1
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Smith JD, Chen R, Osores NN, Gopalan P. Porous Morphology of High Grafting Density Mixed Polyelectrolyte Brushes Grown from a Y-Inimer Coating. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:10623-10633. [PMID: 38726951 DOI: 10.1021/acs.langmuir.4c00556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Mixed A/B polyelectrolyte (PE) brushes of opposite charges are grown from a Y-shaped initiator-bearing coating to facilitate intimate mixing of the A and B polyelectrolytes in a 1:1 grafting ratio. The design of the Y-shaped inimer includes both ATRP and NMP initiators attached to a common Y-junction. A copolymer of a Y-shaped inimer with glycidyl methacrylate is cross-linked to the substrate resulting in a stable ultrathin coating decorated with Y-shaped initiators. Weak PE A/B mixed brushes based on poly(methacrylic acid)/poly(2-vinylpyridine) (PMAA/P2VP) with a high grafting density of ∼1 chain/nm2 are grown by surface-initiated ATRP and NMP, respectively. Detailed morphological characterization of the PMAA/P2VP brushes in response to pH changes reveals a nanoporous morphology under conditions that maximize complex coacervate formation between oppositely charged brushes. The charge ratio between the A and B brushes is varied via the composition of the brushes to further study the morphology evolution. The effect of intimate contact between the A and B brushes on the morphology is probed by comparing with a mixed A/B PE system with random fluctuations in grafting composition. A quantitative and qualitative study of the pore evolution with pH as well as charge composition is presented using a combination of atomic force microscopy, water contact angle measurement, and image analysis using Gwyddion software. These studies demonstrate that the porous morphology is enhanced and most uniform when the brushes are grown from the Y-inimer, indicating that a 1:1 grafting ratio and intimate contact between A and B brushes are essential.
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Affiliation(s)
- Julia D Smith
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Ri Chen
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Nicolas Noriega Osores
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Padma Gopalan
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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2
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Yin L, Liu L, Zhang N. Brush-like polymers: design, synthesis and applications. Chem Commun (Camb) 2021; 57:10484-10499. [PMID: 34550120 DOI: 10.1039/d1cc03940g] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
With the development of controlled polymerisation, almost all polymerisation strategies have been successfully transplanted to surface-initiated polymerisation. The resulting polymer brushes have emerged as an effective tool for surface functionalization and modulation of the surface properties of materials. To meet various demands it is possible to tailor a material surface with polymer brushes that have diverse dimensionalities, morphologies and compositions. The crowded environment within polymer brushes as well as the stretched conformation of polymer chains sometimes provide unique physicochemical properties, which lead to the delicate creation of inorganic-organic hybridised nanostructures, anti-fouling coatings, biomedical carriers, and materials for use in lubrication, photonics and energy storage. So far, challenges remain in the high-precision synthesis and topological control needed to realize extended applications of polymer brushes. In this Feature Article, we highlight the topology, potential application prospects and various synthetic protocols, particularly for recently established methods, for the efficient synthesis of polymer brushes, as well as their benefits and limitations.
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Affiliation(s)
- Liying Yin
- Department of Chemistry, Northeast Normal University, Changchun 130024, P. R. China.
| | - Lin Liu
- Department of Chemistry, Northeast Normal University, Changchun 130024, P. R. China.
| | - Ning Zhang
- Department of Chemistry, Northeast Normal University, Changchun 130024, P. R. China.
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3
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Relevance of Electrostatic Charges in Compactness, Aggregation, and Phase Separation of Intrinsically Disordered Proteins. Int J Mol Sci 2020; 21:ijms21176208. [PMID: 32867340 PMCID: PMC7503639 DOI: 10.3390/ijms21176208] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/22/2020] [Accepted: 08/23/2020] [Indexed: 12/20/2022] Open
Abstract
The abundance of intrinsic disorder in the protein realm and its role in a variety of physiological and pathological cellular events have strengthened the interest of the scientific community in understanding the structural and dynamical properties of intrinsically disordered proteins (IDPs) and regions (IDRs). Attempts at rationalizing the general principles underlying both conformational properties and transitions of IDPs/IDRs must consider the abundance of charged residues (Asp, Glu, Lys, and Arg) that typifies these proteins, rendering them assimilable to polyampholytes or polyelectrolytes. Their conformation strongly depends on both the charge density and distribution along the sequence (i.e., charge decoration) as highlighted by recent experimental and theoretical studies that have introduced novel descriptors. Published experimental data are revisited herein in the frame of this formalism, in a new and possibly unitary perspective. The physicochemical properties most directly affected by charge density and distribution are compaction and solubility, which can be described in a relatively simplified way by tools of polymer physics. Dissecting factors controlling such properties could contribute to better understanding complex biological phenomena, such as fibrillation and phase separation. Furthermore, this knowledge is expected to have enormous practical implications for the design, synthesis, and exploitation of bio-derived materials and the control of natural biological processes.
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4
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Kennemur JG. Poly(vinylpyridine) Segments in Block Copolymers: Synthesis, Self-Assembly, and Versatility. Macromolecules 2019. [DOI: 10.1021/acs.macromol.8b01661] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Justin G. Kennemur
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
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5
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Qin Z, Chen T, Teng W, Jin Q, Ji J. Mixed-Charged Zwitterionic Polymeric Micelles for Tumor Acidic Environment Responsive Intracellular Drug Delivery. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:1242-1248. [PMID: 29940737 DOI: 10.1021/acs.langmuir.8b00471] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A new class of mixed-charged zwitterionic copolymer poly(aminoethyl methacrylate)- co-poly(methacrylic acid)- co-poly( n-butyl methacrylate) (CPMA) was prepared as drug nanocarrier for efficient intracellular delivery of Doxorubicin (DOX). The mixed-charged CPMA copolymer could readily assemble to micelles in physiological environment (pH 7.4) with the size of 42.6 nm and zeta potential of -26 mV, which would lead to a prolonged circulation time and enhanced tumor penetration. However, the micelles formed large aggregates due to the protonation of carboxyl groups at extracellular tumor pH (pH 6.5). Meanwhile, the zeta potential of CPMA micelles increased from -26 mV to -6 mV when the solution pH was changed from pH 7.4 to pH 6.5. The increase of size and zeta potential at extracellular tumor pH could benefit the retention of micelles in tumor matrix and uptake by cancer cells. The DOX-loaded mixed-charged CPMA micelles could induce a higher internalization at pH 6.5 than 7.4 at varied time periods. Moreover, cytotoxicity assay demonstrated that the blank micelles showed excellent biocompatibility, but were highly cytotoxic toward KB cells after loading with DOX. Thus, the mixed-charged zwitterionic polymeric micelles might be a promising carrier for tumor acidic environment responsive drug delivery.
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Affiliation(s)
- Zhihui Qin
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering , Zhejiang University , Hangzhou 310027 , China
| | - Tingting Chen
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering , Zhejiang University , Hangzhou 310027 , China
| | - Wenzhuo Teng
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering , Zhejiang University , Hangzhou 310027 , China
| | - Qiao Jin
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering , Zhejiang University , Hangzhou 310027 , China
| | - Jian Ji
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering , Zhejiang University , Hangzhou 310027 , China
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6
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Ramirez R, Woodcock J, Kilbey SM. ARGET-ATRP synthesis and swelling response of compositionally varied poly(methacrylic acid-co-N,N-diethylaminoethyl methacrylate) polyampholyte brushes. SOFT MATTER 2018; 14:6290-6302. [PMID: 30014055 DOI: 10.1039/c8sm00882e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Modifying the composition of polyampholytes, which are comprised of charge-positive and charge-negative repeat units, directly contributes to trade-offs between charge and structure, which are externally regulated by solution pH and added salt. Here, the relative ratio of anionic and cationic comonomers is varied to tailor the stimuli-responsiveness of poly(methacrylic acid-co-N,N-diethylaminoethyl methacrylate) (P(MAA-co-DEAEMA)) brushes to changes in solution pH and an added zwitterion. These systems display a strong dependence on excess repeating units of either type and the random incorporation appears to facilitate self-neutralization of charges. Pseudo-living growth with smooth comonomer incorporation is achieved using activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP), creating well-defined brushes. In situ ellipsometry measurements of solvated brush thickness indicate that at low and high pH, the brushes display polyelectrolyte behavior with a strong compositional dependence, but at intermediate pH values, the brushes show the characteristic collapse attributed to self-neutralization of polyampholytes. The polyampholyte brushes maintain these patterns of behavior across all compositions and in the presence of an added zwitterion, which contributes additional hydrophobic character as evidenced by decreases in the swollen layer thicknesses. The response of the P(MAA-co-DEAEMA) brushes to the organic osmolyte betaine is consistent with its tendency to stabilize proteins and peptides in a kosmotropic fashion. These studies add perspective to efforts to manipulate sequence in polyampholytic polymers, support broader efforts to tailor interfacial soft films for applications in biotechnology and sensing, and understand aggregation and stability of biological polymers.
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Affiliation(s)
- Rachel Ramirez
- Department of Chemistry, University of Tennessee Knoxville, Tennessee 37996, USA.
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7
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Yang C, Chen L, Huang H, Lu Y, Yi J. Synthesis and properties of thermo-responsive azobenzene-based supramolecular dendronized copolymer. Polym Bull (Berl) 2017. [DOI: 10.1007/s00289-017-2255-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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8
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Morphologies of spherical polyampholyte brushes: Effects of counterion valence and charged monomer sequence. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.02.062] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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9
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Conzatti G, Cavalie S, Combes C, Torrisani J, Carrere N, Tourrette A. PNIPAM grafted surfaces through ATRP and RAFT polymerization: Chemistry and bioadhesion. Colloids Surf B Biointerfaces 2017; 151:143-155. [DOI: 10.1016/j.colsurfb.2016.12.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 11/25/2016] [Accepted: 12/07/2016] [Indexed: 12/23/2022]
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10
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Zoppe JO, Ataman NC, Mocny P, Wang J, Moraes J, Klok HA. Surface-Initiated Controlled Radical Polymerization: State-of-the-Art, Opportunities, and Challenges in Surface and Interface Engineering with Polymer Brushes. Chem Rev 2017; 117:1105-1318. [PMID: 28135076 DOI: 10.1021/acs.chemrev.6b00314] [Citation(s) in RCA: 578] [Impact Index Per Article: 82.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The generation of polymer brushes by surface-initiated controlled radical polymerization (SI-CRP) techniques has become a powerful approach to tailor the chemical and physical properties of interfaces and has given rise to great advances in surface and interface engineering. Polymer brushes are defined as thin polymer films in which the individual polymer chains are tethered by one chain end to a solid interface. Significant advances have been made over the past years in the field of polymer brushes. This includes novel developments in SI-CRP, as well as the emergence of novel applications such as catalysis, electronics, nanomaterial synthesis and biosensing. Additionally, polymer brushes prepared via SI-CRP have been utilized to modify the surface of novel substrates such as natural fibers, polymer nanofibers, mesoporous materials, graphene, viruses and protein nanoparticles. The last years have also seen exciting advances in the chemical and physical characterization of polymer brushes, as well as an ever increasing set of computational and simulation tools that allow understanding and predictions of these surface-grafted polymer architectures. The aim of this contribution is to provide a comprehensive review that critically assesses recent advances in the field and highlights the opportunities and challenges for future work.
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Affiliation(s)
- Justin O Zoppe
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Nariye Cavusoglu Ataman
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Piotr Mocny
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Jian Wang
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - John Moraes
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Harm-Anton Klok
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
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11
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Abstract
This review summarizes pH-responsive monomers, polymers and their derivative nano- and micro-structures including micelles, cross-linked micelles, microgels and hydrogels.
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Affiliation(s)
- G. Kocak
- Department of Chemistry
- Faculty of Arts and Science
- Eskisehir Osmangazi University
- Eskisehir
- Turkey
| | - C. Tuncer
- Department of Chemistry
- Faculty of Arts and Science
- Eskisehir Osmangazi University
- Eskisehir
- Turkey
| | - V. Bütün
- Department of Chemistry
- Faculty of Arts and Science
- Eskisehir Osmangazi University
- Eskisehir
- Turkey
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12
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Willott JD, Murdoch TJ, Webber GB, Wanless EJ. Physicochemical behaviour of cationic polyelectrolyte brushes. Prog Polym Sci 2017. [DOI: 10.1016/j.progpolymsci.2016.09.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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13
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Léonforte F, Müller M. Functional Poly(N-isopropylacrylamide)/Poly(acrylic acid) Mixed Brushes for Controlled Manipulation of Nanoparticles. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00535] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Fabien Léonforte
- Institut
für Theoretische Physik, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Marcus Müller
- Institut
für Theoretische Physik, Georg-August-Universität, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
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14
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Bhagawati M, Rubashkin MG, Lee JP, Ananthanarayanan B, Weaver VM, Kumar S. Site-Specific Modulation of Charge Controls the Structure and Stimulus Responsiveness of Intrinsically Disordered Peptide Brushes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:5990-5996. [PMID: 27203736 PMCID: PMC5343758 DOI: 10.1021/acs.langmuir.6b01099] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Intrinsically disordered proteins (IDPs) are an important and emerging class of materials for tailoring biointerfaces. While the importance of chain charge and resultant electrostatic interactions in controlling conformational properties of IDPs is beginning to be explored through in silico approaches, there is a dearth of experimental studies motivated toward a systematic study of these effects. In an effort to explore this relationship, we measured the conformations of two peptides derived from the intrinsically disordered neurofilament (NF) side arm domain: one depicting the wild-type sequence with four lysine-serine-proline repeats (KSP peptide) and another in which the serine residues were replaced with aspartates (KDP peptide), a strategy sometimes used to mimic phosphorylation. Using a variety of biophysical measurements including a novel application of scanning angle interference microscopy, we demonstrate that the KDP peptide assumes comparatively more expanded conformations in solution and forms significantly thicker brushes when immobilized on planar surfaces at high densities. In both settings, the peptides respond to changes in ambient ionic strength, with each peptide showing distinct stimulus-responsive characteristics. While the KDP peptide undergoes compaction with increasing ionic strength as would be expected for a polyampholyte, the KSP peptide shows biphasic behavior, with an initial compaction followed by an expanded state at a higher ionic strength. Together these results support the notion that modulation of charge on IDPs can regulate conformational and interfacial properties.
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Affiliation(s)
- Maniraj Bhagawati
- Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - Matt G. Rubashkin
- Center for Bioengineering and Tissue Regeneration, University of California, San Francisco, San Francisco, California 94143, United States
- UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - Jessica P. Lee
- Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | | | - Valerie M. Weaver
- Center for Bioengineering and Tissue Regeneration, University of California, San Francisco, San Francisco, California 94143, United States
- UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
| | - Sanjay Kumar
- Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
- UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, California 94720, United States
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States
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15
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Dry–wet phase inversion block copolymer membranes with a minimum evaporation step from NMP/THF mixtures. J Memb Sci 2016. [DOI: 10.1016/j.memsci.2015.12.069] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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16
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Venault A, Huang CW, Zheng J, Chinnathambi A, Alharbi SA, Chang Y, Chang Y. Hemocompatible biomaterials of zwitterionic sulfobetaine hydrogels regulated with pH-responsive DMAEMA random sequences. INT J POLYM MATER PO 2015. [DOI: 10.1080/00914037.2015.1055632] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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17
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Qu Z, Xu H, Gu H. Synthesis and Biomedical Applications of Poly((meth)acrylic acid) Brushes. ACS APPLIED MATERIALS & INTERFACES 2015; 7:14537-14551. [PMID: 26067846 DOI: 10.1021/acsami.5b02912] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Poly((meth)acrylic acid) (P(M)AA) brushes possess a number of distinctive properties that are particularly attractive for biomedical applications. This minireview summarizes recent advances in the synthesis and biomedical applications of P(M)AA brushes and brushes containing P(M)AA segments. First, we review different surface-initiated polymerization (SIP) methods, with a focus on recent progress in the surface-initiated controlled/living radical polymerization (SI-CLRP) techniques used to generate P(M)AA brushes with a tailored structure. Next, we discuss biomolecule immobilization methods for P(M)AA brushes, including physical adsorption, covalent binding, and affinity interactions. Finally, typical biomedical applications of P(M)AA brushes are reviewed, and their performance is discussed based on their unique properties. We conclude that P(M)AA brushes are promising biomaterials, and more potential biomedical applications are expected to emerge with the further development of synthetic techniques and increased understanding of their interactions with biological systems.
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Affiliation(s)
- Zhenyuan Qu
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Hong Xu
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Hongchen Gu
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
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18
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Cao Q, You H. Polyampholyte Brushes Grafted on the Surface of a Spherical Cavity: Effect of the Charged Monomer Sequence, Grafting Density, and Chain Stiffness. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:6375-6384. [PMID: 26011023 DOI: 10.1021/acs.langmuir.5b01190] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Molecular dynamics simulations are used to study the conformational behaviors of the flexible and semiflexible polyampholytes coated onto the internal surface of a spherical cavity. Dependences of the brush structure and the local conformation of grafted chains on the sequence of charged monomers, the grafting density, and the chain stiffness are addressed. In the range of parameters studied, it was found that a significant transition of the brush structure occurs due to the variation of the charged monomer sequence. As the number of repeat charged monomers increases, both the flexible and semiflexible polyampholyte brushes change to the collapsed conformation. The spherical concave geometry tends to exclude the conformation of chains perpendicular to the grafting surface for the semiflexible case. In addition, we find that most counterions are depleted in the polyampholyte brush due to the strong electrostatic correlation between the oppositely charged monomers.
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Affiliation(s)
- Qianqian Cao
- †College of Mechanical and Electrical Engineering, Jiaxing University, Jiaxing 314001, PR China
- ‡Fachbereich Physik, Freie Universität Berlin, 14195 Berlin, Germany
- §College of Mechanical Science and Engineering, Jilin University, Changchun 130022, PR China
| | - Hao You
- ∥Department of Chemistry and Physics, Georgia Regents University, 1120 15th Street, Augusta, Georgia 30912, United States
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19
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Srinivasan N, Bhagawati M, Ananthanarayanan B, Kumar S. Stimuli-sensitive intrinsically disordered protein brushes. Nat Commun 2014; 5:5145. [PMID: 25312006 DOI: 10.1038/ncomms6145] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Accepted: 09/04/2014] [Indexed: 12/11/2022] Open
Abstract
Grafting polymers onto surfaces at high density to yield polymer brush coatings is a widely employed strategy to reduce biofouling and interfacial friction. These brushes almost universally feature synthetic polymers, which are often heterogeneous and do not readily allow incorporation of chemical functionalities at precise sites along the constituent chains. To complement these synthetic systems, we introduce a biomimetic, recombinant intrinsically disordered protein that can assemble into an environment-sensitive brush. This macromolecule adopts an extended conformation and can be grafted to solid supports to form oriented protein brushes that swell and collapse dramatically with changes in solution pH and ionic strength. We illustrate the value of sequence specificity by using proteases with mutually orthogonal recognition sites to modulate brush height in situ to predictable values. This study demonstrates that stimuli-responsive brushes can be fabricated from proteins and introduces them as a new class of smart biomaterial building blocks.
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Affiliation(s)
- Nithya Srinivasan
- Department of Bioengineering, University of California, Berkeley, California 94720, USA
| | - Maniraj Bhagawati
- Department of Bioengineering, University of California, Berkeley, California 94720, USA
| | | | - Sanjay Kumar
- Department of Bioengineering, University of California, Berkeley, California 94720, USA
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20
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Narayanan Nair AK, Uyaver S, Sun S. Conformational transitions of a weak polyampholyte. J Chem Phys 2014; 141:134905. [PMID: 25296835 DOI: 10.1063/1.4897161] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Arun Kumar Narayanan Nair
- Computational Transport Phenomena Laboratory, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Sahin Uyaver
- Istanbul Commerce University, Faculty of Applied Sciences, Istanbul, Turkey
| | - Shuyu Sun
- Computational Transport Phenomena Laboratory, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
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21
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Kulkarni SA, Lyles VD, Serem WK, Lu L, Kumar R, Garno JC. Solvent-responsive properties of octadecyltrichlorosiloxane nanostructures investigated using atomic force microscopy in liquid. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:5466-5473. [PMID: 24788214 DOI: 10.1021/la500799u] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
An emerging challenge for nanoscale measurements is to capture and quantify the magnitude of structural changes in response to environmental changes. Certain environmental parameters can affect the nanoscale morphology of samples, such as changing the pH, solvent polarity, ionic strength, and temperature. We prepared test platforms of n-octadecyltrichlorosilane ring nanostructures to study surface morphology changes at the nanoscale in selected liquid media compared to dry conditions in air. Particle lithography combined with organosilane vapor deposition was used to fabricate nanostructures of regular dimensions. Multilayer nanostructures of OTS were used as a test platform for scanning probe studies of solvent-responsive properties where the sides of designed ring structures expose a 3D interface for studying the interaction of solvents with molecular side groups. In dry, ambient conditions, nanostructures of OTS were first imaged using contact mode atomic force microscopy (AFM). Next, ethanol or buffer was introduced to the sample cell, and images were acquired using the same probe. We observed substantial changes in the lateral and vertical dimensions of the ring nanostructures in AFM topography frames; the sizes of the rings were observed to swell by tens of nanometers. Even after heat treatment of samples to promote cross-linking, the samples still evidenced swelling in liquid media. This research will have consequences for studies of the properties of nanomaterials, such as solvent-responsive organic films and polymers.
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Affiliation(s)
- Shalaka A Kulkarni
- Department of Chemistry, Louisiana State University , 232 Choppin Hall, Baton Rouge, Louisiana 70803, United States
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22
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Synthesis, characterization and self-assembly of hybrid pH-sensitive block copolymer containing polyhedral oligomeric silsesquioxane (POSS). REACT FUNCT POLYM 2013. [DOI: 10.1016/j.reactfunctpolym.2013.09.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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23
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Clarke KC, Lyon LA. Modulation of the deswelling temperature of thermoresponsive microgel films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:12852-12857. [PMID: 24053386 DOI: 10.1021/la403280s] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We demonstrate fine-tuning of the deswelling temperatures of thermoresponsive microgels within a biologically relevant range (30-40 °C). This was achieved by copolymerizing N-isopropylacrylamide and N-isopropylmethacrylamide (NIPAm and NIPMAm, respectively) in varying ratios; the parent homopolymers are well-known thermoresponsive polymers. Polyelectrolyte layer-by-layer (LbL) assemblies of these microgels retain the temperature response properties as demonstrated by temperature-dependent light scattering. Furthermore, films composed of more than one type of microgel building block were shown to have multiple temperature responses similar to those observed for the individual building blocks, permitting further tailoring of the temperature responsive interface. Additional experiments with mixed composition films, investigating multiple assembly processes, show that the location of the microgels within the film does not interfere with the temperature response. This suggests that microgels within the polyelectrolyte assembly behave independently of neighboring microgels with respect to their thermally induced deswelling.
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Affiliation(s)
- Kimberly C Clarke
- School of Chemistry and Biochemistry and the Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
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24
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Byambaa B, Konno T, Ishihara K. Cell adhesion control on photoreactive phospholipid polymer surfaces. Colloids Surf B Biointerfaces 2012; 99:1-6. [DOI: 10.1016/j.colsurfb.2011.08.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 08/30/2011] [Accepted: 08/31/2011] [Indexed: 11/29/2022]
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25
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Galvin CJ, Genzer J. Applications of surface-grafted macromolecules derived from post-polymerization modification reactions. Prog Polym Sci 2012. [DOI: 10.1016/j.progpolymsci.2011.12.001] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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26
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Release of Ftorafur from pH-sensitive hydrogels with hyperbranched poly(4-vinylbenzyl chloride) moieties. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2012. [DOI: 10.1016/j.msec.2012.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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27
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Synthesis and Characterization of Poly(acrylic acid) Brushes: “Grafting-Onto” Route. MACROMOL CHEM PHYS 2012. [DOI: 10.1002/macp.201100394] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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28
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Jhon YK, Arifuzzaman S, Özçam AE, Kiserow DJ, Genzer J. Formation of polyampholyte brushes via controlled radical polymerization and their assembly in solution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:872-882. [PMID: 22112235 DOI: 10.1021/la203697a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We describe the formation of polyampholytic block copolymer brushes and their assembly in solution. Specifically, we employ "surface-initiated" activators regenerated by electron transfer atom transfer radical polymerization (ARGET-ATRP) sequentially to form diblock copolymer grafts comprising blocks of poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) and poly(sodium methacrylate) (PNaMA) on flat impenetrable silica surfaces, i.e., SiO(x)/PNaMA-b-PDMAEMA and SiO(x)/PDMAEMA-b-PNaMA. Protonation of the PNaMA block results in formation of poly(methacrylic acid) (PMAA). We demonstrate that ARGET-ATRP of NaMA provides a convenient route to preparation of PMAA, which is an alternative method to the more traditional approach based on preparing PMAA by polymerizing tert-butyl methacrylate (tBMA) followed by cleavage of the tert-butyl group. We also discuss conformational changes of the individual polyelectrolyte blocks in solution as a function of solution pH by monitoring adsorption behavior of functionalized polystyrene spheres.
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Affiliation(s)
- Young K Jhon
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695-7905, United States
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29
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Qu LJ, Man X, Han CC, Qiu D, Yan D. Responsive Behaviors of Diblock Polyampholyte Brushes within Self-Consistent Field Theory. J Phys Chem B 2012; 116:743-50. [DOI: 10.1021/jp210165t] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Li-Jian Qu
- Beijing National Laboratory for Molecular Sciences, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Xingkun Man
- Beijing National Laboratory for Molecular Sciences, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Charles C. Han
- Beijing National Laboratory for Molecular Sciences, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Dong Qiu
- Beijing National Laboratory for Molecular Sciences, Joint Laboratory of Polymer Science and Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Dadong Yan
- Department of Physics, Beijing Normal University, Beijing 100875
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30
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Meng D, Wang Q. Stimuli-response of charged diblock copolymer brushes. J Chem Phys 2011; 135:224904. [DOI: 10.1063/1.3665924] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Escalé P, Rubatat L, Derail C, Save M, Billon L. pH Sensitive Hierarchically Self-Organized Bioinspired Films. Macromol Rapid Commun 2011; 32:1072-6. [DOI: 10.1002/marc.201100296] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Indexed: 11/11/2022]
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32
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Xu Y, Hoshi Y, Ober CK. Photo-switchable polyelectrolyte brush for dual protein patterning. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm12062j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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33
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34
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Jia X, Jiang X, Liu R, Yin J. Multi-stimuli responsive poly(ether amine) (PEA) brush fabricated by “thiol-ene” click chemistry. POLYMER 2010. [DOI: 10.1016/j.polymer.2010.07.041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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35
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Yu Q, Zhang Y, Chen H, Zhou F, Wu Z, Huang H, Brash JL. Protein adsorption and cell adhesion/detachment behavior on dual-responsive silicon surfaces modified with poly(N-isopropylacrylamide)-block-polystyrene copolymer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:8582-8588. [PMID: 20170172 DOI: 10.1021/la904663m] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Diblock copolymer grafts covalently attached to surfaces have attracted considerable attention because of their special structure and novel properties. In this work, poly(N-isopropylacrylamide)-block-polystyrene (PNIPAAm-b-PS) brushes were prepared via surface-initiated consecutive atom-transfer radical polymerization on initiator-immobilized silicon. Because of the inherent thermosensitivity of PNIPAAm and the hydrophobicity difference between the two blocks, the modified surfaces were responsive to both temperature and solvent. Moreover, the diblock copolymer brushes exhibited both resistance to nonspecific protein adsorption and unique cell interaction properties. They showed strong protein resistance in both phosphate-buffered saline and blood plasma. In particular, fibrinogen adsorption from plasma at either room temperature or body temperature was less than 8 ng/cm(2), suggesting that the surfaces might possess good blood compatibility. In addition, the adhesion and detachment of L929 cells could be "tuned", and the ability to control the detachment of cells thermally was restored by block polymerization of hydrophobic, cell-adhesive PS onto a thicker PNIPAAm layer. In addition to providing a simple and effective design for advanced cell-culture surfaces, these results suggest new biomedical applications for PNIPAAm.
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Affiliation(s)
- Qian Yu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, PR China
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36
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Kelby TS, Huck WTS. Controlled Bending of Microscale Au−Polyelectrolyte Brush Bilayers. Macromolecules 2010. [DOI: 10.1021/ma100624h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tim S. Kelby
- Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Wilhelm T. S. Huck
- Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
- Radboud University Nijmegen, Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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37
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Singamaneni S, McConney ME, Tsukruk VV. Swelling-induced folding in confined nanoscale responsive polymer gels. ACS NANO 2010; 4:2327-2337. [PMID: 20232813 DOI: 10.1021/nn901886y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Mechanical instabilities such as buckling, wrinkling, creasing, and folding are commonplace in both natural and synthetic systems over a wide range of length scales. In this study, we focus on the spontaneous folding behavior of the highly swellable confined nanoscale (thickness below 100 nm) gel films resulting in the formation of a network of regularly folded structures spontaneously emerging in the course of their swelling and drying. We suggest that regular self-folding is originated from periodic instabilities (wrinkles) caused by swelling-initiated stresses under confined conditions. Furthermore, folded gel structures can be organized into regular serpentine-like manner by imposing various boundary conditions on microimprinted surfaces. We suggest that this demonstration of uniform gel to mechanically mediate morphogenesis has far-reaching implications in the creation of complex, large-area, 3D gel nanostructures.
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Affiliation(s)
- Srikanth Singamaneni
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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38
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Stuart MAC, Huck WTS, Genzer J, Müller M, Ober C, Stamm M, Sukhorukov GB, Szleifer I, Tsukruk VV, Urban M, Winnik F, Zauscher S, Luzinov I, Minko S. Emerging applications of stimuli-responsive polymer materials. NATURE MATERIALS 2010; 9:101-13. [PMID: 20094081 DOI: 10.1038/nmat2614] [Citation(s) in RCA: 3639] [Impact Index Per Article: 259.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Responsive polymer materials can adapt to surrounding environments, regulate transport of ions and molecules, change wettability and adhesion of different species on external stimuli, or convert chemical and biochemical signals into optical, electrical, thermal and mechanical signals, and vice versa. These materials are playing an increasingly important part in a diverse range of applications, such as drug delivery, diagnostics, tissue engineering and 'smart' optical systems, as well as biosensors, microelectromechanical systems, coatings and textiles. We review recent advances and challenges in the developments towards applications of stimuli-responsive polymeric materials that are self-assembled from nanostructured building blocks. We also provide a critical outline of emerging developments.
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Affiliation(s)
- Martien A Cohen Stuart
- Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands
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39
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Barbey R, Lavanant L, Paripovic D, Schüwer N, Sugnaux C, Tugulu S, Klok HA. Polymer brushes via surface-initiated controlled radical polymerization: synthesis, characterization, properties, and applications. Chem Rev 2010; 109:5437-527. [PMID: 19845393 DOI: 10.1021/cr900045a] [Citation(s) in RCA: 1218] [Impact Index Per Article: 87.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Raphaël Barbey
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut des Matériaux, Laboratoire des Polymères, Bâtiment MXD, Station 12, CH-1015 Lausanne, Switzerland
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40
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41
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Koylu D, Carter KR. Stimuli-Responsive Surfaces Utilizing Cleavable Polymer Brush Layers. Macromolecules 2009. [DOI: 10.1021/ma901627c] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Damla Koylu
- Polymer Science and Engineering Department, University of Massachusetts—Amherst, Conte Center for Polymer Research, 120 Governors Drive, Amherst, Massachusetts 01003
| | - Kenneth R. Carter
- Polymer Science and Engineering Department, University of Massachusetts—Amherst, Conte Center for Polymer Research, 120 Governors Drive, Amherst, Massachusetts 01003
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42
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Hinrichs K, Aulich D, Ionov L, Esser N, Eichhorn KJ, Motornov M, Stamm M, Minko S. Chemical and structural changes in a pH-responsive mixed polyelectrolyte brush studied by infrared ellipsometry. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:10987-10991. [PMID: 19572506 DOI: 10.1021/la901219f] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This work provides direct chemical and structural insight into pH-dependent changes of an ultrathin (d=12 nm) mixed polyelectrolyte brush. In-situ infrared spectroscopic ellipsometry was used for the first time to study the gradual pH-responsive behavior of the brush, constituted of weak anionic and cationic polyelectrolytes, poly(acrylic acid) (PAA) and poly(2-vinylpyridine) (P2VP), respectively. The pH-dependent infrared fingerprints in the mid-infrared spectral range were analyzed as a function of chemical and structural changes in the mixed brush caused by pH changes. Thereby, the IR spectra were directly correlated to different chemical states of the brush, giving previously not accessible new information on the ionization of the thin film. In contrast to other techniques (e.g., classical attenuated total reflection IR spectroscopy) we used almost plane Si-substrates for the IR ellipsometric approach with application of a single reflection mode. The optical path through Si is of minimal length, which makes a large spectral range accessible. For the most pronounced bands of the carboxyl group at 1718 cm(-1) and the carboxylate ion at 1565 cm(-1), the band amplitudes were correlated with the degree of ionization of the carboxylic groups. Interpretation of the pH-dependent changes in the spectral signature reveals gradual changes of the chemical structures of the mixed brush between three distinct switchable states: strongly ionized PAA at pH 10, strongly ionized P2VP at pH 2, and mainly nonionized functional groups in a "dry" PAA-P2VP polyelectrolyte complex in the range from pH=4 to pH=7. At intermediate pH, the IR spectra confirm the previously made hypothesis of the formation of a polyelectrolyte complex between P2VP and PAA in the mixed brush. From IR spectra it is also concluded that the polyelectrolyte complex is formed as a result of a small fraction of ionized functional groups.
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Affiliation(s)
- Karsten Hinrichs
- ISAS-Institute for Analytical Sciences, Department Berlin, Albert-Einstein-Strasse 9, 12489 Berlin, Germany.
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43
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Lewis GT, Nguyen V, Shih WY, Cohen Y. Reverse atom transfer radical graft polymerization of 4-vinylpyridine onto inorganic oxide surfaces. J Appl Polym Sci 2009. [DOI: 10.1002/app.29978] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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44
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Cullen SP, Mandel IC, Gopalan P. Surface-anchored poly(2-vinyl-4,4-dimethyl azlactone) brushes as templates for enzyme immobilization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:13701-13709. [PMID: 18956849 DOI: 10.1021/la8024952] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We explored surface-anchored poly(2-vinyl-4,4-dimethyl azlactone) (PVDMA) brushes as potential templates for protein immobilization. The brushes were grown using atom transfer radical polymerization from surface-anchored initiators and characterized by a combination of ellipsometry, atomic force microscopy, and X-ray photoelectron spectroscopy. RNase A was immobilized as a model enzyme through the nucleophilic attack of azlactone by the amine groups in the lysines located in the protein. The surface density of RNase A increased linearly from 5 to 50 nm. For 50 nm thick poly(2-vinyl-4,4-dimethyl azlactone) brushes, 7.5 microg/cm2 of RNase A was bound. The kinetics and thermodynamics of RNase A immobilization, the activity relative to surface density, and the pH and temperature dependence were examined. A Langmuir-like model for binding kinetics indicates that the kinetics are controlled by the rate of adsorption of RNase A and has an adsorption rate constant, k(ads), of 2.8 x 10(-8) microg(-1) s(-1) cm3. A maximum relative activity of approximately 0.95, which is near the activity of free RNase A, was reached at 1.2 microg/cm2 (approximately 3.0 monolayers) of immobilized RNase A. The immobilized RNase A had a similar temperature and pH dependence as free RNase A, indicating no significant change in conformation. The PVDMA template was extended to other biotechnologically relevant enzymes, such as deoxyribonuclease I, glucose oxidase, glucoamylase, and trypsin, with relative activities higher than or comparable to those of enzymes immobilized by other means. PVDMA brushes offer an efficient route to immobilize proteins via the ring opening of azlactone without the need for activation or pretreatment while retaining high relative activities of the bound enzymes.
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Affiliation(s)
- Sean P Cullen
- Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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45
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Sanjuan S, Tran Y. Stimuli-Responsive Interfaces Using Random Polyampholyte Brushes. Macromolecules 2008. [DOI: 10.1021/ma8018798] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sarah Sanjuan
- Laboratoire de Physico-chimie des Polymères et des Milieux Dispersés, ESPCI, UPMC Univ Paris 6, CNRS UMR 7615, 10, rue Vauquelin, 75231 Paris Cedex 05, France
| | - Yvette Tran
- Laboratoire de Physico-chimie des Polymères et des Milieux Dispersés, ESPCI, UPMC Univ Paris 6, CNRS UMR 7615, 10, rue Vauquelin, 75231 Paris Cedex 05, France
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46
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Lindqvist J, Nyström D, Östmark E, Antoni P, Carlmark A, Johansson M, Hult A, Malmström E. Intelligent Dual-Responsive Cellulose Surfaces via Surface-Initiated ATRP. Biomacromolecules 2008; 9:2139-45. [DOI: 10.1021/bm800193n] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Josefina Lindqvist
- Royal Institute of Technology, KTH School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden
| | - Daniel Nyström
- Royal Institute of Technology, KTH School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden
| | - Emma Östmark
- Royal Institute of Technology, KTH School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden
| | - Per Antoni
- Royal Institute of Technology, KTH School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden
| | - Anna Carlmark
- Royal Institute of Technology, KTH School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden
| | - Mats Johansson
- Royal Institute of Technology, KTH School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden
| | - Anders Hult
- Royal Institute of Technology, KTH School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden
| | - Eva Malmström
- Royal Institute of Technology, KTH School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56-58, SE-100 44, Stockholm, Sweden
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47
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Rowe MD, Hammer BAG, Boyes SG. Synthesis of Surface-Initiated Stimuli-Responsive Diblock Copolymer Brushes Utilizing a Combination of ATRP and RAFT Polymerization Techniques. Macromolecules 2008. [DOI: 10.1021/ma800154c] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Misty D. Rowe
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado 80401
| | - Brenton A. G. Hammer
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado 80401
| | - Stephen G. Boyes
- Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, Colorado 80401
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48
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Cullen SP, Liu X, Mandel IC, Himpsel FJ, Gopalan P. Polymeric brushes as functional templates for immobilizing ribonuclease A: study of binding kinetics and activity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:913-920. [PMID: 18076197 DOI: 10.1021/la702510z] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The ability to immobilize proteins with high binding capacities on surfaces while maintaining their activity is critical for protein microarrays and other biotechnological applications. We employed poly(acrylic acid) (PAA) brushes as templates to immobilize ribonuclease A (RNase A), which is commonly used to remove RNA from plasmid DNA preparations. The brushes are grown by surface-anchored atom-transfer radical polymerization (ATRP) initiators. RNase A was immobilized by both covalent esterification and a high binding capacity metal-ion complexation method to PAA brushes. The polymer brushes immobilized 30 times more enzyme compared to self-assembled monolayers. As the thickness of the brush increases, the surface density of the RNase A increases monotonically. The immobilization was investigated by ellipsometry, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and near-edge X-ray absorption fine structure spectroscopy (NEXAFS). The activity of the immobilized RNase A was determined using UV absorbance. As much as 11.0 microg/cm(2) of RNase A was bound to PAA brushes by metal-ion complexation compared to 5.8 microg/cm(2) by covalent immobilization which is 30 and 16 times the estimated mass bound in a monolayer. The calculated diffusion coefficient D was 0.63 x 10(-14) cm(2)/s for metal-ion complexation and 0.71 x 10(-14) cm(2)/s for covalent immobilization. Similar values of D indicate that the binding kinetics is similar, but the thermodynamic equilibrium coverage varies with the binding chemistry. Immobilization kinetics and thermodynamics were characterized by ellipsometry for both methods. A maximum relative activity of 0.70-0.80 was reached between five and nine monolayers of the immobilized enzyme. However, the relative activity for covalent immobilization was greater than that of metal-ion complexation. Covalent esterification resulted in similar temperature dependence as free enzyme, whereas metal-ion complexation showed no temperature dependence indicating a significant change in conformation.
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Affiliation(s)
- Sean P Cullen
- Chemical and Biological Engineering, Department of Physics, and Materials Science and Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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49
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Sanjuan S, Tran Y. Synthesis of random polyampholyte brushes by atom transfer radical polymerization. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/pola.22726] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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50
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Limpoco FT, Advincula RC, Perry SS. Solvent dependent friction force response of polystyrene brushes prepared by surface initiated polymerization. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:12196-12201. [PMID: 17949015 DOI: 10.1021/la701272a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Polystyrene (PS) brushes were prepared on oxide passivated silicon by the surface initiated polymerization (SIP) technique. From an AIBN-type free radical initiator, which was silanized and immobilized on silicon wafers, styrene brushes were directly polymerized and grafted from the surface. The formation of the initiator monolayer and, subsequently, the polymer brush on the surface were monitored by X-ray photoelectron spectroscopy (XPS) and ellipsometry. Friction force measurements were performed by atomic force microscopy (AFM), using a 5 microm SiO2 colloidal sphere tip and under systematically varied solvent environments (nonpolar to polar), to demonstrate the dependence of brush lubricity on solvation. The relative uptake of solvents in the PS brush was determined by quartz crystal microbalance (QCM), and it correlates well with friction data. It is surmised that, in poor solvent environments, the polymer brush exists in a collapsed conformation, giving rise to the higher observed friction response.
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Affiliation(s)
- F T Limpoco
- Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA
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