351
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Amin I, Steenackers M, Zhang N, Beyer A, Zhang X, Pirzer T, Hugel T, Jordan R, Gölzhäuser A. Polymer carpets. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2010; 6:1623-30. [PMID: 20635346 DOI: 10.1002/smll.201000448] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The fabrication of defined polymer objects of reduced dimensions such as polymer-coated nanoparticles (zero-dimensional (0D)), cylindrical brushes (1D), and polymer membranes (2D), is currently the subject of intense research. In particular, ultrathin polymer membranes with high aspect ratios are being discussed as novel materials for miniaturized sensors because they would provide extraordinary sensitivity and dynamic range when sufficient mechanical stability can be combined with flexibility and chemical functionality. Unlike current approaches that rely on crosslinking of polymer layers for stabilization, this report presents the preparation of a new class of polymer material, so-called "polymer carpets," a freestanding polymer brush grown by surface-initiated polymerization on a crosslinked 1-nm-thick monolayer. The solid-supported, as well as freestanding, polymer carpets are found to be mechanically robust and to react instantaneously and reversibly to external stimuli by buckling. The carpet mechanics and the dramatic changes of the film properties (optical, wetting) upon chemical stimuli are investigated in detail as they allow the development of completely new integrated micro-/nanotechnology devices.
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Affiliation(s)
- Ihsan Amin
- Physik Supramolekularer Systeme, Universität Bielefeld, Universitätsstrasse 25, 33615 Bielefeld, Germany
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352
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353
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Marques SM, Tavares CJ, Lanceros-Méndez S, Denchev Z. X-ray scattering experiments on sputtered titanium dioxide coatings onto PVDF polymers for self-cleaning applications. J Appl Polym Sci 2010. [DOI: 10.1002/app.32744] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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354
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Litmanovich EA, Chernikova EV, Stoychev GV, Zakharchenko SO. Unusual Phase Behavior of the Mixture of Poly(acrylic acid) and Poly(diallyldimethylammonium chloride) in Acidic Media. Macromolecules 2010. [DOI: 10.1021/ma1003562] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ekaterina A. Litmanovich
- Department of Polymer Science, Faculty of Chemistry, Lomonosov Moscow State University, Leninskie gory, 119991, Moscow, Russian Federation
| | - Elena V. Chernikova
- Department of Polymer Science, Faculty of Chemistry, Lomonosov Moscow State University, Leninskie gory, 119991, Moscow, Russian Federation
| | - Georgi V. Stoychev
- Department of Polymer Science, Faculty of Chemistry, Lomonosov Moscow State University, Leninskie gory, 119991, Moscow, Russian Federation
| | - Svetlana O. Zakharchenko
- Department of Polymer Science, Faculty of Chemistry, Lomonosov Moscow State University, Leninskie gory, 119991, Moscow, Russian Federation
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355
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Zhang BY, He WD, Li LY, Sun XL, Li WT, Zhang KR. Reducibly degradable hydrogels of PNIPAM and PDMAEMA: Synthesis, stimulus-response and drug release. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/pola.24141] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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356
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Connal LA, Franks GV, Qiao GG. Photochromic, metal-absorbing honeycomb structures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:10397-10400. [PMID: 20524646 DOI: 10.1021/la100686m] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We demonstrate the synthesis and use of a spiropyran functional polymer to form highly ordered honeycomb materials by the breath figure technique, which is based on the self-assembly of water droplets. These materials undergo rapid and intense color changes both in solution and as porous films by irradiation with light (UV or visible). We also demonstrate the metal binding ability of these polymers ultimately to create hybrid organic-inorganic porous structures. Furthermore, by reduction of the metal and calcination of the organic materials, unique palladium microrings can be prepared. The methods described are general techniques that may be applied to a range of heavy metals.
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Affiliation(s)
- Luke A Connal
- The Polymer Science Group, The Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
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357
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Junk M, Li W, Schlüter A, Wegner G, Spiess H, Zhang A, Hinderberger D. EPR-Spektroskopische Charakterisierung lokaler nanoskopischer Heterogenitäten beim thermischen Kollaps thermoresponsiver dendronisierter Polymere. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201001469] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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358
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Junk M, Li W, Schlüter A, Wegner G, Spiess H, Zhang A, Hinderberger D. EPR Spectroscopic Characterization of Local Nanoscopic Heterogeneities during the Thermal Collapse of Thermoresponsive Dendronized Polymers. Angew Chem Int Ed Engl 2010; 49:5683-7. [DOI: 10.1002/anie.201001469] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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359
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Li M, Li GL, Zhang Z, Li J, Neoh KG, Kang ET. Self-assembly of pH-responsive and fluorescent comb-like amphiphilic copolymers in aqueous media. POLYMER 2010. [DOI: 10.1016/j.polymer.2010.05.032] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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360
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Choi CK, Fowlkes JD, Retterer ST, Siuti P, Iyer S, Doktycz MJ. Surface charge- and space-dependent transport of proteins in crowded environments of nanotailored posts. ACS NANO 2010; 4:3345-55. [PMID: 20515056 PMCID: PMC2892340 DOI: 10.1021/nn901831q] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The reaction and diffusion of molecules across barriers and through crowded environments is integral to biological system function and to separation technologies. Ordered, microfabricated post arrays are a promising route to creating synthetic barriers with controlled chemical and physical characteristics. They can be used to create crowded environments, to mimic aspects of cellular membranes, and to serve as engineered replacements of polymer-based separation media. Here, the translational diffusion of fluorescein isothiocyante and various forms of green fluorescent protein (GFP), including "supercharged" variants, are examined in a silicon-based post array environment. The technique of fluorescence recovery after photobleaching (FRAP) is combined with analytical approximations and numerical simulations to assess the relative effects of reaction and diffusion on molecular transport, respectively. FRAP experiments were conducted for 64 different cases where the molecular species, the density of the posts, and the chemical surface charge of the posts were varied. In all cases, the dense packing of the posts hindered the diffusive transport of the fluorescent species. The supercharged GFPs strongly interacted with oppositely charged surfaces. With similar molecular and surface charges, transport is primarily limited by hindered diffusion. For conventional, enhanced GFP in a positively charged surface environment, transport was limited by the coupled action of hindered diffusion and surface interaction with the posts. Quantification of the size-, space-, time-, and charge-dependent translational diffusion in the post array environments can provide insight into natural processes and guide the design and development of selective membrane systems.
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Affiliation(s)
- Chang Kyoung Choi
- Mechanical Engineering-Engineering Mechanics, Michigan Technological University, Houghton, MI 49931-1295
| | - Jason D. Fowlkes
- Center for Nanoscale Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831
| | - Scott T. Retterer
- Center for Nanoscale Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
| | - Piro Siuti
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
- Graduate Program in Genome Science and Technology, University of Tennessee, Knoxville, TN 37996
| | - Sukanya Iyer
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
- Graduate Program in Genome Science and Technology, University of Tennessee, Knoxville, TN 37996
| | - Mitchel J. Doktycz
- Center for Nanoscale Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831
- Graduate Program in Genome Science and Technology, University of Tennessee, Knoxville, TN 37996
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361
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Cirillo G, Iemma F, Spizzirri UG, Puoci F, Curcio M, Parisi OI, Picci N. Synthesis of stimuli-responsive microgels for in vitro release of diclofenac diethyl ammonium. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2010; 22:823-44. [PMID: 20566061 DOI: 10.1163/092050610x496279] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thermal and dual stimuli-responsive microspheres (pH and temperature) were prepared by free radical polymerization of methacrylate bovine serum albumin (BSA-MA) as cross-linker and sodium methacrylate (NaMA) and/or N-isopropylacrylamide (NIPAAm), as hydrophilic/pH-sensitive and thermo-responsive monomers, respectively. Microgels were characterized by infrared spectroscopy, morphological analysis, particle size distribution and determination of swelling properties. The network density and the shape of the microgels were found to depend on the concentration of the reactive species in the polymerization feed. Thermal analyses were performed to determine lower critical solution temperature values, which become close to the body temperature by increasing the content of the hydrophilic moieties in the network. In order to test the preformed materials as drug carriers, in vitro release studies of Diclofenac diethyl ammonium salt were performed. For all the co-polymers, a predominant drug release in the collapsed state was observed, while below the microgel transition temperature, a drug release through the swollen network occurs. The data recorded during the release tests demonstrated that the pH of the surrounding environment influences the drug release more than the temperature of the imbibing medium.
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Affiliation(s)
- Giuseppe Cirillo
- Dipartimento di Scienze Farmaceutiche, Università della Calabria, Edificio Polifunzionale, Rende (CS) 87036, Italia
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362
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Weber J, Bergström L. Mesoporous hydrogels: revealing reversible porosity by cryoporometry, X-ray scattering, and gas adsorption. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:10158-10164. [PMID: 20307060 DOI: 10.1021/la100290j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Mesoporous poly(2-hydroxyethyl methacrylate-co-ethylene glycol dimethacrylate) networks, with cross-linker contents ranging from 100 to 5 mol %, were prepared using a hard-templating approach. The imbibition of the silica pellets with a monomer/cross-linker mixture resulted in mesoporous gels with a pore size of approximately 10 nm, which corresponds well with the average size of the fumed silica particles (10-11 nm). The highly cross-linked materials showed permanent surface areas of up to 230 m(2) g(-1) and porosities up to approximately 33 vol %. The porosity of the hydrogels was investigated in both dry and water-saturated state by nitrogen sorption, cryoporometry, and small-angle X-ray scattering (SAXS). It is only polymeric materials that contain 50 mol % or more of the cross-linker that showed a significant porosity after evaporative drying. Freeze-drying is able to preserve the porosity also for hydrogels of intermediate cross-linker content, but the pores of the materials of low cross-linker content collapses completely upon solvent removal. The observed critical cross-linker ratio for pore stability compared favorably with a simple estimate of the critical cross-linker density needed to make the material sufficiently stiff to withstand the Laplace pressure during solvent removal. Analysis of the hydrogels in the water swollen state revealed that gels having cross-linker contents down to 5 mol % still possessed mesoporosity. The pores got less defined at very low cross-linker contents, while their size was rather constant at intermediate to high cross-linking densities. Closed pores could be reopened upon swelling, which suggests that the observed pore collapse upon drying may be at least partly reversible.
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Affiliation(s)
- Jens Weber
- Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden.
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363
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Truong MY, Dutta NK, Choudhury NR, Kim M, Elvin CM, Hill AJ, Thierry B, Vasilev K. A pH-responsive interface derived from resilin-mimetic protein Rec1-resilin. Biomaterials 2010; 31:4434-46. [DOI: 10.1016/j.biomaterials.2010.02.019] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 02/08/2010] [Indexed: 10/19/2022]
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364
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Contreras-García A, Alvarez-Lorenzo C, Concheiro A, Bucio E. PP films grafted with N-isopropylacrylamide and N-(3-aminopropyl) methacrylamide by γ radiation: synthesis and characterization. Radiat Phys Chem Oxf Engl 1993 2010. [DOI: 10.1016/j.radphyschem.2009.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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365
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Gao M, Jia X, Li Y, Liang D, Wei Y. Synthesis and Thermo-/pH- Dual Responsive Properties of Poly(amidoamine) Dendronized Poly(2-hydroxyethyl) Methacrylate. Macromolecules 2010. [DOI: 10.1021/ma1000783] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Min Gao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 China
| | - Xinru Jia
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 China
| | - Yan Li
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 China
| | - Dehai Liang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 China
| | - Yen Wei
- Department of Chemistry, Tsinghua University, Beijing 100084, China
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366
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Moura LM, Martinho JMG, Farinha JPS. DNA Hybridization in Thermoresponsive Polymer Nanoparticles. Chemphyschem 2010; 11:1749-56. [DOI: 10.1002/cphc.201000015] [Citation(s) in RCA: 8] [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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367
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368
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Vo CD, Rosselgong J, Armes SP, Tirelli N. Stimulus-responsive polymers based on 2-hydroxypropyl acrylate prepared by RAFT polymerization. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/pola.23973] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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369
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Fujii Y, Nagamura T, Tanaka K. Relaxation Behavior of Poly(methyl methacrylate) at a Water Interface. J Phys Chem B 2010; 114:3457-60. [DOI: 10.1021/jp909373g] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Yoshihisa Fujii
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
| | - Toshihiko Nagamura
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
| | - Keiji Tanaka
- Department of Applied Chemistry, Kyushu University, Fukuoka 819-0395, Japan
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370
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Abstract
Here we show 2'-deoxyguanosine derivatives that self-assemble in aqueous media into discrete supramolecular hexadecamers and exhibit the lower critical solution temperature (LCST) phenomenon. Spectroscopic, calorimetric, and electron microscopy studies support the fact that above the transition temperature (T(t)) the supramolecules further assemble into nanoscopic spherical globules of low polydispersity. Furthermore, the T(t) can be tuned to higher values by the addition of a more hydrophilic derivative. These findings uncover a new paradigm in the development of smart thermosensitive materials with properties and applications complementary to those of polymers.
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Affiliation(s)
- José E Betancourt
- Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, Rio Piedras, Puerto Rico
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371
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Romão RIS, Beija M, Charreyre MT, Farinha JPS, Gonçalves da Silva AMPS, Martinho JMG. Schizophrenic behavior of a thermoresponsive double hydrophilic diblock copolymer at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:1807-1815. [PMID: 19928784 DOI: 10.1021/la902510q] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The thermoresponsive behavior of the rhodamine B end-labeled double hydrophilic block copolymer (DHBC) poly(N,N-dimethylacrylamide)-b-poly(N,N-diethylacrylamide) (RhB-PDMA(207)-b-PDEA(177)) and the 1:1 segmental mixture of PDEA and rhodamine B end-labeled PDMA homopolymers was studied over the range of 10-40 degrees C at the air-water interface. The increase in collapse surface pressure (second plateau regime) of the DHBC with temperature confirms the thermoresponsiveness of PDEA at the interface. The sum of the pi-A isotherms of the two single homopolymers weighted by composition closely follows the pi-A isotherm of the DHBC, suggesting that the behavior of each block of the DHBC is not influenced by the presence of the other block. Langmuir-Blodgett monolayers of DHBC deposited on glass substrates were analyzed by laser scanning confocal fluorescence microscopy (LSCFM), showing schizophrenic behavior: at low temperature, the RhB-PDMA block dominates the inside of bright (core) microdomains, switching to the outside (shell) at temperatures above the lower critical solution temperature (LCST) of PDEA. This core-shell inversion triggered by the temperature increase was not detected in the homopolymer mixture. The present results suggest that both the covalent bond between the two blocks of the DHBC and the tendency of rhodamine B to aggregate play a role in the formation of the bright cores at low temperature whereas PDEA thermoaggregation is responsible for the formation of the dark cores above the LCST of PDEA.
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Affiliation(s)
- Rute I S Romão
- Centro de Quimica Estrutural, Instituto Superior Técnico, Universidade Técnica de Lisboa, 1049-001 Lisboa, Portugal
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372
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Aseyev V, Tenhu H, Winnik FM. Non-ionic Thermoresponsive Polymers in Water. ADVANCES IN POLYMER SCIENCE 2010. [DOI: 10.1007/12_2010_57] [Citation(s) in RCA: 374] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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373
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Itahara T, Tsuchida T, Morimoto M. Solvent-driven swelling and shrinking of poly(NIPAM) gels crosslinked by tris-methacrylated phloroglucinol derivatives. Polym Chem 2010. [DOI: 10.1039/c0py00068j] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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374
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375
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376
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Soliman M, Allen S, Davies MC, Alexander C. Responsive polyelectrolyte complexes for triggered release of nucleic acid therapeutics. Chem Commun (Camb) 2010; 46:5421-33. [DOI: 10.1039/c0cc00794c] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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377
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Siegel RA, Gu Y, Lei M, Baldi A, Nuxoll EE, Ziaie B. Hard and soft micro- and nanofabrication: An integrated approach to hydrogel-based biosensing and drug delivery. J Control Release 2009; 141:303-13. [PMID: 20036310 DOI: 10.1016/j.jconrel.2009.12.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Accepted: 12/09/2009] [Indexed: 11/16/2022]
Abstract
We review efforts to produce microfabricated glucose sensors and closed-loop insulin delivery systems. These devices function due to the swelling and shrinking of glucose-sensitive microgels that are incorporated into silicon-based microdevices. The glucose response of the hydrogel is due to incorporated phenylboronic acid (PBA) side chains. It is shown that in the presence of glucose, these polymers alter their swelling properties, either by ionization or by formation of glucose-mediated reversible crosslinks. Swelling pressures impinge on microdevice structures, leading either to a change in resonant frequency of a microcircuit, or valving action. Potential areas for future development and improvement are described. Finally, an asymmetric nano-microporous membrane, which may be integrated with the glucose-sensitive devices, is described. This membrane, formed using photolithography and block polymer assembly techniques, can be functionalized to enhance its biocompatibility and solute size selectivity. The work described here features the interplay of design considerations at the supramolecular, nano, and micro scales.
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Affiliation(s)
- Ronald A Siegel
- Department of Pharmaceutics, University of Minnesota, Minneapolis, MN 55455, USA.
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378
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Pinhassi RI, Assaraf YG, Farber S, Stark M, Ickowicz D, Drori S, Domb AJ, Livney YD. Arabinogalactan−Folic Acid−Drug Conjugate for Targeted Delivery and Target-Activated Release of Anticancer Drugs to Folate Receptor-Overexpressing Cells. Biomacromolecules 2009; 11:294-303. [DOI: 10.1021/bm900853z] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Roy I. Pinhassi
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Yehuda G. Assaraf
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Shimon Farber
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Michal Stark
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Diana Ickowicz
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Stavit Drori
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Abraham J. Domb
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Yoav D. Livney
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
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379
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Ohno S, Nese A, Cusick B, Kowalewski T, Matyjaszewski K. Polymer micelles from tadpole-shaped amphiphilic block-graft copolymers prepared by “Grafting-through” ATRP. POLYMER SCIENCE SERIES A 2009. [DOI: 10.1134/s0965545x09110054] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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380
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Guo Z, Zhu W, Tian H. Hydrophilic Copolymer Bearing Dicyanomethylene-4H-pyran Moiety As Fluorescent Film Sensor for Cu2+ and Pyrophosphate Anion. Macromolecules 2009. [DOI: 10.1021/ma902466g] [Citation(s) in RCA: 154] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Zhiqian Guo
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, Shanghai 200237, P. R. China
| | - Weihong Zhu
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, Shanghai 200237, P. R. China
| | - He Tian
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, Shanghai 200237, P. R. China
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381
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Li J, Ren J, Cao Y, Yuan W. Preparation and characterization of thermosensitive and biodegradable PNDH-g-PLLA nanoparticles for drug delivery. REACT FUNCT POLYM 2009. [DOI: 10.1016/j.reactfunctpolym.2009.09.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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382
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Motornov M, Tam TK, Pita M, Tokarev I, Katz E, Minko S. Switchable selectivity for gating ion transport with mixed polyelectrolyte brushes: approaching 'smart' drug delivery systems. NANOTECHNOLOGY 2009; 20:434006. [PMID: 19801770 DOI: 10.1088/0957-4484/20/43/434006] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A pH-responsive mixed polyelectrolyte brush from tethered polyacrylic acid (PAA) and poly(2-vinylpyridine) (P2VP) (PAA:P2VP = 69:31 by weight) was prepared and used for selective gating transport of anions and cations across the thin film. An ITO glass electrode was modified with the polymer brush and used to study the switchable permeability of the mixed brush triggered by changes in pH of the aqueous environment in the presence of two soluble redox probes: [Fe(CN)(6)](4-) and [Ru(NH(3))(6)](3+). The responsive behavior of the brush was also investigated using the in situ ellipsometric measurements of the brush swelling, examination of the brush morphology with atomic force microscopy (AFM), and contact angle measurements of the brush samples extracted from aqueous solutions at different pH values. The mixed brush demonstrated a bipolar permselective behavior. At pH<3 the positively charged P2VP chains enabled the electrochemical process for the negatively charged redox probe, [Fe(CN)(6)](4-), while the redox process for the positively charged redox probe was effectively inhibited. On the contrary, at pH>6 a reversible redox process for the positively charged redox probe, [Ru(NH(3))(6)](3+), was observed, while the redox process for the negatively charged redox species, [Fe(CN)(6)](4-), was fully inhibited. Stepwise changing the pH value and recording cyclic voltammograms for the intermediate states of the polymer brush allowed electrochemical observation of the brush transition from the positively charged state, permeable for the negatively charged species, to the negatively charged state, permeable for the positively charged species. The data of ellipsometric, AFM and contact angle measurements are in accord with the electrochemical study. The discovered properties of the brush could be used for the development of 'smart' sensors and drug delivery systems, for example, a smart drug delivery capsule which could release negatively charged molecules of drugs in acidic conditions, while positively charged molecules of drugs will be released in neutral conditions.
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Affiliation(s)
- Mikhail Motornov
- Department of Chemistry and Biomolecular Science, and NanoBio Laboratory (NABLAB), Clarkson University, Potsdam, NY 13699-5810, USA
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383
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Li W, Wu D, Schlüter AD, Zhang A. Synthesis of an oligo(ethylene glycol)‐based third‐generation thermoresponsive dendronized polymer. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/pola.23705] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Wen Li
- Department of Materials, Institute of Polymers, ETH Zurich, Wolfgang‐Pauli‐Str. 10, HCI G525, Zurich 8093, Switzerland
| | - Dalin Wu
- Department of Materials, Institute of Polymers, ETH Zurich, Wolfgang‐Pauli‐Str. 10, HCI G525, Zurich 8093, Switzerland
| | - A. Dieter Schlüter
- Department of Materials, Institute of Polymers, ETH Zurich, Wolfgang‐Pauli‐Str. 10, HCI G525, Zurich 8093, Switzerland
| | - Afang Zhang
- Department of Materials, Institute of Polymers, ETH Zurich, Wolfgang‐Pauli‐Str. 10, HCI G525, Zurich 8093, Switzerland
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384
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SCHNEIDER HANSJÖRG, STRONGIN ROBERTM. Supramolecular interactions in chemomechanical polymers. Acc Chem Res 2009; 42:1489-500. [PMID: 19839651 PMCID: PMC2765657 DOI: 10.1021/ar800274u] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Molecular recognition is the basis for the operation of most biological functions; outside of nature, it has also been developed to a high degree of sophistication within the framework of supramolecular chemistry. More recently, selective noncovalent interactions, which constitute molecular recognition, are being used in intelligent new materials that transform chemical signals into actions, such as the release of drugs. The presence of supramolecular binding sites allows chemomechanical polymers to operate as sensors and actuators within a single unit without the need for any additional devices such as transducers or power supplies. A polymer can be designed so that a particular chemical substance, most often in aqueous surroundings, will trigger either a large expansion or a large contraction, depending on the mechanism. The translation of binding energy into mechanical motion can, with a suitable arrangement of the materials in tubes or on flexible films, be harnessed for unidirectional drives, flow control, the liberation of drugs, or the uptake of toxic compounds, among other applications. Miniaturization of the polymer particles allows one to enhance both the sensitivity and speed of the response, which is of particular importance in sensing. The basis for the selective response to external effector compounds, such as metal ions, amino acids, peptides, or nucleotides, is their noncovalent interaction with complementary functions covalently bound to the polymer network. With suitable polymers, selectivity between structural isomers, and even between enantiomers, as triggers can be achieved. As with supramolecular complexes in solution, the underlying interactions in polymers comprise a variety of noncovalent binding mechanisms, which are not easy to distinguish and quantify, and more so with polymers that are not monodisperse. In this Account, we present systematic comparisons of different polymers and effector classes that allow, for the first time, the characterization of these contributions in chemomechanical polymers: they comprise ion pairing, metal coordination, stacking, cation-pi, dispersive, and hydrophobic forces. In contrast, hydrogen bonding has a major role primarily in the hydrogel network structure itself. The fully reversible polymer volume changes are essentially determined by water uptake or release. In gels derived from boronic acid, glucose can serve as a cross-linking effector in promoting contractions via strong, reversible covalent bond formation in a highly distinctive manner. Cooperativity between two different effector compounds is more frequently seen with such polymers than in solution: it leads to logical AND gates by different motions of the particles, with a direct communication link to the outside world. For example, with a polymer that bears several recognition sites, triggering peptides induce motion only if Zn(2+) or Cu(2+) ions are simultaneously present. The molecular recognition mechanisms that cause volume changes in polymers share similarities with extensively studied supramolecular systems in solution, but there are also remarkable differences. In this Account, we bring the knowledge learned from solution studies to bear on our systematic analysis of polymeric systems in an effort to promote the effective harnessing of the forces involved in chemomechanical polymers and the smart materials that can be created with them.
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Affiliation(s)
- HANS-JÖRG SCHNEIDER
- FR Organische Chemie, Universität des Saarlandes, D 66041 Saarbrücken, Germany, E-mail: ; Department of Chemistry, Portland State University, Portland, OR 97207 USA
| | - ROBERT M. STRONGIN
- FR Organische Chemie, Universität des Saarlandes, D 66041 Saarbrücken, Germany, E-mail: ; Department of Chemistry, Portland State University, Portland, OR 97207 USA
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385
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Mathieu M, Friebe A, Franzka S, Ulbricht M, Hartmann N. Surface-initiated polymerization on laser-patterned templates: morphological scaling of nanoconfined polymer brushes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:12393-12398. [PMID: 19685895 DOI: 10.1021/la901718k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Nonlinear laser processing of silane-based monolayers is used to fabricate nanostructured chemical templates for the selective growth of polymer brushes in confined domains via surface-initiated polymerization (SIP). Upon varying the laser parameters, reactive domains with lateral dimensions from several micrometers down to the sub-100-nm range are fabricated. This provides a versatile means for studying the morphological scaling behavior of confined polymer brushes. Here, the surface-initiated growth of a stimuli-responsive polymer, poly(N-isopropylacrylamide) (PNiPAAm), via atom transfer radical polymerization (ATRP) is investigated. Polymer chains at the domain boundaries extend into the surrounding polymer-free areas. For this reason the width of confined polymer brushes is significantly larger than that of the underlying domains. Within experimental error, though, the excess width does not depend on the domain size. In contrast, the brush height decreases more and more when the domain size falls below a certain value. Simple considerations point to a geometrical scaling relation between height and width of the polymer brushes. These results are considered as essential for implementation of SIP routines in laser-assisted fabrication schemes targeting micro- and nanofluidic applications.
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Affiliation(s)
- Mareike Mathieu
- CeNIDE - Center for Nanointegration Duisburg-Essen, 47057 Duisburg, Germany
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386
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Geismann C, Tomicki F, Ulbricht M. Block Copolymer Photo-Grafted Poly(Ethylene Terephthalate) Capillary Pore Membranes Distinctly Switchable by Two Different Stimuli. SEP SCI TECHNOL 2009. [DOI: 10.1080/01496390903212755] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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387
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Asatekin A, Mayes AM. Responsive Pore Size Properties of Composite NF Membranes Based on PVDF Graft Copolymers. SEP SCI TECHNOL 2009. [DOI: 10.1080/01496390903212516] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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388
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Ahn HH, Kim KS, Lee JH, Lee JY, Kim BS, Lee IW, Chun HJ, Kim JH, Lee HB, Kim MS. In vivo osteogenic differentiation of human adipose-derived stem cells in an injectable in situ-forming gel scaffold. Tissue Eng Part A 2009; 15:1821-32. [PMID: 19132893 DOI: 10.1089/ten.tea.2008.0386] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The sol-to-gel transition occurring at around body temperature makes the MPEG-PCL diblock copolymer an ideal candidate material for use as an injectable in situ-forming gel containing human adipose tissue-derived stem cells (hADSCs). The sol can be prepared at room temperature, and the gel forms at body temperature. Solutions of the copolymer containing hADSCs and osteogenic factors injected into rats formed gel scaffolds at the injection sites. The gels thus formed showed the interconnective pore structure required to support growth, proliferation, and differentiation of hADSCs. Bromodeoxyuridine-labeled hADSCs were confirmed to be present in gels formed in vivo. Bone formation was observed only in gel implants containing both hADSCs and osteogenic factors. Subcutaneous implantation of the in situ-forming gel scaffold demonstrated that hADSCs embedded in the gel stimulated much lower host tissue responses than did the gel alone, probably because of the unique immunomodulatory properties of hADSCs. In conclusion, our data on hADSCs embedded in an in situ gel scaffold suggest that this formulation may provide numerous benefits as a noninvasive alternative for tissue-engineered bone formation.
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Affiliation(s)
- Hyun Hee Ahn
- Fusion Biotechnology Research Center, Korea Research Institute of Chemical Technology, Daejeon, Korea
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389
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Martinho JMG, Prazeres TJV, Moura L, Farinha JPS. Fluorescence of oligonucleotides adsorbed onto the thermoresponsive poly(isopropyl acrylamide) shell of polymer nanoparticles: Application to bioassays. PURE APPL CHEM 2009. [DOI: 10.1351/pac-con-08-11-11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The fluorescence of a rhodamine X dye covalently linked to the 5' terminus of a 25-mers thymine oligodeoxynucleotide (dT25-ROX), adsorbed on the shell of thermoresponsive core-shell polymer particles, was used to probe the polarity, mobility, and distribution of the oligodeoxynucleotides (ODNs) in the shell. The particles have a glassy core of poly(methyl methacrylate) (PMMA) with a 67-nm radius, and a thermoresponsive shell of poly(N-isopropyl acrylamide) (PNIPAM) whose thickness changes from 42 nm at 11 ºC to 5 nm at 45 ºC. The variation in polarity of the shell with temperature was obtained both from the lifetimes and from the solvatochromic shifts of the dye and shows a sharp transition at the volume phase transition temperature (TVPT) of the PNIPAM shell. Förster resonance energy transfer (FRET) between dT25-ROX and a malachite green (MG)-labeled ODN (dT25-MG) was used to obtain the distribution of the ODNs in the thermoresponsive shell. Our results show that at 23 ºC (belowTVPT) the ODNs are distributed inside the shell, sensing an environment similar to water. At this temperature, the PNIPAM shell is composed of hydrated chains with high mobility, as probed by the fluorescence anisotropy of dT25-ROX. By increasing the temperature aboveTVPT, the shell collapses and the chain mobility drastically slows down owing to the anchoring of the ODN to the dense shell of PNIPAM. Furthermore, FRET shows that the ODNs are absorbed on the 5-nm-thick collapsed shell but extend into the water. The polarity probed by the ROX averages the dyes distributed in the interior of the particle shell and in water, with 60 % of the dyes outside the particle shell (i.e., sensing pure water). Another indication that above theTVPTmost of the ODNs are oriented with the dye toward the water phase is that the mobility of the dye covalently bound to the ODNs is identical in water and in the collapsed particle shell. The hybridization efficiency between an ODN supported in the particle shell (by adsorbing the ODN belowTVPTand subsequently increasing the temperature aboveTVPT) and the complementary ODN in solution is identical to that of hybridization in water. This result opens good perspectives toward the use of the core-shell thermoresponsive nanoparticles as supports in DNA bioassays.
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Affiliation(s)
- José M. G. Martinho
- 1Centro de Química-Física Molecular and IN - Institute of Nanosciences and Nanotechnology, Instituto Superior Técnico, Av. Rovisco Pais, 1, 1040-001 Lisbon, Portugal
| | - Telmo J. V. Prazeres
- 1Centro de Química-Física Molecular and IN - Institute of Nanosciences and Nanotechnology, Instituto Superior Técnico, Av. Rovisco Pais, 1, 1040-001 Lisbon, Portugal
| | - Leila Moura
- 1Centro de Química-Física Molecular and IN - Institute of Nanosciences and Nanotechnology, Instituto Superior Técnico, Av. Rovisco Pais, 1, 1040-001 Lisbon, Portugal
| | - José P. S. Farinha
- 1Centro de Química-Física Molecular and IN - Institute of Nanosciences and Nanotechnology, Instituto Superior Técnico, Av. Rovisco Pais, 1, 1040-001 Lisbon, Portugal
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390
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Zhang R, Liberski A, Sanchez-Martin R, Bradley M. Microarrays of over 2000 hydrogels--identification of substrates for cellular trapping and thermally triggered release. Biomaterials 2009; 30:6193-201. [PMID: 19700191 DOI: 10.1016/j.biomaterials.2009.07.055] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Accepted: 07/24/2009] [Indexed: 10/20/2022]
Abstract
In this paper we describe an approach whereby over 2000 individual polymers were synthesized, in situ, on a microscope slide using inkjet printing. Subsequent biological analysis of the entire library allowed the rapid identification of specific polymers with the desired properties. Herein we demonstrate how this array of new materials could be used for the identification of polymers that allow cellular adherence, proliferation and then mild thermal release, for multiple cell lines, including mouse embryonic stem (mES) cells. The optimal, identified hydrogels were successfully scaled-up and demonstrated excellent cell viability after thermal detachment for all cell lines tested. We believe that this approach offers an avenue to the discovery of a specific thermal release polymer for every cell line.
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Affiliation(s)
- Rong Zhang
- School of Chemistry, Kings Building, West Mains Road, University of Edinburgh, Edinburgh EH9 3JJ, UK
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391
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Siegwart DJ, Srinivasan A, Bencherif SA, Karunanidhi A, Oh JK, Vaidya S, Jin R, Hollinger JO, Matyjaszewski K. Cellular uptake of functional nanogels prepared by inverse miniemulsion ATRP with encapsulated proteins, carbohydrates, and gold nanoparticles. Biomacromolecules 2009; 10:2300-9. [PMID: 19572639 PMCID: PMC5305297 DOI: 10.1021/bm9004904] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Atom transfer radical polymerization (ATRP) was used to produce a versatile drug delivery system capable of encapsulating a range of molecules. Inverse miniemulsion ATRP permitted the synthesis of biocompatible and uniformly cross-linked poly(ethylene oxide)-based nanogels entrapping gold nanoparticles, bovine serum albumin, rhodamine B isothiocyanate-dextran, or fluoresceine isothiocyanate-dextran. These moieties were entrapped to validate several biological outcomes and to model delivery of range of molecules. Cellular uptake of nanogels was verified by transmission electron microscopy, gel electrophoresis, Western blotting, confocal microscopy, and flow cytometry. Fluorescent colocalization of nanogels with a fluorophore-conjugated antibody for clathrin indicated clathrin-mediated endocytosis. Furthermore, internalization of nanogels either with or without GRGDS cell attachment-mediating peptides was quantified using flow cytometry. After 45 min of incubation, the uptake of unmodified FITC-Dx-loaded nanogels was 62%, whereas cellular uptake increased to >95% with the same concentration of GRGDS-modified FITC-Dx nanogels. In addition, a spheroidal coculture of human umbilical vascular endothelial cells (HUVECs) and human mesenchymal stem cells (hMSCs) validated cell endocytosis. Application of ATRP enabled the synthesis of a functionalized drug delivery system with a uniform network that is capable of encapsulating and delivering inorganic, organic, and biological molecules.
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Affiliation(s)
- Daniel J. Siegwart
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213
| | - Abiraman Srinivasan
- Bone Tissue Engineering Center, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213
| | - Sidi A. Bencherif
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213
| | - Anuradha Karunanidhi
- Bone Tissue Engineering Center, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213
| | - Jung Kwon Oh
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213
| | - Swaroopa Vaidya
- Bone Tissue Engineering Center, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213
| | - Rongchao Jin
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213
| | - Jeffrey O. Hollinger
- Bone Tissue Engineering Center, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213
| | - Krzysztof Matyjaszewski
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213
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392
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Zhang Y, Lavin JM, Shimizu KD. Solvent Programmable Polymers Based on Restricted Rotation. J Am Chem Soc 2009; 131:12062-3. [DOI: 10.1021/ja904234w] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yagang Zhang
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
| | - Judith M. Lavin
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
| | - Ken D. Shimizu
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
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393
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Muñoz-Muñoz F, Ruiz JC, Alvarez-Lorenzo C, Concheiro A, Bucio E. Novel interpenetrating smart polymer networks grafted onto polypropylene by gamma radiation for loading and delivery of vancomycin. Eur Polym J 2009. [DOI: 10.1016/j.eurpolymj.2009.04.023] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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394
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Garcia Y, Hemantkumar N, Collighan R, Griffin M, Rodriguez-Cabello JC, Pandit A. In vitro characterization of a collagen scaffold enzymatically cross-linked with a tailored elastin-like polymer. Tissue Eng Part A 2009; 15:887-99. [PMID: 18976154 DOI: 10.1089/ten.tea.2008.0104] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Collagen, the main structural component of the extracellular matrix (ECM), provides tensile stiffness to different structures and organs against rupture. However, collagen tissue-engineered implants are hereto still lacking in mechanical strength. Attempts to create stiffer scaffolds have resulted in increased brittleness of the material, reducing the versatility of the original component. The hypothesis behind this research is that the introduction of an elastic element in the scaffold will enhance the mechanical properties of the collagen-based scaffolds, as elastin does in the ECM to prevent irreversible deformation. In this study, an elastin-like polymer (ELP) designed and synthesized using recombinant DNA methodology is used with the view to providing increased proteolytic resistance and increased functionality to the scaffolds by carrying specific sequences for microbial transglutaminase cross-linking, endothelial cell adhesion, and drug delivery. Evaluation of the effects that cross-linking ELP-collagen has on the physicochemical properties of the scaffold such as porosity, presence of cross-linking, thermal behavior, and mechanical strength demonstrated that the introduction of enzymatically resistant covalent bonds between collagen and ELP increases the mechanical strength of the scaffolds in a dose-dependent manner without significantly affecting the porosity or thermal properties of the original scaffold. Importantly, the scaffolds also showed selective behavior, in a dose (ELP)-dependent manner toward human umbilical vein endothelial cells and smooth muscle cells when compared to fibroblasts.
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Affiliation(s)
- Yolanda Garcia
- Department of Anatomy, National University of Ireland Galway, Galway, Ireland.
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395
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Zenkl G, Klimant I. Fluorescent acrylamide nanoparticles for boronic acid based sugar sensing — from probes to sensors. Mikrochim Acta 2009. [DOI: 10.1007/s00604-009-0172-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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396
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Gao M, Jia X, Kuang G, Li Y, Liang D, Wei Y. Thermo- and pH-Responsive Dendronized Copolymers of Styrene and Maleic Anhydride Pendant with Poly(amidoamine) Dendrons as Side Groups. Macromolecules 2009. [DOI: 10.1021/ma900085j] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Min Gao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 China
| | - Xinru Jia
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 China
| | - Guichao Kuang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 China
| | - Yan Li
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 China
| | - Dehai Liang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of the Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 China
| | - Yen Wei
- Department of Chemistry, Drexel University, Philadelphia, Pennsylvania 19104
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397
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He E, Yue CY, Tam KC. Association behavior of star-shaped pH-responsive block copolymer: four-arm poly(ethylene oxide)-b-poly(methacrylic acid) in aqueous medium. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:4892-4899. [PMID: 19290652 DOI: 10.1021/la804056p] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A four arm pH-responsive poly(ethylene oxide)-b-poly(methacrylic acid) block copolymer was synthesized by atom transfer radical polymerization technique. The conformation transition over the course of neutralization was investigated using a combination of potentiometric and conductometric titrations, dynamic and static light scattering, and transmission electron microscopy. The multiarm block copolymer existed as an extended unimer at high pH due to the negatively charged carboxylate groups and hydrophilic poly(ethylene oxide) segments. The block copolymers self-assembled into core-shell micelles and large spherical aggregates that flocculated at low degree of neutralization (alpha). Such behavior is controlled by the fine balance of electrostatic, hydrophobic, and hydrogen bond interactions. The hydrodynamic radius (R(h)) of the aggregates was approximately 84 nm at alpha of 0.3, and it decreased to 63 and 46 nm at alpha approximately 0.2 and 0.1, respectively, as a result of the reduced electrostatic interaction between ionized carboxylate groups. The thermodynamic parameters obtained from isothermal titration calorimetric technique in different salt concentrations indicated that the energy to extract a proton from a charged polyion was reduced by the addition of salt, which favors the neutralization process.
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Affiliation(s)
- E He
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798
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398
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Klaikherd A, Nagamani C, Thayumanavan S. Multi-stimuli sensitive amphiphilic block copolymer assemblies. J Am Chem Soc 2009; 131:4830-8. [PMID: 19290632 PMCID: PMC2693022 DOI: 10.1021/ja809475a] [Citation(s) in RCA: 471] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Stimuli-responsive polymers are arguably the most widely considered systems for a variety of applications in biomedical arena. We report here a novel triple stimuli sensitive block copolymer assembly that responds to changes in temperature, pH and redox potential. Our block copolymer design constitutes an acid-sensitive THP-protected HEMA as the hydrophobic part and a temperature-sensitive PNIPAM as the hydrophilic part with an intervening disulfide bond. The micellar properties and the release kinetics of the encapsulated guest molecule in response to one stimulus as well as combinations of stimuli have been evaluated. Responsiveness to combination of stimuli not only allows for fine-tuning the guest molecule release kinetics, but also provides the possibility of achieving location-specific delivery.
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Affiliation(s)
- Akamol Klaikherd
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003
| | | | - S. Thayumanavan
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003
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399
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Bivigou-Koumba AM, Kristen J, Laschewsky A, Müller-Buschbaum P, Papadakis CM. Synthesis of Symmetrical Triblock Copolymers of Styrene andN-isopropylacrylamide Using Bifunctional Bis(trithiocarbonate)s as RAFT Agents. MACROMOL CHEM PHYS 2009. [DOI: 10.1002/macp.200800575] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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400
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Chromatography-free recovery of biopharmaceuticals through aqueous two-phase processing. Trends Biotechnol 2009; 27:240-7. [DOI: 10.1016/j.tibtech.2009.01.004] [Citation(s) in RCA: 182] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Revised: 12/15/2008] [Accepted: 01/05/2009] [Indexed: 11/23/2022]
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