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Kehrein J, Gürsöz E, Davies M, Luxenhofer R, Bunker A. Unravel the Tangle: Atomistic Insight into Ultrahigh Curcumin-Loaded Polymer Micelles. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2303066. [PMID: 37403298 DOI: 10.1002/smll.202303066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 06/22/2023] [Indexed: 07/06/2023]
Abstract
Amphiphilic ABA-triblock copolymers, comprised of poly(2-oxazoline) and poly(2-oxazine), can solubilize poorly water-soluble molecules in a structure-dependent manner forming micelles with exceptionally high drug loading. All-atom molecular dynamics simulations are conducted on previously experimentally characterized, curcumin-loaded micelles to dissect the structure-property relationships. Polymer-drug interactions for different levels of drug loading and variation in polymer structures of both the inner hydrophobic core and outer hydrophilic shell are investigated. In silico, the system with the highest experimental loading capacity shows the highest number of drug molecules encapsulated by the core. Furthermore, in systems with lower loading capacity outer A blocks show a greater extent of entanglement with the inner B blocks. Hydrogen bond analyses corroborate previous hypotheses: poly(2-butyl-2-oxazoline) B blocks, found experimentally to have reduced loading capacity for curcumin compared to poly(2-propyl-2-oxazine), establish fewer but longer-lasting hydrogen bonds. This possibly results from different sidechain conformations around the hydrophobic cargo, which is investigated by unsupervised machine learning to cluster monomers in smaller model systems mimicking different micelle compartments. Exchanging poly(2-methyl-2-oxazoline) with poly(2-ethyl-2-oxazoline) leads to increased drug interactions and reduced corona hydration; this suggests an impairment of micelle solubility or colloidal stability. These observations can help driving forward a more rational a priori nanoformulation design.
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Affiliation(s)
- Josef Kehrein
- Soft Matter Chemistry, Department of Chemistry, Faculty of Science, University of Helsinki, Helsinki, 00014, Finland
- Division of Pharmaceutical Biosciences, Drug Research Program, Faculty of Pharmacy, University of Helsinki, Helsinki, 00014, Finland
| | - Ekinsu Gürsöz
- Soft Matter Chemistry, Department of Chemistry, Faculty of Science, University of Helsinki, Helsinki, 00014, Finland
- Division of Pharmaceutical Biosciences, Drug Research Program, Faculty of Pharmacy, University of Helsinki, Helsinki, 00014, Finland
| | - Matthew Davies
- Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond Street, London, Ontario, N6A 5B7, Canada
| | - Robert Luxenhofer
- Soft Matter Chemistry, Department of Chemistry, Faculty of Science, University of Helsinki, Helsinki, 00014, Finland
| | - Alex Bunker
- Division of Pharmaceutical Biosciences, Drug Research Program, Faculty of Pharmacy, University of Helsinki, Helsinki, 00014, Finland
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Direct and Reverse Pluronic Micelles: Design and Characterization of Promising Drug Delivery Nanosystems. Pharmaceutics 2022; 14:pharmaceutics14122628. [PMID: 36559122 PMCID: PMC9787366 DOI: 10.3390/pharmaceutics14122628] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/19/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022] Open
Abstract
Pluronics are a family of amphiphilic block copolymers broadly explored in the pharmaceutical field. Under certain conditions, Pluronics self-assemble in different structures including nanosized direct and reverse micelles. This review provides an overview about the main parameters affecting the micellization process of Pluronics, such as polymer length, fragments distribution within the chain, solvents, additives and loading of cargo. Furthermore, it offers a guide about the most common techniques used to characterize the structure and properties of the micelles. Finally, it presents up-to-date approaches to improve the stability and drug loading of Pluronic micelles. Special attention is paid to reverse Pluronics and reverse micelles, currently underexplored in the literature. Pluronic micelles present a bright future as drug delivery agents. A smart design and thorough characterization will improve the transfer to clinical applications.
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Li B, Wang YL. Self-Assembly of Miktoarm Star Polyelectrolytes in Solutions with Various Ionic Strengths. ACS OMEGA 2022; 7:20791-20799. [PMID: 35755333 PMCID: PMC9219065 DOI: 10.1021/acsomega.2c01317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
We studied the self-assembly of miktoarm star polyelectrolytes with different numbers of arms in solutions with various ionic strengths using coarse-grained molecular dynamic simulations. Spherical micelles are obtained for star polyelectrolytes with fewer arms, whereas wormlike clusters are obtained for star polyelectrolytes with more arms at a low ionic strength environment, with hydrophilic arms showing a stretched conformation. The number of clusters shows an overall decreasing tendency with increasing the number of arms in star polyelectrolytes due to strong electrostatic coupling between polycations and polyanions. The formation of wormlike clusters follows an overall stepwise pathway with an intermittent association-dissociation process for star polyelectrolytes with weak electrostatic coupling. These computational results can provide relevant physical insights to understand the self-assembly mechanism of star polyelectrolytes in solvents with various ionic strengths and to design star polyelectrolytes with functional groups that can fine-tune self-assembled structures for specific applications.
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Affiliation(s)
- Bin Li
- School
of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, China
| | - Yong-Lei Wang
- Department
of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-106 91 Stockholm, Sweden
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