Wednesday 30 April 2014

Lab-on-a-chip based blood plasma separation

Researchers have developed a cheap microfluidic device to separate plasma from whole blood with efficiency similar to centrifugation.  A filter at the top of a channel with blood flowing upwards separated the fluid phase from the cells. Gravity-assisted sedimentation prevented cells clogging the filter and subsequent hemolysis.

Hemolysis-free blood plasma separation, JH Son et al, Lab-on-a-chip, 2014, Accepted Manuscript, DOI: 10.1039/C4LC00149D

Link to article:

Tuesday 29 April 2014

Mechanism of cell migration in confined channels

Cells may experience physical confinement when migrating through extracellular matrices.  In confinement, processes typically associated with 2D migration e.g. actin polymerization are inhibited.  Now, a chemotaxis-based microfluidic device containing microchannels of varying cross-sectional areas reveals an alternative mechanism of migration in confinement: water permeation and active and passive ion transport.



Water Permeation Drives Tumor Cell Migration in Confined Microenvironments; K.M. Stroka et al, Cell 157, 611–623, April 24, 2014

Monday 28 April 2014

Gene delivery at the bionic interface

Researchers report that intense electrical signals from the electrode array forming the interface between cochlear implant and cochlea stimulate gene delivery by electroporation.  Mesenchymal cells were transfected with genes which generated brain-derived neurotrophic factor stimulating neurite growth and improving neurite-electrode contact.  This more integrated interface could improve hearing dynamic range. 


Close-Field Electroporation Gene Delivery Using the Cochlear Implant Electrode Array Enhances the Bionic Ear; J.L.Pinyon et al; Science Translational Medicine; 23 April 2014: 
Vol. 6, Issue 233, p. 233ra54. 

Sunday 27 April 2014

Nano-factories of DNA for safer gene delivery

Traditional gene carriers are cationic to allow efficient loading with anionic genes but these carriers are toxic limiting clinical applications.  Now researchers report neutral liposomes containing DNA and PCR components which amplify the DNA.  Transfection rates are similar to the traditional cationic vectors, but cell viability significantly improved.

http://pubs.acs.org/doi/pdfplus/10.1021/nn501106a

DNA amplification in neutral liposomes for safe and efficient gene delivery; S. Lee et al; ACS Nano Just Accepted Manuscript; DOI: 10.1021/nn501106a





Friday 25 April 2014

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.

Thursday 24 April 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

Wednesday 23 April 2014

Barriers to commercially viable cell- and tissue therapies

Experts have identified hurdles to the successful commercialisation of innovations in regenerative medicine. Particularly, they recognised challenges in bioreactor-based manufacturing hindering the scale-up of therapies. This field is expensive and risky to invest in so the experts suggest developing manufacturing processes within academia rather than hoping for angel investment.

Manufacturing challenges in regenerative medicine; I. Martin et al; Science Translational Medicine; Vol. 6(232); p. 232; 2014.

http://stm.sciencemag.org/content/6/232/232fs16.full

Introduction

Hello and welcome to my little blog. This is going to be more of a research news feed, where I will highlight interesting research papers, perspectives and reviews from the bioengineering research community in 50 word ‘bites’. I’ll aim for papers to be less than a week old. Happy reading!