2020同步年報

082 ACTIVITY REPORT 2020 A ntimicrobial resistance is becoming a severe threat to human health. Nanoparticles have increasingly emerged as new tools to combat fatal bacterial infections caused by resistant bacteria. Neutron scattering has been utilized to probe the changes in bacterial membrane struc- ture upon nanoparticle actions, whereby the bactericidal process was seen, and the mechanism was deduced. Hsin-Hui Shen’s group in Monash University, Australia, found that lytropic liquid-crystalline lipid nanoparticles, i.e. cubosomes, were highly bactericidal against lipopoly- saccharide (LPS)-deficient, Acinetobacter baumannii ( Ab ) strains. 1 The antibiotic-resistant strains of Ab strains are being reported increasingly in clinical settings. To unveil the killing mechanism, biomimetic membrane bilayers were reconstituted to replicate the composition of LPS-deficient strains, whereby neutrons can be employed to investigate the structure changes on bilayers upon cubosome treat- ment. In their experiment, synthetic 1-palmitoyl-2-oleoyl-snglycero- 3-phosphoethanolamine (16:0−18:1 POPE), 1-palmitoyl-2- oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (sodium salt) (16:0−18:1 POPG) and 1',3'-bis-[1,2-dioleoyl-sn-glycero Fig. 1 : SANS profiles (symbols) and best-fitted curves (lines) using a lamellar model for a biomimetic membrane before and after cubosome treatment in D 2 O at 25 °C. The Gaussian signals indicate the lipid bilayer. (a) Ab 5075D OM; (b) Ab 19606R OM; (c) Ab 5075D IM, the inset magnifies the data around the scattering peak to unify the intensity scale; (d) Ab 19606R IM. [Reproduced from Ref. 1] Seeing Nanoparticles Combat Superbugs Through Neutrons SANS is a powerful neutron technology to serve a new strategy to combat LPS-de cient Gram-negative pathogens with nano-technology which provides hints of innovative bacterial membrane-based therapies for treatment.