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Ciccia NR, Shi JX, Pal S, Hua M, Malollari KG, Lizandara-Pueyo C, Risto E, Ernst M, Helms BA, Messersmith PB, Hartwig JF. Diverse functional polyethylenes by catalytic amination. Science 2023; 381:1433-1440. [PMID: 37769088 DOI: 10.1126/science.adg6093] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 08/28/2023] [Indexed: 09/30/2023]
Abstract
Functional polyethylenes possess valuable bulk and surface properties, but the limits of current synthetic methods narrow the range of accessible materials and prevent many envisioned applications. Instead, these materials are often used in composite films that are challenging to recycle. We report a Cu-catalyzed amination of polyethylenes to form mono- and bifunctional materials containing a series of polar groups and substituents. Designed catalysts with hydrophobic moieties enable the amination of linear and branched polyethylenes without chain scission or cross-linking, leading to polyethylenes with otherwise inaccessible combinations of functional groups and architectures. The resulting materials possess tunable bulk and surface properties, including toughness, adhesion to metal, paintability, and water solubility, which could unlock applications for functional polyethylenes and reduce the need for complex composites.
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Affiliation(s)
- Nicodemo R Ciccia
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jake X Shi
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Subhajit Pal
- Departments of Materials Science and Engineering and Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Mutian Hua
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Katerina G Malollari
- Departments of Materials Science and Engineering and Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | | | - Eugen Risto
- BASF SE, 67056 Ludwigshafen am Rhein, Germany
| | | | - Brett A Helms
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Phillip B Messersmith
- Departments of Materials Science and Engineering and Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - John F Hartwig
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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2
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Ahmad I, Khan MFA, Rahdar A, Hussain S, Tareen FK, Salim MW, Ajalli N, Amirzada MI, Khan A. Design and Evaluation of pH Sensitive PEG-Protamine Nanocomplex of Doxorubicin for Treatment of Breast Cancer. Polymers (Basel) 2022; 14:polym14122403. [PMID: 35745979 PMCID: PMC9229304 DOI: 10.3390/polym14122403] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 05/29/2022] [Accepted: 06/10/2022] [Indexed: 02/06/2023] Open
Abstract
Cancer is the most common cause of mortality worldwide. There is dire need of modern strategies—such as surface modification of nanocarriers—to combat this global illness. Incorporation of active targeting ligands has arisen as a novel platform for specific tumor targeting. The aim of the current study was to formulate PEG-protamine complex (PPC) of doxorubicin (DOX) for treatment of breast cancer (BC). DOX coupling with PEG can enhance cell-penetrating ability: combating resistance in MDA-MB 231 breast cancer cells. Ionic gelation method was adopted to fabricate a pH sensitive nanocomplex. The optimized nanoformulation was characterized for its particle diameter, zeta potential, surface morphology, entrapment efficiency, crystallinity, and molecular interaction. In vitro assay was executed to gauge the release potential of nanoformulation. The mean particle size, zeta potential, and polydispersity index (PDI) of the optimized nanoparticles were observed to be 212 nm, 15.2 mV, and 0.264, respectively. Crystallinity studies and Fourier transform infrared (FTIR) analysis revealed no molecular interaction and confirmed the amorphous nature of drug within nanoparticles. The in vitro release data indicate sustained drug release at pH 4.8, which is intracellular pH of breast cancer cells, as compared to the drug solution. PPC loaded with doxorubicin can be utilized as an alternative and effective approach for specific targeting of breast cancer.
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Affiliation(s)
- Ikhlaque Ahmad
- Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; (I.A.); (M.F.A.K.); (S.H.); (M.W.S.)
| | - Muhammad Farhan Ali Khan
- Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; (I.A.); (M.F.A.K.); (S.H.); (M.W.S.)
| | - Abbas Rahdar
- Department of Physics, Faculty of Science, University of Zabol, Zabol 98613-35856, Iran
- Correspondence: (A.R.); (M.I.A.); (A.K.)
| | - Saddam Hussain
- Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; (I.A.); (M.F.A.K.); (S.H.); (M.W.S.)
| | - Fahad Khan Tareen
- Faculty of Pharmacy, Capital University of Science and Technology, Islamabad Expressway, Kahuta Road, Zone-V, Islamabad 45320, Pakistan;
| | - Muhammad Waqas Salim
- Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; (I.A.); (M.F.A.K.); (S.H.); (M.W.S.)
| | - Narges Ajalli
- Department of Chemical Engineering, Faculty of Engineering, University of Tehran, Tehran 98613-35859, Iran;
| | - Muhammad Imran Amirzada
- Department of Pharmacy, COMSATS University Islamabad, Abbottabad Campus, Abbottabad 22010, Pakistan
- Correspondence: (A.R.); (M.I.A.); (A.K.)
| | - Ahmad Khan
- Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; (I.A.); (M.F.A.K.); (S.H.); (M.W.S.)
- Correspondence: (A.R.); (M.I.A.); (A.K.)
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3
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Wilson J, Ristic M, Kirkwood J, Hargreaves D, Newman J. Predicting the Effect of Chemical Factors on the pH of Crystallization Trials. iScience 2020; 23:101219. [PMID: 32540772 PMCID: PMC7298652 DOI: 10.1016/j.isci.2020.101219] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 05/14/2020] [Accepted: 05/27/2020] [Indexed: 01/13/2023] Open
Abstract
In macromolecular crystallization, success is often dependent on the pH of the experiment. However, little is known about the pH of reagents used, and it is generally assumed that the pH of the experiment will closely match that of any buffering chemical in the solution. We use a large dataset of experimentally measured solution pH values to show that this assumption can be very wrong and generate a model that can be used to successfully predict the overall solution pH of a crystallization experiment. Furthermore, we investigate the time dependence of the pH of some polyethylene glycol polymers widely used in protein crystallization under different storage conditions. The overall pH of crystallization solutions can be modeled The model was trained and tested on a set of more than 40,000 measured pH values A pH value can be assigned to a non-buffered crystallization cocktail A 12-month stability study of polyethylene glycol suggests ways to store PEGs
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Affiliation(s)
- Julie Wilson
- Department of Mathematics, University of York, York, UK.
| | - Marko Ristic
- Collaborative Crystallisation Centre, CSIRO, Parkville, VIC, Australia
| | | | - David Hargreaves
- AstraZeneca, Darwin Building, Cambridge Science Park, Cambridge, UK
| | - Janet Newman
- Collaborative Crystallisation Centre, CSIRO, Parkville, VIC, Australia.
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4
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Kang RH, Kwon JY, Kim Y, Lee SM. Cisplatin-Mediated Formation of Polyampholytic Chitosan Nanoparticles with Attenuated Viscosity and pH-Sensitive Drug Release. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:9091-9099. [PMID: 28853583 DOI: 10.1021/acs.langmuir.7b02043] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Chitosan is a biocompatible natural polysaccharide, which has been employed as a polymeric scaffold for versatile, systemic delivery platforms and for locally injectable gels with temperature-sensitive viscosity modulation. Despite the extensive investigation on the chemical modification strategies, however, most of the chitosan-based delivery platforms have been focused on the encapsulation of hydrophobic drugs, which can be simply adsorbed on the chitosan scaffolds by hydrophobic interaction via the postparticle-formation drug-loading process. Herein, we present the facile formation of a cisplatin-coordinated chitosan nanoplatform by exploiting the divalent metal (PtII)-mediated conformational changes of chitosan chains, which allows for the simultaneous drug-loading and nanoparticle formation. To this end, the native chitosan has been chemically modified with short polyethylene glycol and malonic acid as a colloidal stabilizer and a bidentate chelating ligand for PtII coordination, respectively. The resulting PtII-modified polyampholytic chitosan (PtII-MPC) has been self-associated in aqueous media by hydrophobic segregation into a compact nanostructure, which exhibited an attenuated viscosity and pH-sensitive release of PtII compounds. Once the cationic drug molecules have been released under mild acidic conditions, the neutralized PtII-free MPC undergoes interchain flocculation near the isoelectric point because of the polyampholytic property, possibly allowing for the facilitated endosomal escape during the cellular endocytosis by the known membrane perturbation property of chitosan.
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Affiliation(s)
- Ra-Hye Kang
- Department of Chemistry, The Catholic University of Korea , Wonmi-gu, Bucheon-si, Gyeonggi-do 14662, Korea
| | - Ji-Yeong Kwon
- Department of Chemistry, The Catholic University of Korea , Wonmi-gu, Bucheon-si, Gyeonggi-do 14662, Korea
| | - Yeojin Kim
- Department of Chemistry, The Catholic University of Korea , Wonmi-gu, Bucheon-si, Gyeonggi-do 14662, Korea
| | - Sang-Min Lee
- Department of Chemistry, The Catholic University of Korea , Wonmi-gu, Bucheon-si, Gyeonggi-do 14662, Korea
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5
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Liu D, Bielawski CW. Synthesis of Degradable Poly[(Ethylene Glycol)-co-(Glycolic Acid)] via the Post-Polymerization Oxyfunctionalization of Poly(Ethylene Glycol). Macromol Rapid Commun 2016; 37:1587-1592. [PMID: 27461401 DOI: 10.1002/marc.201600336] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Revised: 07/02/2016] [Indexed: 01/28/2023]
Abstract
To enhance the limited degradability of poly(ethylene glycol) (PEG), a straightforward method of synthesizing poly[(ethylene glycol)-co-(glycolic acid)] (P(EG-co-GA)) via a ruthenium-catalyzed, post-polymerization oxyfunctionalization of various PEGs is developed. Using this method, a set of copolymers with GA compositions of up to 8 mol% are prepared with minimal reduction in molecular weight (<10%) when compared to their commercially available starting materials. The P(EG-co-GA) copolymers are shown to undergo hydrolysis under mild conditions.
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Affiliation(s)
- Di Liu
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Christopher W Bielawski
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea. .,Department of Chemistry and Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
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6
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Kachbi-Khelfallah S, Monteil M, Cortes-Clerget M, Migianu-Griffoni E, Pirat JL, Gager O, Deschamp J, Lecouvey M. Towards potential nanoparticle contrast agents: Synthesis of new functionalized PEG bisphosphonates. Beilstein J Org Chem 2016; 12:1366-71. [PMID: 27559386 PMCID: PMC4979661 DOI: 10.3762/bjoc.12.130] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 06/14/2016] [Indexed: 12/21/2022] Open
Abstract
The use of nanotechnologies for biomedical applications took a real development during these last years. To allow an effective targeting for biomedical imaging applications, the adsorption of plasmatic proteins on the surface of nanoparticles must be prevented to reduce the hepatic capture and increase the plasmatic time life. In biologic media, metal oxide nanoparticles are not stable and must be coated by biocompatible organic ligands. The use of phosphonate ligands to modify the nanoparticle surface drew a lot of attention in the last years for the design of highly functional hybrid materials. Here, we report a methodology to synthesize bisphosphonates having functionalized PEG side chains with different lengths. The key step is a procedure developed in our laboratory to introduce the bisphosphonate from acyl chloride and tris(trimethylsilyl)phosphite in one step.
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Affiliation(s)
- Souad Kachbi-Khelfallah
- Université Paris 13, Sorbonne Paris Cité, Laboratoire de Chimie, Structure, Propriétés de Biomatériaux et d'Agents Thérapeutiques (CSPBAT), CNRS UMR 7244, F-93017 Bobigny, France
| | - Maelle Monteil
- Université Paris 13, Sorbonne Paris Cité, Laboratoire de Chimie, Structure, Propriétés de Biomatériaux et d'Agents Thérapeutiques (CSPBAT), CNRS UMR 7244, F-93017 Bobigny, France
| | - Margery Cortes-Clerget
- Université Paris 13, Sorbonne Paris Cité, Laboratoire de Chimie, Structure, Propriétés de Biomatériaux et d'Agents Thérapeutiques (CSPBAT), CNRS UMR 7244, F-93017 Bobigny, France
| | - Evelyne Migianu-Griffoni
- Université Paris 13, Sorbonne Paris Cité, Laboratoire de Chimie, Structure, Propriétés de Biomatériaux et d'Agents Thérapeutiques (CSPBAT), CNRS UMR 7244, F-93017 Bobigny, France
| | - Jean-Luc Pirat
- ICG Montpellier-UMR 5253, Equipe AM2N, ENSCM, 8, Rue de l'Ecole Normale, F-34296 Montpellier Cedex 5, France
| | - Olivier Gager
- Université Paris 13, Sorbonne Paris Cité, Laboratoire de Chimie, Structure, Propriétés de Biomatériaux et d'Agents Thérapeutiques (CSPBAT), CNRS UMR 7244, F-93017 Bobigny, France
| | - Julia Deschamp
- Université Paris 13, Sorbonne Paris Cité, Laboratoire de Chimie, Structure, Propriétés de Biomatériaux et d'Agents Thérapeutiques (CSPBAT), CNRS UMR 7244, F-93017 Bobigny, France
| | - Marc Lecouvey
- Université Paris 13, Sorbonne Paris Cité, Laboratoire de Chimie, Structure, Propriétés de Biomatériaux et d'Agents Thérapeutiques (CSPBAT), CNRS UMR 7244, F-93017 Bobigny, France
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7
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Guastavino JF, Vaillard VA, Cristaldi MD, Rossini L, Vaillard SE. Simple Synthesis of Aldehyde and Carboxylic Acid Terminated Methoxypoly(ethylene glycol). MACROMOL CHEM PHYS 2016. [DOI: 10.1002/macp.201600094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Javier F. Guastavino
- Instituto de Desarrollo Tecnológico para la Industria Química (INTEC, CCT-Santa Fe, CONICET-UNL); Colectora Ruta Nac. 168, Km 472 Santa Fe 3000 Argentina
| | - Victoria A. Vaillard
- Instituto de Desarrollo Tecnológico para la Industria Química (INTEC, CCT-Santa Fe, CONICET-UNL); Colectora Ruta Nac. 168, Km 472 Santa Fe 3000 Argentina
| | | | - Lorena Rossini
- Laboratorio Horian I+D; Colectora Ruta Nac. 168, Km 472 Santa Fe 3000 Argentina
| | - Santiago E. Vaillard
- Instituto de Desarrollo Tecnológico para la Industria Química (INTEC, CCT-Santa Fe, CONICET-UNL); Colectora Ruta Nac. 168, Km 472 Santa Fe 3000 Argentina
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8
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Catauro M, Bollino F, Nocera P, Piccolella S, Pacifico S. Entrapping quercetin in silica/polyethylene glycol hybrid materials: Chemical characterization and biocompatibility. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 68:205-212. [PMID: 27524014 DOI: 10.1016/j.msec.2016.05.082] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/09/2016] [Accepted: 05/18/2016] [Indexed: 11/26/2022]
Abstract
Sol-gel synthesis was exploited to entrap quercetin, a natural occurring antioxidant polyphenol, in silica-based hybrid materials, which differed in their polyethylene glycol (PEG) content (6, 12, 24 and 50wt%). The materials obtained, whose nano-composite nature was ascertained by Scanning Electron Microscopy (SEM), were chemically characterized by Fourier Transform InfraRed (FT-IR) and UV-Vis spectroscopies. The results prove that a reaction between the polymer and the drug occurred. Bioactivity tests showed their ability to induce hydroxyapatite nucleation on the sample surfaces. The direct contact method was applied to screen the cytotoxicity of the synthetized materials towards fibroblast NIH 3T3 cells, commonly used for in vitro biocompatibility studies, and three nervous system cell lines (neuroblastoma SH-SY5Y, glioma U251, and pheochromocytoma PC12 cell lines), adopted as models in oxidative stress related studies. Using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay NIH 3T3 proliferation was assessed and the morphology was not compromised by direct exposure to the materials. Analogously, PC-12, and U-251 cell lines were not affected by new materials. SH-SY5Y appeared to be the most sensitive cell line with cytotoxic effects of 20-35%.
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Affiliation(s)
- Michelina Catauro
- Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa, Italy.
| | - Flavia Bollino
- Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa, Italy
| | - Paola Nocera
- Department Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy
| | - Simona Piccolella
- Department Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy
| | - Severina Pacifico
- Department Environmental, Biological and Pharmaceutical Sciences and Technologies, Second University of Naples, Via Vivaldi 43, 81100 Caserta, Italy
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9
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Kamalov MI, Lavrov IA, Yergeshov AA, Siraeva ZY, Baltin ME, Rizvanov AA, Kuznetcova SV, Petrova NV, Savina IN, Abdullin TI. Non-invasive topical drug delivery to spinal cord with carboxyl-modified trifunctional copolymer of ethylene oxide and propylene oxide. Colloids Surf B Biointerfaces 2016; 140:196-203. [PMID: 26764102 DOI: 10.1016/j.colsurfb.2015.12.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 11/20/2015] [Accepted: 12/18/2015] [Indexed: 01/14/2023]
Abstract
In this study the effect of oxidative modification on micellar and drug delivery properties of copolymers of ethylene oxide (EO) and propylene oxide (PO) was investigated. Carboxylated trifunctional copolymers were synthesized in the reaction with chromium(VI) oxide. We found that carboxylation significantly improved the uniformity and stability of polymeric micelles by inhibiting the microphase transition. The cytotoxicity of copolymers was studied in relation to their aggregative state on two cell types (cancer line vs. primary fibroblasts). The accumulation of rhodamine 123 in neuroblastoma SH-SY5Y cells was dramatically increased in the presence of the oxidized block copolymer with the number of PO and EO units of 83.5 and 24.2, respectively. The copolymer was also tested as an enhancer for topical drug delivery to the spinal cord when applied subdurally. The oxidized copolymer facilitated the penetration of rhodamine 123 across spinal cord tissues and increased its intraspinal accumulation. These results show the potential of using oxidized EO/PO based polymers for non-invasive delivery of protective drugs after spinal cord injury.
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Affiliation(s)
- Marat I Kamalov
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya St., 420008 Kazan, Russia
| | - Igor A Lavrov
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya St., 420008 Kazan, Russia.
| | - Abdulla A Yergeshov
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya St., 420008 Kazan, Russia
| | - Zulfira Y Siraeva
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya St., 420008 Kazan, Russia
| | - Maxim E Baltin
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya St., 420008 Kazan, Russia
| | - Albert A Rizvanov
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya St., 420008 Kazan, Russia
| | | | - Natalia V Petrova
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya St., 420008 Kazan, Russia
| | - Irina N Savina
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building, Lewes Road, Brighton BN2 4GJ, UK
| | - Timur I Abdullin
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya St., 420008 Kazan, Russia.
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10
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Zhang L, Lin Y, Zhang Y, Chen R, Zhu Z, Wu W, Jiang X. Fluorescent Micelles Based on Star Amphiphilic Copolymer with a Porphyrin Core for Bioimaging and Drug Delivery. Macromol Biosci 2011; 12:83-92. [DOI: 10.1002/mabi.201100197] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2011] [Indexed: 02/02/2023]
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11
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Janaratne TK, Okach L, Brock A, Lesley SA. Solubilization of native integral membrane proteins in aqueous buffer by noncovalent chelation with monomethoxy poly(ethylene glycol) (mPEG) polymers. Bioconjug Chem 2011; 22:1513-8. [PMID: 21740061 DOI: 10.1021/bc200019x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Highly hydrophobic integral membrane proteins (IMPs)are typically purified in excess detergent media, often resulting in rapid inactivation and denaturation of the protein. One promising approach to solve this problem is to couple hydrophilic polymers, such as monomethoxypolyethylene glycol (mPEG) to IMPs under mild conditions in place of detergents. However, the broad application of this approach is hampered by poor reaction efficiencies, low tolerance of detergent stabilized membrane proteins to reaction conditions, and a lack of proper site-specific reversible approaches. Here, we have developed a straightforward, efficient, and mild approach to site-specific noncovalent binding of long-chain polymers to recombinant IMPs. This method uses the hexa-histidine tag (His-Tag) often used for purification of recombinant proteins as an attachment site for mPEGs. Solubility studies performed using five different IMPs confirmed that all tested mPEG-bound IMPs were completely soluble and stable in detergent free aqueous buffer compared to their precipitated native proteins under the identical circumstances. Activity assays and circular dichroism (CD) spectroscopy confirmed the structural integrity of modified IMPs.
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Affiliation(s)
- Thamara K Janaratne
- The Joint Center for Structural Genomics and The Scripps Research Institute, Department of Molecular Biology, La Jolla, California 92037, United States
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12
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Detecting extracellular carbonic anhydrase activity using membrane inlet mass spectrometry. Anal Biochem 2010; 403:74-8. [PMID: 20417171 DOI: 10.1016/j.ab.2010.04.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2010] [Revised: 04/03/2010] [Accepted: 04/17/2010] [Indexed: 11/22/2022]
Abstract
Current research into the function of carbonic anhydrases (CAs) in cell physiology emphasizes the role of membrane-bound CAs such as CA IX, which has been identified in malignant tumors and is associated with extracellular acidification as a response to hypoxia. Here we present a mass spectrometric method to determine the extent to which total CA activity is due to extracellular CA in whole cell preparations. The method is based on the biphasic rate of depletion of (18)O from CO(2) measured by membrane inlet mass spectrometry. The slopes of the biphasic depletion are a sensitive measure of the presence of CA inside and outside of the cells. This property is demonstrated here using suspensions of human red cells in which external CA was added to the suspending solution. It is also applied to breast and prostate cancer cells, both of which express exofacial CA IX. Inhibition of external CA is achieved by the use of a membrane impermeant inhibitor that was synthesized for this purpose, p-aminomethylbenzenesulfonamide attached to a polyethylene glycol polymer.
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13
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König HM, Kilbinger AFM. An Improved Rapid Synthesis of Oligo(p
-benzamide) Block Copolymers. Macromol Rapid Commun 2008. [DOI: 10.1002/marc.200800414] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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14
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Wang T, Xu J, Qiu F, Zhang H, Yang Y. Force spectrum of a few chains grafted on an AFM tip: Comparison of the experiment to a self-consistent mean field theory simulation. POLYMER 2007. [DOI: 10.1016/j.polymer.2007.07.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Fishman A, Acton A, Lee‐Ruff E. Efficient Preparation of Hybrid Linear‐Branched Esters of PEG‐PEE Derivatives. SYNTHETIC COMMUN 2006. [DOI: 10.1080/00397910500377289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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16
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Sedlák M. Recent Advances in Chemistry and Applications of Substituted Poly(ethylene glycol)s. ACTA ACUST UNITED AC 2005. [DOI: 10.1135/cccc20050269] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Poly(ethylene glycol)s are well defined and easily accessible macromolecules with suitable properties for applications in chemistry, biotechnologies and medicine. The terminal hydroxy groups of poly(ethylene glycol)s can easily be converted into reactive functional groups by a number of routine reactions of organic chemistry. The chemical reagents or catalysts anchored to poly(ethylene glycol) chains were used in a number of syntheses including the enantioselective ones. Poly(ethylene glycol)s serve as carriers in combinatorial syntheses in the liquid phase. Coupling of poly(ethylene glycol)s with other polymers was used to prepare series of block copolymers having numerous applications. From the point of view of medical applications it is significant that substituted poly(ethylene glycol)s are non-toxic and resistant to recognition by the immunity system. That is why they are often used as carriers of many low-molecular-weight as well as high-molecular-weight medical drugs (drug delivery systems). In the conjugates with drugs their biological activity increases and their toxicity decreases. A review with 41 references.
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