Chemical Science Blog

Chinese chemists have created an epoxy that can be rapidly hardened and reshaped by shining a light on it. Unlike traditional epoxies which are cured using heat, this approach uses carbon nanotubes to translate light energy into localised heat to set the epoxy. Shining additional light on the set polymer initiates self-healing and reshaping.

Read the full article in Chemistry World»

Read the original journal article in Chemical Science – it’s free to access until 17th June:
Carbon nanotube-Vitrimer composite for facile and efficient photo-welding of epoxy
Yang Yang, Zhiqiang Pei, Xiqi Zhang, lei tao, yen wei and Yan Ji  
Chem. Sci., 2014, Accepted Manuscript, DOI: 10.1039/C4SC00543K, Edge Article

At the mention of DNA most people think of the storage of genetic information, but due to its biocompatibility and the ease with which it can be manipulated, it is becoming increasingly common for DNA to be used as a building material in nanotechnology.

DNA cages have attracted interest in the world of drug delivery as they can encapsulate small molecule drugs and are easily taken up by cells. The precision with which the size and shape of the cages can be controlled is another attractive aspect. Past studies have established that DNA cages can target cells, deliver encapsulated cargo and have a cytotoxic effect in cancer cells. However, specific control of the cellular delivery profile of DNA cages has not yet been achieved.

Sleinman and co-workers, from McGill University based in Montréal, Canada, have created dynamic DNA cubes which ‘unzip’ in a specific cellular environment. The cages are assembled from six DNA strands which make up the six sides of the cube and only disassemble in the presence of a trigger found in prostate cancer cells. The authors tested the uptake and disassembly, or ‘unzipping’, of their DNA cubes in vitro using three different mammalian cell lines.

Hydrophobic and hydrophilic dendritic chains were added to the cube after initial testing. It was determined that these chains coat the exterior of the cube and have a significant effect on the uptake of the structure. While the addition of hydrophobic chains to the cube increase uptake, addition of hydrophilic chains increase the stability of the cube in cellular environments.

One of the exciting aspects about this work is the scope for adaptation; the cubes could potentially be designed to respond to any nucleic acid sequence found specifically in diseased cells. Future work in the group will also look at encapsulating and delivering cargo, such as oligonucleotide drugs, using this new delivery system.

To download the full article for free* click the link below:

Sequence-responsive unzipping DNA cubes with tunable cellular uptake profiles

Katherine E. Bujold, Johans Fakhoury, Thomas G. W. Edwardson, Karina M. M. Carneiro, Joel Neves Briard, Antoine G. Godin, Lilian Amrein, Graham D. Hamblin, Lawrence C. Panasci, Paul W. Wiseman and Hanadi F. Sleiman
DOI: 10.1039/C4SC00646A

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For over 20 years the infrared spectra of many astronomical objects have been interpreted as flat two-dimensional polycyclic aromatic hydrocarbons (PAHs) that are also thought to be the source of organic matter on our own planet. More recently the detection of molecules such as fullerenes – molecules composed entirely of carbon, including the spherical C₆₀ – has revealed a more complicated picture of carbon in space. The links between these different molecules have been rather unclear but new research from Héctor Alvaro Galué at VU University of Amsterdam, in the Netherlands, has taken a fresh approach to this long-standing puzzle.

Energetic particles in interstellar space induce strain and re-hybridisation within flat carbon structures. Background image: © NASA, ESA, M Robberto (Space Telescope Science Institute/ESA) and the Hubble Space Telescope Orion Treasury Project Team

Read the full article in Chemistry World»

Read the original journal article in Chemical Science – it’s free to download until 6th June:
Decoding the infrared signatures of pyramidal carbons in graphenic molecular nanostructures of interstellar origin
Hector Alvaro Galue  
Chem. Sci., 2014, Accepted Manuscript, DOI: 10.1039/C4SC00890A, Edge Article

Scientists in Canada have made DNA cubes that are programmed to unzip and reveal molecules locked inside them in response to a carefully chosen trigger. Hanadi Sleiman and colleagues at McGill University and the Jewish General Hospital in Montreal, designed the cubes to release the drug cargo they might be carrying only in diseased cells and not normal cells.

The mRNA trigger binds tothe overhangs and opens the cube by strand displacement and strategically placed nicks on the structure

Read the full article in Chemistry World»

Read the original journal article in Chemical Science – it’s free to download until 7th May:
Sequence-responsive unzipping DNA cubes with tunable cellular uptake profiles
Katherine E. Bujold, Johans Fakhoury, Thomas G. W. Edwardson, Karina M. M. Carneiro, Joel Neves Briard, Antoine G. Godin, Lilian Amrein, Graham D. Hamblin, Lawrence C. Panasci, Paul W. Wiseman and Hanadi F. Sleiman  
Chem. Sci., 2014, Advance Article, DOI: 10.1039/C4SC00646A, Edge Article

All of the articles below are free to access until 14th May

Boron–boron J coupling constants are unique probes of electronic structure: a solid-state NMR and molecular orbital study
Frédéric A. Perras and David L. Bryce  
Chem. Sci., 2014, Advance Article
DOI: 10.1039/C4SC00603H, Edge Article

Disubstituted sialic acid ligands targeting siglecs CD33 and CD22 associated with myeloid leukaemias and B cell lymphomas
Cory D. Rillahan, Matthew S. Macauley, Erik Schwartz, Yuan He, Ryan McBride, Britni M. Arlian, Janani Rangarajan, Valery V. Fokin and James C. Paulson  
Chem. Sci., 2014, Advance Article
DOI: 10.1039/C4SC00451E, Edge Article

Solvatochromic AIE luminogens as supersensitive water detectors in organic solvents and highly efficient cyanide chemosensors in water
Yuping Zhang, Dongdong Li, Yi Li and Jihong Yu  
Chem. Sci., 2014, Accepted Manuscript
DOI: 10.1039/C4SC00721B, Edge Article

Catalytic enantioselective synthesis of 2-aryl-chromenes
Bi-Shun Zeng, Xinyi Yu, Paul W. Siu and Karl A. Scheidt  
Chem. Sci., 2014, Advance Article
DOI: 10.1039/C4SC00423J, Edge Article

All of the articles below are free to access until 13th April 

Turn-ON fluorescent affinity labeling using a small bifunctional O-nitrobenzoxadiazole unit
Takao Yamaguchi, Miwako Asanuma, Shuichi Nakanishi, Yohei Saito, Masateru Okazaki, Kosuke Dodo and Mikiko Sodeoka
Chem. Sci., 2014,5, 1021-1029
DOI: 10.1039/C3SC52704B, Edge Article  

DNAzyme-based 2:1 and 4:1 multiplexers and 1:2 demultiplexer
Ron Orbach, Francoise Remacle, R. D. Levine and Itamar Willner
Chem. Sci., 2014,5, 1074-1081
DOI: 10.1039/C3SC52752B, Edge Article  

Incorporation of electrically charged N-alkyl amino acids into ribosomally synthesized peptides via post-translational conversion
Takashi Kawakami, Toru Sasaki, Patrick C. Reid and Hiroshi Murakami
Chem. Sci., 2014,5, 887-893
DOI: 10.1039/C3SC52744A, Edge Article   

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