Sunday, 8 June 2014
Friday, 6 June 2014
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
Thursday, 5 June 2014
A simple cell culture model has captured biomechanical effects similar to those observed in myocardial tissue during the onset of diabetic cardiomyopathy. Cardiac myocytes were co-cultured with cardiac fibroblasts in bilayers mimicking the layered structure of the heart and then exposed to hyperglycaemic or hyperlipidemic conditions associated with diabetes. In both cases, particle-tracking microrheology revealed myocyte (but not fibroblast) stiffening; AFM measurements supported the microrheological data. Excess fatty acid also led to increased cFOS expression – and indicator of hypertrophy. Further experiments hinted at a possible mediating role for reactive oxygen species but more work is required to understand the complex mechanisms underlying the observations.
Hyperglycemic and Hyperlipidemic Conditions Alter Cardiac Cell
Biomechanical Properties; J. Michaelson et al; Biophysical Journal; Volume 106 June 2014 2322–2329
Wednesday, 4 June 2014
Researchers have designed a minimally-invasive device that can selectively and dynamically illuminate multiple brain regions for optogenetics applications. The device is a waveguide comprising a single thin optical fibre with a sharp, tapered tip coated with gold (except for the tip). Emission of desired modes of light was permitted at specific sites along the taper by locally removing the coating to create windows. Each window could be addressed by adjusting the angle of the incident light on the input facet of the fibre. In vivo proof of principle experiments demonstrated the effectiveness of the device.
Multipoint-Emitting Optical Fibers for Spatially Addressable In Vivo Optogenetics; F. Pisanello et al, Neuron; http://dx.doi.org/10.1016/j.neuron.2014.04.041
Tuesday, 3 June 2014
A new targeted cancer therapy termed quadrapeutics (after the four components of the therapy) radically accelerated and improved the effect of combined chemotherapy and radiation in vivo. Cancer cells self-assembled systemically administered antibody-functionalized gold nanoparticles and drug-loaded nanocarriers into intracellular nanoclusters via receptor-mediated endocytosis. Near-infra-red laser pulses heated the gold nanoparticles generating vapour plasmonic nanobubbles which then exploded, releasing the drugs from the nanocarriers into the cytoplasm. Subsequently, xray pulses were locally amplified in the cancer cells through the emission of secondary electrons by the gold nanoparticles in the nanoclusters. Nanocluster size and thus effectiveness increased with the cancer aggressiveness.
On-demand intracellular amplification of chemoradiation with cancer-specific plasmonic nanobubbles; Ekaterina Y Lukianova-Hleb et al; Nature Medicine; doi:10.1038/nm.3484
Monday, 2 June 2014
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.
Sunday, 1 June 2014
The movement of nanotube-labelled kinesin-1 motor proteins in cells was analysed using fluorescence microscopy. At timeframes above 100 ms, researchers observed a regime of kinesin molecular motion different from thermal motion or directed motor activity. In this regime, the kinesins were bound to the microtubule network, and moved randomly but remained locally constrained. Their dynamics reflected nonequilibrium fluctuations in the microtubule network. These fluctuations were driven by cytoplasmic myosin activity generating a random stirring effect.
High-resolution mapping of intracellular fluctuations using carbon nanotubes; N. Fakhri et al; Science; Vol 344(6187); p 1031