1
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Zhang H, Gao Y, Han CC. Understanding the viscosity decline of poly(amic acid) solution from the correlation point of view. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122728] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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2
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Fang JY, Lin YK, Wang SW, Yu YC, Lee RS. Acid and light dual- stimuli-cleavable polymeric micelles. JOURNAL OF POLYMER RESEARCH 2016. [DOI: 10.1007/s10965-016-1166-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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3
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Othman R, Vladisavljević GT, Nagy ZK, Holdich RG. Encapsulation and Controlled Release of Rapamycin from Polycaprolactone Nanoparticles Prepared by Membrane Micromixing Combined with Antisolvent Precipitation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10685-10693. [PMID: 27690454 DOI: 10.1021/acs.langmuir.6b03178] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Rapamycin-loaded polycaprolactone nanoparticles (RAPA-PCL NPs) with a polydispersity index of 0.006-0.073 were fabricated by antisolvent precipitation combined with micromixing using a ringed stainless steel membrane with 10 μm diameter laser-drilled pores. The organic phase composed of 6 g L-1 PCL and 0.6-3.0 g L-1 RAPA in acetone was injected through the membrane at 140 L m-2 h-1 into 0.2 wt % aqueous poly(vinyl alcohol) solution stirred at 1300 rpm, resulting in a Z-average mean of 189-218 nm, a drug encapsulation efficiency of 98.8-98.9%, and a drug loading in the NPs of 9-33%. The encapsulation of RAPA was confirmed by UV-vis spectroscopy, XRD, DSC, and ATR-FTIR. The disappearance of sharp characteristic peaks of crystalline RAPA in the XRD pattern of RAPA-PCL NPs revealed that the drug was molecularly dispersed in the polymer matrix or RAPA and PCL were present in individual amorphous domains. The rate of drug release in pure water was negligible due to low aqueous solubility of RAPA. RAPA-PCL NPs released more than 91% of their drug cargo after 2.5 h in the release medium composed of 0.78-1.5 M of the hydrotropic agent N,N-diethylnicotinamide, 10 vol % ethanol, and 2 vol % Tween 20 in phosphate buffered saline. The dissolution of RAPA was slower when the drug was embedded in the PCL matrix of the NPs than dispersed in the form of pure RAPA nanocrystals.
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Affiliation(s)
- Rahimah Othman
- Department of Chemical Engineering, Loughborough University , Ashby Road, Loughborough, Leicestershire LE11 3TU, U.K
- School of Bioprocess Engineering, Universiti Malaysia Perlis , Kompleks Pusat Pengajian Jejawi 3, 02600 Arau, Perlis, Malaysia
| | - Goran T Vladisavljević
- Department of Chemical Engineering, Loughborough University , Ashby Road, Loughborough, Leicestershire LE11 3TU, U.K
| | - Zoltan K Nagy
- Department of Chemical Engineering, Loughborough University , Ashby Road, Loughborough, Leicestershire LE11 3TU, U.K
- School of Chemical Engineering, Purdue University , West Lafayette, Indiana 47907-2100, United States
| | - R G Holdich
- Department of Chemical Engineering, Loughborough University , Ashby Road, Loughborough, Leicestershire LE11 3TU, U.K
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4
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Cao Z, Zhang G. Dynamics of polyzwitterions in salt-free and salt solutions. Phys Chem Chem Phys 2016; 17:27045-51. [PMID: 26411726 DOI: 10.1039/c5cp04827c] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Dynamics of polyzwitterions remains largely unclear. We have prepared zwitterionic poly[1-(3-sulphopropyl) betaine-2-vinylpyridinium] (PSB) and investigated its dynamics in aqueous solution as a function of added salt (NaCl) concentration (Cs) by dynamic laser light scattering (DLS) and sedimentation velocity (SV) in analytical ultracentrifugation (AUC). A fast and a slow mode can be observed by DLS in a salt-free and low-salt solution, where the latter exhibits a maximum intensity at Cs ∼ 10(-3) M. SV measurements demonstrate that the fast mode corresponds to the diffusion of individual chains and the slow mode arises from the dynamic inhomogeneity due to interchain electrostatic repulsion. As Cs increases, the sedimentation coefficient exhibits a maximum at Cs ∼ 0.1 M whereas the diffusion coefficient has a minimum at Cs ∼ 10(-3) M and a maximum at Cs ∼ 0.1 M. Namely, PSB shows a complex dynamics in a salt-free and low-salt solution and anti-polyelectrolyte behavior in a high-salt solution. Our studies reveal that the dynamics of polyzwitterions is mediated by the long range interchain electrostatic repulsion and short range intrachain attraction, which are determined by effective charges on the chains.
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Affiliation(s)
- Zhonglin Cao
- Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, 230026, China.
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Fang JY, Wang SW, Li YC, Lee RS. Bio-recognizable and photo-cleavable block copolymers based on sugar and poly(4-substituted-ε-caprolactone) bearing a photo-cleavable junction. JOURNAL OF POLYMER RESEARCH 2015. [DOI: 10.1007/s10965-015-0803-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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6
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Lee RS, Wang SW, Li YC, Fang JY. Synthesis and characterization of thermo-responsive and photo-cleavable block copolymers as nanocarriers. RSC Adv 2015. [DOI: 10.1039/c4ra13702g] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In this study, we synthesized thermo-responsive and photo-cleavable amphiphilic block copolymers containing photodegradable linkers as junction points between hydrophilic and hydrophobic chains.
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Affiliation(s)
- Ren-Shen Lee
- Division of Natural Science
- Center of General Education
- Chang Gung University
- Tao-Yuan 333
- Taiwan
| | - Shiu-Wei Wang
- Division of Natural Science
- Center of General Education
- Chang Gung University
- Tao-Yuan 333
- Taiwan
| | - You-Chen Li
- Division of Natural Science
- Center of General Education
- Chang Gung University
- Tao-Yuan 333
- Taiwan
| | - Jia-You Fang
- Graduate Institute of Natural Products
- Chang Gung University
- Tao-Yuan
- Taiwan
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7
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Synthesis and characterization of amphiphilic poly(pseudo-amino acid) polymers containing a nucleobase. Polym J 2014. [DOI: 10.1038/pj.2014.52] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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8
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Zhu H, Huinink HP, Magusin PCMM, Adan OCG, Kopinga K. T₂ distribution spectra obtained by continuum fitting method using a mixed Gaussian and Exponential kernel function. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 235:109-114. [PMID: 23999531 DOI: 10.1016/j.jmr.2013.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 08/02/2013] [Accepted: 08/06/2013] [Indexed: 06/02/2023]
Abstract
Static (1)H NMR Free Induction Decay (FID) signals of polymer solids contain a lot of information about the molecular dynamics. A T2 analysis of the FID has generally been performed in terms of discrete two- or three-component models. However, this requires a priori assumption of the number of proton species before analysis. This paper presents a method of analyzing the FIDs of the polymer solid samples in terms of a continuous T2 distribution. A mixed Gaussian and Exponential kernel function was used to represent the true characteristic of FIDs of the polymer solids. A simple and realistic assumption has been made to reduce the number of degrees of freedom in the continuum fitting and to make the fitting stable. An experimental static (1)H NMR FID of a typical polymer solid sample was analyzed as an example in the end to demonstrate the application of this method.
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Affiliation(s)
- Haijin Zhu
- Department of Applied Physics, Transport in Permeable Media, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands; Duth Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands; Institute for Frontier Materials and the ARC Centre of Excellence for Electromaterials Science, Deakin University, Geelong, VIC 3216, Australia.
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Zhang H, Yuan G, Zhao C, Han CC. Liquid-gel-liquid transition and shear thickening in mixed suspensions of silica colloid and hyperbranched polyethyleneimine. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:12110-12117. [PMID: 24001334 DOI: 10.1021/la402577q] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The rheological property of mixed suspensions of silica colloid and hyperbranched polyethyleneimine (hPEI) was studied as functions of particle volume fraction, ratio of polymer to particle, and pH value. A mechanism of liquid-gel-liquid transition for this mixed system was proposed based on the amount and the conformation of polyelectrolyte bridges which were able to self-arrange with solution environments. The hPEI, which is adsorptive to the surface of silica colloid, can induce bridging or stabilizing effect between particles depending on whether the concentration of hPEI (Cp) is smaller or larger than the equilibrium adsorbed amount (Cp*) for a given volume fraction of particles. In dilute colloid suspensions, the Cp* can be determined by dynamic light scattering as the correlation function returns back to a narrow distributing single relaxation with increasing Cp. In concentrated colloid suspensions, the Cp* can be determined by rheological measurement as gel-liquid transition occurs with increasing Cp. The Cp* is an important concentration ratio of polymer to particle denoting the transition of irreversible and reversible bridging. For mixed suspensions at equilibrium adsorbed state (Cp ≈ Cp*), the adsorption-desorption of polymer bridges on the particles can reversibly take place, and shear thickening is observed under a steady shear flow as a result of rapid extension of bridges when the relaxation time scale of extension is shorter than that of desorption.
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Affiliation(s)
- Huan Zhang
- State Key Laboratory of Polymer Physics and Chemistry, Joint Laboratory of Polymer Science and Materials, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, CAS , Beijing 100190, China
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10
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Muller F, Jean B, Perrin P, Heux L, Boué F, Cousin F. Mechanism of Associations of Neutral Semiflexible Biopolymers in Water: The Xyloglucan Case Reveals Inherent Links. MACROMOL CHEM PHYS 2013. [DOI: 10.1002/macp.201300265] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- François Muller
- NaNo@ECE, ECE-Paris Ecole d'Ingénieurs; 37 Quai de Grenelle F-75015 Paris France
- Laboratoire Léon Brillouin; CEA Saclay 91191 Gif sur Yvette Cedex France
| | - Bruno Jean
- CERMAV, CNRS UPR 5301; BP 53 38041 Grenoble Cedex France
| | - Patrick Perrin
- PPMD/SIMM, CNRS-ESPCI-UPMC UMR 7615; 10 rue Vauquelin 75231 Paris Cedex 05
| | - Laurent Heux
- CERMAV, CNRS UPR 5301; BP 53 38041 Grenoble Cedex France
| | - François Boué
- Laboratoire Léon Brillouin; CEA Saclay 91191 Gif sur Yvette Cedex France
| | - Fabrice Cousin
- Laboratoire Léon Brillouin; CEA Saclay 91191 Gif sur Yvette Cedex France
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11
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Peng KY, Wang SW, Lee RS. Amphiphilic diblock copolymers based on poly(2-ethyl-2-oxazoline) and poly(4-substituted-ε-caprolactone): Synthesis, characterization, and cellular uptake. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/pola.26690] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Kang-Yu Peng
- Department of Natural Science; Center of General Education; Chang Gung University; 259 Wen-Hwa 1st Road Kwei-Shan Tao-Yuan 333 Taiwan
| | - Shiu-Wei Wang
- Department of Natural Science; Center of General Education; Chang Gung University; 259 Wen-Hwa 1st Road Kwei-Shan Tao-Yuan 333 Taiwan
| | - Ren-Shen Lee
- Department of Natural Science; Center of General Education; Chang Gung University; 259 Wen-Hwa 1st Road Kwei-Shan Tao-Yuan 333 Taiwan
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12
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Synthesis of diblock functional poly(ɛ-caprolactone) amphiphilic copolymers grafted with bioactive molecules and characterization of their micelles. Polym J 2013. [DOI: 10.1038/pj.2012.233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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13
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Peng KY, Wang SW, Hua MY, Lee RS. Amphiphilic photocleavable block copolymers based on monomethyl poly(ethylene glycol) and poly(4-substituted-ε-caprolactone): synthesis, characterization, and cellular uptake. RSC Adv 2013. [DOI: 10.1039/c3ra42763c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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14
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15
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Synthesis and characterization of amphiphilic PLA-(PαN3CL-g-PBA) copolymers by ring-opening polymerization and click reaction. POLYMER 2012. [DOI: 10.1016/j.polymer.2012.06.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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16
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Chen WH, Hua MY, Lee RS. Synthesis and characterization of poly(ethylene glycol)-b-poly(ε-caprolactone) copolymers with functional side groups on the polyester block. J Appl Polym Sci 2012. [DOI: 10.1002/app.36225] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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17
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Su RJ, Yang HW, Leu YL, Hua MY, Lee RS. Synthesis and characterization of amphiphilic functional polyesters by ring-opening polymerization and click reaction. REACT FUNCT POLYM 2012. [DOI: 10.1016/j.reactfunctpolym.2011.08.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Acharya DP, Moffat BA, Polyzos A, Waddington L, Coia G, Wright DK, Wang HX, Egan GF, Muir BW, Hartley PG. Cubic mesophase nanoparticles doped with superparamagnetic iron oxide nanoparticles: a new class of MRI contrast agent. RSC Adv 2012. [DOI: 10.1039/c2ra20135f] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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19
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Lee RS, Wu KP. Synthesis and characterization of temperature-sensitive block-graft PNiPAAm-b
-(PαN3
CL-g
-alkyne) copolymers by ring-opening polymerization and click reaction. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/pola.24753] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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20
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Barenholz Y, Bombelli C, Bonicelli MG, Profio PD, Giansanti L, Mancini G, Pascale F. Influence of lipid composition on the thermotropic behavior and size distribution of mixed cationic liposomes. J Colloid Interface Sci 2011; 356:46-53. [DOI: 10.1016/j.jcis.2010.11.062] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 11/18/2010] [Accepted: 11/20/2010] [Indexed: 01/22/2023]
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21
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Lee RS, Chen WH. Organocatalytic synthesis of temperature-sensitive degradable PNiPAAm-b-PTMC block copolymers and micellar characterizations. REACT FUNCT POLYM 2011. [DOI: 10.1016/j.reactfunctpolym.2011.01.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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22
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Bansil R, Cao X, Bhaskar KR, Lamont JT. Gelation and aggregation of mucin in relation to the stomach's protective barrier. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/masy.19961090110] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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23
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Concentrated Gas-in-Liquid Emulsions in Artificial Media. II. Characterization by Photon Correlation Spectroscopy. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/b978-0-444-53798-0.00012-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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24
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Gill R, Mazhar M, Siddiq M. Structural characterization and thermal behaviour of block copolymers of polydimethylsiloxane and polyamide having trichlorogermyl pendant groups. POLYM INT 2010. [DOI: 10.1002/pi.2892] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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25
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Synthesis and characterization of dual stimuli-responsive block copolymers based on poly(N-isopropylacrylamide)-b-poly(pseudoamino acid). POLYMER 2010. [DOI: 10.1016/j.polymer.2010.10.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Lee RS, Chen WH. Synthesis of amphiphilic temperature-sensitive poly(N
-isopropylacrylamide)-block
-poly(tetramethylene carbonate) block copolymers and micellar characterization. POLYM INT 2010. [DOI: 10.1002/pi.2937] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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27
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Lee RS, Huang YT, Chen WH. Synthesis and characterization of temperature-sensitive block copolymers from poly(N-isopropylacrylamide) and 4-methyl-ε-caprolactone or 4-phenyl-ε-caprolactone. J Appl Polym Sci 2010. [DOI: 10.1002/app.32546] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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28
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Ye X, Fei J, Xu K, Bai R. Effect of polystyrene-b-poly(ethylene oxide) on self-assembly of polystyrene-b-poly(N-isopropylacrylamide) in aqueous solution. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/polb.22006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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29
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Viscoelastic solutions formed by worm-like micelles of amine oxide surfactant. J Colloid Interface Sci 2010; 346:100-6. [DOI: 10.1016/j.jcis.2010.02.035] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 02/10/2010] [Accepted: 02/13/2010] [Indexed: 11/18/2022]
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30
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Zhang Y, Li S, Zhang L. Aggregation Behavior of Triple Helical Polysaccharide with Low Molecular Weight in Diluted Aqueous Solution. J Phys Chem B 2010; 114:4945-54. [DOI: 10.1021/jp9100398] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yangyang Zhang
- Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Sheng Li
- Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Lina Zhang
- Department of Chemistry, Wuhan University, Wuhan 430072, China
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31
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Lee RS, Li HR, Chiu FC. Synthesis of amphiphilic pseudopolyamino acid-containing ABC-triblock copolymers and micellar characterizations. J Appl Polym Sci 2010. [DOI: 10.1002/app.31213] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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32
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Lee RS, Huang YT. Tuning the hydrophilic–hydrophobic balance of block-graft copolymers by click strategy: synthesis and characterization of amphiphilic PCL-b-(PαN3CL-g-PBA) copolymers. Polym J 2010. [DOI: 10.1038/pj.2010.6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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33
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Synthesis and characterization of amphiphilic triblock-graft PEG-(b-PαN3CL-g-Alkyne)2 degradable copolymers. JOURNAL OF POLYMER RESEARCH 2009. [DOI: 10.1007/s10965-009-9358-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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34
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Zhou K, Li J, Lu Y, Zhang G, Xie Z, Wu C. Re-examination of Dynamics of Polyeletrolytes in Salt-Free Dilute Solutions by Designing and Using a Novel Neutral−Charged−Neutral Reversible Polymer. Macromolecules 2009. [DOI: 10.1021/ma900541x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kejin Zhou
- Shanghai-Hong Kong Joint Laboratory in Chemical Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, China
| | - Junfang Li
- The Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, China
| | - Yijie Lu
- The Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, China
| | - Guangzhao Zhang
- The Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, China
| | - Zuowei Xie
- Shanghai-Hong Kong Joint Laboratory in Chemical Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, China
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
| | - Chi Wu
- The Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, China
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
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35
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Gèze A, Putaux JL, Choisnard L, Jéhan P, Wouessidjewe D. Long-term shelf stability of amphiphilicβ-cyclodextrin nanosphere suspensions monitored by dynamic light scattering and cryo-transmission electron microscopy. J Microencapsul 2008; 21:607-13. [PMID: 15762318 DOI: 10.1080/02652040400008457] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Amphiphilic beta-cyclodextrins (betaCDa) were synthesized by statistically grafting hexanoyl carbon chains on the secondary hydroxyl functions of the betaCD glucopyranosyl units. The obtained derivative was used to prepare submicronic colloidal nanosphere suspensions using a nano-precipitation method. The fresh suspensions contained particles with a diameter ranging from 60-100 nm. Taking into account that the physical stability of colloidal systems remains one of the major problems which can restrict their use in pharmaceutical particulate carrier formulations, the long-term stability of the aqueous nano-dispersions was investigated. Two complementary characterization methods, namely dynamic light scattering and cryo-transmission electron microscopy, were used to control the size distribution and morphology of the nanospheres during storage. The zeta potential was measured as well. An unexpected good physical stability of the suspensions after 3 year storage at room temperature was observed. This behaviour appears to be related to the small size and structural organization of the nanoparticles. The mean diameters determined from light scattering experiments are consistent with those measured from electron micrographs. The slight difference between the values obtained by both methods is discussed.
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Affiliation(s)
- A Gèze
- UMR CNRS 5063, DPM-Pharmacotechnie, UFR de Pharmacie, Université Joseph Fourier-Grenoble I, 5 avenue de Verdun, F-38243 Meylan Cedex, France
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36
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Vidal RRL, Balaban R, Borsali R. Amphiphilic derivatives of carboxymethylcellulose: Evidence for intra- and intermolecular hydrophobic associations in aqueous solutions. POLYM ENG SCI 2008. [DOI: 10.1002/pen.21180] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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37
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Li J, Li W, Huo H, Luo S, Wu C. Reexamination of the Slow Mode in Semidilute Polymer Solutions: The Effect of Solvent Quality. Macromolecules 2008. [DOI: 10.1021/ma071284b] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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38
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Liang X, Guo C, Ma J, Wang J, Chen S, Liu H. Temperature-Dependent Aggregation and Disaggregation of Poly(ethylene oxide)-Poly(propylene oxide)-Poly(ethylene oxide) Block Copolymer in Aqueous Solution. J Phys Chem B 2007; 111:13217-20. [DOI: 10.1021/jp074990n] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiangfeng Liang
- Laboratory of Separation Science and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100080, China
| | - Chen Guo
- Laboratory of Separation Science and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100080, China
| | - Junhe Ma
- Laboratory of Separation Science and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100080, China
| | - Jing Wang
- Laboratory of Separation Science and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100080, China
| | - Shu Chen
- Laboratory of Separation Science and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100080, China
| | - Huizhou Liu
- Laboratory of Separation Science and Engineering, State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100080, China
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39
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Synthesis and characterization of amphiphilic block copolymers from poly(ethylene glycol)methyl ether and 4-methyl-ɛ-caprolactone or 4-phenyl-ɛ-caprolactone. POLYMER 2007. [DOI: 10.1016/j.polymer.2007.03.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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40
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Chiu FC, Lai CS, Lee RS. Synthesis functional poly(carbonate-b-ester) copolymers and micellar characterizations. J Appl Polym Sci 2007. [DOI: 10.1002/app.26454] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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41
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Lórenz-Fonfría VA, Kandori H. Practical aspects of the maximum entropy inversion of the laplace transform for the quantitative analysis of multi-exponential data. APPLIED SPECTROSCOPY 2007; 61:74-84. [PMID: 17311720 DOI: 10.1366/000370207779701460] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The number, position, area, and width of the bands in a lifetime distribution give the number of exponentials present in time-resolved data and their time constants, amplitudes, and heterogeneities. The maximum entropy inversion of the Laplace transform (MaxEnt-iLT) provides a lifetime distribution from time-resolved data, which is very helpful in the analysis of the relaxation of complex systems. In some applications both positive and negative values for the lifetime distribution amplitudes are physical, but most studies to date have focused on positive-constrained solutions. In this work, we first discuss optimal conditions to obtain a sign-unrestricted maximum entropy lifetime distribution, i.e., the selection of the entropy function and the regularization value. For the selection of the regularization value we compared four methods: the chi2 criterion and Bayesian inference (already used in sign-restricted MaxEnt-iLT), and the L-curve and the generalized cross-validation methods (not yet used in MaxEnt-iLT to our knowledge). Except for the frequently used chi2 criterion, these methods recommended similar regularization values, providing close to optimum solutions. However, even when an optimal entropy function and regularization value are used, a MaxEnt lifetime distribution will contain noise-induced errors, as well as systematic distortions induced by the entropy maximization (regularization-induced errors). We introduce the concept of the apparent resolution function in MaxEnt, which allows both the noise and regularization-induced errors to be estimated. We show the capability of this newly introduced concept in both synthetic and experimental time-resolved Fourier transform infrared (FT-IR) data from the bacteriorhodopsin photocycle.
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Affiliation(s)
- Víctor A Lórenz-Fonfría
- Department of Materials Science and Engineering, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan.
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42
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Lee J, Yang B, Li R, Seery TAP, Papadimitrakopoulos F. Poly(allylamine)-Encapsulated Water-Soluble CdSe Nanocrystals. J Phys Chem B 2006; 111:81-7. [PMID: 17201431 DOI: 10.1021/jp0603841] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Water-soluble CdSe nanocrystal/poly(allylamine) clusters with sizes ranging between 50 and 200 nm were prepared using 3-amino-1-propanol as a compatibilizing agent. Photoluminescence (PL) quantum yields (QY) up to 20% were achieved in water without the need to clad these CdSe nanocrystals (NCs) with higher band gap inorganic layers. The polymer-to-nanocrystal ratio plays an important role in the internal structure and stability of these polymer/NC clusters, as determined by static and dynamic light scattering in conjunction with PL studies. These results were modeled by using an effective-mass approximation and perturbation theory on the change in dielectric constant of the immediate NC environment. The time evolution of the average cluster radius of gyration and hydrodynamic radius revealed that a higher polymer-to-NC ratio leads to increased PL stability and QY. This is a result of a denser cluster configuration, which affords improved NC passivation. Increasing the ionic strength results in greater nanocluster compaction and higher PL QYs. Decreasing the pH value below 12 resulted in dramatic reduction in PL brightness, despite cluster densification, due to partial ionization and dissolution of the amine-based NC surface-capping agents.
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Affiliation(s)
- Jeunghoon Lee
- Nanomaterials Optoelectronics Laboratory, Polymer Program, Institute of Material Science, Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269-3136, USA
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43
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Bello C, Bombelli C, Borocci S, di Profio P, Mancini G. Role of the spacer stereochemistry on the aggregation properties of cationic gemini surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:9333-8. [PMID: 17042550 DOI: 10.1021/la061230f] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The preparation and characterization of three stereoisomeric cationic gemini surfactants, 2,3-dimethoxy-1,4-bis(N-hexadecyl-N,N-dimethylammonio)butane dibromide, are described. The aggregation properties have been studied by fluorescence, electrical conductivity, and quasi-elastic light scattering. A conformational study of the surfactant headgroups has been performed by molecular mechanics calculations to investigate the effect of the stereogenic centers on the surfactant molecular shape and therefore on the different organizations of the monomers in the aggregates. Results show that the stereochemistry of the spacer strongly influences the aggregation behavior of the diasteromeric gemini in water.
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Affiliation(s)
- Cristiano Bello
- CNR, Istituto di Metodologie Chimiche-Sezione Meccanismi di Reazione and Dipartimento di Chimica, Università La Sapienza, P.le Aldo Moro 5, 00185 Roma, Italy
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44
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Zweers MLT, Engbers GHM, Grijpma DW, Feijen J. Release of anti-restenosis drugs from poly(ethylene oxide)-poly(DL-lactic-co-glycolic acid) nanoparticles. J Control Release 2006; 114:317-24. [PMID: 16884807 DOI: 10.1016/j.jconrel.2006.05.021] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 05/18/2006] [Accepted: 05/29/2006] [Indexed: 11/17/2022]
Abstract
Dexamethasone- or rapamycin-loaded nanoparticles based on poly(ethylene oxide) and poly(dl-lactic-co-glycolic acid) block copolymers (PEO-PLGA) were prepared without additional stabilizer using the salting-out method. A fast release of drug in PBS (pH 7.4) at 37 degrees C resulting in 100% release within 5 h was observed for both drugs. The rate of drug release was substantially reduced by treating the particles with gelatin or albumin after drug loading, resulting in a linear drug release in time. It was shown that the rate of drug release is related to the amount of protein associated with the nanoparticles. After gelatin treatment of drug-loaded nanoparticles, sustained release of dexamethasone for 17 days and of rapamycin for 50 days could be achieved.
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Affiliation(s)
- Miechel L T Zweers
- Department of Polymer Chemistry and Biomaterials, Institute for Biomedical Technology, Faculty of Science and Technology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
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45
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Lee RS, Lin ZK, Yang JM, Lin FH. Synthesis and characterization of biodegradable A-B-A triblock copolymers containing poly(ϵ-caprolactone) A blocks and poly(trans
-4-hydroxy-L
-proline) B blocks. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/pola.21524] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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46
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Yuan G, Wang X, Han CC, Wu C. Reexamination of Slow Dynamics in Semidilute Solutions: From Correlated Concentration Fluctuation to Collective Diffusion. Macromolecules 2006. [DOI: 10.1021/ma060060a] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Guangcui Yuan
- State Key Laboratory of Polymer Physics & Chemistry, Joint Laboratory of Polymer Science & Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, People's Republic of China, and Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - Xiaohong Wang
- State Key Laboratory of Polymer Physics & Chemistry, Joint Laboratory of Polymer Science & Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, People's Republic of China, and Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - Charles C. Han
- State Key Laboratory of Polymer Physics & Chemistry, Joint Laboratory of Polymer Science & Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, People's Republic of China, and Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
| | - Chi Wu
- State Key Laboratory of Polymer Physics & Chemistry, Joint Laboratory of Polymer Science & Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, People's Republic of China, and Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
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47
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Yin H, Lei S, Zhu S, Huang J, Ye J. Micelle-to-Vesicle Transition Induced by Organic Additives in Catanionic Surfactant Systems. Chemistry 2006; 12:2825-35. [PMID: 16416498 DOI: 10.1002/chem.200501053] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A micelle-to-vesicle transition (MVT) induced by the addition of a series of apolar hydrocarbons (n-butylbenzene, n-hexane, n-octane, and n-dodecane) to the catanionic surfactant system n-dodecyltriethylammonium bromide/sodium n-dodecylsulfate (DTEAB/SDS) has been investigated for the first time by means of rheology and turbidity measurements, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Interestingly, a MVT can take place within certain micellar regions, which are dependent on the structure and chain length of the hydrocarbon. However, these hydrocarbons are unable to induce a MVT in another catanionic surfactant system, namely, n-dodecyltriethylammonium bromide/sodium n-dodecylsulfonate (DTEAB/SDSO(3)), in which the molecular interactions are weaker than in the DTEAB/SDS system. On the other hand, polar additives, such as n-octanol and n-octylamine, exhibit much higher efficiency and activity in inducing MVT than hydrocarbons in both DETAB/SDS and DTEAB/SDSO(3). Moreover, DLS, TEM, and time-resolved fluorescence quenching (TRFQ) results demonstrate that the ratio of vesicles to micelles in the system can be actively controlled by addition of polar additives. Possible mechanisms for the above phenomena are presented, and the potential application of controllable micelle/vesicle systems in the synthesis of tailored bimodal mesoporous materials is discussed.
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Affiliation(s)
- Haiqing Yin
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
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48
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Maia AMS, Costa M, Borsali R, Garcia RB. Rheological Behavior and Scattering Studies of Acrylamide-Based Copolymer Solutions. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/masy.200551127] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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49
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Lee RS, Li HR, Yang JM, Tsai FY. Synthesis of biodegradable poly(trans-4-hydroxy-N-benzyloxycarbonyl-l-proline)-block-poly(ε-caprolactone) copolymers and micellar characterizations. POLYMER 2005. [DOI: 10.1016/j.polymer.2005.09.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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50
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Bombelli C, Caracciolo G, Di Profio P, Diociaiuti M, Luciani P, Mancini G, Mazzuca C, Marra M, Molinari A, Monti D, Toccacieli L, Venanzi M. Inclusion of a photosensitizer in liposomes formed by DMPC/gemini surfactant: correlation between physicochemical and biological features of the complexes. J Med Chem 2005; 48:4882-91. [PMID: 16033268 DOI: 10.1021/jm050182d] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mixed cationic liposomes composed by different ratios of dimyristoyl-sn-glycero-phosphatidylcoline (DMPC) and a cationic gemini surfactant have been studied by various physicochemical tools as vehicles for m-tetrahydroxyphenylchlorin (m-THPC), a photosensitizer used in photodynamic therapy. Entrapment and location of m-THPC within the lipid double layer have been evaluated by different techniques and the new formulations have been tested on a stabilized cell line from a human colon tumor, COLO206. A correlation between the physicochemical features of formulations and their efficiency as photosensitizers vector was found.
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Affiliation(s)
- Cecilia Bombelli
- CNR Istituto di Metodologie Chimiche-Sezione Meccanismi di Reazione, and Dipartimento di Chimica, Università degli Studi di Roma "La Sapienza", P.le A. Moro 5, I-00185 Roma, Italy
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