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Cyclo- and Polyphosphazenes for Biomedical Applications. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238117. [PMID: 36500209 PMCID: PMC9736570 DOI: 10.3390/molecules27238117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022]
Abstract
Cyclic and polyphosphazenes are extremely interesting and versatile substrates characterized by the presence of -P=N- repeating units. The chlorine atoms on the P atoms in the starting materials can be easily substituted with a variety of organic substituents, thus giving rise to a huge number of new materials for industrial applications. Their properties can be designed considering the number of repetitive units and the nature of the substituent groups, opening up to a number of peculiar properties, including the ability to give rise to supramolecular arrangements. We focused our attention on the extensive scientific literature concerning their biomedical applications: as antimicrobial agents in drug delivery, as immunoadjuvants in tissue engineering, in innovative anticancer therapies, and treatments for cardiovascular diseases. The promising perspectives for their biomedical use rise from the opportunity to combine the benefits of the inorganic backbone and the wide variety of organic side groups that can lead to the formation of nanoparticles, polymersomes, or scaffolds for cell proliferation. In this review, some aspects of the preparation of phosphazene-based systems and their characterization, together with some of the most relevant chemical strategies to obtain biomaterials, have been described.
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Gascón E, Otal I, Maisanaba S, Llana-Ruiz-Cabello M, Valero E, Repetto G, Jones PG, Oriol L, Jiménez J. Gold(I) metallocyclophosphazenes with antibacterial potency and antitumor efficacy. Synergistic antibacterial action of a heterometallic gold and silver-cyclophosphazene. Dalton Trans 2022; 51:13657-13674. [PMID: 36040292 DOI: 10.1039/d2dt01963a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
One of the most important uses of phosphazenes today involves its biomedical applications. They can also be employed as scaffolds for the design and construction of a variety of ligands in order to coordinate them to metallic drugs. The coordination chemistry of the (amino)cyclotriphosphazene ligand, [N3P3(NHCy)6], towards gold(I) complexes has been studied. Neutral complexes, [N3P3(NHCy)6{AuX}n] (X = Cl or C6F5; n = 1 or 2) (1-4), cationic complexes, [N3P3(NHCy)6{Au(PR3)}n](NO3)n (PR3 = PPh3, PPh2Me, TPA; n = 1, 2 or 3) (6-12) [TPA = 1,3,5-triaza-7-phosphaadamantane] and a heterometallic compound [N3P3(NHCy)6{Au(PPh3)}2{Ag(PPh3)}](NO3)3 (13) have been obtained and characterized by various methods including single-crystal X-ray diffraction for 7, which confirms the coordination of gold atoms to the nitrogens of the phosphazene ring. Compounds 1, 4, 6-13 were screened for in vitro cytotoxic activity against two tumor human cell lines, MCF7 (breast adenocarcinoma) and HepG2 (hepatocellular carcinoma), and for antimicrobial activity against five bacterial species including Gram-positive, Gram-negative, and Mycobacteria. Both the median inhibitory concentration (IC50) and minimum inhibitory concentration (MIC) values are among the lowest found for any gold or silver derivatives against the cell lines and particularly against the Gram-positive (S. aureus) strain and the mycobacteria used in this work. Structure-activity relationships are discussed in order to determine the influence of ancillary ligands and the number and type of metal atoms (silver or gold). Compounds 4 and 8 showed not only maximal potency on human cells but also some tumour selectivity. Remarkably, compound 13, with both gold and silver atoms, showed outstanding activity against both Gram-positive and Gram-negative strains (nanomolar range), thus having a cooperative effect between gold and silver, with MIC values which are similar or lower than those of gentamicine, ciprofloxacin and rifampicine. The broad spectrum antimicrobial efficacy of all these metallophosphazenes and particularly of heterometallic compound 13 could be very useful to obtain materials for surfaces with antimicrobial properties that are increasingly in demand.
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Affiliation(s)
- Elena Gascón
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza-C.S.I.C., Pedro Cerbuna 12, 50009 Zaragoza, Spain.
| | - Isabel Otal
- Grupo de Genética de Micobacterias, Departamento de Microbiología, Pediatría, Radiología y Salud Pública, Universidad de Zaragoza, Zaragoza, Spain.,CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, E-28029 Madrid, Spain
| | - Sara Maisanaba
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología, Universidad Pablo de Olavide, Ctra. Utrera, Km 1, 41013 Sevilla, Spain
| | - María Llana-Ruiz-Cabello
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología, Universidad Pablo de Olavide, Ctra. Utrera, Km 1, 41013 Sevilla, Spain
| | - Eva Valero
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área Nutrición y Bromatología, Universidad Pablo de Olavide, Ctra. Utrera, Km 1, 41013 Sevilla, Spain
| | - Guillermo Repetto
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología, Universidad Pablo de Olavide, Ctra. Utrera, Km 1, 41013 Sevilla, Spain
| | - Peter G Jones
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, D-38106, Braunschweig, Germany
| | - Luis Oriol
- Departamento de Química Orgánica, Instituto de Nanociencia y Materiales de Aragón-Facultad de Ciencias, Universidad de Zaragoza-C.S.I.C., Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Josefina Jiménez
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), Universidad de Zaragoza-C.S.I.C., Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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Carboué Q, Fadlallah S, Lopez M, Allais F. Progress in degradation behavior of most common types of functionalized polymers: a review. Macromol Rapid Commun 2022; 43:e2200254. [DOI: 10.1002/marc.202200254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Indexed: 11/05/2022]
Affiliation(s)
- Quentin Carboué
- URD Agro‐Biotechnologies Industrielles (ABI) CEBB AgroParisTech Pomacle 51110 France
| | - Sami Fadlallah
- URD Agro‐Biotechnologies Industrielles (ABI) CEBB AgroParisTech Pomacle 51110 France
| | - Michel Lopez
- URD Agro‐Biotechnologies Industrielles (ABI) CEBB AgroParisTech Pomacle 51110 France
| | - Florent Allais
- URD Agro‐Biotechnologies Industrielles (ABI) CEBB AgroParisTech Pomacle 51110 France
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4
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Zhang T, Conrad ED, Gates DP. Di- and tri-block copolymers from the sequential living anionic copolymerization a phosphaalkene with styrene. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.124831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Daglar O, Alkan B, Gunay US, Hizal G, Tunca U, Durmaz H. Ultrafast synthesis of phosphorus-containing polythioethers in the presence of TBD. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2021.110931] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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6
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Nifant'ev IE, Shlyakhtin AV, Bagrov VV, Tavtorkin AN, Ilyin SO, Gavrilov DE, Ivchenko PV. Cyclic ethylene phosphates with (CH 2) nCOOR and CH 2CONMe 2 substituents: synthesis and mechanistic insights of diverse reactivity in aryloxy-Mg complex-catalyzed (co)polymerization. Polym Chem 2021. [DOI: 10.1039/d1py01277k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Herein we present a comparative study of the reactivity of ethylene phosphates with –O(CH2)nCOOMe (n = 1–3, 5), –CH2COOtBu, –OCHMeCOOMe, and –OCH2CONMe2 substituents in BHT-Mg catalyzed ROP.
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Affiliation(s)
- Ilya E. Nifant'ev
- A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russian Federation
- M. V. Lomonosov Moscow State University, Department of Chemistry, Moscow, Russian Federation
| | - Andrey V. Shlyakhtin
- A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russian Federation
- M. V. Lomonosov Moscow State University, Department of Chemistry, Moscow, Russian Federation
| | - Vladimir V. Bagrov
- A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russian Federation
- M. V. Lomonosov Moscow State University, Department of Chemistry, Moscow, Russian Federation
| | - Alexander N. Tavtorkin
- A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russian Federation
- M. V. Lomonosov Moscow State University, Department of Chemistry, Moscow, Russian Federation
| | - Sergey O. Ilyin
- A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russian Federation
| | - Dmitry E. Gavrilov
- A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russian Federation
- M. V. Lomonosov Moscow State University, Department of Chemistry, Moscow, Russian Federation
| | - Pavel V. Ivchenko
- A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russian Federation
- M. V. Lomonosov Moscow State University, Department of Chemistry, Moscow, Russian Federation
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7
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Ding S, Shi W, Zhang K, Xie Z. Bifunctional cyclomatrix polyphosphazene-based hybrid with abundant decorating groups: Synthesis and application as efficient electrochemical Pb(II) probe and methylene blue absorbent. J Colloid Interface Sci 2020; 587:683-692. [PMID: 33223242 DOI: 10.1016/j.jcis.2020.11.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 11/06/2020] [Accepted: 11/08/2020] [Indexed: 11/18/2022]
Abstract
HYPOTHESIS The construction of novel functional cyclomatrix polyphosphazenes (CPPs) hybrid, which with diverse decorating groups, is a challenging task due to the structural limitation of available reaction substrates (phenols and amines). EXPERIMENTS Herein, a phenolic hydroxyl (OH) modified ployamide derivative (P2) was successfully prepared via novel benzoxazine-isocyanide chemistry (BIC). A kind of CPP hybrid (P3), which with abundant functional groups (amide, tertiary amine, benzoxazine and phenolic hydroxyl) was prepared subsequently by the condensation between P2 and hexachlorocyclotriphosphazene (HCCP). Chemical structure, elemental composition, morphology, porous properties and crystallinity of P3 were systematically analyzed here. The electrochemical detection of lead ion (Pb2+) was realized by using P3-modified glassy carbon electrode (GCE/Nafion/P3) as the working electrode. Besides this, given the unique chemical structure and morphology of P3, the selective adsorption of methylene blue (MB) by P3 was also studied here. FINDINGS Experimental results indicated that that P3 can act as bifunctional hybrid material to solve environmental issues.
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Affiliation(s)
- Sheng Ding
- Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, China
| | - Wei Shi
- Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, China.
| | - Kesong Zhang
- Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, China
| | - Zhengfeng Xie
- Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, China
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Steinmann M, Wurm FR. Water-soluble and degradable polyphosphorodiamidates via thiol-ene polyaddition. Polym Degrad Stab 2020. [DOI: 10.1016/j.polymdegradstab.2020.109224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Wang S, Liu R, Fu Y, Kao WJ. Release mechanisms and applications of drug delivery systems for extended-release. Expert Opin Drug Deliv 2020; 17:1289-1304. [PMID: 32619149 DOI: 10.1080/17425247.2020.1788541] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Drug delivery systems with extended-release profiles are ideal in improving patient compliance with enhanced efficacy. To develop devices capable of a prolonged delivery kinetics, it is crucial to understand the various underlying mechanisms contributing to extended drug release and the impact thereof on modulating the long-term performance of such systems in a practical application environment. AREAS COVERED This review article intends to provide a comprehensive summary of release mechanisms in extended-release drug delivery systems, particularly polymer-based systems; however, other material types will also be mentioned. Selected current research in the delivery of small molecule drugs and macromolecules is highlighted. Emphasis is placed on the combined impact of different release mechanisms and drug properties on the long-term release kinetics in vitro and in vivo. EXPERT OPINION The development of drug delivery systems over an extended duration is promising but also challenging when considering the numerous interrelated delivery-related parameters. Achieving a well-controlled extended drug release requires advanced techniques to minimize burst release and lag phase, a better understanding of the dynamic interrelationship between drug properties and release profiles over time, and a thorough elucidation of the impact of multiple in vivo conditions to methodically evaluate the eventual clinical efficacy.
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Affiliation(s)
- Shuying Wang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University , Chengdu, China
| | - Renhe Liu
- Global Health Drug Discovery Institute , Beijing, China
| | - Yao Fu
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University , Chengdu, China
| | - W John Kao
- Department of Industrial and Manufacturing Systems Engineering, Biomedical Engineering Programme, Chemical Biology Centre, and Li Ka Shing Faculty of Medicine, The University of Hong Kong , Pokfulam, China
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10
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Strasser P, Teasdale I. Main-Chain Phosphorus-Containing Polymers for Therapeutic Applications. Molecules 2020; 25:E1716. [PMID: 32276516 PMCID: PMC7181247 DOI: 10.3390/molecules25071716] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/02/2020] [Accepted: 04/04/2020] [Indexed: 02/07/2023] Open
Abstract
Polymers in which phosphorus is an integral part of the main chain, including polyphosphazenes and polyphosphoesters, have been widely investigated in recent years for their potential in a number of therapeutic applications. Phosphorus, as the central feature of these polymers, endears the chemical functionalization, and in some cases (bio)degradability, to facilitate their use in such therapeutic formulations. Recent advances in the synthetic polymer chemistry have allowed for controlled synthesis methods in order to prepare the complex macromolecular structures required, alongside the control and reproducibility desired for such medical applications. While the main polymer families described herein, polyphosphazenes and polyphosphoesters and their analogues, as well as phosphorus-based dendrimers, have hitherto predominantly been investigated in isolation from one another, this review aims to highlight and bring together some of this research. In doing so, the focus is placed on the essential, and often mutual, design features and structure-property relationships that allow the preparation of such functional materials. The first part of the review details the relevant features of phosphorus-containing polymers in respect to their use in therapeutic applications, while the second part highlights some recent and innovative applications, offering insights into the most state-of-the-art research on phosphorus-based polymers in a therapeutic context.
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Affiliation(s)
- Paul Strasser
- Institute of Polymer Chemistry, Johannes Kepler University Linz (JKU), Altenberger Straße 69, A-4040 Linz, Austria
| | - Ian Teasdale
- Institute of Polymer Chemistry, Johannes Kepler University Linz (JKU), Altenberger Straße 69, A-4040 Linz, Austria
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11
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Gascón E, Maisanaba S, Otal I, Valero E, Repetto G, Jones PG, Jiménez J. (Amino)cyclophosphazenes as Multisite Ligands for the Synthesis of Antitumoral and Antibacterial Silver(I) Complexes. Inorg Chem 2020; 59:2464-2483. [PMID: 31984738 DOI: 10.1021/acs.inorgchem.9b03334] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The reactivity of the multisite (amino)cyclotriphosphazene ligands, [N3P3(NHCy)6] and [N3P3(NHCy)3(NMe2)3], has been explored in order to obtain silver(I) metallophosphazene complexes. Two series of cationic silver(I) metallophosphazenes were obtained and characterized: [N3P3(NHCy)6{AgL}n](TfO)n [n = 2, L = PPh3 (2), PPh2Me (4); n = 3, L = PPh3 (3), PPh2Me (5), TPA (TPA = 1,3,5-triaza-7-phosphaadamantane, 6)] and nongem-trans-[N3P3(NHCy)3(NMe2)3{AgL}n](TfO)n [n = 2, L = PPh3 (7), PPh2Me (9); n = 3, L = PPh3 (8), PPh2Me (10)]. 5, 7, and 9 have also been characterized by single-crystal X-ray diffraction, thereby allowing key bonding information to be obtained. Compounds 2-6, 9, and 10 were screened for in vitro cytotoxic activity against two tumor human cell lines, MCF7 (breast adenocarcinoma) and HepG2 (hepatocellular carcinoma), and for antimicrobial activity against five bacterial species including Gram-positive, Gram-negative, and Mycobacteria strains. Both the IC50 and MIC values revealed excellent biological activity for these metal complexes, compared with their precursors and cisplatin and also AgNO3 and silver sulfadiazine, respectively. Both IC50 and MIC values are among the lowest values found for any silver derivatives against the cell lines and bacterial strains used in this work. The structure-activity relationships were clear. The most cytotoxic and antimicrobial derivatives were those with the triphenylphosphane and [N3P3(NHCy)6] ligands. A significant improvement in the activity was also observed upon a rise in the number of silver atoms linked to the phosphazene ring.
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Affiliation(s)
- Elena Gascón
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea , Universidad de Zaragoza-CSIC , Pedro Cerbuna 12 , 50009 Zaragoza , Spain
| | - Sara Maisanaba
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología , Universidad Pablo de Olavide , Ctra. Utrera, Km 1 , 41013 Sevilla , Spain
| | - Isabel Otal
- Grupo de Genética de Micobacterias, Departamento de Microbiología, Medicina Preventiva y Salud Pública , Universidad de Zaragoza , Zaragoza 50009 , Spain.,Instituto de Salud Carlos III , CIBER de Enfermedades Respiratorias , E-28029 Madrid , Spain
| | - Eva Valero
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área Nutrición y Bromatología , Universidad Pablo de Olavide , Ctra. Utrera, Km 1 , 41013 Sevilla , Spain
| | - Guillermo Repetto
- Departamento de Biología Molecular e Ingeniería Bioquímica, Área de Toxicología , Universidad Pablo de Olavide , Ctra. Utrera, Km 1 , 41013 Sevilla , Spain
| | - Peter G Jones
- Institut für Anorganische und Analytische Chemie , Technische Universität Braunschweig , Hagenring 30 , D-38106 Braunschweig , Germany
| | - Josefina Jiménez
- Departamento de Química Inorgánica, Facultad de Ciencias, Instituto de Síntesis Química y Catálisis Homogénea , Universidad de Zaragoza-CSIC , Pedro Cerbuna 12 , 50009 Zaragoza , Spain
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Aromatic vs. Aliphatic Hyperbranched Polyphosphoesters as Flame Retardants in Epoxy Resins. Molecules 2019; 24:molecules24213901. [PMID: 31671913 PMCID: PMC6864611 DOI: 10.3390/molecules24213901] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 12/03/2022] Open
Abstract
The current trend for future flame retardants (FRs) goes to novel efficient halogen-free materials, due to the ban of several halogenated FRs. Among the most promising alternatives are phosphorus-based FRs, and of those, polymeric materials with complex shape have been recently reported. Herein, we present novel halogen-free aromatic and aliphatic hyperbranched polyphosphoesters (hbPPEs), which were synthesized by olefin metathesis polymerization and investigated them as a FR in epoxy resins. We compare their efficiency (aliphatic vs. aromatic) and further assess the differences between the monomeric compounds and the hbPPEs. The decomposition and vaporizing behavior of a compound is an important factor in its flame-retardant behavior, but also the interaction with the pyrolyzing matrix has a significant influence on the performance. Therefore, the challenge in designing a FR is to optimize the chemical structure and its decomposition pathway to the matrix, with regards to time and temperature. This behavior becomes obvious in this study, and explains the superior gas phase activity of the aliphatic FRs.
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Kneidinger M, Iturmendi A, Ulbricht C, Truglas T, Groiss H, Teasdale I, Salinas Y. Mesoporous Silica Micromotors with a Reversible Temperature Regulated On-Off Polyphosphazene Switch. Macromol Rapid Commun 2019; 40:e1900328. [PMID: 31637803 DOI: 10.1002/marc.201900328] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/19/2019] [Indexed: 12/12/2022]
Abstract
The incorporation of an extraneous on-off braking system is necessary for the effective motion control of the next generation of micrometer-sized motors. Here, the design and synthesis of micromotors is reported based on mesoporous silica particles containing bipyridine groups, introduced by cocondensation, for entrapping catalytic cobalt(II) ions within the mesochannels, and functionalized on the surface with silane-derived temperature responsive bottle-brush polyphosphazene. Switching the polymers in a narrow temperature window of 25-30 °C between the swollen and collapsed state, allows the access for the fuel H2 O2 contained in the dispersion medium to cobalt(II) bipyridinato catalyst sites. The decomposition of hydrogen peroxide is monitored by optical microscopy, and effectively operated by reversibly closing or opening the pores by the grafted gate-like polyphosphazene, to control on demand the oxygen bubble generation. This design represents one of the few examples using temperature as a trigger for the reversible on-off external switching of mesoporous silica micromotors.
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Affiliation(s)
- Michael Kneidinger
- Institute of Polymer Chemistry (ICP), Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria
| | - Aitziber Iturmendi
- Institute of Polymer Chemistry (ICP), Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria
| | - Christoph Ulbricht
- Institute of Polymer Chemistry (ICP), Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria.,Institute of Physical Chemistry-Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria
| | - Tia Truglas
- Christian Doppler Laboratory for Nanoscale Phase Transformations Center of Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria
| | - Heiko Groiss
- Christian Doppler Laboratory for Nanoscale Phase Transformations Center of Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria
| | - Ian Teasdale
- Institute of Polymer Chemistry (ICP), Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria
| | - Yolanda Salinas
- Institute of Polymer Chemistry (ICP), Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria
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14
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Vidal F, Jäkle F. Functional Polymeric Materials Based on Main‐Group Elements. Angew Chem Int Ed Engl 2019; 58:5846-5870. [DOI: 10.1002/anie.201810611] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Indexed: 12/11/2022]
Affiliation(s)
- Fernando Vidal
- Department of Chemistry Rutgers University—Newark 73 Warren Street Newark NJ 07102 USA
| | - Frieder Jäkle
- Department of Chemistry Rutgers University—Newark 73 Warren Street Newark NJ 07102 USA
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15
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Vidal F, Jäkle F. Funktionelle polymere Materialien auf der Basis von Hauptgruppen‐Elementen. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201810611] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Fernando Vidal
- Department of Chemistry Rutgers University—Newark 73 Warren Street Newark NJ 07102 USA
| | - Frieder Jäkle
- Department of Chemistry Rutgers University—Newark 73 Warren Street Newark NJ 07102 USA
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16
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Quiñones JP, Iturmendi A, Henke H, Roschger C, Zierer A, Brüggemann O. Polyphosphazene-based nanocarriers for the release of agrochemicals and potential anticancer drugs. J Mater Chem B 2019; 7:7783-7794. [DOI: 10.1039/c9tb01985e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesised polyphosphazene-based nanocarriers allowed sustained diosgenin and brassinosteroid release over 4 days, with strong to moderate MCF-7 cytotoxicity and good agrochemical activity at medium and low concentrations.
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Affiliation(s)
| | - Aitziber Iturmendi
- Institute of Polymer Chemistry (ICP)
- Johannes Kepler University Linz
- 4040 Linz
- Austria
| | - Helena Henke
- Institute of Polymer Chemistry (ICP)
- Johannes Kepler University Linz
- 4040 Linz
- Austria
| | - Cornelia Roschger
- Johannes Kepler University Linz
- Kepler University Hospital GmbH
- Department for Cardiac-, Vascular- and Thoracic Surgery
- 4020 Linz
- Austria
| | - Andreas Zierer
- Johannes Kepler University Linz
- Kepler University Hospital GmbH
- Department for Cardiac-, Vascular- and Thoracic Surgery
- 4020 Linz
- Austria
| | - Oliver Brüggemann
- Institute of Polymer Chemistry (ICP)
- Johannes Kepler University Linz
- 4040 Linz
- Austria
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Wolf T, Wurm FR. Organocatalytic Ring-opening Polymerization Towards Poly(cyclopropane)s, Poly(lactame)s, Poly(aziridine)s, Poly(siloxane)s, Poly(carbosiloxane)s, Poly(phosphate)s, Poly(phosphonate)s, Poly(thiolactone)s, Poly(thionolactone)s and Poly(thiirane)s. ORGANIC CATALYSIS FOR POLYMERISATION 2018. [DOI: 10.1039/9781788015738-00406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The following chapter is a collection of monomers that undergo organocatalyzed ring-opening polymerizations and have not been covered in a separate chapter of this book. This includes polymers widely used in industrial applications, but also solely academically relevant and more “exotic” polymer classes. As most of these polymers contain heteroatoms in their backbone, the chapter is divided according to the respective heteroatoms. Each sub-section first gives a short introduction to the respective polymer or monomer properties and industrial applications (if available), followed by a brief summary of the traditional synthetic pathways. Afterwards, important milestones for the organocatalytic ROP are presented in chronological order. Special emphasis is put on the advantages and disadvantages of organocatalysis over traditional (ROP) methods on the basis of appropriate literature examples.
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Affiliation(s)
- Thomas Wolf
- Max Planck-Institut für Polymerforschung Ackermannweg 10 55128 Mainz Germany
| | - Frederik R. Wurm
- Max Planck-Institut für Polymerforschung Ackermannweg 10 55128 Mainz Germany
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18
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Carriedo GA, de la Campa R, Soto AP. Polyphosphazenes - Synthetically Versatile Block Copolymers (“Multi-Tool”) for Self-Assembly. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800126] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Gabino A. Carriedo
- Department of Organic and Inorganic Chemistry; Facultad de Química; Universidad de Oviedo; Julián Clavería s/n 33006 Oviedo Spain
| | - Raquel de la Campa
- Department of Organic and Inorganic Chemistry; Facultad de Química; Universidad de Oviedo; Julián Clavería s/n 33006 Oviedo Spain
| | - Alejandro Presa Soto
- Department of Organic and Inorganic Chemistry; Facultad de Química; Universidad de Oviedo; Julián Clavería s/n 33006 Oviedo Spain
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19
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Linhardt A, König M, Iturmendi A, Henke H, Brüggemann O, Teasdale I. Degradable, Dendritic Polyols on a Branched Polyphosphazene Backbone. Ind Eng Chem Res 2018; 57:3602-3609. [PMID: 29568158 PMCID: PMC5857928 DOI: 10.1021/acs.iecr.7b05301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/16/2018] [Accepted: 02/23/2018] [Indexed: 11/30/2022]
Abstract
Herein, we present the design, synthesis, and characterization of fully degradable, hybrid, star-branched dendritic polyols. First multiarmed polyphosphazenes were prepared as a star-branched scaffold which upon functionalization produced globular branched hydroxyl-functionalized polymers with over 1700 peripheral functional end groups. These polyols with unique branched architectures could be prepared with controlled molecular weights and relatively narrow dispersities. Furthermore, the polymers are shown to undergo hydrolytic degradation to low molecular weight degradation products, the rate of which could be controlled through postpolymerization functionalization of the phosphazene backbone.
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Affiliation(s)
- Anne Linhardt
- Institute of Polymer Chemistry, Johannes
Kepler University Linz (JKU), Altenberger Straße 69, A-4040 Linz, Austria
| | - Michael König
- Institute of Polymer Chemistry, Johannes
Kepler University Linz (JKU), Altenberger Straße 69, A-4040 Linz, Austria
| | - Aitziber Iturmendi
- Institute of Polymer Chemistry, Johannes
Kepler University Linz (JKU), Altenberger Straße 69, A-4040 Linz, Austria
| | - Helena Henke
- Institute of Polymer Chemistry, Johannes
Kepler University Linz (JKU), Altenberger Straße 69, A-4040 Linz, Austria
| | - Oliver Brüggemann
- Institute of Polymer Chemistry, Johannes
Kepler University Linz (JKU), Altenberger Straße 69, A-4040 Linz, Austria
| | - Ian Teasdale
- Institute of Polymer Chemistry, Johannes
Kepler University Linz (JKU), Altenberger Straße 69, A-4040 Linz, Austria
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20
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Khan RU, Wang L, Yu H, Zain-ul-Abdin, Akram M, Wu J, Haroon M, Ullah RS, Deng Z, Xia X. Recent progress in the synthesis of poly(organo)phosphazenes and their applications in tissue engineering and drug delivery. RUSSIAN CHEMICAL REVIEWS 2018. [DOI: 10.1070/rcr4757] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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21
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Tsao YYT, Smith TH, Wooley KL. Regioisomeric Preference in Ring-Opening Polymerization of 3',5'-Cyclic Phosphoesters of Functional Thymidine DNA Analogues. ACS Macro Lett 2018; 7:153-158. [PMID: 35610911 DOI: 10.1021/acsmacrolett.7b00858] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Regioregularity is a crucial property in the synthesis of DNA analogues, as natural DNA is synthesized exclusively in the 5' to 3' direction. We have focused our attention on the determination of the regioisomeric distribution of poly(3',5'-cyclic 3-(3-butenyl) thymidine ethylphosphate)s obtained from the ring-opening polymerization of (R)-3',5'-cyclic 3-(3-butenyl) thymidine ethylphosphate. The regioisomeric preference was investigated by comparison to synthesized model compounds of 3',3'-, 3',5'-, and 5',5'-linkages, where the model 3'-phosphoester linkages were to the secondary alcohol of 3-hydroxytetrahydrofuran and the model 5'-linkages derived from coupling to the primary alcohol of tetrahydrofurfuryl alcohol. From the 31P resonance frequency assignments of those small molecule model compounds, 31P NMR spectra revealed the major connectivity in the polymer backbone to be 3',5'-linkages, with ≤30% of other isomeric forms. Model reactions employing a series of alcohol initiators imparting various degrees of steric hindrance, to mimic the increased steric hindrance of the propagating alcohol relative to the initiator, were then conducted to afford the corresponding ring-opened unimer adducts and to gain understanding of the regioselectivity during the ring-opening polymerization. 1H-31P heteronuclear multiple-bond correlation spectroscopy showed ethanol and 4-methoxybenzyl alcohol initiation to yield only the P-O5' bond cleavage product, whereas attack by isopropyl alcohol upon (R)-3',5'-cyclic 3-(3-butenyl) thymidine ethylphosphate afforded both P-O3' and P-O5' bond cleavage products, supporting our hypothesis that the increased steric hindrance of the propagating species dictates the regioselectivity of the P-O bond cleavage. Further model reactions suggested that the P-O5' bond cleavage products can be detected upon the formation of dimers during the ring-opening polymerization. Overall, this work provides a fundamental understanding of the polymerization behavior of six-membered cyclic phosphoesters and broadens the scope of DNA analogues from the ring-opening polymerization of 3',5'-cyclic phosphoesters.
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Affiliation(s)
- Yi-Yun Timothy Tsao
- Departments of Chemistry, Chemical Engineering, Materials Science & Engineering, and The Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842-3012, United States
| | - Travis H. Smith
- Departments of Chemistry, Chemical Engineering, Materials Science & Engineering, and The Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842-3012, United States
| | - Karen L. Wooley
- Departments of Chemistry, Chemical Engineering, Materials Science & Engineering, and The Laboratory for Synthetic-Biologic Interactions, Texas A&M University, College Station, Texas 77842-3012, United States
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22
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Bashmakov YK, Petyaev IM. Dendrimers, Carotenoids, and Monoclonal Antibodies. Monoclon Antib Immunodiagn Immunother 2017; 36:208-213. [PMID: 28994638 DOI: 10.1089/mab.2017.0032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Dendrimers are unimolecular architectural nano- or microparticle entities that can accommodate various nutraceuticals and pharmaceuticals between their branches (dendrons) and provide targeted delivery of biomimetics into different tissues upon addition of functionalized groups to the dendrimer's surface. Covalent binding, hydrogen bonds, and electrostatic interactions between dendrimer-composing molecules are known to form and stabilize dendrimer structure. Carotenoids have recently been shown to form dendrimer-like structures and promote targeted delivery of "cargo" molecules into organs characterized by high-carotenoid uptake (adrenal glands, prostate, liver, and brain). The use of carotenoid dendrimers, in particular lycosome particles loaded with various xenobiotics (resveratrol, cocoa flavanols, and HMG-CoA reductase inhibitors), reportedly has a beneficial effect in diabetic foot syndrome, prehypertension, and cardiovascular disease. New applications for carotenoid dendrimers may arise from the use of complexes formed by carotenoid dendrimers and monoclonal antibodies (mAbs). The internalization of carotenoid dendrimer-mAb complexes through receptor-mediated mechanisms may prevent interactions of dendrimer-incorporated xenobiotics with membrane-associated P-glycoprotein, a major factor of drug resistance in tumor cells. The incorporation of mAb fragments with higher binding capacity to the membrane receptors and higher affinity to the target molecule may further increase the bioavailability of "cargo" molecules transported by the carotenoid dendrimer-mAb complexes and open new doors in nanodelivery technologies.
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23
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Yang DP, Oo MNNL, Deen GR, Li Z, Loh XJ. Nano-Star-Shaped Polymers for Drug Delivery Applications. Macromol Rapid Commun 2017; 38. [PMID: 28895248 DOI: 10.1002/marc.201700410] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 06/28/2017] [Indexed: 12/19/2022]
Abstract
With the advancement of polymer engineering, complex star-shaped polymer architectures can be synthesized with ease, bringing about a host of unique properties and applications. The polymer arms can be functionalized with different chemical groups to fine-tune the response behavior or be endowed with targeting ligands or stimuli responsive moieties to control its physicochemical behavior and self-organization in solution. Rheological properties of these solutions can be modulated, which also facilitates the control of the diffusion of the drug from these star-based nanocarriers. However, these star-shaped polymers designed for drug delivery are still in a very early stage of development. Due to the sheer diversity of macromolecules that can take on the star architectures and the various combinations of functional groups that can be cross-linked together, there remain many structure-property relationships which have yet to be fully established. This review aims to provide an introductory perspective on the basic synthetic methods of star-shaped polymers, the properties which can be controlled by the unique architecture, and also recent advances in drug delivery applications related to these star candidates.
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Affiliation(s)
- Da-Peng Yang
- College of Chemical Engineering & Materials Science, Quanzhou Normal University, Quanzhou, 362000, China
| | - Ma Nwe Nwe Linn Oo
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive Singapore, Singapore, 637459, Singapore
| | - Gulam Roshan Deen
- Soft Materials Laboratory, Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, Singapore, 637459, Singapore
| | - Zibiao Li
- Institute of Materials Research and Engineering (IMRE), A*STAR, 2 Fusionopolis Way, Innovis, #08-03, Singapore, 138634, Singapore
| | - Xian Jun Loh
- Institute of Materials Research and Engineering (IMRE), A*STAR, 2 Fusionopolis Way, Innovis, #08-03, Singapore, 138634, Singapore.,Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Singapore
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24
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Hackl CM, Schoenhacker-Alte B, Klose MHM, Henke H, Legina MS, Jakupec MA, Berger W, Keppler BK, Brüggemann O, Teasdale I, Heffeter P, Kandioller W. Synthesis and in vivo anticancer evaluation of poly(organo)phosphazene-based metallodrug conjugates. Dalton Trans 2017; 46:12114-12124. [PMID: 28862707 DOI: 10.1039/c7dt01767g] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Within this work we aimed to improve the pharmacodynamics and toxicity profile of organoruthenium and -rhodium complexes which had previously been found to be highly potent in vitro but showed unselective activity in vivo. Different organometallic complexes were attached to a degradable poly(organo)phosphazene macromolecule, prepared via controlled polymerization techniques. The conjugation to hydrophilic polymers was designed to increase the aqueous solubility of the typically poorly soluble metal-based half-sandwich compounds with the aim of a controlled, pH-triggered release of the active metallodrug. The synthesized conjugates and their characteristics have been thoroughly studied by means of 31P NMR and UV-Vis spectroscopy, ICP-MS analyses and SEC coupled to ICP-MS. In order to assess their potential as possible anticancer drug candidates, the complexes, as well as their respective macromolecular prodrug formulations were tested against three different cancer cell lines in cell culture. Subsequently, the anticancer activity and organ distribution of the poly(organo)phosphazene drug conjugates were explored in vivo in mice bearing CT-26 colon carcinoma. Our investigations revealed a beneficial influence of this macromolecular prodrug by a significant reduction of adverse effects compared to the free metallodrugs.
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Affiliation(s)
- Carmen M Hackl
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, 1090 Wien, Austria.
| | - Beatrix Schoenhacker-Alte
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, 1090 Wien, Austria. and Institute of Cancer Research and Comprehensive Cancer Center, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, 1090 Vienna, Austria. and Research Cluster "Translational Cancer Therapy Research", University of Vienna, Waehringer Str. 42, 1090 Wien, Austria
| | - Matthias H M Klose
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, 1090 Wien, Austria.
| | - Helena Henke
- Institute of Polymer Chemistry, Johannes Kepler University Linz (JKU), Altenberger Straße 69, 4040 Linz, Austria
| | - Maria S Legina
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, 1090 Wien, Austria.
| | - Michael A Jakupec
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, 1090 Wien, Austria. and Research Cluster "Translational Cancer Therapy Research", University of Vienna, Waehringer Str. 42, 1090 Wien, Austria
| | - Walter Berger
- Institute of Cancer Research and Comprehensive Cancer Center, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, 1090 Vienna, Austria. and Research Cluster "Translational Cancer Therapy Research", University of Vienna, Waehringer Str. 42, 1090 Wien, Austria
| | - Bernhard K Keppler
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, 1090 Wien, Austria. and Research Cluster "Translational Cancer Therapy Research", University of Vienna, Waehringer Str. 42, 1090 Wien, Austria
| | - Oliver Brüggemann
- Institute of Polymer Chemistry, Johannes Kepler University Linz (JKU), Altenberger Straße 69, 4040 Linz, Austria
| | - Ian Teasdale
- Institute of Polymer Chemistry, Johannes Kepler University Linz (JKU), Altenberger Straße 69, 4040 Linz, Austria
| | - Petra Heffeter
- Institute of Cancer Research and Comprehensive Cancer Center, Department of Medicine I, Medical University of Vienna, Borschkegasse 8a, 1090 Vienna, Austria. and Research Cluster "Translational Cancer Therapy Research", University of Vienna, Waehringer Str. 42, 1090 Wien, Austria
| | - Wolfgang Kandioller
- Institute of Inorganic Chemistry, University of Vienna, Waehringer Str. 42, 1090 Wien, Austria. and Research Cluster "Translational Cancer Therapy Research", University of Vienna, Waehringer Str. 42, 1090 Wien, Austria
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25
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Iturmendi A, Monkowius U, Teasdale I. Oxidation Responsive Polymers with a Triggered Degradation via Arylboronate Self-Immolative Motifs on a Polyphosphazene Backbone. ACS Macro Lett 2017; 6:150-154. [PMID: 28251035 PMCID: PMC5322476 DOI: 10.1021/acsmacrolett.7b00015] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 01/31/2017] [Indexed: 01/25/2023]
Abstract
Oxidation responsive polymers with triggered degradation pathways have been prepared via attachment of self-immolative moieties onto a hydrolytically unstable polyphosphazene backbone. After controlled main-chain growth, postpolymerization functionalization allows the preparation of hydrolytically stable poly(organo)phosphazenes decorated with a phenylboronic ester caging group. In oxidative environments, triggered cleavage of the caging group is followed by self-immolation, exposing the unstable glycine-substituted polyphosphazene which subsequently undergoes to backbone degradation to low-molecular weight molecules. As well as giving mechanistic insights, detailed GPC and 1H and 31P NMR analysis reveal the polymers to be stable in aqueous solutions, but show a selective, fast degradation upon exposure to hydrogen peroxide containing solutions. Since the post-polymerization functionalization route allows simple access to polymer backbones with a broad range of molecular weights, the approach of using the inorganic backbone as a platform significantly expands the toolbox of polymers capable of stimuli-responsive degradation.
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Affiliation(s)
- Aitziber Iturmendi
- Institute of Polymer Chemistry and Institute of Inorganic Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria
| | - Uwe Monkowius
- Institute of Polymer Chemistry and Institute of Inorganic Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria
| | - Ian Teasdale
- Institute of Polymer Chemistry and Institute of Inorganic Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz, Austria
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