Table of contents



Returning to the fold p245


This month marks ten years since the general principles of DNA origami were established, a technique that changed the field of DNA nanotechnology and that promises new physical and biomedical applications.



Toxicity of organometal halide perovskite solar cells pp247 - 251

Aslihan Babayigit, Anitha Ethirajan, Marc Muller & Bert Conings


In the last few years, the advent of metal halide perovskite solar cells has revolutionized the prospects of next-generation photovoltaics. As this technology is maturing at an exceptional rate, research on its environmental impact is becoming increasingly relevant.


News and Views

Spintronics: Chiral damping pp253 - 254

Kyoung-Whan Kim & Hyun-Woo Lee


Analysis of the magnetic domain-wall motion in a nanostructured magnetic system with strong spin–orbit coupling shows that the energy dissipation can be chiral when the inversion symmetry is broken.

See also: Letter by Jué et al.

Molecular thermopower: Feeling the squeeze pp254 - 255

Gemma C. Solomon


Optimizing the electronic functionality of a thermoelectric molecular junction depends on both the chemistry of the molecule and external environmental conditions.

See also: Letter by Rincón-García et al.

Nanoporous films: From conventional to conformal pp255 - 257

Mark D. Allendorf & Vitalie Stavila


Thin and continuous films of porous metal–organic frameworks can now be conformally deposited on various substrates using a vapour-phase synthesis approach that departs from conventional solution-based routes.

See also: Article by Stassen et al.

Arterial calcification: Conscripted by collagen pp257 - 258

Jordan D. Miller


In atherosclerotic plaques, patterns of calcification — which have profound implications for plaque stability and vulnerability to rupture — are determined by the collagen's content and patterning throughout the plaque.

See also: Article by Hutcheson et al.

Material Witness: The Roman melting pot p259

Philip Ball


Stem cell reprogramming: A 3D boost pp259 - 261

Oscar J. Abilez & Joseph C. Wu


Biophysical factors in an optimized three-dimensional microenvironment enhance the reprogramming efficiency of human somatic cells into pluripotent stem cells when compared to traditional cell-culture substrates.

See also: Article by Caiazzo et al.


Progress Article

Electromagnetic toroidal excitations in matter and free space pp263 - 271

N. Papasimakis, V. A. Fedotov, V. Savinov, T. A. Raybould & N. I. Zheludev


A review on toroidal excitations, from static toroidal moments in condensed matter, to dynamic toroidal multipoles demonstrated experimentally with metamaterials.



Chiral damping of magnetic domain walls pp272 - 277

Emilie Jué, C. K. Safeer, Marc Drouard, Alexandre Lopez, Paul Balint, Liliana Buda-Prejbeanu, Olivier Boulle, Stephane Auffret, Alain Schuhl, Aurelien Manchon, Ioan Mihai Miron & Gilles Gaudin


Structural inversion asymmetry in magnetic materials leads to a dissipative chiral damping mechanism. This mechanism is evidenced in the field-driven domain-wall motion in perpendicularly magnetized asymmetric Pt/Co/Pt trilayers.

See also: News and Views by Kim & Lee

Tunable spin polarization and superconductivity in engineered oxide interfaces pp278 - 283

D. Stornaiuolo, C. Cantoni, G. M. De Luca, R. Di Capua, E. Di. Gennaro, G. Ghiringhelli, B. Jouault, D. Marrè, D. Massarotti, F. Miletto Granozio, I. Pallecchi, C. Piamonteze, S. Rusponi, F. Tafuri & M. Salluzzo


The insertion of a few unit-cell-thick EuTiO3 layers at the interface between LaAlO3 and SrTiO3 leads to the formation of an electric-field-tunable quasi-two-dimensional electron system where ferromagnetism and superconductivity coexist.

Counting electrons on supported nanoparticles pp284 - 288

Yaroslava Lykhach, Sergey M. Kozlov, Tomáš Skála, Andrii Tovt, Vitalii Stetsovych, Nataliya Tsud, Filip Dvořák, Viktor Johánek, Armin Neitzel, Josef Mysliveček, Stefano Fabris, Vladimír Matolín, Konstantin M. Neyman & Jörg Libuda


The electronic interaction between deposited metal nanoparticles and their support material can influence their functionality. Here, a quantification of the charge transfer between platinum nanoparticles and a ceria support is presented.

Molecular design and control of fullerene-based bi-thermoelectric materials pp289 - 293

Laura Rincón-García, Ali K. Ismael, Charalambos Evangeli, Iain Grace, Gabino Rubio-Bollinger, Kyriakos Porfyrakis, Nicolás Agraït & Colin J. Lambert


The thermoelectric response of a fullerene–gold electrode single-molecule junction has been studied in a scanning tunnelling microscope. The junction exhibits positive and negative thermopower, dependent on molecule orientation and applied pressure.

See also: News and Views by Solomon

Fundamental limits of material toughening in molecularly confined polymers pp294 - 298

Scott G. Isaacson, Krystelle Lionti, Willi Volksen, Teddie P. Magbitang, Yusuke Matsuda, Reinhold H. Dauskardt & Geraud Dubois


In polymer-based nanocomposites the polymeric phase is often confined between stiff inorganic phases. The effect of this confinement on mechanical properties is assessed.



Metal–insulator transition in films of doped semiconductor nanocrystals pp299 - 303

Ting Chen, K. V. Reich, Nicolaas J. Kramer, Han Fu, Uwe R. Kortshagen & B. I. Shklovskii


The critical concentration of dopants required to trigger an insulator-to-metal transition in films of semiconductor nanocrystals has been calculated, and experimentally verified with highly doped silicon nanocrystal films.

Chemical vapour deposition of zeolitic imidazolate framework thin films pp304 - 310

Ivo Stassen, Mark Styles, Gianluca Grenci, Hans Van Gorp, Willem Vanderlinden, Steven De Feyter, Paolo Falcaro, Dirk De Vos, Philippe Vereecken & Rob Ameloot


The authors show that thin films of microporous metal–organic frameworks can be deposited on a broad range of substrates and on high-aspect-ratio features by means of chemical vapour deposition.

See also: News and Views by Allendorf & Stavila

Thermodynamics of the hybrid interaction of hydrogen with palladium nanoparticles pp311 - 317

Ronald Griessen, Nikolai Strohfeldt & Harald Giessen


The absorption and desorption mechanism of hydrogen in palladium nanoparticles is complex. Based on thermodynamic considerations a mechanism consistent with an interfacial model different from bulk Pd behaviour is now proposed.

Stress-stiffening-mediated stem-cell commitment switch in soft responsive hydrogels pp318 - 325

Rajat K. Das, Veronika Gocheva, Roel Hammink, Omar F. Zouani & Alan E. Rowan


The commitment and differentiation of human mesenchymal stem cells encapsulated in synthetic hydrogels that mimic the stiffness of adult-stem-cell niches can be switched by changing the hydrogels onset of stress stiffening.

Hydrogels with tunable stress relaxation regulate stem cell fate and activity pp326 - 334

Ovijit Chaudhuri, Luo Gu, Darinka Klumpers, Max Darnell, Sidi A. Bencherif, James C. Weaver, Nathaniel Huebsch, Hong-pyo Lee, Evi Lippens, Georg N. Duda & David J. Mooney


Hydrogels with faster stress relaxation enhance the spreading, proliferation, and osteogenic differentiation of embedded mesenchymal stem cells.

Genesis and growth of extracellular-vesicle-derived microcalcification in atherosclerotic plaques pp335 - 343

Joshua D. Hutcheson, Claudia Goettsch, Sergio Bertazzo, Natalia Maldonado, Jessica L. Ruiz, Wilson Goh, Katsumi Yabusaki, Tyler Faits, Carlijn Bouten, Gregory Franck, Thibaut Quillard, Peter Libby, Masanori Aikawa, Sheldon Weinbaum & Elena Aikawa


The formation of atherosclerotic plaques involves the aggregation of calcifying extracellular vesicles and the formation of microcalcifications.

See also: News and Views by Miller

Defined three-dimensional microenvironments boost induction of pluripotency pp344 - 352

Massimiliano Caiazzo, Yuya Okawa, Adrian Ranga, Alessandra Piersigilli, Yoji Tabata & Matthias P. Lutolf


The confinement imposed by the three-dimensional microenvironment promotes the induction of pluripotency in somatic cells through an accelerated mesenchymal-to-epithelial transition and increased epigenetic remodelling.

See also: News and Views by Abilez & Wu

Self-assembled RNA-triple-helix hydrogel scaffold for microRNA modulation in the tumour microenvironment pp353 - 363

João Conde, Nuria Oliva, Mariana Atilano, Hyun Seok Song & Natalie Artzi


Tissue-adhesive scaffolds made by the conjugation of RNA triple helices to dendrimers lead to ~90% shrinkage of tumours two weeks after implantation in a triple-negative breast cancer mouse model.



Erratum: The surface science of nanocrystals p364

Michael A. Boles, Daishun Ling, Taeghwan Hyeon & Dmitri V. Talapin




Corrigendum: Activating and optimizing MoS2 basal planes for hydrogen evolution through the formation of strained sulphur vacancies p364

Hong Li, Charlie Tsai, Ai Leen Koh, Lili Cai, Alex W. Contryman, Alex H. Fragapane, Jiheng Zhao, Hyun Soo Han, Hari C. Manoharan, Frank Abild-Pedersen, Jens K. Nørskov & Xiaolin Zheng