Polymer CommunicationThe direct polymerization of 2-methacryloxyethyl glucoside via aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization
Introduction
In recent years there has been increasing interest in (co)polymers bearing sugar moieties—so called ‘glycopolymers’—due in part to their biomimetic properties [1]. Synthetic glycopolymers may be synthesized via two broad methods: (1) the polymerization of sugar-bearing monomers and (2) the post-polymerization modification of preformed polymers with sugar-containing reagents. The polymerization of glycomonomers has been reported by a wide variety of techniques such as traditional free radical, [2] ring-opening, [3], [4] anionic, [5] coordination, [6] cationic, [7], [8] stable free radical, [9], [10], [11] and atom transfer radical [12], [13] polymerization (ATRP) methods. However, with only a few exceptions, notably hydrogels prepared by traditional free radical polymerization, certain statistical copolymers prepared by cyanoxyl-mediated polymerizations, and a recent report detailing the polymerization of 2-gluconamidoethyl methacrylate via ATRP, the above techniques have typically employed the use of protected glycomonomers for successful polymerization, followed by selective deprotection.
Clearly, the ability to directly polymerize glycomonomers without the need for protecting group chemistry is beneficial. To this end, we recently examined reversible addition-fragmentation chain transfer (RAFT) [14] polymerization as a possible candidate for accomplishing this. RAFT has proven to be an extremely versatile controlled free radical polymerization (CRP) technique, applicable to a wide range of monomers, [15], [16], [17] functionality, [17], [18], [19], [20], [21] and conditions, [22], [23], [24], [25], [26], [27], [28], [29] and importantly is also readily conducted in aqueous media [30]. For example, historically ‘problematic’ monomers such as acrylamido [17], [20], [31], [32], [33], [34], [35], [36], [37], [38] derivatives are generally readily polymerized in a controlled fashion under RAFT conditions in both aqueous and non-aqueous media. Herein, we report preliminary observations for the direct polymerization of 2-methacryloxyethyl glucoside (MAGlu) directly in aqueous media without the use of protecting group chemistries, see Scheme 1.
Section snippets
Materials
MAGlu was purchased from Polysciences Inc. as a 50 wt% aqueous solution (mixture of anomers) and was purified by passage over a column of basic alumina. The azo initiator, V-501, was a gift from Wako and was recrystallized from methanol prior to use. 4-Cyano-4-methyl-4-thiobenzoylsulfanyl butyric acid (CTP) was prepared according to the method previously reported [21].
Homopolymerization of MAGlu
To a 20 ml scintillation vial equipped with a magnetic stir bar was added MAGlu (as a 50 wt% solution, 2.53 g, 1.71 M) and CTP
Homopolymerization of MAGlu
The direct polymerization of the glycomonomer MAGlu in aqueous media via RAFT has been attempted using CTP as the RAFT CTA, and V-501 as the azo initiator. CTP was chosen for its inherent water-solubility and the fact that cyanoalkyl derivatives of dithiobenzoates are particularly effective for the controlled polymerization of methacrylates [39]. Fig. 1 shows the experimentally determined molecular weight (MW) distributions with increasing conversion for a polyMAGlu (PMAGlu) homopolymer.
It is
Concluding remarks
Herein we have reported preliminary observations regarding the aqueous RAFT polymerization of MAGlu, without the need for protecting group chemistries, at 70 °C employing CTP as the RAFT CTA. The homopolymerization displays the characteristics of a controlled/living polymerization although deviations from the theoretical MW are observed at higher conversions. Also, we have shown that it is possible to produce novel sugar-based AB-diblock copolymers in which MAGlu may be polymerized first or
Acknowledgements
ABL wishes to thank the Chair of the Department of Chemistry and Biochemistry, the Dean of the College of Science and Technology and the VP for Research at the University of Southern Mississippi for generous start-up funds.
References (45)
Prog Polym Sci
(2001)- et al.
J Biomed Mater Res
(1998) - et al.
Macromolecules
(1996) - et al.
Macromolecules
(1999) - et al.
J Polym Sci Polym Chem
(2001) - et al.
Macromolecules
(2001) - et al.
Macromol Chem Phys
(2002) - et al.
Macromolecules
(2002) - et al.
Macromolecules
(2001) - et al.
J Polym Sci Polym Chem
(2002)
Macromolecules
Polym Sci Polym Chem
Chem Commun
Macromolecules
Controlled/living radical polymerization
Macromolecules
J Polym Sci Polym Chem
J Polym Sci Polym Chem
Macromol Rapid Commun
Macromolecules
Macromolecules
Macromolecules
Cited by (146)
Glycopolymers based on carbohydrate or vinyl backbones and their biomedical applications
2023, Polymer ChemistryMolecular imprinting and surface grafting of glycoprotein fragments in polymeric nanosystems: from cancer diagnosis to virus targeting
2023, Polymeric Nanosystems: Theranostic Nanosystems: Volume 1Synthesis of core-shell structure based on silica nanoparticles and methacrylic acid via RAFT method: An efficient pH-sensitive hydrogel for prolonging doxorubicin release
2021, Journal of Drug Delivery Science and TechnologyCitation Excerpt :CRP consists of several polymerization techniques like nitroxide-mediated radical polymerization (NMP), atom transfer radical polymerization (ATRP), and RAFT polymerization [56,57]. RAFT polymerization to comparison with other CRP techniques demonstrated more advantages such as the ability to synthesize high molecular weight (Mw) polymer by controlling Mw distribution, uses approximately all types of monomers, low sensitivity for environmental conditions, and temperature, and macromolecular architecture [58–60]. This paper aimed to design a new pH-responsive prolonged drug delivery system (DDS) based on core-shell hydrogel via RAFT polymerization using Ethylene glycol dimethacrylate as cross-linker, including SNPs as a core and PMAA Hydrogel as a shell.
Glyco-Nanomedicines and Their Applications in Cancer Treatment
2021, Comprehensive Glycoscience: Second Edition
- 1
Present address: Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, USA.