Highly Stable, Ultrasmall Polymer-Grafted Nanobins (usPGNs) with Stimuli-Responsive Capability
| Autor: | SonBinh T. Nguyen, Aysenur Iscen, Joshua N. Leonard, Bong Jin Hong, One Sun Lee, Anthony J. Chipre, George C. Schatz, Mei Mei Li |
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| Rok vydání: | 2018 |
| Předmět: |
chemistry.chemical_classification
Hydrogen bond Vesicle 02 engineering and technology Polymer 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Article 0104 chemical sciences Molecular dynamics chemistry.chemical_compound Membrane chemistry Biophysics Moiety General Materials Science lipids (amino acids peptides and proteins) Physical and Theoretical Chemistry 0210 nano-technology Lipid bilayer Acrylic acid |
| Zdroj: | The journal of physical chemistry letters. 9(5) |
| ISSN: | 1948-7185 |
| Popis: | Highly stable and stimuli/pH-responsive ultra-small polymer-grafted nanobins (usPGNs) have been developed by grafting a small amount (10 mol %) of short (4.3 kDa) cholesterol-terminated poly(acrylic acid) (Chol-PAA) into an ultra-small unilamellar vesicle (uSUV). The usPGNs are stable against fusion and aggregation over several weeks and exhibit over 10-fold enhanced cargo retention in biologically relevant media at pH 7.4 in comparison with the parent uSUV template. Coarse-grained molecular dynamics (CGMD) simulations confirm that the presence of the cholesterol moiety can greatly stabilize the lipid bilayer. They also show extended PAA chain conformations that can be interpreted as causing repulsion between colloidal particles, thus stabilizing them against fusion. Notably, CGMD predicted a clustering of the Chol-PAA chains on the lipid bilayer under acidic conditions due to intra- and interchain hydrogen bonding, leading to the destabilization of local membrane areas. This explains the experimental observation that usPGNs can be triggered to release a significant amount of cargo upon acidification to pH 5. These developments put the lipid-bilayer-embedded Chol-PAA in stark contrast to traditional poly(acrylic acid) systems where the molar mass (M(n)) of the polymer chains must exceed 16.5 kDa to achieve stimuli-responsive conformation changes. They also distinguish the small usPGNs from the much-larger polymer-caged nanobin (PCN) platform where the Chol-PAA chains must be covalently crosslinked to engender stimuli-responsive behaviors. |
| Databáze: | OpenAIRE |
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