Cotton-wool-like sol-gel glass from electrospinning

Researchers have combined sol-gel processing with electrospinning to produce cotton-wool-like CaO-SiO₂ glass structures.  The cotton-wool-like morphology was attributed to the rheological properties of the electrospinning solution causing branching of the primary jet and to fibre regions rich in calcium ions creating bending instabilites in the applied electric field.  The material was moldable and could be packed into complex bone defects.  Preliminary results suggested the materials were bioactive and non-cytotoxic.

Cotton-wool-like bioactive glasses for bone regeneration; G. Poologasundarampillai et al; Acta Biomaterialia; http://dx.doi.org/10.1016/jactbio.2014.05.020

http://www.sciencedirect.com/science/article/pii/S1742706114002323

An open access paper

The future of polymer therapeutics

Ruth Duncan offers her perspective of the challenges and opportunities for the polymer therapeutics community.  She discusses recent clinical successes and failures and offers valuable suggestions which could improve translation of products from the lab to the clinic.  Key considerations include (amongst others) appropriate selection of polymer and drug for a specific application, sufficient materials characterization (not just biological analysis), clinically relevant preclinical models and improved clinical trial design.

Polymer therapeutics: Top 10 selling pharmaceuticals — What next?, R.Duncan, Journal of Controlled Release, http://dx.doi.org/10.1016/j.jconrel.2014.05.001

http://www.sciencedirect.com/science/article/pii/S0168365914002922

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

Graphenes in biology

Kostas Kostarelos and Kostya Novoselov discuss the difficulties of investigating how graphenes interact with biological systems. This family of materials can be produced in different ways, which control their thickness, size and surface functionalization all of which will modify cell-material interactions. Article also touches on issues of biodegradation and safety.

http://www.sciencemag.org/content/344/6181/261.full

Exploring the interface of graphene and biology; K. Kostarelos and K Novoselov; Science; Vol. 344 no. 6181 pp. 261-263; 2014.

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