Fig. 4: Unprotected particles trigger vesicle rupture and cargo release.
From: Responsive core-shell DNA particles trigger lipid-membrane disruption and bacteria entrapment
a Schematic representation of particle-induced disruption of Giant Unilamellar Vesicles (GUVs). Upon addition of the trigger strand and displacement of the hydrophilic corona, unprotected particles adhere to each other and to the GUVs owing to the hydrophobic nature of cholesterol molecules. DNA aggregates lead to GUV rupture and/or cargo release. b Confocal micrographs demonstrating the accumulation of amphiphilic DNA (fluorescein, cyan) onto a GUV before and after addition of the trigger strand. Scale bar 5 μm. Bottom: line profiles highlighting DNA accumulation onto the GUV surface. c Particle-induced GUV rupture as quantified from confocal time-lapse microscopy as the fraction of “surviving” GUVs over time. On the bottom, the left panel compares the effect of protected particles and unprotected ones exposed (at t = 0) to the trigger on otherwise stable GUVs. The right panel quantifies the effect of changing particle concentration ρc, expressed as the mass density of core C-stars. Legends as in panel d Top: confocal micrographs of membrane rupture induced by unprotected particles. Core C-stars are shown in cyan, the lipid membrane in red. Scale bar 10 μm. d Progressive leakage of fluorescein-sodium initially encapsulated in GUVs as quantified with confocal microscopy. Bottom: unprotected particles significantly increase the spontaneous leakage rate compared to control samples of unperturbed GUVs and those exposed to stabilized DNA particles. Top: Confocal micrographs demonstrating fluorescein-sodium (cyan) leakage following the adhesion of DNA particles (TXRED, red) onto GUVs. Scale bar 5 μm. Data shown in panels (b), (c), and (d) represent three and two independent experiments, respectively. The (mass) concentration of GUVs was 3.12 ± 0.16 g L−1 for the data in panels (c, d).
