Fishing for rare cells in blood samples

A multi-stage microfluidic device separated tumour or leukaemic cells spiked into blood with high efficiency.  A filtration stage removed cell aggregates and debris.  Then a carefully designed microfluidic channel generated hydrodynamic forces which focussed the larger cancer cells into the channel centre; smaller blood cells were separated off.  The central fluid component entered a third steric hindrance region which further purified the rare cells by their size and mechanical properties. 

High-throughput rare cell separation from blood samples using steric hindrance and inertial microfluidics; S. Chen et al, Lab on a Chip; DOI: 10.1039/c3lc51384j

http://pubs.rsc.org/en/content/articlelanding/2014/lc/c3lc51384j#!divAbstract 

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

Self-powered sensor for human-machine interfacing

Researchers have created a thin-film triboelectric sensor which uses a polymer-nanowire-decorated triboelectric-negative polymer surface to achieve ultrasensitive tactile sensing. The device harnessed the triboelectric charges generated in the polymer surface upon contact with a foreign object to generate an output voltage.  The sensor retained its functionality even when applied to a curved surface.  Demonstrated applications included various alarm systems powered by touch alone.  Approach also offers possibilities for electronic-skin-type technologies. 

Self-Powered, Ultrasensitive, Flexible Tactile Sensors Based on Contact Electrification; G. Zhu et al, Nano Letters; dx.doi.org/10.1021/nl5005652

http://pubs.acs.org/doi/abs/10.1021/nl5005652 

Manipulating cells on magnetic circuit boards

A circuit board of magnetic pathways has enable precise manipulation of magnetic particles and magnetic-nanoparticle-labeled cells in fluidic environments upon application of a rotating magnetic field.  The trajectory of particles was programmable with conducting lines integrated into the circuit board which allowed transportation of particles from one pathway to another. The device had a multiplexed design to facilitate massively parallel single cell operations such as cell sorting, experimentation and retrieval. 

Magnetophoretic circuits for digital control of single particles and cells; B. Lim et al, Nature Communications; DOI: 10.1038/ncomms4846

http://www.nature.com/ncomms/2014/140514/ncomms4846/full/ncomms4846.html

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 

Enhancing photodynamic therapy using biomolecules

Researchers have demonstrated that the upconversion of near-infra-red laser light to visible or ultra-violet by interactions with biomolecules in-situ makes photodynamic therapy more effective.  A known photosensitizer was activated by both near-infra-red light and the upconverted radiation generated by nonlinear optical processes operating in either lipid molecules or collagen.  The approach substantially increased the efficiency with which the photosensitizer destroyed cells in vitro compared to two-photon absorption by near-infra-red alone. 

Photodynamic therapy by in situ nonlinear photon conversion, A. V. Kachynski et al, Nature Photonics AOP, DOI: 10.1038/NPHOTON.2014.90

http://www.nature.com/nphoton/journal/vaop/ncurrent/abs/nphoton.2014.90.html