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

Concerted folding and networking of short peptides

Short peptide sequences have been concomitantly folded into a specific helical conformation and networked into a single crystal co-ordination material by silver(I) co-ordination.  The new material contained two types of chiral nanochannel.  The larger of the nanochannels, with a diameter of around 2nm, offered a high degree of both chiral recognition and biomolecular recognition.  BF₄^- counterions in the crystalline network could be exchanged with other anions in a single-crystal-to-single-crystal transformation.

Coordination-Driven Folding and Assembly of a Short Peptide into a Protein-like Two-Nanometer-Sized Channel; T. Sawada et al, Angewandte Chemie International Edition, DOI: 10.1002/anie.201403506

http://onlinelibrary.wiley.com/doi/10.1002/anie.201403506/abstract

Artificial biocomposites of silk fibroin and amyloid fibrils

Researchers have combined two widely-studied fibrous protein assemblies – silk fibroin fibrils and amyloid fibrils – into a novel composite material. By varying the weight ratio of the two components, mechanical properties could be tuned: more amyloid fibril increased tensile modulus whereas more silk fibroin promotes tougher composites. The amyloid component could be enzymatically removed to generate a porous silk membrane.  Inorganic components were also added and a shape memory effect observed.  

Modulating Materials by Orthogonally Oriented β-Strands: Composites of Amyloid and Silk Fibroin Fibrils; S. Ling et al; Advanced Materials; DOI: 10.1002/adma.201400730

http://onlinelibrary.wiley.com/doi/10.1002/adma.201400730/abstract