An efficient and metal‐catalyst free method of glycopolymer synthesis via thiol/para‐fluorine “click” reaction was used to graft acetylated 1‐thio‐β‐D ‐glucopyranose and 1‐thio‐β‐D ‐galactopyranose onto a homopolymer of pentafluorostyrene (PFS) as well as onto a block copolymer of styrene and PFS. Subsequent deprotection of the carbohydrate moieties yielded well‐defined, sugar‐modified polymers (PDI < 1.2). The prepared polymers were not cytotoxic against 3T3 fibroblasts and MC3T3‐E1 preosteoblasts. Furthermore, the water‐insoluble copolymers were drop‐cast and examined as synthetic biocompatible coatings on poly(propylene) substrates for culturing the investigated cell types. Both fibro‐ and preosteoblasts showed stable adhesion and proliferation on the glycopolymer‐coated surfaces.
The synthesis and characterization of spherical sugar-containing polymer brushes consisting of PS cores onto which chains of sugar-containing polymers have been grafted via two different techniques are described. Photopolymerization in aqueous dispersion using the functional monomer MAGlc and crosslinked or non-crosslinked PS particles covered with a thin layer of photo-initiator yielded homogeneous glycopolymer brushes attached to spherical PS cores. As an alternative, ATRP was used to graft poly-(N-acetylglucosamine) arms from crosslinked PS cores. Deprotection of the grafted brushes led to water-soluble particles that act as carriers for catalytically active gold nanoparticles. These glycopolymer chains show a high affinity to adsorb WGA whereas no binding to BSA or PNA could be detected. 相似文献
Binding of mannose presenting macromolecules to the protein receptor concanavalin A (ConA) is investigated by means of single‐molecule atomic force spectroscopy (SMFS) in combination with dynamic light scattering and molecular modeling. Oligomeric (Mw ≈ 1.5–2.5 kDa) and polymeric (Mw ≈ 22–30 kDa) glycomacromolecules with controlled number and positioning of mannose units along the scaffolds accessible by combining solid phase synthesis and thiol–ene coupling are used as model systems to assess the molecular mechanisms that contribute to multivalent ConA–mannose complexes. SMFS measurements show increasing dissociation force from monovalent (≈57 pN) to pentavalent oligomers (≈75 pN) suggesting subsite binding to ConA. Polymeric glycomacromolecules with larger hydrodynamic diameters compared to the binding site spacing of ConA exhibit larger dissociation forces (≈80 pN), indicating simultaneous dissociation from multiple ConA binding sites. Nevertheless, although simultaneous dissociation of multiple ligands could be expected for such multivalent systems, predominantly single dissociation events are observed. This is rationalized by strong coiling of the macromolecules' polyamide backbone due to intramolecular hydrogen bonding hindering unfolding of the coil. Therefore, this study shows that the design of glycopolymers for multivalent receptor binding and clustering must consider 3D structure and intramolecular interactions of the scaffold. 相似文献
A thermoresponsive block copolymer, namely poly(acryloyl glucosamine)‐block‐poly(N‐isopropylacryamide) (PAGA180‐b‐PNIPAAM350) was simultaneously self‐assembled and crosslinked in aqueous medium via RAFT polymerization at 60 °C to afford core‐crosslinked micelles exhibiting a glycopolymer corona and a PNIPAAM stimuli‐responsive core. An acid‐labile crosslinking agent, 3,9‐divinyl‐2,4,8,10‐tetraoxaspiro[5.5]undecane, was employed to generate thermosensitive and acid‐degradable core‐shell nanoparticles. Stable against degradation at pH = 6 and 8.2, the resulting core crosslinked micelles readily hydrolyzed into well‐defined free block copolymers at lower pH (30 min and 12 h respectively at pH = 2 and 4).
There is a common phenomenon that the heterogeneity of natural oligosaccharides contains various sugar units, which can be used to enhance affinity and selectivity toward a specific receptor, so the synthesis of heterogeneous glycopolymers is always an important issue in the glycopolymer field. Herein, this study conducts a one‐pot method to prepare polyrotaxane‐based heteroglycopolymers anchored with different sugar units and fluorescent moieties via the combination of host–guest interaction, thiol‐ene, and copper‐catalyzed click chemistry in water. Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography, X‐ray diffraction, and Ellman's assay test are used in the paper to characterize the compounds. Quartz crystal microbalance‐dissipation (QCD‐D) experiments and bacterial adhesion assay are utilized to study the interactions of polyrotaxane‐based heteroglycopolymers with Con A and Escherichia coli . The results reveal that polyrotaxanes (PRs) with mannose and glucose present better specificity toward Con A and E. coli than PRs with glucose due to synergistic effects. 相似文献
Summary: The chemo-enzymatic synthesis of 6-O-methacryloyl mannose (MaM) glycomonomer was successfully performed for the first time. Subsequent aqueous RAFT polymerization of the monomer yielded well-defined, linear poly(6-O-methacryloyl mannose) (PMaM) glycopolymers without the need for protecting and deprotecting group chemistry. As well as investigating the RAFT polymerization kinetics of this monomer using various initial monomer to chain transfer agent concentration ratios, the protein binding ability of the generated glycopolymer was tested using concanavalin A, a known mannose-residue binding lectin. 相似文献
A poly(tert‐butyl acrylate) (P(tBA)) with a glycodendric endfunctionality with eight glucose moieties was synthesised in four steps via a combination of esterification, thiol‐alkyne conjugation and hetero‐Diels–Alder (HDA) cycloaddition. A linear glycopolymer of similar size and composition was also synthesised in order to compare the protein binding characteristics of the polymer with glycodendritic endfunctionality to the linear glycol blockcopolymer. The two amphiphilic polymers were self‐assembled in water into micelles. These particles were then tested for their ability to bind to Concanavalin A (Con A). In a turbidity assay, the polymer glycodendron exhibited a significantly faster clustering rate to the lectin as compared to the linear glycopolymer. In a precipitation assay, it is found that significantly less glucose residue is required for binding per Con A for the polymer with the glycodendritic endfunctionality.
A new multivalent glycopolymer platform for lectin recognition is introduced in this work by combining the controlled growth of glycopolymer brushes with highly specific glycosylation reactions. Glycopolymer brushes, synthetic polymers with pendant saccharides, are prepared by surface‐initiated atom transfer radical polymerization (SI‐ATRP) of 2‐O‐(N‐acetyl‐β‐d ‐glucosamine)ethyl methacrylate (GlcNAcEMA). Here, the fabrication of multivalent glycopolymers consisting of poly(GlcNAcEMA) is reported with additional biocatalytic elongation of the glycans directly on the silicon substrate by specific glycosylation using recombinant glycosyltransferases. The bioactivity of the surface‐grafted glycans is investigated by fluorescence‐linked lectin assay. Due to the multivalency of glycan ligands, the glycopolymer brushes show very selective, specific, and strong interactions with lectins. The multiarrays of the glycopolymer brushes have a large potential as a screening device to define optimal‐binding environments of specific lectins or as new simplified diagnostic tools for the detection of cancer‐related lectins in blood serum.