability in salt solutions and obtain greater fluorescence signals.

MBs with 3 different fluorophores were employed in order to enable multiplexed detection of miRNAs in simulated serum samples. The authors reported that each MB specifically bound to its corresponding miRNA target in the presence of 10% fetal bovine serum (FBS), thereby demonstrating the applicability of this method for real biological sample detection.

In recent years, miRNA has emerged as a potential biomarker for many types of diseases, such as cancer, neurological disorders and cardiovascular disease. The need for rapid and sensitive assays for miRNA detection is therefore of great interest. Wang et al. have demonstrated a step in this direction with the research presented here.

Elaborately designed diblock nanoprobes for simultaneous multicolor detection of microRNAs
Chenguang Wang, Huan Zhang, Dongdong Zeng, Wenliang Sun, Honglu Zhang, Ali Aldalbahi, Yunsheng Wang, Lili San, Chunhai Fan, Xiaolei Zuo and Xianqiang Mi
Nanoscale, 2015,7, 15822-15829, DOI: 10.1039/C5NR04618A

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