Showing posts with label nanoparticles. Show all posts
Showing posts with label nanoparticles. Show all posts

Friday, 30 May 2014

Mechanics in Biology and Medicine

Researchers from eleven different institutions have identified specific areas of biology and medicine in which mechanics could make significant contributions in a new Perspective article.  Three areas were analysed: nanoparticle-based drug delivery, medical devices, and cell mechanics.

Nanoparticle –based drug delivery is one area ripe with opportunitiy.  In particular, modelling of the drug delivery process would reduce the need for physical experiments and expedite nanoparticle design for improved delivery.  Integrating computational modelling into the rational design of nanoparticles offers the opportunity to improve nanoparticle performance during, for example, vascular transport and endocytosis. 

Modeling also has a role to play in improving a variety of medical devices.  For example, recent developments in “organ-on-chip” devices require understanding of complex transport behaviours through channels, gels and complex tissues.  In another area, advances in ventricular assist devices could greatly benefit from computational mechanics simulations to optimise design and hopefully mitigate problems such as thrombus formation. 

Finally, in the section entitled “cell mechanics”, the authors identified a critical need for better constitutive models for single-cell mechanical behaviour, taking into account the active behaviour of cells.  The mechanics community could also contribute to the development of integrated tools for single cell studies exploring biological variability.

This is just a brief summary of issues that particularly resonated with me.  If you’re interested in the topic, I recommend you go to the full article. This is a long paper, and so my “Bites” length rules are waived for this one.  

USNCTAM perspectives on mechanics in medicine; G. Bao et al, J. R. Soc. Interface 2014 11, 20140301


Friday, 16 May 2014

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

Tuesday, 13 May 2014

Delivering siRNAs to endothelial cells

Scientists have synthesised nanoparticles which efficiently delivered siRNAs to endothelial cells in vivo and facilitated silencing of up to five different endothelial genes concurrently.  Gene expression in several other cell types was not significantly affected by the presence of the delivery agent.  The nanoparticles, made of low-molecular-weight polyamines and lipids, reduced target gene expression in multiple animal models.  In lung cancer models, primary tumour growth and metastases were both reduced. 

In vivo endothelial siRNA delivery using polymeric nanoparticles with low molecular weight; J.E. Dahlman et al, Nature Nanotechnology, DOI: 10.1038/NNANO.2014.84.

Friday, 9 May 2014

How cells change nanoparticles

The protein corona surrounding nanoparticles exposed to biological cells changes according to nanoparticle characteristics, cell type and length of exposure, studies show.  These changes alter nanoparticle aggregation, cell membrane affinity, uptake and retention.  Results suggest nanoparticles have an ever-changing biological ‘identity’ as they travel through numerous microenvironments in the body.

Secreted Biomolecules Alter the Biological Identity and Cellular Interactions of Nanoparticles; A. Albanese et al; ACS Nano; DOI: 10.1021/nn4061012