Gibson Group News

Collaborative work with the optics laboratory at EPFL on the direct visualisation of metallic nanoparticles inside living cells has been accepted for publication in Optics Express.

Read the paper here

The use of gold nanoparticles (AuNPs) for diagnostic applications and for drug and genedelivery is currently under intensive investigation. For such applications, biocompatibility and the absence of cytotoxicity of AuNPs is essential. Although generally considered as highly biocompatible, previous in vitro studies have shown that cytotoxicity of AuNPs in certain human epithelial cells was observed. In particular, the degree of purification of AuNPs (presence of sodium citrate residues on the particles) was shown to affect the proliferation and induce cytotoxicity in these cells. To expand these studies, we have examined if the effects are related to nanoparticle size (10, 11 nm, 25 nm), to the presence of sodium citrate on the particles' surface or they are due to a varying degree of internalization of the AuNPs. Since two cell types are present in the major barriers to the outside in the human body, we have also included endothelial cells from the vasculature and blood brain barrier.

Our paper describing how bioreduction of single polymer end groups can trigger an LCST type transistion has been accepted. Here we introduce hydrophilic or hydrophobic end groups via disulfide bond onto one end of a thermoresponsive polymer. Bioreduction of the end group by intracellular glutathione levels results in a solubility switch, normally associated with a temperature change (i.e. LCST). This work will allow us to alter the lipophilicity of drug carriers intracellularly along with delivery of bioactive compounds.

A collaborative manuscript (with REPAIR lab, Mainz) investigating the cytoxicity and uptake of gold nanoparticles into primary endothelial cells (major cell type in vasculature) is studied. This shows differences between immortalised and primary cell cultures as well contributions from residual citrate from their synthesis.

A tandem post-polymerization modification strategy was used to systematically probe the multivalent inhibition of a bacterial toxin as a function of linker length (see scheme), carbohydrate density, and glycopolymer chain length. Guided by structural-biology information, the binding-pocket depth of the toxin was probed and used as a means to specifically improve inhibition of the toxin by the glycopolymer.

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Lucienne won a prize for her post/flash presentaiton at the Syst. Bio. Annual Meeting. Well done!!

Rob Deller has won the prize for best poster presentation at the RSC younger members' symposium in Nottingham. Well done!

Our Manuscript "Probing Bacterial Toxin Inhibition with Synthetic Glycopolymers using Tandem Post-Polymerization Modification: Role of Linker and Carbohydrate Density" has been accepted for publication in the prestigious journal Angew. Chem. This paper describes our efforts to interface materials with biology through a combination of traditional structural biology and modern polymer chemistry.