Stem cell culture

June’s issue of Nature Materials has a focus on stem cell culture.  The first of three reviews discusses how various inherent properties of materials may be engineered to regulate stem cell decisions, while a second focuses on the influence of the nano scale extracellular environment on stem cell fate via integrin-matrix interactions.  The third review outlines progress in high-throughput materials discovery of growth substrates for large-scale human pluripotent stem cell culture.  A Perspective article discusses the interplay between soluble factors and physical microenvironment in the control of stem cell fate.  A variety of primary research articles and supporting “News and Views” pieces are also contained in the focus.  Worth a look.

http://www.nature.com/nmat/focus/cell-culture/index.html

Polymer synthesis at microbial surfaces

A redox system operating in bacteria produces copper species which can catalyse an ATRP-type polymerization at the bacterial surface, researchers have shown.  The resulting macromolecules selectively bound to the microbial strain which templated them.  The approach was also used to label polymer side chains in-situ.  Potential applications include diagnostics.

Bacteria-instructed synthesis of polymers for self-selective microbial binding and labelling; E.P. Magennis et al, Nature Materials AOP; DOI: 10.1038/NMAT3949

http://www.nature.com/nmat/journal/vaop/ncurrent/pdf/nmat3949.pdf

Mechanics of stem cell nuclei

The cross-section of most materials contracts when stretched and expands when compressed. Auxetic materials do the opposite. Researchers now show that embryonic stem cell nuclei become auxetic when they enter a metastable state prior to differentiation. Data suggest that this is driven at least in part by global chromatin decondensation.

http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat3943.html

Auxetic nuclei in embryonic stem cells exiting pluripotency; S. Pagliara et al; Nature Materials (AOP); doi:10.1038/nmat3943