Subscriber access provided by AUSTRALIAN NATIONAL UNIV
Article
Structure-property relationships of amphiphilic nanoparticles that penetrate or fuse lipid membranes Prabhani Atukorale, Zekiye P. Guven, Ahmet Bekdemir, Randy Carney, Reid C. Van Lehn, Dong Soo Yun, Paulo H. Jacob Silva, Davide Demurtas, Yusang Sabrina Yang, Alfredo Alexander-Katz, Francesco Stellacci, and Darrell J. Irvine Bioconjugate Chem., Just Accepted Manuscript • DOI: 10.1021/acs.bioconjchem.7b00777 • Publication Date (Web): 21 Feb 2018 Downloaded from http://pubs.acs.org on February 23, 2018
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
Bioconjugate Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Bioconjugate Chemistry
90x39mm (300 x 300 DPI)
ACS Paragon Plus Environment
Bioconjugate Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Figure 1. Nonpolar fluorophores tethered to amphiphilic NPs act as optical sensors for membrane embedding nanoparticles. (a) Chemical structures of MUS, OT, and brOT organic ligands and schematic depiction of ligand-coated gold NPs. (b) Alkyl chain-tethered BODIPY dye structure and schematic depiction of BODIPYlabeled NPs in solution. (c-d) Molecular dynamics simulations of 2:1 MUS:OT NPs conjugated with 1 BODIPY ligand/particle, in aqueous solution or embedded in DOPC bilayers. Shown are (c) PMF measurements from atomistic molecular dynamics simulations (mean ± standard error from 2 independent runs) and (d) simulation snapshots of BODIPY ligand configurations for particles in solution vs. bilayer-embedded. Left panel: cutaway view that depicts only the BODIPY ligand (red), Au core (yellow), and lipid headgroups (gray); Right panel: depicts all atoms involved (water molecules and ions are included in the simulations but not drawn for visual clarity). (e) MUS/OT NPs at 0.28 mg/mL (MUS:OT 2:1-2.5, Supplementary Table 1) were incubated for 1 hr at 25°C with DOPC liposomes at varying concentrations and BODIPY fluorescence was measured by fluorescence spectrometry (plotted as mean ± standard error, n=3). (f) Cryoelectron micrograph tilt series of MUS/OT NPs (0.28 mg/mL MUS/OT 1:1-2.6, Supplementary Table 1) incubated with
ACS Paragon Plus Environment
Page 2 of 35
Page 3 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Bioconjugate Chemistry
DOPC liposomes overnight at 25°C (scale bars 50 nm, with red arrows indicating membrane-embedded NPs). (g) Single frame capture from a cryoelectron tomogram of DOPC liposomes incubated with 0.28 mg/mL MUS/OT NPs (MUS/OT 2:1-2.1, Supplementary Table 1) overnight at 25°C (scale bar 50 nm, with cartoon inset depiction of embedding and red arrow indicating an embedded NP). (h) Confocal micrographs of DOPC GMVs co-incubated with the membrane-impermeable dye calcein (20 µg/mL, green) and 0.28 mg/mL MUS NPs (MUS-2.4, Supplementary Table 1) labeled with BODIPY ligand (red) after 1 hr at 25°C (scale bar 50 µm). (i) Mean fluorescence intensity linescan of BODIPY signal from confocal micrograph in (h) (scale bar 50 µm). 215x279mm (300 x 300 DPI)
ACS Paragon Plus Environment
Bioconjugate Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
Figure 2. BODIPY fluorescence sensor reveals electrostatics and membrane fluidity govern NP penetration of lipid membranes. (a, b) BODIPY-labeled NPs (0.28 mg/mL, MUS-1.7, MUS/OT 2:1-2.5, or MUS/brOT 2:12.4) were incubated with DOPC GMVs for 1 hr at 25°C, then analyzed by flow cytometry. Shown are (a) histograms of BODIPY fluorescence in GMVs and (b) mean fluorescence intensities from replicate samples, plotted as mean ± standard error (n=3) and not significant (n.s.) by one-way ANOVA with Bonferroni posttest. (c) Confocal micrographs of NBD-PE-labeled GMVs (green) incubated for 1 hr at 25°C with 0.28 mg/mL BODIPY-labeled NPs (red, MUS:OT 1:1-2.6 for i-iii and MUS:OT 1:1-2.1 for iv-v). Shown are DOPC GMVs in water (i), 80:20 mol:mol DOPC:DOPG GMVs in water (ii), 80:20 mol:mol DOPC:DOPG GMVs in PBS (iii), 50:50 mol:mol DOPC:DPPC GMVs in water (iv), or DPPC GMVs in water (v). Scale bars 50 µm. (d) Quantification of confocal fluorescence signals from (c)(i-iii). Shown are mean ± standard error (n=3); *P < 0.05 by one-way ANOVA with Bonferroni post-test. (e) Quantification of flow cytometry analysis of (c)(iv-v). Shown are mean ± standard error (n=3); *P
