title: Size dependent disruption of tethered lipid bilayers by functionalized polystyrene nanoparticles.
abstract: Molecular interactions between engineered nanomaterials (ENM) and biomembranes are not well understood. This study investigated the effects of particle size and surface functional group on polystyrene nanoparticles' (PNPs) potency for biomembrane disruption. Electrochemical impedance spectroscopy was used to measure changes in the electrical resistance (Rm) of a tethered bilayer lipid membrane BLM (tBLM) composed of 1,2-dioleoyl-sn-glycero-phosphocholine (DOPC) following PNP exposure. All PNPs tested triggered a decline in the Rm that could be described using an exponential-decay model. Statistical hierarchical clustering analysis of two model parameters (exponential rate constant and fractional loss of Rm) could distinguish between the PNPs based on both size and surface functional group. For COOH modified nanoparticles, 20nm PNPs were more potent in reducing Rm than 100nm PNP. However, for amidine modified nanoparticles, 120nm PNPs were more potent in reducing Rm than 23nm PNP. The COOH modified PNPs were more potent in reducing Rm than amidine modified PNP, which tended to aggregate following exposure to a tBLM. Ultra performance liquid chromatography-mass spectroscopy analysis suggested that the aggregation may have been triggered by DOPC that was removed from the tBLM by the amidine PNP.
authors.affiliation: Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI 48824, USA. Electronic address: worden@egr.msu.edu.
authors.forename: R
authors.initials: R
authors.lastname: Mark Worden
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods; D016000:Cluster Analysis; D058266:Dielectric Spectroscopy / Q000379:methods; D017097:Electric Impedance; D008051:Lipid Bilayers / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry* / Q000145:classification; D010316:Particle Size; D010713:Phosphatidylcholines / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D011137:Polystyrenes; C017251:1,2-oleoylphosphatidylcholine
keywords: Aggregation; Biomembrane; Clustering; Disruption; Electrochemical impedance; Lipid bilayer; Polystyrene nanoparticle