Cells in silica

Individual mammalian cells have been encapsulated in silica coatings using a quick and relatively mild process carried out in cell culture medium.  The coatings contain thiol groups from molecules left over from the synthesis process offering opportunities for post-functionalisation.  Cell proliferation was suppressed by the silica coat which also protected the cells from the effects of trypsin and highly toxic poly (allylamine hydrochloride).  Researchers suggest that modifications of the coating could protect cells against a variety of other stressors such as heat and UV.   The approach might ultimately be useful for applications where cells require protection and preservation such as cell-based sensors as well as in single-cell studies. 

Cytoprotective Silica Coating of Individual Mammalian Cells Through Bioinspired Silicification, J. Lee et al, Angewandte Chemie International Edition; DOI: 10.1002/anie.201402280

http://onlinelibrary.wiley.com/doi/10.1002/anie.201402280/abstract 

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

Antibiotic AuPt nanoparticles

Researchers have discovered that bimetallic nanoparticles containing gold and platinum act as antimicrobial agents and are effective against a range of bacteria including E.coli, Salmonella Choleraesius and Pseudomonas Aeruginosa.  Pure gold or pure platinum nanoparticles were not antibiotic at all.  Investigations suggested two mechanisms in operation: disruption of the cell membranes and increased intracellular ATP.  The nanoparticles were not toxic to mammalian cells in vitro. 

Tuning the Composition of AuPt Bimetallic Nanoparticles for Antibacterial Applications, Y. Zhao et al, Angewandte Chemie International Edition, DOI: 10.1002/anie.201401035

http://onlinelibrary.wiley.com/doi/10.1002/anie.201401035/abstract 

Micro-RNA sensor for cancer diagnostics

Micro-RNA-21 is overexpressed in many cancers.  A new magnetobiosensor selectively detected micro-RNA-21 at low concentrations in cancer cells and tissue samples. RNA plant-virus proteins tethered to magnetic beads captured DNA duplexes formed by adding anti-Micro-RNA-21 to the Micro-RNA-21-containing samples.  Beads were captured on screen-printed electrodes for electrochemical detection of microRNA. 

http://onlinelibrary.wiley.com/doi/10.1002/anie.201403270/full

Magnetobiosensors based on viral protein p19 for micro-RNA

determination in cancer cells and tissues; S. Campuzano et al; Angewandte Chemie International Edition, DOI: 10.1002/anie.201403270