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Krishnan J, Poomalai P, Ravichandran A, Reddy A, Sureshkumar R. A Concise Review on Effect of PEGylation on the Properties of Lipid-Based Nanoparticles. Assay Drug Dev Technol 2024; 22:246-264. [PMID: 38828531 DOI: 10.1089/adt.2024.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024] Open
Abstract
Nanoparticle-based drug delivery systems have emerged as promising platforms for enhancing therapeutic efficacy while minimizing off-target effects. Among various strategies employed to optimize these systems, polyethylene glycol (PEG) modification, known as PEGylation-the covalent attachment of PEG to nanoparticles, has gained considerable attention for its ability to impart stealth properties to nanoparticles while also extending circulation time and improving biocompatibility. PEGylation extends to different drug delivery systems, in specific, nanoparticles for targeting cancer cells, where the concentration of drug in the cancer cells is improved by virtue of PEGylation. The primary challenge linked to PEGylation lies in its confirmation. Numerous research findings provide comprehensive insights into selecting PEG for various PEGylation methods. In this review, we have endeavored to consolidate the outcomes concerning the choice of PEG and diverse PEGylation techniques.
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Affiliation(s)
- Janesha Krishnan
- Department of Pharmaceutics, Center for Nano Engineering Science & Technology (C-NEST), JSS Academy of Higher Education and Research, JSS College of Pharmacy, Ooty, India
| | - Praveena Poomalai
- Department of Pharmaceutics, Center for Nano Engineering Science & Technology (C-NEST), JSS Academy of Higher Education and Research, JSS College of Pharmacy, Ooty, India
| | - Ashwin Ravichandran
- Department of Pharmaceutics, Center for Nano Engineering Science & Technology (C-NEST), JSS Academy of Higher Education and Research, JSS College of Pharmacy, Ooty, India
| | - Aishwarya Reddy
- Department of Pharmaceutics, Center for Nano Engineering Science & Technology (C-NEST), JSS Academy of Higher Education and Research, JSS College of Pharmacy, Ooty, India
| | - Raman Sureshkumar
- Department of Pharmaceutics, Center for Nano Engineering Science & Technology (C-NEST), JSS Academy of Higher Education and Research, JSS College of Pharmacy, Ooty, India
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Bento C, Katz M, Santos MMM, Afonso CAM. Striving for Uniformity: A Review on Advances and Challenges To Achieve Uniform Polyethylene Glycol. Org Process Res Dev 2024; 28:860-890. [PMID: 38660381 PMCID: PMC11036406 DOI: 10.1021/acs.oprd.3c00428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 03/01/2024] [Accepted: 03/08/2024] [Indexed: 04/26/2024]
Abstract
Poly(ethylene glycol) (PEG) is the polymer of choice in drug delivery systems due to its biocompatibility and hydrophilicity. For over 20 years, this polymer has been widely used in the drug delivery of small drugs, proteins, oligonucleotides, and liposomes, improving the stability and pharmacokinetics of many drugs. However, despite the extensive clinical experience with PEG, concerns have emerged related to its use. These include hypersensitivity, purity, and nonbiodegradability. Moreover, conventional PEG is a mixture of polymers that can complicate drug synthesis and purification leading to unwanted immunogenic reactions. Studies have shown that uniform PEGylated drugs may be more effective than conventional PEGylated drugs as they can overcome issues related to molecular heterogeneity and immunogenicity. This has led to significant research efforts to develop synthetic procedures to produce uniform PEGs (monodisperse PEGs). As a result, iterative step-by-step controlled synthesis methods have been created over time and have shown promising results. Nonetheless, these procedures have presented numerous challenges due to their iterative nature and the requirement for multiple purification steps, resulting in increased costs and time consumption. Despite these challenges, the synthetic procedures went through several improvements. This review summarizes and discusses recent advances in the synthesis of uniform PEGs and its derivatives with a focus on overall yields, scalability, and purity of the polymers. Additionally, the available characterization methods for assessing polymer monodispersity are discussed as well as uniform PEG applications, side effects, and possible alternative polymers that can overcome the drawbacks.
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Affiliation(s)
- Cláudia Bento
- Hovione
Farmaciência S.A., Estrada do Paço do Lumiar, Campus do Lumiar, Edifício
R, 1649-038 Lisboa, Portugal
- Research
Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003 Lisboa, Portugal
| | - Marianna Katz
- Hovione
Farmaciência S.A., Estrada do Paço do Lumiar, Campus do Lumiar, Edifício
R, 1649-038 Lisboa, Portugal
| | - Maria M. M. Santos
- Research
Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003 Lisboa, Portugal
| | - Carlos A. M. Afonso
- Research
Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003 Lisboa, Portugal
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3
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Li C, Li T, Tian X, An W, Wang Z, Han B, Tao H, Wang J, Wang X. Research progress on the PEGylation of therapeutic proteins and peptides (TPPs). Front Pharmacol 2024; 15:1353626. [PMID: 38523641 PMCID: PMC10960368 DOI: 10.3389/fphar.2024.1353626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 02/22/2024] [Indexed: 03/26/2024] Open
Abstract
With the rapid advancement of genetic and protein engineering, proteins and peptides have emerged as promising drug molecules for therapeutic applications. Consequently, there has been a growing interest in the field of chemical modification technology to address challenges associated with their clinical use, including rapid clearance from circulation, immunogenicity, physical and chemical instabilities (such as aggregation, adsorption, deamination, clipping, oxidation, etc.), and enzymatic degradation. Polyethylene glycol (PEG) modification offers an effective solution to these issues due to its favorable properties. This review presents recent progress in the development and application of PEGylated therapeutic proteins and peptides (TPPs). For this purpose, firstly, the physical and chemical properties as well as classification of PEG and its derivatives are described. Subsequently, a detailed summary is provided on the main sites of PEGylated TPPs and the factors that influence their PEGylation. Furthermore, notable instances of PEG-modified TPPs (including antimicrobial peptides (AMPs), interferon, asparaginase and antibodies) are highlighted. Finally, we propose the chemical modification of TPPs with PEG, followed by an analysis of the current development status and future prospects of PEGylated TPPs. This work provides a comprehensive literature review in this promising field while facilitating researchers in utilizing PEG polymers to modify TPPs for disease treatment.
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Affiliation(s)
- Chunxiao Li
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Ting Li
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Biotechnology, Beijing, China
| | - Xinya Tian
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Wei An
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Zhenlong Wang
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Bing Han
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Hui Tao
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Jinquan Wang
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Xiumin Wang
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, Beijing, China
- Key Laboratory of Feed Biotechnology, Ministry of Agriculture and Rural Affairs, Beijing, China
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Liu L, Zhao J, Zhang G. Chemoselectivity Streamlines the Approach to Linear and Y-Shaped Thiol-Polyethers Starting from Thiocarboxylic Acids. ACS Macro Lett 2023; 12:1185-1192. [PMID: 37552569 DOI: 10.1021/acsmacrolett.3c00407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
Thiol-functionalized polyethers, especially poly(ethylene oxide) (PEO), have extensive applications in biomedicine and materials sciences. Herein, we report a simple one-pot synthesis of α-thiol-ω-hydroxyl polyethers through ring-opening polymerization (ROP) of epoxides using thiocarboxylic acid initiators followed by in situ aminolysis. The efficient and chemoselective metal-free Lewis pair catalyst avoids transthioesterification thus achieving well-controlled molar mass, low dispersity, and high end-group fidelity. Kinetic and calculation results demonstrated a fast-initiation mode of the ROP for the strong nucleophilicity of the thiocarboxylate anion and its weak interaction with Lewis acid. The method is expanded for α-thiol-ω-dihydroxyl (Y-shaped) PEO by virtue of the stability of thioester during the ROP. The thiol functionality in linear/Y-shaped PEO is further corroborated by the intensified interaction with gold surface and the resultant protein resistance behavior.
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Affiliation(s)
- Lijun Liu
- Faculty of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, People's Republic of China
| | - Junpeng Zhao
- Faculty of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, People's Republic of China
- Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou 510640, China
| | - Guangzhao Zhang
- Faculty of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, People's Republic of China
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Abstract
The optimal clinical exploitation of viruses as gene therapy or oncolytic vectors will require them to be administered intravenously. Strategies must therefore be deployed to enable viruses to survive the harsh neutralizing environment of the bloodstream and achieve deposition within and throughout target tissues or tumor deposits. This chapter describes the genetic and chemical engineering approaches that are being developed to overcome these challenges.
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Affiliation(s)
- Claudia A P Hill
- Institute of Biomedical Engineering, University of Oxford, Oxford, UK
| | - Luca Bau
- Institute of Biomedical Engineering, University of Oxford, Oxford, UK
| | - Robert Carlisle
- Institute of Biomedical Engineering, University of Oxford, Oxford, UK.
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Tayeb HH, Stienecker M, Middelberg APJ, Sainsbury F. Impact of Site-Specific Bioconjugation on the Interfacial Activity of a Protein Biosurfactant. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13588-13594. [PMID: 31557042 DOI: 10.1021/acs.langmuir.9b01684] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Biosurfactants are surface active molecules that can be produced by renewable, industrially scalable biologic processes. DAMP4, a designer biosurfactant, enables the modification of interfaces via genetic or chemical fusion to functional moieties. However, bioconjugation of addressable amines introduces heterogeneity that limits the precision of functionalization as well as the resolution of interfacial characterization. Here, we designed DAMP4 variants with cysteine point mutations to allow for site-specific bioconjugation. The DAMP4 variants were shown to retain the structural stability and interfacial activity characteristic of the parent molecule, while permitting efficient and specific conjugation of polyethylene glycol (PEG). PEGylation results in a considerable reduction on the interfacial activity of both single and double mutants. Comparison of conjugates with one or two conjugation sites shows that both the number of conjugates as well as the mass of conjugated material impact the interfacial activity of DAMP4. As a result, the ability of DAMP4 variants with multiple PEG conjugates to impart colloidal stability on peptide-stabilized emulsions is reduced. We suggest that this is due to steric constraints on the structures of amphiphilic helices at the interface. Specific and efficient bioconjugation permits the exploration and investigation of the interfacial properties of designer protein biosurfactants with molecular precision. Our findings should therefore inform the design and modification of biosurfactants for their increasing use in industrial processes and nutritional and pharmaceutical formulations.
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Affiliation(s)
- Hossam H Tayeb
- The University of Queensland , Australian Institute for Bioengineering and Nanotechnology , St. Lucia , QLD 4072 , Australia
| | - Marina Stienecker
- The University of Queensland , Australian Institute for Bioengineering and Nanotechnology , St. Lucia , QLD 4072 , Australia
| | - Anton P J Middelberg
- The University of Queensland , Australian Institute for Bioengineering and Nanotechnology , St. Lucia , QLD 4072 , Australia
| | - Frank Sainsbury
- The University of Queensland , Australian Institute for Bioengineering and Nanotechnology , St. Lucia , QLD 4072 , Australia
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7
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Pathak S, Pham TT, Jeong JH, Byun Y. Immunoisolation of pancreatic islets via thin-layer surface modification. J Control Release 2019; 305:176-193. [DOI: 10.1016/j.jconrel.2019.04.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 04/15/2019] [Accepted: 04/22/2019] [Indexed: 12/13/2022]
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9
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Koçum C, Bulmuş V, Pişkin E. Imaging of Poly(N-Isopropyl Acrylamide-Co-Acrylic Acid)–Amino Acid Conjugates with Scanning Tunnelling Microscopy. J BIOACT COMPAT POL 2016. [DOI: 10.1106/088391102027132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
A copolymer of N-isopropyl acrylamide (NIPAAm) and acrylic acid (AAc), Mw 1,400, AAc content of 3.1 mmol carboxylic acid groups per gram of the copolymer, was synthesised by a free radical polymerisation. Mono-, di-, and tripeptide conjugates of this copolymer were prepared by using the carboxylprotected alanine, glycine and serine, with a water-soluble carbodiimide. Scanning tunnelling microscope images of the conjugates were taken after each synthesis step. The average length and width of the copolymer with no amino acid were measured as 17 and 2.5 nm, respectively. The lengths of the mono-, di-, and tri-peptide conjugates were similar to the length of the copolymer chain while the widths were in the range of 3.0–3.2, 3.5–4.0 and 4.2–4.4 nm, respectively.
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Affiliation(s)
| | - Volga Bulmuş
- Chemical Engineering Department and Bioengineering Division, Hacettepe University, Beytepe, 06532 Ankara, Turkey
| | - Erhan Pişkin
- Chemical Engineering Department and Bioengineering Division, Hacettepe University, Beytepe, 06532 Ankara, Turkey
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10
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Hooftman G, Herman S, Schacht E. Review: Poly(Ethylene Glycol)s with Reactive Endgroups. II. Practical Consideration for the Preparation of Protein-PEG Conjugates. J BIOACT COMPAT POL 2016. [DOI: 10.1177/088391159601100205] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Gert Hooftman
- Department of Organic Chemistry, Polymer Materials Research Group, University of Ghent, Krijgslaan 281 S4-Bis, B-9000 Ghent, Belgium
| | - Sabine Herman
- Department of Organic Chemistry, Polymer Materials Research Group, University of Ghent, Krijgslaan 281 S4-Bis, B-9000 Ghent, Belgium
| | - Etienne Schacht
- Department of Organic Chemistry, Polymer Materials Research Group, University of Ghent, Krijgslaan 281 S4-Bis, B-9000 Ghent, Belgium
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11
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Ciucurel EC, Sefton MV. A poloxamine-polylysine acrylate scaffold for modular tissue engineering. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2016; 22:2515-28. [PMID: 21144169 DOI: 10.1163/092050610x541133] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A new polymer, poloxamine-polylysine acrylate (PPA), was synthesized for tissue-engineering applications. Polylysine was used to confer endothelial cell attachment properties to the poloxamine-based polymer, while the acrylate groups made it photo-cross-linkable. The PPA polymer was synthesized in three reaction steps. (1) Polylysine was acrylated using N-hydroxysuccinimide acrylic acid ester and the reaction product was characterised by (1)H-NMR. (2) The hydroxyl groups on poloxamine were activated by tresylation with tresyl chloride and the reaction product (tresylated poloxamine) was characterised by ICP-AES for sulphur content. (3) The acrylated polylysine was reacted with the activated poloxamine to obtain the final product, poloxamine-polylysine acrylate. The final product was characterised by CHN elemental analysis. Aqueous solutions containing a mixture of PPA and poloxamine methacrylate were photo-cross-linked by exposure to a 365 nm UV light source in the presence of a photoinitiator to obtain hydrogels. The synthesized PPA polymer enhanced endothelial cell adhesion on poloxamine-based, photo-cross-linked hydrogel scaffolds. The same synthesis methods can be used in the future to introduce other desired functions (through other peptides) into the scaffold biomaterial.
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Affiliation(s)
- Ema C Ciucurel
- a Department of Chemical Engineering and Applied Chemistry, Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
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12
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Vitz J, Majdanski TC, Meier A, Lutz PJ, Schubert US. Polymerization of ethylene oxide under controlled monomer addition via a mass flow controller for tailor made polyethylene oxides. Polym Chem 2016. [DOI: 10.1039/c6py00402d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The synthesis of polymers with controlled molecular and structural parameters is challenging due to the required purity of the chemicals and the exclusion of protic impurities and oxygen in particular in the case of an anionic process as shown here.
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Affiliation(s)
- Jürgen Vitz
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - Tobias C. Majdanski
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - Alexander Meier
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
| | - Pierre J. Lutz
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- University of Strasbourg
| | - Ulrich S. Schubert
- Laboratory of Organic and Macromolecular Chemistry (IOMC)
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center for Soft Matter (JCSM)
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13
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A review of advanced oral drug delivery technologies facilitating the protection and absorption of protein and peptide molecules. Biotechnol Adv 2014; 32:1269-1282. [DOI: 10.1016/j.biotechadv.2014.07.006] [Citation(s) in RCA: 197] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/21/2014] [Accepted: 07/28/2014] [Indexed: 12/26/2022]
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14
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Kim MJ, Lee DY. Pancreas-like extracellular matrix scaffold for successful pancreatic islet transplantation. Macromol Res 2014. [DOI: 10.1007/s13233-014-2097-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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15
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Parviz M, Darwish N, Alam MT, Parker SG, Ciampi S, Gooding JJ. Investigation of the Antifouling Properties of Phenyl Phosphorylcholine-Based Modified Gold Surfaces. ELECTROANAL 2014. [DOI: 10.1002/elan.201400102] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Abdel-Aziz MS, Janson JC. Hydrolytic and chromatographic studies on the PEGylation of dextranase from Penicillium sp. J Genet Eng Biotechnol 2012. [DOI: 10.1016/j.jgeb.2012.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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17
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Lee DY, Nam JH, Byun Y. Effect of polyethylene glycol grafted onto islet capsules on prevention of splenocyte and cytokine attacks. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 15:753-66. [PMID: 15255524 DOI: 10.1163/156856204774196144] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the graft rejection of transplanted islets, the host's immune cells recognize the islets as antigens, which then stimulate the immune cells to begin the cytokine secretion and also the proliferation of immune cells. To prevent the recognition of islets by the immune cells, we grafted biocompatible polyethylene glycol (PEG) onto the collagen capsule of islets without incurring any changes in the morphology and function of islets. To evaluate the efficiency of PEG grafting, PEG-grafted islets were cultured with splenocytes consisting mainly of lymphocytes and macrophages. A splenocyte proliferation assessment using a BrdU incorporation assay showed that the PEG-grafted islets did not stimulate the splenocytes. In addition, the viability and microorganisms in islet cells of co-cultured PEG-grafted islets were not altered. However, in the co-culture of free islets (control) splenocytes were stimulated; they mainly secreted TNF-alpha and strongly affected the viability and structure of free islets. Furthermore, when islets were treated with the rat recombinant TNF-alpha for 7 days, the viabilities of PEG-grafted and free islets were significantly damaged, although the viability of PEG-grafted islets was higher than that of free islets by nearly three times. These results demonstrate that PEG grafted on the surface of islets could prevent the recognition of islets by splenocytes, but could not completely protect islets from cytokines.
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Affiliation(s)
- Dong Yun Lee
- Department of Materials Science and Engineering, Kwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712, South Korea
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18
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Polymer coatings for delivery of nucleic acid therapeutics. J Control Release 2012; 161:537-53. [PMID: 22366547 DOI: 10.1016/j.jconrel.2012.02.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Revised: 02/08/2012] [Accepted: 02/11/2012] [Indexed: 12/15/2022]
Abstract
Gene delivery remains the greatest challenge in applying nucleic acid therapeutic for a broad range of diseases. Combining stability during the delivery phase with activation and transgene expression following arrival at the target site requires sophisticated vectors that can discriminate between cell types and respond to target-associated conditions to trigger expression. Efficient intravenous delivery is the greatest single hurdle, with synthetic vectors frequently found to be unstable in the harsh conditions of the bloodstream, and viral vectors often recognized avidly by both the innate and the adaptive immune system. Both types of vectors benefit from coating with hydrophilic polymers. Self-assembling polyelectrolyte non-viral vectors can achieve both steric and lateral stabilization following surface coating, endowing them with much improved systemic circulation properties and better access to disseminated targets; similarly viral vectors can be 'stealthed' and their physical properties modulated by surface coating. Both types of vectors may also have their tropism changed following chemical linkage of novel ligands to the polymer coating. These families of vectors go some way towards realizing the goal of efficient systemic delivery of genes and should find a range of important uses in bringing this still-emerging field to fruition.
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19
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Hofmann AM, Wurm F, Frey H. Rapid Access to Polyfunctional Lipids with Complex Architecture via Oxyanionic Ring-Opening Polymerization. Macromolecules 2011. [DOI: 10.1021/ma200367c] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Anna Maria Hofmann
- Institut für Organische Chemie, Johannes Gutenberg-Universität, Duesbergweg 10-14, 55099 Mainz, Germany
| | - Frederik Wurm
- Institut des Matériaux, Laboratoire des Polymères Batiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 12, 1015 Lausanne, Switzerland
| | - Holger Frey
- Institut für Organische Chemie, Johannes Gutenberg-Universität, Duesbergweg 10-14, 55099 Mainz, Germany
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20
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Steinhauer W, Keul H, Möller M. Synthesis of reversible and irreversible cross-linked (M)PEG-(meth)acrylate based functional copolymers. Polym Chem 2011. [DOI: 10.1039/c1py00087j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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The effect of two different polyethylene glycol (PEG) derivatives on the immunological response of PEG grafted pancreatic islets. J Artif Organs 2010; 13:218-24. [PMID: 21127930 DOI: 10.1007/s10047-010-0525-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Accepted: 10/21/2010] [Indexed: 10/18/2022]
Abstract
Islet transplantation is one of the promising ways to treat diabetes. To reduce the immune system response, several methods have been developed, a novel one being the grafting of methoxy polyethylene glycol (mPEG) derivatives onto collagen capsules of islets. In this study, the effects of the first and second generations of activated mPEG on the immunological response of polyethylene glycol (PEG) grafted pancreatic islets were studied. mPEG-Succinimidyl carbonate (mPEG-SC) and mPEG-succinimidyl propionic acid (mPEG-SPA) (with nominal molecular weight 5 kDa), typical of the first and second generations of activated mPEG, were selected, respectively. Both activated mPEGs did not affect the morphology, viability, or functionality of PEGylated islets compared to free islets (naked islets). The amount of IL-2 secreted from lymphocytes co-cultured with mPEG-SPA grafted islets (131.83 ± 15.28 pg/ml) was not significantly different from that with mPEG-SC grafted islets (156.09 ± 27.94 pg/ml). These results indicated that both mPEG-SC and mPEG-SPA had the same effect for camouflaging Langerhans islets, but the former is more suitable due to its easier synthesis process.
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22
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Effect of molecular mass of methoxypoly(ethylene glycol) activated with succinimidyl carbonate on camouflaging pancreatic islets. Biotechnol Appl Biochem 2010; 57:25-30. [DOI: 10.1042/ba20100145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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23
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24
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Lee DY, Byun Y. Pancreatic islet PEGylation as an immunological polymeric restraint. BIOTECHNOL BIOPROC E 2010. [DOI: 10.1007/s12257-009-3063-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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25
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Obermeier B, Wurm F, Frey H. Amino Functional Poly(ethylene glycol) Copolymers via Protected Amino Glycidol. Macromolecules 2010. [DOI: 10.1021/ma902245d] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Boris Obermeier
- Institute of Organic Chemistry, Organic and Macromolecular Chemistry, Duesbergweg 10-14, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - Frederik Wurm
- Institute of Organic Chemistry, Organic and Macromolecular Chemistry, Duesbergweg 10-14, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - Holger Frey
- Institute of Organic Chemistry, Organic and Macromolecular Chemistry, Duesbergweg 10-14, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
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Ryan SM, Mantovani G, Wang X, Haddleton DM, Brayden DJ. Advances in PEGylation of important biotech molecules: delivery aspects. Expert Opin Drug Deliv 2008; 5:371-83. [DOI: 10.1517/17425247.5.4.371] [Citation(s) in RCA: 262] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Lee DY, Park SJ, Lee S, Nam JH, Byun Y. Highly Poly(Ethylene) Glycolylated Islets Improve Long-Term Islet Allograft Survival without Immunosuppressive Medication. ACTA ACUST UNITED AC 2007; 13:2133-41. [PMID: 17516853 DOI: 10.1089/ten.2006.0009] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The surface modification of islets using poly(ethylene glycol) (PEG) is being studied as a means of preventing host immune responses against transplanted islets. In this study, to completely shield islets with PEG molecules, we increased the amount of PEG conjugated to islet surfaces, by multiple PEGylation or amplified PEGylation using poly-L-lysine, poly(allylamine), or poly(ethyleneimine), respectively. Amplified PEGylation was associated with islet cytotoxicity and functional impairment, but multiple PEGylation affected neither islet viability nor functionality. In addition, when triply PEGylated islets were allotransplanted into diabetic recipients, these islets survived in 3 of the 7 recipients for more than 100 days without any immunosuppressive treatment. Moreover, the blood glucose levels of these 3 recipients were stable and in the normal range. Immunohistochemical analysis showed that 3 of 7 triply PEGylated islets transplants survived for 100 days and that 4 that were rejected before day 20 were all immunologically protected from immune cells. However, unmodified islets were completely destroyed within 1 week. Consequently, we suggest that multiple PEGylation offers an effective means of reducing the immunogenicity of transplanted islets by increasing the amount of surface-bound PEG.
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Affiliation(s)
- Dong Yun Lee
- College of Pharmacy, Seoul National University, Seoul, South Korea
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Lee DY, Park SJ, Nam JH, Byun Y. A new strategy toward improving immunoprotection in cell therapy for diabetes mellitus: long-functioning PEGylated islets in vivo. ACTA ACUST UNITED AC 2006; 12:615-23. [PMID: 16579694 DOI: 10.1089/ten.2006.12.615] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Surface modification of islets using poly(ethylene glycol) (PEG) has been studied toward preventing immune responses of host for successful islet transplantation. In this study, we assessed the functionality of PEGylated islets and immune responses of host, as well as the synergistic effects of using PEGylation simultaneously with cyclosporine A (CsA) to prevent immune reactions. The average period of time for which PEGylated islets functioned normally following islets transplantation was 14 days, whereas it was only 5 days for unmodified islets. Host's immune cells did not eliminate the PEGylated islets but were observed to gather around the islets. On the other hand, unmodified islets were completely eliminated. When a low dose of CsA (3 mg/kg/day) was intravenously administered at the same time, the PEGylated islets showed stable activity and survived for 100 days before, that is, the PEGylated islets secreted insulin and were preserved from the immune cells. However, unmodified islets survived for 14 days on the average, even when CsA was administered. Consequently, it can be suggested that the PEGylation of islet surfaces can be an effective approach toward reducing the immunogenecity of islets, thus improving the functionality and survival time of transplanted islets, especially when CsA was simultaneously administered.
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Affiliation(s)
- Dong Yun Lee
- College of Pharmacy, Seoul National University, Seoul, South Korea
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Lee DY, Park SJ, Nam JH, Byun Y. A New Strategy Toward Improving Immunoprotection in Cell Therapy for Diabetes Mellitus: Long-Functioning PEGylated Islets In Vivo. ACTA ACUST UNITED AC 2006. [DOI: 10.1089/ten.2006.12.ft-55] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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31
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Wang Y, Yuan F. Delivery of viral vectors to tumor cells: extracellular transport, systemic distribution, and strategies for improvement. Ann Biomed Eng 2006; 34:114-27. [PMID: 16520902 DOI: 10.1007/s10439-005-9007-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2004] [Accepted: 06/30/2005] [Indexed: 12/23/2022]
Abstract
It is a challenge to deliver therapeutic genes to tumor cells using viral vectors because (i) the size of these vectors are close to or larger than the space between fibers in extracellular matrix and (ii) viral proteins are potentially toxic in normal tissues. In general, gene delivery is hindered by various physiological barriers to virus transport from the site of injection to the nucleus of tumor cells and is limited by normal tissue tolerance of toxicity determined by local concentrations of transgene products and viral proteins. To illustrate the obstacles encountered in the delivery and yet limit the scope of discussion, this review focuses only on extracellular transport in solid tumors and distribution of viral vectors in normal organs after they are injected intravenously or intratumorally. This review also discusses current strategies for improving intratumoral transport and specificity of viral vectors.
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Affiliation(s)
- Yong Wang
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
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32
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Abstract
The intricate problems associated with the delivery and various unnecessary in vivo transitions of proteins and drugs needs to be tackled soon to be able to exploit the myriad of putative therapeutics created by the biotechnology boom. Nanomedicine is one of the most promising applications of nanotechnology in the field of medicine. It has been defined as the monitoring, repair, construction and control of human biological systems at the molecular level using engineered nanodevices and nanostructures. These nanostructured medicines will eventually turn the world of drug delivery upside down. PEGylation (i.e. the attachment of polyethylene glycol to proteins and drugs) is an upcoming methodology for drug development and it has the potential to revolutionise medicine by drastically improving the pharmacokinetic and pharmacodynamic properties of the administered drug. This article provides a total strategy for improving the therapeutic efficacy of various biotechnological products in drug delivery. This article also presents an extensive analysis of most of the PEGylated proteins, peptides and drugs, together with extensive clinical data. Nanomedicines and PEGylation, the latest offshoots of nanotechnology will definitely pave a way in the field of drug delivery where targeted delivery, formulation, in vivo stability and retention are the major challenges.
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Affiliation(s)
- Suphiya Parveen
- Laboratory of Nanomedicine, Institute of Life Sciences, Chandrasekharpur, Bhubaneswar, Orissa, India
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33
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Lee DY, Park SJ, Nam JH, Byun Y. A combination therapy of PEGylation and immunosuppressive agent for successful islet transplantation. J Control Release 2005; 110:290-295. [PMID: 16324765 DOI: 10.1016/j.jconrel.2005.10.023] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2005] [Revised: 09/14/2005] [Accepted: 10/31/2005] [Indexed: 11/26/2022]
Abstract
Several immunosuppressive medications are used simultaneously to protect transplanted islets. However, reports of severe side effects induced by immunosuppressive drugs have prompted attention on developing ways to reduce their toxicities. Toward attenuating the immunogenicity of islets, we studied a combination therapy of PEGylation and cyclosporin A (CsA) as a new immunoprotective strategy. This study aimed to find out whether PEGylation combined with cyclosporine and applied on islet surfaces could bring about a synergistic effect of reducing the dose of immunosuppressive medications as well as enhancing their medical effects. After islets were transplanted into the kidney of diabetic rats, different doses of CsA were administered daily. When 3 mg/kg of CsA was administered for 2 weeks, unmodified islets were completely rejected within 2 weeks, whereas the PEGylated islets survived for 32+/-14.6 days. When 1 mg/kg of CsA was further administered following the initial, 2-week CsA treatment of 3 mg/kg, the PEGylated islets in all recipients survived up to 100 days prior to nephrectomy and also rapidly responded to the fluctuation of blood glucose level. PEGylated islets were also present in large numbers in the transplantation site without causing the infiltration of immune cells. Therefore, these findings suggest that, when combined with an immunosuppressive drug, PEGylation of islets could have a dose reducing effect on the immunosuppressive medication and thus synergistically improve the survival time of islets.
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Affiliation(s)
- Dong Yun Lee
- College of Pharmacy, Seoul National University, San 56-1, Sillim 9-dong, Gwanak-gu, Seoul 151-742, Korea
| | - Sang Jin Park
- Department of Life Science, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | - Jong Hee Nam
- Department of Pathology, School of Medicine, Chonnam National University, Gwangju 500-757, Korea
| | - Youngro Byun
- College of Pharmacy, Seoul National University, San 56-1, Sillim 9-dong, Gwanak-gu, Seoul 151-742, Korea.
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Tattini V, Parra DF, Polakiewicz B, Pitombo RNM. Effect of lyophilization on the structure and phase changes of PEGylated-bovine serum albumin. Int J Pharm 2005; 304:124-34. [PMID: 16188407 DOI: 10.1016/j.ijpharm.2005.08.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2005] [Revised: 06/30/2005] [Accepted: 08/10/2005] [Indexed: 10/25/2022]
Abstract
Poly (ethylene glycol) (PEG) conjugation masks the protein's surface and increases the molecular size of the polypeptide, thus preventing the approach of antibodies or antigen processing cells and reducing the degradation by proteolytic enzymes. Proteins are readily denatured by numerous stresses arising in solution (e.g., heating, agitation, freezing and pH changes) or by chemical reactions (e.g., hydrolysis and deamidation), many of which are mediated by water. Lyophilization is most commonly used to prepare dehydrated proteins, which, theoretically, should have the desired long-term stability at ambient temperatures. Through Raman spectroscopy, differential scanning calorimetry (DSC) associated with the determination of water content by Karl Fisher titration, it was observed that after the modification of BSA-PEG in a ratio of 1:0.25 showed lower degree of structural alterations and consequently lower variation on the physical-chemical characteristics when it was compared to BSA-PEG (1:0.5). Moreover, the BSA-PEG (1:0.25) optimizes the conditions during the lyophilization process and storage of the protein.
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Affiliation(s)
- Virgilio Tattini
- Department of Biochemical and Pharmaceutical Technology, Pharmaceutical Sciences School, University of São Paulo, Av. Prof. Lineu Prestes, 580, Bloco 16, CEP 05508-900 São Paulo, SP, Brazil
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35
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Wirsén A, Sun H, Albertsson AC. Solvent free vapour phase photografting of acrylamide onto poly(methyl methacrylate). POLYMER 2005. [DOI: 10.1016/j.polymer.2005.03.074] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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36
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Ahn CH, Chae SY, Bae YH, Kim SW. Synthesis of biodegradable multi-block copolymers of poly(L-lysine) and poly(ethylene glycol) as a non-viral gene carrier. J Control Release 2005; 97:567-74. [PMID: 15212887 DOI: 10.1016/j.jconrel.2004.04.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2003] [Accepted: 04/02/2004] [Indexed: 10/26/2022]
Abstract
Biodegradable and non-toxic multi-block copolymers based on poly(L-lysine) and poly(ethylene glycol) were synthesized. Synthesized copolymers showed almost negligible cytotoxicity above 95% cell viability and transfection efficiency compared to the PLL homopolymer with molecular weight of 25,700. Biodegradation under physiological conditions revealed that the molecular weight of copolymers decreased to 20% of the initial molecular weight within 72 h. Transfection efficiencies of copolymers were not affected by the presence of serum, while that of PLL homopolymer decreased to the level of naked DNA in the presence of serum. Based on the results, the new copolymers are believed to be a potentially efficient carrier for the delivery of bioactive agents.
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Affiliation(s)
- Cheol-Hee Ahn
- School of Materials Science and Engineering, Hyperstructured Organic Materials Research Center, Seoul National University, Seoul 151-742, South Korea.
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37
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Lebouc F, Dez I, Desbrières J, Picton L, Madec PJ. Different ways for grafting ester derivatives of poly(ethylene glycol) onto chitosan: related characteristics and potential properties. POLYMER 2005. [DOI: 10.1016/j.polymer.2004.11.104] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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38
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Pişkin E. Molecularly designed water soluble, intelligent, nanosize polymeric carriers. Int J Pharm 2004; 277:105-18. [PMID: 15158974 DOI: 10.1016/j.ijpharm.2003.06.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2003] [Revised: 05/23/2003] [Accepted: 06/29/2003] [Indexed: 11/30/2022]
Abstract
Intelligent polymers, also referred as "stimuli-responsive polymers" undergo strong property changes (in shape, surface characteristics, solubility, etc.) when only small changes in their environment (changes in temperature, pH, ionic strength light, electrical and magnetic field, etc.). They have been used in several novel applications, drug delivery systems, tissue engineering scaffolds, bioseparation, biomimetic actuators, etc. The most popular member of these type of polymers is poly(N-isopropylacrylamide) (poly(NIPA)) which exhibits temperature-sensitive character, in which the polymer chains change from water-soluble coils to water-insoluble globules in aqueous solution as temperature increases above the lower critical solution temperature (LCST) of the polymer. Copolymerization of NIPA with acrylic acid (AAc) allows the synthesis of both pH and temperature-responsive copolymers. This paper summarizes some of our related studies in which NIPA and its copolymers were synthesized and used as intelligent carriers in diverse applications.
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Affiliation(s)
- Erhan Pişkin
- Chemical Engineering Department, TUBITAK Centre of Excellence, Hacettepe University, BIYOMUH, Ankara, Turkey.
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39
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Abstract
A new class of methoxy-poly(ethylene glycol) (mPEG) derivatives having a cleavable group of oligo-lactic acid (OLA) was synthesized by ring opening polymerization of L-lactide using a terminal hydroxyl end of mPEG as an initiator. The synthesized mPEG derivatives had 0.8 and 3.6 lactic acid units based on the MALDI-TOF data. A terminal end group of mPEG-OLA was further activated with p-nitrophenyl chloroformate to produce mPEG-OLA-p-nitrophenyl carbonate (PC). mPEG-OLA-PC derivatives were conjugated to primary amine groups of recombinant human granulocyte-colony stimulating factor. PEGylated G-CSF conjugated with mPEG-OLA-PC derivatives consisted of native, mono-, di-, and tri-PEGylated species, and they did not show any apparent conformational changes even after PEGylation. When incubating in pH 7.4 buffer at 37 degrees C for 2 days, mPEG-OLA-G-CSF conjugates liberated mPEG by cleaving the OLA spacer, resulting in the gradual regeneration of G-CSF.
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Affiliation(s)
- Seung Ho Choi
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, South Korea
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40
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Bulmu? V, Pat?r S, Ali Tuncel S, Pi?kin E. Conjugates of poly(N-isopropyl acrylamide-co-acrylic acid) with alanine monopeptide, dipeptide, and tripeptide. J Appl Polym Sci 2003. [DOI: 10.1002/app.11901] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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41
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Kurusu F, Ohno H, Kaneko M, Nagasaki Y, Kataoka K. Functionalization of gold electrode surface with heterobifunctional poly(ethylene oxide)s having both mercapto and aldehyde groups. POLYM ADVAN TECHNOL 2003. [DOI: 10.1002/pat.286] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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42
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Lee DY, Yang K, Lee S, Chae SY, Kim KW, Lee MK, Han DJ, Byun Y. Optimization of monomethoxy-polyethylene glycol grafting on the pancreatic islet capsules. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2002; 62:372-7. [PMID: 12209922 DOI: 10.1002/jbm.10246] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
As a new approach to islet transplantation, biocompatible monomethoxy-poly(ethylene glycol) (mPEG) was chemically grafted onto the pancreatic islet capsule. The aim of this study was to determine the optimal conditions for completely covering the islet by the mPEG while maintaining a high viability of islets according to the reaction time and the repeating number of the reaction. By grafting the fluorescein-PEG instead of mPEG, we determined the optimal mPEG grafting time as 1 h, during which time the procedure did not reduce islet viability. Insulin secretion from islets where the mPEG was grafted on for 3 times was similar to that of control islets. Moreover, the mPEG-grafted islets rapidly responded to the changes in the glucose concentration in the same pattern as did control islets. These results showed that mPEG grafting did not damage the function of islets. In conclusion, when the mPEG grafting was performed for 1 h and repeated twice with 1-day culture between each mPEG-grafting step, the mPEG completely covered the islet capsules without any damage to the viability and function of the islets. The main advantage of mPEG grafting on the islet capsule is that it can protect the islet against the host's immune system without increasing the islet size so that it can be administered into the portal vein by the catheter.
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Affiliation(s)
- Dong Yun Lee
- Department of Materials Science and Engineering, Kwangju Institute of Science and Technology, 1 Oryong-dong, Puk-gu, Gwangju 500-712, Korea
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43
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Abstract
Poly(ethylenimine) (PEI) has been known as an efficient gene carrier with the highest cationic charge potential. High transfection efficiency of PEI, along with its cytotoxicity, strongly depends on the molecular weight. Synthesis of cationic copolymers derived from the low molecular weight of PEI and hydrophilic poly(ethylene glycol) (PEG), which are water soluble and degradable under physiological conditions, was investigated for plasmid delivery. Hydrophilic PEG is expected to reduce the toxicity of the copolymer, improve the poor solubility of the PEI and DNA complexes, and help to introduce degradable bonds by reaction with the primary amines in the PEI. Considering the dependence of transfection efficiency and cytotoxicity on the molecular weight of the PEI, high transfection efficiency is expected from an increased molecular weight of the copolymer and low cytotoxicity from the introduction of PEG and the degradation of the copolymer into low molecular weight PEIs. Reaction conditions were carefully controlled to produce water soluble copolymers. Results from a gel retardation assay and zetapotentiometer indicated that complete neutralization of the complexes was achieved at the charge ratios of copolymer/pSV-beta-gal plasmid from 0.8 to 1.0 with the mean particle size of the polyplexes ranging from 129.8+/-0.9 to 151.8+/-3.4 nm. In vitro transfection efficiency of the synthesized copolymer increased up to three times higher than that of starting low molecular weight PEI, while the cell viability was maintained over 80%.
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Affiliation(s)
- Cheol-Hee Ahn
- Center for Controlled Chemical Delivery, Department of Pharmaceutics and Pharmaceutical Chemistry, Biomedical Polymers Research Building, University of Utah, RM 205, 84112, Salt Lake City, UT, USA
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Guiotto A, Pozzobon M, Sanavio C, Schiavon O, Orsolini P, Veronese FM. An improved procedure for the synthesis of branched polyethylene glycols (PEGs) with the reporter dipeptide Met-betaAla for protein conjugation. Bioorg Med Chem Lett 2002; 12:177-80. [PMID: 11755348 DOI: 10.1016/s0960-894x(01)00694-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A new and more efficient route to the synthesis of branched PEG for protein conjugation, bearing a reporter dipeptide Met-betaAla, is described, which allows better purification of the final product by ion exchange chromatography. The product has the combined advantages of an 'umbrella-like' branched structure, which allows a better coverage of the protein surface, and the presence of the dipeptide Met-betaAla which has been used to detect the position of PEGylation within the peptide sequence.
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Affiliation(s)
- Andrea Guiotto
- Dipartimento di Science Farmaceutiche, Via Marzolo 5, 35100 Padova, Italy
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45
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Pharmaceutical Polymeric Controlled Drug Delivery Systems. FILLED ELASTOMERS DRUG DELIVERY SYSTEMS 2002. [DOI: 10.1007/3-540-45362-8_2] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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46
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Bulmuş V, Patir S, Tuncel SA, Pişkin E. Stimuli-responsive properties of conjugates of N-isopropylacrylamide-co-acrylic acid oligomers with alanine, glycine and serine mono-, di- and tri-peptides. J Control Release 2001; 76:265-74. [PMID: 11578741 DOI: 10.1016/s0168-3659(01)00433-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A random oligomer of N-isopropylacrylamide (NIPAAm) and acrylic acid (AAc) with a AAc content of 3.1+/-0.19 mmol carboxylic acid groups per gram of the oligomer and with a number average molecular weight of 1400 was synthesised by a free radical polymerisation using AIBN in DMF. Then, mono-, di-, and tri-peptide conjugates of this oligomer were prepared by using carboxyl-ends-protected (with methyl ester hydrochloride) forms of alanine, glycine and serine, with a water-soluble carbodiimide. 95, 93, and 31% of the carboxylic acids were conjugated (loaded) at the first step (mono-peptides) with glycine, alanine and serine, respectively. At the second step, percentage of the conjugation of carboxylic acid groups with glycine, alanine and serine were between 99 and 80, 68 and 100, and 21 and 58%, respectively, while the third amino acids were attached to only 21-64% of the carboxylic acids available on the conjugate chains. A decrease was observed in the lower critical solution temperatures (LCSTs) of the amino acid conjugates at pH 4.0 compared with the unconjugated oligomer, which has LCST at 37.7 degrees C at the same pH. LCSTs of di- and tri-peptide conjugates at pH 4.0 were in the range of 38.4-43.3 degrees C, and 42.6-50.8 degrees C, respectively. At pH 7.4, LCSTs of the mono- and di-peptide conjugates were observed in the range of 41.6-43.9 degrees C, and 46.2-60.2 degrees C, respectively, while the co-oligomer at pH 7.4 did not show a LCST up to 60 degrees C. Tri-peptide conjugates did not display LCST at pH 7.4, except the one with glycine-alanine-serine sequence.
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Affiliation(s)
- V Bulmuş
- Faculty of Engineering, Chemical Engineering Department, Hacettepe University, Beytepe, 06532, Ankara, Turkey
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47
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Abstract
No low molecular weight (<20000) poly(ethylene glycol) (PEG) small molecule drug conjugates, prepared over a 20-year period, have led to a clinically approved product. In this area, published studies for these types of compounds have been scrutinized and their properties compared and contrasted to higher molecular weight conjugates where, during the past 5 years, a renaissance in the field of PEG (anticancer) drug conjugates has taken place. This new development has been attributed to the use of higher molecular weight PEGs (>20000), and especially employing PEG 40000 which is estimated to have a plasma circulating half life of approximately 8-9 h in the mouse. This recent resuscitation of small organic molecule delivery by high molecular weight PEG conjugates was founded on meaningful in vivo testing using established tumor models, and has led to a clinical candidate. Recent applications of high molecular weight PEG prodrug strategies to amino containing drugs are also detailed, and potential applications to proteins are proposed.
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Affiliation(s)
- R B Greenwald
- Enzon Inc., 20 Kingsbridge Road, Piscataway, NJ 08854-3969, USA.
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48
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Abstract
The paper discusses general problems in using PEG for conjugation to high or low molecular weight molecules. Methods of binding PEG to different functional groups in macromolecules is reported together with their eventual limitations. Problems encountered in conjugation, such as the evaluation of the number of PEG chains bound, the localisation of the site of conjugation in polypeptides and the procedure to direct PEGylation to the desired site in the molecule are discussed. Finally, the paper reports on more specific methods regarding reversible PEGylation, cross-linking reagents with PEG arms, PEG for enzyme solubilization in organic solvent and new polymers as alternative to PEG.
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Affiliation(s)
- F M Veronese
- Department of Pharmaceutical Sciences, CNR, Center for Chemical Investigation of Drugs, University of Padova, Italy.
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49
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Sedaghat-Herati MR. Synthesis and Characterization of 5-[Methoxypoly(oxyethylene)]-(3E)-1,3- pentadiene and Its Diels−Alder Reactions. Macromolecules 2000. [DOI: 10.1021/ma991419g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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50
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Uhrich KE, Cannizzaro SM, Langer RS, Shakesheff KM. Polymeric systems for controlled drug release. Chem Rev 1999; 99:3181-98. [PMID: 11749514 DOI: 10.1021/cr940351u] [Citation(s) in RCA: 1822] [Impact Index Per Article: 72.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- K E Uhrich
- Department of Pharmaceutical Science, University of Nottingham, Nottingham NG7-2RD, U.K
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