eprintid: 1470550 rev_number: 29 eprint_status: archive userid: 608 dir: disk0/01/47/05/50 datestamp: 2015-11-05 14:00:50 lastmod: 2021-10-04 00:52:34 status_changed: 2015-11-05 14:00:50 type: article metadata_visibility: show creators_name: Ficici, E creators_name: Andricioaei, I creators_name: Howorka, S title: Dendrimers in Nanoscale Confinement: The Interplay between Conformational Change and Nanopore Entrance ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F56 keywords: dendrimer, ionization, molecular dynamics, nanopore, single-molecule, transport note: This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx/doi/org/10.1021/acs.nanolett.5b01960 abstract: Hyperbranched dendrimers are nanocarriers for drugs, imaging agents, and catalysts. Their nanoscale confinement is of fundamental interest and occurs when dendrimers with bioactive payload block or pass biological nanochannels or when catalysts are entrapped in inorganic nanoporous support scaffolds. The molecular process of confinement and its effect on dendrimer conformations are, however, poorly understood. Here, we use single-molecule nanopore measurements and molecular dynamics simulations to establish an atomically detailed model of pore dendrimer interactions. We discover and explain that electrophoretic migration of polycationic PAMAM dendrimers into confined space is not dictated by the diameter of the branched molecules but by their size and generation-dependent compressibility. Differences in structural flexibility also rationalize the apparent anomaly that the experimental nanopore current read-out depends in nonlinear fashion on dendrimer size. Nanoscale confinement is inferred to reduce the protonation of the polycationic structures. Our model can likely be expanded to other dendrimers and be applied to improve the analysis of biophysical experiments, rationally design functional materials such as nanoporous filtration devices or nanoscale drug carriers that effectively pass biological pores. date: 2015-07-08 date_type: published official_url: http://dx.doi.org/10.1021/acs.nanolett.5b01960 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green article_type: letter article_type_text: Journal Article verified: verified_manual elements_id: 1038588 doi: 10.1021/acs.nanolett.5b01960 language_elements: eng lyricists_name: Howorka, Stefan lyricists_id: SHOWO39 actors_name: Howorka, Stefan actors_id: SHOWO39 actors_role: owner full_text_status: public publication: Nano Letters volume: 15 number: 7 pagerange: 4822-4828 event_location: United States issn: 1530-6992 citation: Ficici, E; Andricioaei, I; Howorka, S; (2015) Dendrimers in Nanoscale Confinement: The Interplay between Conformational Change and Nanopore Entrance. [Letter]. Nano Letters , 15 (7) pp. 4822-4828. 10.1021/acs.nanolett.5b01960 <https://doi.org/10.1021/acs.nanolett.5b01960>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1470550/1/Ficici%20Nano%20Letters%202015.pdf