Supporting Information for Rupture of Lipid Membranes Induced by Amphiphilic Janus Nanoparticles Kwahun Lee, Liuyang Zhang, Yi Yi, Xianqiao Wang, Yan Yu* Department of Chemistry, Indiana University, Bloomington, IN 47405, USA State Key Laboratory for Manufacturing Systems Engineering, Xi an Jiaotong University, Xi an, Shaanxi, 710049, China College of Engineering, University of Georgia, Athens, GA 30602, USA Contents Table S1 Figures S1-S12 Movie S1
SI Figures Figure S1. (a) Schematics showing the fabrication of amphiphilic and dipolar Janus particles. (b) SEM image of Janus particles after gold coating. Scale bar: 500 nm. (c) Photos showing phase transfer behavior of +/pho JPs and +/- JPs. +/pho JPs accumulated only at the toluene (oil)-water interface, but +/- JPs were dispersed in water phase. Figure S2. Characterization of surface chemistry of different types of particles by measuring their phase transfer behavior in toluene/water mixture and zeta-potential in deionized water.
Figure S3. Morphology of defects in bilayers at different temperatures as indicated. Scale bars: 10 µm. Figure S4. Fluorescence image showing adsorption of BSA-Alexa 647 on +/Pho JPs. Scale bar: 10 µm.
Figure S5. Fluorescence intensity of +UPs on different substrates as indicated. Average intensity per particle was 870 ± 53 (a.u.) on hydrophilic substrates, 818 ± 91 (a.u.) on hydrophobic substrates, and 861± 121 (a.u.) on lipid bilayers. Each data point in the scattered plots is the average intensity per particle obtained from a single image containing at least 30 particles. Each box plot indicates the mean (squared dot), median (horizontal line), and the interquartile range from 25 % to 75 % of the corresponding data set.
Figure S6. (a) Fluorescence images showing the propagation of defects in bilayers induced by 150 pm - /Pho JPs. (b) Images showing the adsorption of fluorescently labeled BSA in defective areas. (c) Linescan intensity profile of BSA and the lipid bilayer. (d) Morphology of defects in the bilayer at different temperatures as indicated. Scale bars: 10 µm.
Figure S7. Fluorescence images showing morphology of lipid bilayers at 70 minutes after interaction with different types of particles at various concentrations as indicated. Scale bars: 10 µm.
Figure S8. Fluorescence images showing the colocalization between small lipid aggregates that were diffusive in solution and fluorescently labeled -/pho JPs. Scale bars: 10 µm.
Figure S9. Plots showing the number of particles adsorbed on bilayers as a function of time. Each plot is fitted linearly.
Figure S10. Schematic illustration of the computational model for a Janus NP and a bilayer bilayer. The head group and hydrophobic tail of a lipid are shown in grey and red, respectively. The hydrophobic ligands and cationic ligands on each Janus NP are shown in green and blue, respectively. The core of each Janus NP is shown in dark blue color. Figure S11. Computer simulation of the disruption of a lipid bilayer induced by nanoparticles with a uniform cationic hydrophilic coating (shown in green). (Top) Images showing the formation of the lipidparticle complex and defect. (Bottom) Spatial distribution of membrane tension (γ) corresponding to different stages in the NP-bilayer interaction process.
Figure S12. Computer simulation of the disruption of a lipid bilayer induced by nanoparticles with a uniform hydrophobic coating (shown in blue). (Top) Images showing the formation of the lipid-particle complex and defect. (Bottom) Spatial distribution of membrane tension (γ) corresponding to different stages in the NP-bilayer interaction process. Table S1. Interaction parameters used in computer simulation for the bilayer membrane and coated NPs Bead type Bead type Interaction Potential Parameters H H 0.95 H T 0.95 T T, 1.6 H P 1 H C H N 0.95 T P, 1.6 T C 0.95 T N 0.95 P P P C 0.95 P N 0.95 C C C N 0.95 N N 0.95 Movie S1. A video shows the fluorescently labeled lipid bilayer (green) and +/pho JPs (red) during their interaction, including the adsorption of +/pho JPs, subsequent formation of lipid-particle complexes, and the formation and propagation of defects in the bilayer. Frame rate of the video is 80 times of the actual image acquisition rate. Scale bar is 10 µm.