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Interactions of hydrophilic quantum dots with defect-free and defect containing supported lipid membranes

Year: 2022

Journal: Colloid Surf. B-Biointerfaces, Volume 210, FEB

Authors: Bar, L.; Perissinotto, F.; Redondo-Morata, L.; Giannotti, M., I; Goole, J.; Losada-Perez, P.

Organizations: Fonds de la Recherche Scientifique (FNRS) Project MIS [F.4525.20]; Universite Libre de Bruxelles (ULB), Project ARC [20061]; Agence National de la Recherche (ANR), as part of the 'Investments d'Avenir' Program [I-SITE ULNE/ANR-16-IDEX-0004 ULNE]; Agency for Management of University and Research Grants/Generalitat de Catalunya (CERCA Programme) [2017-SGR-1442]

Keywords: Hydrophilic quantum dots; Lipid membrane defects; Supported lipid bilayers; Quartz crystal microbalance with dissipation; Atomic force microscopy; Nanomechanics

Quantum dots (QDs) are semiconductor nanoparticles with unique optical and electronic properties, whose interest as potential nano-theranostic platforms for imaging and sensing is increasing. The design and use of QDs requires the understanding of cell-nanoparticle interactions at a microscopic and nanoscale level. Model systems such as supported lipid bilayers (SLBs) are useful, less complex platforms mimicking physico-chemical properties of cell membranes. In this work, we investigated the effect of topographical homogeneity of SLBs bearing different surface charge in the adsorption of hydrophilic QDs. Using quartz-crystal microbalance, a label-free surface sensitive technique, we show significant differences in the interactions of QDs onto homogeneous and inhomogeneous SLBs formed following different strategies. Within short time scales, QDs adsorb onto topographically homogeneous, defect-free SLBs is driven by electrostatic interactions, leading to no layer disruption. After prolonged QD exposure, the nanomechanical stability of the SLB decreases suggesting nanoparticle insertion. In the case of inhomogeneous, defect containing layers, QDs target preferentially membrane defects, driven by a subtle interplay of electrostatic and entropic effects, inducing local vesicle rupture and QD insertion at membrane edges.