A tethered bilayer lipid membrane that mimics microbial membranes.

A model membrane system has been developed, which mimics the outer membrane of Gram negative bacteria. The structure is based on a tethered monolayer which has been fused with vesicles containing lipopolysaccharide molecules. The effect of the composition of the monolayer and the lipids in the outer layer on the structural and electrical properties of the membrane has been investigated. By using electrochemical impedance spectroscopy as well as neutron scattering techniques, it could be shown that a relatively high tethering density and a small amount of diluting lipids in the outer membrane leaflet leads to the formation of a stable solid supported membrane. The influence of divalent ions on the membrane stability has been probed as well as the interaction of the bilayer with the antibiotic colistin. A number of different architectures were developed, suited to both the study of bacterial membrane proteins and the screening of antimicrobial activity of potential drug candidates.

Biomedical applications of polyelectrolyte coated spherical gold nanoparticles.

Surface modified gold nanoparticles are becoming more and more popular for use in biomaterials due to the possibility for specific targeting and increased biocompatibility. This review provides a summary of the recent literature surrounding polyelectrolyte coatings on spherical gold nanoparticles and their potential biomedical applications. The synthesis and layer-by layer coating approach are briefly discussed together with common characterisation methods. The potential applications and recent developments in drug delivery, gene therapy, photothermal therapy and imaging are summarized as well as the effects on cellular uptake and toxicity. Finally, the future outlook for polyelectrolyte coated gold nanoparticles is explored, focusing on their use in biomedicine.

Nanoparticles in an antibiotic-loaded nanomesh for drug delivery.

Antibiotic loaded nanomeshes were fabricated by electrospinning polycaprolactone, a biocompatible polymer, with 12.5% w/w Colistin, 1.4% w/w Vancomycin and either cationic or anionic gold nanoparticles in varying combinations. The resulting nanomeshes had different antibiotic release profiles, with citrate capped gold nanoparticles combined with Colistin having the highest sustained release over 14 days for a 4 mg, 1.5 cm2 nanomesh. The electrospinning parameters were optimised to ensure the spinning of a homogenous mesh and the addition of antibiotics was confirmed through 1H NMR and ATR-FTIR. This research, as a proof of concept, suggests an opportunity for fabricating nanomeshes which contain gold nanoparticles as a drug release mechanism for antibiotics.