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Cai C, Tang H, Li F, Xu Z, Lin J, Li D, Tang Z, Yang C, Gao L. Archimedean Spirals with Controllable Chirality: Disk Substrate-Mediated Solution Assembly of Rod-Coil Block Copolymers. JACS AU 2024; 4:2363-2371. [PMID: 38938804 PMCID: PMC11200227 DOI: 10.1021/jacsau.4c00324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 05/24/2024] [Accepted: 06/03/2024] [Indexed: 06/29/2024]
Abstract
Spirals are common in nature; however, they are rarely observed in polymer self-assembly systems, and the formation mechanism is not well understood. Herein, we report the formation of two-dimensional (2D) spiral patterns via microdisk substrate-mediated solution self-assembly of polypeptide-based rod-coil block copolymers. The spiral pattern consists of multiple strands assembled from the block copolymers, and two central points are observed. The spirals fit well with the Archimedean spiral model, and their chirality is dependent on the chirality of the polypeptide blocks. As revealed by a combination of experiments and theoretical simulations, these spirals are induced by an interplay of the parallel ordering tendency of the strands and circular confinement of the microdisks. This work presents the first example regarding substrate-mediated self-assembly of block copolymers into spirals. The gained information could not only enhance our understanding of natural spirals but also assist in both the controllable preparations and applications of spiral nanostructures.
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Affiliation(s)
- Chunhua Cai
- Shanghai
Key Laboratory of Advanced Polymeric Materials, Key Laboratory for
Ultrafine Materials of Ministry of Education, Frontiers Science Center
for Materiobiology and Dynamic Chemistry, School of Materials Science
and Engineering, East China University of
Science and Technology, Shanghai 200237, China
| | - Hongfeng Tang
- Shanghai
Key Laboratory of Advanced Polymeric Materials, Key Laboratory for
Ultrafine Materials of Ministry of Education, Frontiers Science Center
for Materiobiology and Dynamic Chemistry, School of Materials Science
and Engineering, East China University of
Science and Technology, Shanghai 200237, China
| | - Feiyan Li
- Shanghai
Key Laboratory of Advanced Polymeric Materials, Key Laboratory for
Ultrafine Materials of Ministry of Education, Frontiers Science Center
for Materiobiology and Dynamic Chemistry, School of Materials Science
and Engineering, East China University of
Science and Technology, Shanghai 200237, China
| | - Zhanwen Xu
- State
Key Laboratory of Molecular Engineering of Polymers, Department of
Macromolecular Science, Fudan University, Shanghai 200433, China
| | - Jiaping Lin
- Shanghai
Key Laboratory of Advanced Polymeric Materials, Key Laboratory for
Ultrafine Materials of Ministry of Education, Frontiers Science Center
for Materiobiology and Dynamic Chemistry, School of Materials Science
and Engineering, East China University of
Science and Technology, Shanghai 200237, China
| | - Da Li
- Shanghai
Key Laboratory of Advanced Polymeric Materials, Key Laboratory for
Ultrafine Materials of Ministry of Education, Frontiers Science Center
for Materiobiology and Dynamic Chemistry, School of Materials Science
and Engineering, East China University of
Science and Technology, Shanghai 200237, China
| | - Zhengmin Tang
- Department
of Laboratory Medicine, the First Affiliated Hospital, College of
Medicine, Zhejiang University, Hangzhou 311121, China
| | - Chunming Yang
- Shanghai
Synchrotron Radiation Facility, Shanghai
Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201204, China
| | - Liang Gao
- Shanghai
Key Laboratory of Advanced Polymeric Materials, Key Laboratory for
Ultrafine Materials of Ministry of Education, Frontiers Science Center
for Materiobiology and Dynamic Chemistry, School of Materials Science
and Engineering, East China University of
Science and Technology, Shanghai 200237, China
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2
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Spyridakou M, Tsimenidis K, Gkikas M, Steinhart M, Graf R, Floudas G. Effects of Nanometer Confinement on the Self-Assembly and Dynamics of Poly(γ-benzyl- l-glutamate) and Its Copolymer with Poly(isobutylene). Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Kostas Tsimenidis
- Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States
| | - Manos Gkikas
- Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States
| | - Martin Steinhart
- Institut für Chemie neuer Materialien, Universität Osnabrück, D-49069 Osnabrück, Germany
| | - Robert Graf
- Max Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - George Floudas
- Department of Physics, University of Ioannina, 45110 Ioannina, Greece
- Max Planck Institute for Polymer Research, 55128 Mainz, Germany
- Institute of Materials Science and Computing, University Research Center of Ioannina (URCI), 45110 Ioannina, Greece
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3
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Magnotti EL, Hughes SA, Dillard RS, Wang S, Hough L, Karumbamkandathil A, Lian T, Wall JS, Zuo X, Wright ER, Conticello VP. Self-Assembly of an α-Helical Peptide into a Crystalline Two-Dimensional Nanoporous Framework. J Am Chem Soc 2016; 138:16274-16282. [PMID: 27936625 PMCID: PMC5739522 DOI: 10.1021/jacs.6b06592] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sequence-specific peptides have been demonstrated to self-assemble into structurally defined nanoscale objects including nanofibers, nanotubes, and nanosheets. The latter structures display significant promise for the construction of hybrid materials for functional devices due to their extended planar geometry. Realization of this objective necessitates the ability to control the structural features of the resultant assemblies through the peptide sequence. The design of a amphiphilic peptide, 3FD-IL, is described that comprises two repeats of a canonical 18 amino acid sequence associated with straight α-helical structures. Peptide 3FD-IL displays 3-fold screw symmetry in a helical conformation and self-assembles into nanosheets based on hexagonal packing of helices. Biophysical evidence from TEM, cryo-TEM, SAXS, AFM, and STEM measurements on the 3FD-IL nanosheets support a structural model based on a honeycomb lattice, in which the length of the peptide determines the thickness of the nanosheet and the packing of helices defines the presence of nanoscale channels that permeate the sheet. The honeycomb structure can be rationalized on the basis of geometrical packing frustration in which the channels occupy defect sites that define a periodic superlattice. The resultant 2D materials may have potential as materials for nanoscale transport and controlled release applications.
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Affiliation(s)
| | - Spencer A. Hughes
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Rebecca S. Dillard
- Department of Pediatrics, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, Georgia 30322, United States
| | - Shengyuan Wang
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Lillian Hough
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | | | - Tianquan Lian
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Joseph S. Wall
- Brookhaven National Laboratory, P.O. Box 5000, Upton, New York 11973, United States
| | - Xiaobing Zuo
- X-ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Elizabeth R. Wright
- Department of Pediatrics, Emory University School of Medicine, Children’s Healthcare of Atlanta, Atlanta, Georgia 30322, United States
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4
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Song Z, Kim H, Ba X, Baumgartner R, Lee JS, Tang H, Leal C, Cheng J. Polypeptide vesicles with densely packed multilayer membranes. SOFT MATTER 2015; 11:4091-4098. [PMID: 25939493 DOI: 10.1039/c5sm00820d] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Multilamellar membranes are important building blocks for constructing self-assembled structures with improved barrier properties, such as multilamellar lipid vesicles. Polymeric vesicles (polymersomes) have attracted growing interest, but multilamellar polymersomes are much less explored. Here, we report the formation of polypeptide vesicles with unprecedented densely packed multilayer membrane structures with poly(ethylene glycol)-block-poly(γ-(4,5-dimethoxy-2-nitrobenzyl)-l-glutamate) (PEG-b-PL), an amphiphilic diblock rod-coil copolymer containing a short PEG block and a short hydrophobic rod-like polypeptide segment. The polypeptide rods undergo smectic ordering with PEG buried between the hydrophobic polypeptide layers. The size of both blocks and the rigidity of the hydrophobic polypeptide block are critical in determining the membrane structures. Increase of the PEG length in PEG-b-PL results in the formation of bilayer sheets, while using random-coil polypeptide block leads to the formation of large compound micelles. UV treatment causes ester bond cleavage of the polypeptide side chain, which induces helix-to-coil transition, change of copolymer amphiphilicity, and eventual disassembly of vesicles. These polypeptide vesicles with unique membrane structures provide a new insight into self-assembly structure control by precisely tuning the composition and conformation of polymeric amphiphiles.
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Affiliation(s)
- Ziyuan Song
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 1304 West Green Street, Urbana, Illinois 61801, USA.
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5
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Wen GH, Zhang B, Xie HL, Liu X, Zhong GQ, Zhang HL, Chen EQ. Microphase Separation Facilitating and Stabilizing Hierarchical Segment Self-Assembly of Combined Main-Chain/Side-Chain Liquid Crystalline Polymer in Diblock Copolymer. Macromolecules 2013. [DOI: 10.1021/ma400325g] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Guo-Hui Wen
- Key Laboratory of Special Functional Polymer Materials of Hunan Province,
Key Laboratory of Advanced Functional Polymer Materials of Colleges
and Universities of Hunan Province and Key Lab of Environment-friendly
Chemistry and Application in Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, Hunan Province,
China
| | - Ben Zhang
- Beijing National
Laboratory for Molecular Sciences, College of Chemistry and Molecular
Engineering, Peking University, Beijing
100871, China
| | - He-Lou Xie
- Key Laboratory of Special Functional Polymer Materials of Hunan Province,
Key Laboratory of Advanced Functional Polymer Materials of Colleges
and Universities of Hunan Province and Key Lab of Environment-friendly
Chemistry and Application in Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, Hunan Province,
China
| | - Xin Liu
- Beijing National
Laboratory for Molecular Sciences, College of Chemistry and Molecular
Engineering, Peking University, Beijing
100871, China
| | - Guan-Qun Zhong
- Key Laboratory of Special Functional Polymer Materials of Hunan Province,
Key Laboratory of Advanced Functional Polymer Materials of Colleges
and Universities of Hunan Province and Key Lab of Environment-friendly
Chemistry and Application in Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, Hunan Province,
China
| | - Hai-Liang Zhang
- Key Laboratory of Special Functional Polymer Materials of Hunan Province,
Key Laboratory of Advanced Functional Polymer Materials of Colleges
and Universities of Hunan Province and Key Lab of Environment-friendly
Chemistry and Application in Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, Hunan Province,
China
| | - Er-Qiang Chen
- Beijing National
Laboratory for Molecular Sciences, College of Chemistry and Molecular
Engineering, Peking University, Beijing
100871, China
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6
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Ordering of Polypeptides in Liquid Crystals, Gels and Micelles. CONTROLLED POLYMERIZATION AND POLYMERIC STRUCTURES 2013. [DOI: 10.1007/12_2013_221] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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7
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Park C, Lee J, Kim C. Functional supramolecular assemblies derived from dendritic building blocks. Chem Commun (Camb) 2011; 47:12042-56. [PMID: 21785775 DOI: 10.1039/c1cc11531f] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Control of the structure and function of self-assembled materials has been a significant issue in many areas of nanoscience. Among many different types of building blocks, dendritic ones have shown interesting self-assembly behaviour and functional performances due to their unique shape and multiple functionalities. Dendritic building blocks exhibit unique self-assembly behaviour in diverse environments such as aqueous and organic solutions, solid-liquid interfaces, and thermotropic solid conditions. Tuning the balance between hydrophilic and hydrophobic parts, as well as the external conditions for self-assembly, provides unique opportunities for control of supramolecular architectures. Furthermore, the introduction of suitable functional moieties into dendrons enables us to control self-assembly characteristics, allowing nanostructures to exhibit smart performances for electronic or biological applications. The self-assembly characteristics of amphiphilic dendrons under various conditions were investigated to elucidate how dendrons can assemble into nanoscopic structures and how these nanoassemblies exhibit unique properties. Well-defined nanostructures derived from self-assembly of dendrons provide an efficient approach for exhibition of unique functions at the nanoscale. This feature article describes the unique self-assembly characteristics of various types of dendritic building blocks and their potential applications as advanced materials.
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Affiliation(s)
- Chiyoung Park
- Department of Polymer Science and Engineering, Inha University, Incheon 402-751, Korea
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8
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Hwang Y, Je Y, Farrar D, West JE, Yu SM, Moon W. Piezoelectric properties of polypeptide-PMMA molecular composites fabricated by contact charging. POLYMER 2011. [DOI: 10.1016/j.polymer.2011.04.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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9
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Börner HG. Precision Polymers-Modern Tools to Understand and Program Macromolecular Interactions. Macromol Rapid Commun 2010; 32:115-26. [DOI: 10.1002/marc.201000646] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 11/17/2010] [Indexed: 11/11/2022]
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10
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Cheuk KKL, Li BS, Lam JWY, Xie Y, Tang BZ. Synthesis, Chain Helicity, Assembling Structure, and Biological Compatibility of Poly(phenylacetylene)s Containing l-Alanine Moieties. Macromolecules 2008. [DOI: 10.1021/ma800976e] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kevin K. L. Cheuk
- Departments of Chemistry and Biology, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China; Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China; and Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Bing Shi Li
- Departments of Chemistry and Biology, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China; Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China; and Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jacky W. Y. Lam
- Departments of Chemistry and Biology, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China; Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China; and Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Yong Xie
- Departments of Chemistry and Biology, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China; Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China; and Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Ben Zhong Tang
- Departments of Chemistry and Biology, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China; Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China; and Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
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11
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Conformational Transition of Poly(γ-benzyl-L-glutamate)-Poly(ethylene glycol) Block Copolymers in Bulk. B KOREAN CHEM SOC 2007. [DOI: 10.5012/bkcs.2007.28.5.795] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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12
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Cheuk KKL, Lam JWY, Li BS, Xie Y, Tang BZ. Decorating Conjugated Polymer Chains with Naturally Occurring Molecules: Synthesis, Solvatochromism, Chain Helicity, and Biological Activity of Sugar-Containing Poly(phenylacetylene)s. Macromolecules 2007. [DOI: 10.1021/ma062629d] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kevin K. L. Cheuk
- Department of Chemistry and Department of Biology, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China, and Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jacky W. Y. Lam
- Department of Chemistry and Department of Biology, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China, and Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Bing Shi Li
- Department of Chemistry and Department of Biology, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China, and Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Yong Xie
- Department of Chemistry and Department of Biology, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China, and Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Ben Zhong Tang
- Department of Chemistry and Department of Biology, The Hong Kong University of Science & Technology (HKUST), Clear Water Bay, Kowloon, Hong Kong, China, and Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
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13
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Lai LM, Lam JWY, Qin A, Dong Y, Tang BZ. Synthesis, Helicity, and Chromism of Optically Active Poly(phenylacetylene)s Carrying Different Amino Acid Moieties and Pendant Terminal Groups. J Phys Chem B 2006; 110:11128-38. [PMID: 16771375 DOI: 10.1021/jp057179q] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Functional phenylacetylene derivatives containing l-alanine and l-leucine moieties with chiral menthyl and achiral n-octyl terminal groups {HC[triple bond]C-C6H4-p-CONHCH(R)CO2R': R = CH3, R'= (-)-(1R,2S,5R)-menthyl [1(-)]; R = CH2CH(CH2)3, R' = (-)-(1R,2S,5R)-menthyl [2(-)]; R'= CH2CH(CH2)3, R' = (+)-(1S,2R,5S)-menthyl [2(+)]; R'= CH2CH(CH2)3, R' = (CH2)7CH3 (2o)} are synthesized. Polymerizations of the acetylene monomers are effected by organorhodium catalysts, giving corresponding polymers P1(-), P2(-), P2(+), and P2o of high molecular weights (Mw up to 1.2 x 10(6)) in high yields (up to 89%). The polymers are thermally stable (Td >or= 300 degrees C) and soluble in common organic solvents. The polymer structures are characterized by IR, NMR, UV, and CD spectroscopies. Intense CD signals are observed in the visible spectral region, indicating that the polymer chains are taking a helical conformation with an excess of preferred handedness. The backbone conjugation and chain helicity of the polymers can be tuned by changing their molecular structures [(a)chiral pendant groups] and by applying external stimuli (solvent and pH). Addition of trifluoroacetic acid to the polymer solutions decreases their molar ellipticities and enhances their backbone conjugations, inducing a halochromism with a continuous and reversible color change (yellow <==> red).
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Affiliation(s)
- Lo Ming Lai
- Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
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14
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Kim KT, Park C, Kim C, Winnik MA, Manners I. Self-assembly of dendron-helical polypeptide copolymers: organogels and lyotropic liquid crystals. Chem Commun (Camb) 2006:1372-4. [PMID: 16550270 DOI: 10.1039/b516625j] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New macromolecular self-assembling building blocks, dendron-helical polypeptide copolymers, have been synthesized; these materials possess a well-defined 3-D shape and self-assemble in solution to form nanoribbon and lyotropic liquid crystalline phases.
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Affiliation(s)
- Kyoung Taek Kim
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada
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16
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Park Y, Choi YW, Park S, Cho CS, Fasolka MJ, Sohn D. Monolayer formation of PBLG–PEO block copolymers at the air–water interface. J Colloid Interface Sci 2005; 283:322-8. [PMID: 15721901 DOI: 10.1016/j.jcis.2004.09.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2004] [Accepted: 09/15/2004] [Indexed: 10/26/2022]
Abstract
Physicochemical properties of PBLG (poly(gamma-benzyl-l-glutamate))-PEO (poly(ethylene oxide)) diblock copolymers composed of PBLG as the hydrophobic rod component and PEO as the hydrophilic component were investigated at the air-water interface. Surface pressure-area isotherms obtained by the Wilhelmy plate method provide several variables such as molecular size, compressibility of PEO, and the free energy change of the PBLG-PEO block copolymer. GE-1 (M(w) of PBLG:PEO=103,700:12,000), with a relatively longer rod, has negative temperature effects and GE-3 (M(w) of PBLG:PEO=8400:12,000), with a relatively shorter rod, shows a positive temperature effect because of the large entropy loss. These competitions were based on the block size of PBLG and PEO and were affected by various microstructures of the PBLG-PEO diblock copolymer. Monolayer aggregations transferred onto mica from the air-water interface were analyzed with AFM. AFM images of GE-1 monolayers show cylindrical micelles, but the self-assembled structure has many large domains. The monolayer of GE-2 (M(w) of PBLG:PEO=39,800:12,000), which has a medium size rod, forms a spherical structure at the air-water interface. Monolayers of GE-3, with a short rod length, form bilayer structures. These results demonstrate that the microstructures of PBLG-PEO diblock copolymers are related to free energy changes between rod and coil blocks.
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Affiliation(s)
- Youngmi Park
- Department of Chemistry, Hanyang University, Seoul 133-791, South Korea
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17
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Morikawa MA, Yoshihara M, Endo T, Kimizuka N. ?-Helical Polypeptide Microcapsules Formed by Emulsion-Templated Self-Assembly. Chemistry 2005; 11:1574-8. [PMID: 15669072 DOI: 10.1002/chem.200400751] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
alpha-Helical peptide microcapsules were prepared by the emulsion-templated self-assembly of amphiphilic poly(gamma-benzyl L-glutamate)s (PBLG) 1. By mixing solutions of 1 in dichloromethane (in the form of a sodium salt) with water, oil-in-water emulsions were obtained. Spontaneous stripping of the dichloromethane phase caused a decrease in the diameter of the microdroplets and finally stable microcapsules formed. The microcapsules contain an inner aqueous phase as observed by confocal laser scanning microscopy (CLSM). Binding of hydrophobic pyrene molecules to the polypeptide shell was also demonstrated. The present polypeptide microcapsules are stable even after drying in air and they would serve as supramolecular vehicles for both hydrophobic and water-soluble molecules.
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Affiliation(s)
- Masa-aki Morikawa
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka 812-8581, Japan
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18
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Morikawa MA, Kimizuka N. Spatially controlled self-assembly of gold nanoparticles encased in α-helical polypeptide nanospheres. Chem Commun (Camb) 2005:4866-8. [PMID: 16193141 DOI: 10.1039/b507818k] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gold nanoparticles (Au-NPs) are encased in aqueous nanospheres of alpha-helical poly(gamma-benzyl L-glutamate)s (PBLG, number average degree of polymerization: n = 32), with spatially controlled self-assembly structures of solid core-shell nanospheres or double-layered hollow nanocapsules.
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Affiliation(s)
- Masa-aki Morikawa
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
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20
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Abstract
The hybridization of lipid membranes with inorganic silica-based framework results in mechanically stable biomembrane mimics. This account describes three types of silica-based biomimetic membranes. As the first example, a Langmuir monolayer of dialkylalkoxysilane was polymerized and immobilized onto a porous glass plate. Permeability through the monolayer-immobilized glass was regulated by phase transition of the immobilized monolayer. In the second example, spherical vesicles covalently attached to a silica cover layer (Cerasome) were prepared. The Cerasome was stable enough to be assembled into layer-by-layer films without destruction of its vesicular structure. This material could be an example of the multicellular assembly. Mesoporous silica films densely filling peptide assemblies (Proteosilica) are introduced as the third example. The Proteosilica was synthesized as a transparent film through template sol-gel reaction using amphiphilic peptides.
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Affiliation(s)
- Katsuhiko Ariga
- Advanced Materials Laboratory, National Institute for Materials Science (NIMS) 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
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21
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Yeom MS, Ermoshkin AV, de la Cruz MO. Structure and thermodynamics of associating rods solutions. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2003; 12:565-572. [PMID: 15007753 DOI: 10.1140/epje/e2004-00028-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Physical gelation in rod-like associating polymer solutions is analyzed by computer simulations and by mean field models. The structural gelation (SG) transition is determined by a rapid change in the cluster weight average. The analytically determined SG transition is in good agreement with the simulation results. At low temperatures we observe a peak in the heat capacity, which maximum is associated with phase segregation. The SG transition is sensitive to the number of associating groups per rod but nearly insensitive to the spatial distribution of associating groups around the rods. Phase segregation is strongly dependent on both the number and distribution of associating groups per rod. We find negligible overall nematic order near the SG transition and only partial local nematic order of the clusters at the phase segregation transitions.
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Affiliation(s)
- M S Yeom
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208-3108, USA
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Papadopoulos P, Floudas G, Klok HA, Schnell I, Pakula T. Self-Assembly and Dynamics of Poly(γ-benzyl-l-glutamate) Peptides. Biomacromolecules 2003; 5:81-91. [PMID: 14715012 DOI: 10.1021/bm034291q] [Citation(s) in RCA: 160] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structure and the associated dynamics have been investigated in a series of oligopeptides of gamma-benzyl-l-glutamate using DSC, WAXS, FTIR, NMR and dielectric spectroscopy, and rheology, respectively. The peptides with degrees of polymerization below 18 are mixtures of a lamellar assembly of beta sheets and of columnar hexagonal arrangement of alpha helices, whereas for longer chains, the intramolecular hydrogen bonds stabilize only the alpha-helical conformations. Multiple dielectrically active processes were found. Starting from low temperatures, the two Arrhenius processes (gamma and beta), with apparent activation energies of 20.6 and 50.2 kJ/mol, respectively, associate with the local relaxation of the side-chain methylene units (gamma process) and with more cooperative motions of the side chain dipoles sensitive to the 7/2 helical packing (beta process). The glass transition is manifested in the thermal properties with a step in the heat capacity and with an intense dielectric process bearing characteristics (molecular weight dependence, temperature dependence of relaxation times) known from amorphous polymers. Based on these findings, the alpha process is attributed to the relaxation of amorphous segments located between and at the end of helically ordered segments. Two slower processes were identified with opposite molecular weight dependence. The weak intermediate mode with an M2 molecular weight dependence of the characteristic relaxation times suggests amorphous-like chains, whereas the strong slower process originates from the loss of dipole orientational capacity caused by structural defects and reflects the migration of helical sequences along the chains. This identifies the helices as structures extending over rather short fragments of chains (i.e., of low persistence length). The viscoelastic response indicated that the structural defects arise from locally aggregated chains that inhibit the flow of oligopeptides.
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Affiliation(s)
- P Papadopoulos
- University of Ioannina, Department of Physics, 451 10 Ioannina, Greece
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Gopalan P, Li X, Li M, Ober CK, Gonzales CP, Hawker CJ. Rod-coil block copolymers: An iterative synthetic approach via living free-radical procedures. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/pola.10930] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Bosman AW, Vestberg R, Heumann A, Fréchet JMJ, Hawker CJ. A modular approach toward functionalized three-dimensional macromolecules: from synthetic concepts to practical applications. J Am Chem Soc 2003; 125:715-28. [PMID: 12526671 DOI: 10.1021/ja028392s] [Citation(s) in RCA: 294] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new strategy for the preparation of functional, multiarm star polymers via nitroxide-mediated "living" radical polymerization has been explored. The generality of this approach to the synthesis of three-dimensional macromolecular architectures allows for the construction of nanoscopically defined materials from a wide range of different homo, block, and random copolymers combining both apolar and polar vinylic repeat units. Functional groups can also be included along the backbone or as peripheral/chain end groups, thereby modulating the reactivity and polarity of defined portions of the stars. This modular approach to the synthesis of three-dimensional macromolecules permits the application of these tailored materials as multifunctional hosts for hydrogen bonding, nanoparticle formation, and as scaffolds for catalytic groups. Examples of applications of the functional stars in catalysis include their use in a Heck-type coupling as well as an enantioselective addition reaction.
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Affiliation(s)
- Anton W Bosman
- IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, USA
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Harth EM, Hecht S, Helms B, Malmstrom EE, Fréchet JMJ, Hawker CJ. The effect of macromolecular architecture in nanomaterials: a comparison of site isolation in porphyrin core dendrimers and their isomeric linear analogues. J Am Chem Soc 2002; 124:3926-38. [PMID: 11942830 DOI: 10.1021/ja025536u] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The influence of macromolecular architecture on the physical properties of polymeric materials has been studied by comparing poly(benzyl ether) dendrons with their exact linear analogues. The results clearly confirm the anticipation that dendrimers are unique when compared to other architectures. Physical properties, from hydrodynamic volume to crystallinity, were shown to be different, and in a comparative study of core encapsulation in macromolecules of different architecture, energy transduction from the polymer backbone to a porphyrin core was shown to be different for dendrimers as compared to that of isomeric four- or eight-arm star polymers. Fluorescence excitation revealed strong, morphology dependent intramolecular energy transfer in the three macromolecular isomers investigated. Even at high generations, the dendrimers exhibited the most efficient energy transfer, thereby indicating that the dendritic architecture affords superior site isolation to the central porphyrin it surrounds.
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Affiliation(s)
- Eva M Harth
- Contribution from the IBM Almaden Research Center, 650 Harry Road, San Jose, California 95120, USA
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Mawn MV, Fournier MJ, Tirrell DA, Mason TL. Depletion of free 30S ribosomal subunits in Escherichia coli by expression of RNA containing Shine-Dalgarno-like sequences. J Bacteriol 2002; 184:494-502. [PMID: 11751827 PMCID: PMC139575 DOI: 10.1128/jb.184.2.494-502.2002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have constructed synthetic coding sequences for the expression of poly(alpha,L-glutamic acid) (PLGA) as fusion proteins with dihydrofolate reductase (DHFR) in Escherichia coli. These PLGA coding sequences use both GAA and GAG codons for glutamic acid and contain sequence elements (5'-GAGGAGG-3') that resemble the consensus Shine-Dalgarno (SD) sequence found at translation initiation sites in bacterial mRNAs. An unusual feature of DHFR-PLGA expression is that accumulation of the protein is inversely related to the level of induction of its mRNA. Cellular protein synthesis was inhibited >95% by induction of constructs for either translatable or untranslatable PLGA RNAs. Induction of PLGA RNA resulted in the depletion of free 30S ribosomal subunits and the appearance of new complexes in the polyribosome region of the gradient. Unlike normal polyribosomes, these complexes were resistant to breakdown in the presence of puromycin. The novel complexes contained 16S rRNA, 23S rRNA, and PLGA RNA. We conclude that multiple noninitiator SD-like sequences in the PLGA RNA inhibit cellular protein synthesis by sequestering 30S small ribosomal subunits and 70S ribosomes in nonfunctional complexes on the PLGA mRNA.
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Affiliation(s)
- Mary V Mawn
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003, USA
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Harth E, Hawker CJ, Fan W, Waymouth RM. Chain End Functionalization in Nitroxide-Mediated “Living” Free Radical Polymerizations. Macromolecules 2001. [DOI: 10.1021/ma0019297] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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