Search

We report a novel glycan array architecture that binds the mannose-specific glycan binding protein, concanavalin A (ConA), with sub-femtomolar avidity. A new radical photopolymerization developed specifically for this application combines the grafted-from thiol-(meth)acrylate polymerization with thiol-ene chemistry to graft glycans to the growing polymer brushes. The propagation of the brushes was studied by carrying out this grafted-to/grafted-from radical photopolymerization (GTGFRP) at >400 different conditions using hypersurface photolithography, a printing strategy that substantially accelerates reaction discovery and optimization on surfaces. The effect of brush height and the grafting density of mannosides on the binding of ConA to the brushes was studied systematically, and we found that multivalent and cooperative binding account for the unprecedented sensitivity of the GTGFRP brushes. This study further demonstrates the ease with which new chemistry can be tailored for an application as a result of the advantages of hypersurface photolithography.

Multivalent antibody-recruiting glycopolymers (MARGs) composed of hyaluronic acid (HA) grafted with multiple copies of dinitrophenol (DNP) were developed for targeted cancer immunotherapy. Structure-activity studies demonstrated that the MARGs were able to specifically recognize CD44-positive cancer cells and displayed remarkable antibody-recruiting capacities and tumor cell killing activities dependent on the introduced multivalent effect and the length of PEG linker. One of the MARGs, HA-[PEG3 -DNP]8 , showed the best capacity for clustering anti-DNP antibodies onto CD44-positive cancer cells and displayed potent in vitro anti-cancer activity by triggering complement dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC). Moreover, we found that HA-[PEG3 -DNP]8 significantly inhibited the xenograft tumor growth of Babl/c nude mice bearing triple negative breast cancer cells, while it did not cause detectable histological cytotoxicity. Given the easy access of this type of natural glycopolymer and the practical synthesis approach, these MARGs provide promising immunotherapeutics for cancer immunotherapy.

Multiblock glycopolymers have gathered attention because of their potential use as effective ligands for sugar‐binding proteins. The authors report the quantitative preparation of multiblock glycopolymers by reversible addition‐fragmentation chain transfer polymerization. The optimized polymerization condition enabled the complete monomer incorporation into the elongating polymer chains at each polymerization step. The structure of the heptablock glycopolymer was well‐defined (polydispersity index

The capability of a polymer to depolymerize, regenerating its original monomer for further polymerization, is very attractive in terms of sustainability. Recently discovered sugar poly(orthoesters) are an important class of glycopolymer. The high sensitivity of the backbone orthoester linkage toward acidolysis provides a valuable model to study the depolymerization. Herein, a sugar poly(orthoester) is shown to be completely depolymerized under acidic conditions. Interestingly, instead of the original monomer, the depolymerization gave a stable cyclic product (1,6-anhydro glucopyranose) in most cases, which was kinetically and thermodynamically favored. However, this pathway could be inhibited by chemically deactivating a key intermediate and thus favoring the formation of the original monomer. Efficient repolymerizaton of the regenerated monomer is also demonstrated.

Inspired by natural saccharide-protein complexes, a stimuli-responsive biodegradable and branched glycopolymer-pyropheophorbide-a (Ppa) conjugate (BSP) with saccharide units for cancer therapy is constructed. A linear glycopolymeric conjugate (LSP), a branched glycopolymeric conjugate (BShP) from Ppa with long carbon chains, and a branched conjugate (BHSP) based on poly[N-(2-hydroxypropyl) methacrylamide] (polyHPMA) without saccharide units are prepared as controls. Through structure-activity relationship studies, BSP with a 3D network structure forms stable nanostructures via weak intermolecular interactions, regulating the stacking state of Ppa to improve the singlet oxygen quantum yield and the corresponding photodynamic therapy (PDT) effect. BSP shows high loading of olaparib, and are further coated with tumor cell membranes, resulting in a biomimetic nanomedicine (CM-BSPO). CM-BSPO shows highly efficient tumor targeting and cellular internalization properties. The engulfment of CM-BSPO accompanied with laser irradiation results in a prominent antitumor effect, evidenced by disruption of cell cycles in tumor cells, increased apoptosis and DNA damage, and subsequent inhibition of repair for damaged DNA. The mechanism for the synergistic effect from PDT and olaparib is unveiled at the genetic and protein level through transcriptome analysis. Overall, this biodegradable and branched glycopolymer-drug conjugate could be effectively optimized as a biomimetic nanomedicine for cancer therapy.

The hierarchically bicontinuous polystyrene monoliths (HBPMs) with homogeneous skeletons and glycopolymer surfaces are fabricated for the first time based on the medium internal phase emulsion (MIPE) templating method via activator generated by electron transfer for atom transfer radical polymerization (AGET ATRP). The synergistic self-assembly of amphiphilic diblock glycopolymer (ADG) and Pluronic F127 (PF127) at the oil/water interface via hydrogen bonding interaction contributes to the formation of bicontinuous MIPE with deformed neighboring water droplets, resulting in the highly interconnected HBPM after polymerization. There is a bimodal pore size distribution in the HBPM, that is, through pores (150-5000 nm) and mesopores (10-150 nm). The HBPMs as prepared show excellent biocompatibility, homogeneous skeletons, strong mechanical strength, and high bed permeability, overcoming the practical limitations of the second generation of polystyrene (PS) monoliths. Glycoprotein concanavalin A (Con A) can be easily and quickly separated by the HBPM in hydrophilic interaction chromatography (HILIC) mode. These results suggest the HBPMs have great potentials in catalysis, separations, and biomedical applications.

Glycopolymers have been widely used to understand the interactions between carbohydrates and lectins, which facilitate the diagnosis and detection of disease and pathogens as well as the development of vaccines. While studies have been focused on the correlation of glycopolymer structure and their binding to lectins, graft-type glycopolyesters are uncommon. Herein, we report the design and synthesis of mannose-based graft polyesters by “grafting-from” method and investigate their interactions with Concanavalin A (Con A). As confirmed by 1H NMR spectroscopy and sulfuric acid-UV method, graft polyesters with different lengths of mannose graft were successfully synthesized. Our results from turbidimetry binding assay showed that graft polyesters with longer mannose graft exhibit higher initial binding rate (ki). Isothermal titration calorimetry measurements of these graft polyesters with Con A showed that polymers exhibit higher binding affinity (ka) with the number of side chain mannose. This study provides understanding of the interaction between Con A and mannose-based graft polyesters, which can be employed for the development of glycopolymeric therapeutics. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3908–3917

The block glycopolymer, poly(2-(α-d-mannopyranosyloxy)ethyl methacrylate)-b-poly(l-lactide) (PManEMA-b-PLLA), was synthesized via a coupling approach. PLLA having an ethynyl group was successfully synthesized via ring-opening polymerization using 2-propyn-1-ol as an initiator. The ethynyl functionality of the resulting polymer was confirmed by MALDI-TOF mass spectroscopy. In contrast, PManEMA having an azide group was prepared via AGET ATRP using 2-azidopropyl 2-bromo-2-methylpropanoate as an initiator. The azide functionality of the resulting polymer was confirmed by IR spectroscopy. The Cu(I)-catalyzed 1,3-dipolar cycloaddition between PLLA and PManEMA was performed to afford PManEMA-b-PLLA. The block structure was confirmed by 1H NMR spectroscopy and size exclusion chromatography. The aggregating properties of the block glycopolymer, PManEMA16k-b-PLLA6.4k (Mn,PManEMA = 16,000, Mn,PLLA = 6400) was examined by 1H NMR spectroscopy, fluorometry using pyrene, and dynamic light scattering. The block glycopolymer formed complicated aggregates at concentrations above 21 mg·L−1 in water. The d-mannose presenting property of the aggregates was also characterized by turbidimetric assay using concanavalin A. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016

Understanding the diffusion of nanoparticles through permeable membranes in cell mimics paves the way for the construction of more sophisticated synthetic protocells with control over the exchange of nanoparticles or biomacromolecules between different compartments. Nanoparticles postloading by swollen pH switchable polymersomes is investigated and nanoparticles locations at or within polymersome membrane and polymersome lumen are precisely determined. Validation of transmembrane diffusion properties is performed based on nanoparticles of different origin—gold, glycopolymer protein mimics, and the enzymes myoglobin and esterase—with dimensions between 5 and 15 nm. This process is compared with the in situ loading of nanoparticles during polymersome formation and analyzed by advanced multiple‐detector asymmetrical flow field‐flow fractionation (AF4). These experiments are supported by complementary i) release studies of protein mimics from polymersomes, ii) stability and cyclic pH switches test for in polymersome encapsulated myoglobin, and iii) cryogenic transmission electron microscopy studies on nanoparticles loaded polymersomes. Different locations (e.g., membrane and/or lumen) are identified for the uptake of each protein. The protein locations are extracted from the increasing scaling parameters and the decreasing apparent density of enzyme‐containing polymersomes as determined by AF4. Postloading demonstrates to be a valuable tool for the implementation of cell‐like functions in polymersomes.

The use of glycopolymer-functionalized resins (Resin-Glc), as a solid support, in column mode for bacterial/protein capture and quantification is explored. The Resin-Glc is synthesized from commercially available chloromethylated polystyrene resin and glycopolymer, and is characterized by fourier transform infrared spectroscopy, thermogravimetry, and elemental analysis. The percentage of glycopolymer functionalized on Resin-Glc is accounted to be 5 wt%. The ability of Resin-Glc to selectively capture lectin, Concanavalin A, over Peanut Agglutinin, reversibly, is demonstrated for six cycles of experiments. The bacterial sequestration study using SYBR (Synergy Brands, Inc.) Green I tagged Escherichia coli/Staphylococcus aureus reveals the ability of Resin-Glc to selectively capture E. coli over S. aureus. The quantification of captured cells in the column is carried out by enzymatic colorimetric assay using methylumbelliferyl glucuronide as the substrate. The E. coli capture studies reveal a consistent capture efficiency of 105 CFU (Colony Forming Units) g-1 over six cycles. Studies with spiked tap water samples show satisfactory results for E. coli cell densities ranging from 102 to 107 CFU mL-1 . The method portrayed can serve as a basis for the development of a reusable solid support in capture and detection of proteins and bacteria.

International audience; Poly(ethylene terephthalate) (PET) is a semiaromatic thermoplastic polyester used in many fields. For specific applications, controlled of the surface wettability (hydrophily/hydrophoby) could be a great challenge. Aminolysis of PET surfaces with branched polyethylenimine gives amino functional groups on the surface with high grafting density. Then, in a second step, atom transfer radical polymerization (ATRP) initiator was grafted by reaction with 2‐bromoisobutyryl bromide. Surface initiated ATRP of 2‐lactobionamidoethyl methacrylate (LAMA) was performed in solution in the presence of a sacrificial initiator or an appropriate amount of Cu(II) species that act as deactivator. The efficiency of all reactions was confirmed by X‐ray photoelectron spectroscopy. Wetting properties and surface energy were found to vary systematically depending to the type of functionalization and grafting. The quantity of grafted carbohydrate was determined by phenol/sulfuric acid colorimetric titration. The sugar graft density was observed to vary according to the ratio (monomer)/(free initiator). High graft density could be obtained yielding to superhydrophilic polymer brushes. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2689–2697

Thermosensitive polymers enable externally controllable biomolecular interactions but hysteresis effects hamper the reversibility and repeated use of these materials. To quantify the temperature-dependent interactions and hysteresis effects, an optical adhesion assay based on poly(ethylene glycol) microgels (soft colloidal probes, SCPs) with mannose binding concanavalin A surfaces is used. A series of thermoresponsive glycopolymers is synthesized varying the carbohydrate type, their density, and linker type, and then grafted to the SCPs. The carbohydrate-mediated adhesion is influenced by the density of sugar ligands and increased above the lower critical solution temperature (LCST) of the glycopolymer. Importantly, a strong hysteresis is observed, i.e., cooling back below the LCST does not reduce the adhesion back to the initial value before heating. The hysteresis is stronger for hydrophobic linkers and for low carbohydrate functionalization degrees suggesting insufficient reswelling of the polymers due to hydrophobic interactions. The results are confirmed by studying the adhesion of Escherichia coli to the SCPs, where an enhanced capture of the bacteria is observed above the LCST while the detachment upon cooling is not possible. Overall, the quantitative data on the switchable adhesion of specifically binding polymers may provide potential avenues for the design of the next-generation interactive biomaterials.

Establishment of drug delivery system (DDS) in bone substitute materials for local treatment of bone defects still requires ambitious solutions for a retarded drug release. We present two novel DDS, a weakly cationic dendritic glycopolymer and a cationic polyelectrolyte complex, composed of dendritic glycopolymer and cellulose sulfate, for the proteasome inhibitor bortezomib. Both DDS are able to induce short-term retarded release of bortezomib from calcium phosphate bone cement in comparison to a burst-release of the drug from bone cement alone. Different release parameters have been evaluated to get a first insight into the release mechanism from bone cements. In addition, biocompatibility of the calcium phosphate cement, modified with the new DDS was investigated using human mesenchymal stromal cells.

Poly(ethylene oxide)-block-poly(methacryl-d-glucopyranoside) (PEO-GP) and poly(methacryl-d-glucopyranoside) (H-GP) glycopolymers were synthesized by deacetylation of acetylated polymers which were synthesized via atom transfer radical polymerization. The synthesized glycopolymers were characterized using 1H NMR, 13C NMR and Fourier transform infrared (FTIR) spectroscopies, gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The deacetylated polymers exhibited onset decomposition temperatures about 60 °C lower compared to the polymers having acetyl pendants. The glass transition temperature (Tg) of the acetylated homopolymer was 133 °C and that of the PEO-based block copolymer was 124 °C. The deacetylated polymers H-GP and PEO-GP exhibited Tg values of about −30 °C. Biocompatibility of the H-GP and PEO-GP glycopolymers was obtained by studying osteoblast cell adhesion, viability and proliferation in vitro. The cell viability showed an increase with increasing concentration of H-GP from 0.1 to 1 µmol L−1 and then decreased with further increase in its concentration (10–1000 µmol L−1). PEO-GP did not show a significant variation in cell viability on variation of its concentration from 0.1 to 1000 µmol L−1. The significant improvement in biocompatibility with osteoblast cells in the presence of PEO-GP was considered as due to the covalently bonded PEO segment of the methacrylate glycopolymer block. © 2014 Society of Chemical Industry

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.

Functional cationic polymers carrying mannose moieties were synthesized in a facile manner by employing RAFT polymerization. Initially, a protected carbohydrate based monomer, [2-(2,3,4,6-tetra-O-acetyl-α-d-mannopyranosyloxy)ethyl methacrylate (AcManEMA)], was prepared by the O-glycosylation of 2-hydroxyethyl methacrylate (HEMA). Subsequently, a macroRAFT agent of poly[2-(dimethyl)amino ethyl methacrylate] (PDMAEMA) was generated, and a further chain extension polymerization with AcManEMA was carried out in dioxane to form a acetylated mannose cationic diblock copolymer, PDMAEMA-b-PAcManEMA. It was attained in high yields and displayed low dispersity (Ð). Acetylated mannose moieties on the polymer were deprotected with sodium methoxide and the amines from the DMAEMA block were protonated to yield a cationic diblock glycopolymer, PDMAEMA-b-PManEMA. The cationic property of polymers were characterized by mixing with a negatively charged siRNA duplex and a pDNA, and aggregates of 102 and 233 nm were obtained, respectively. Agarose gel shift assay revealed that the polymers were able to retain the nucleic acids as large polymer complexes. Lectin binding assay proved that the mannose residue on the polymers were only able to bind specifically with ConA. PNA lectin was employed as a control and did not show specific binding. The cationic glycopolymer could be advantageous in targeted nucleic acids delivery in specific cells. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44947.

We report the synthesis of glyco(poly(2-oxazoline)s) functionalized with Pt(II) units for targeted tumor applications. To this end, poly(2-ethyl-2-oxazoline-block-2-(3-butenyl)-2-oxazoline) is modified with thiol-modified acetyl protected glucose and galactose, respectively, and terpyridine (tpy) units using thiol-ene photoaddition. Deprotection of the sugars with sodium methoxide and treatment with Pt(COD)Cl2 applying a mild synthesis route yields polymers with monosaccharide targeting moieties and cytotoxic Pt(II) units. The polymers and intermediates are characterized by 1H nuclear magnetic resonance spectroscopy and size exclusion chromatography. Subsequently, the hemolytic activity, induction of erythrocyte aggregation as well as the cytotoxicity against mouse fibroblast L929 cells, human embryonic kidney cells HEK 293, and human hepatocytes HepG2 are studied. The comparison to cisplatin, the standard for cancer therapy, demonstrates the potential of the presented system. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 2703–2714

Novel 2-(β-maltooligooxy)-ethyl (meth)acrylate monomers are successfully synthesized by CGTase from Bacillus macerans catalyzed coupling of 2-(β-glucosyloxy)-ethyl acrylate and methacrylate with α-cyclodextrin or starch. HPLC-UV analysis shows that the CGTase catalyzed reaction yields 2-(β-maltooligooxy)-ethyl acrylates with 1 to 15 glucopyranosyl units. (1) H NMR spectroscopy reveals that the β-linkage in the acceptor molecule is preserved during the CGTase catalyzed coupling reaction, whereas the newly introduced glucose units are attached by α-(1,4)-glycosidic linkages. The synthesized 2-(β-maltooligooxy)-ethyl acrylate monomers are successfully polymerized by aqueous free radical polymerization to yield the comb-shaped glycopolymer poly(2-(β-maltooligooxy)-ethyl acrylate).

Triple stimuli (temperature/pH/photo)-responsive amphiphilic glycopolymer, poly(2-(dimethylamino)ethyl methacrylate-co-6-O-methacryloyl-1,2,3,4-di-O-isopropylidene-D-galactopyranose)-b-poly(4-(4-methoxyphenylazo)phenoxy methacrylate) [P(DMAEMA-co-MAIpGP)-b-PMAZO] was synthesized by atom transfer radical polymerization, followed by the hydrolysis of MAIpGP groups, resulting in the target product poly(2-(dimethylamino)ethyl methacrylate-co-6-O-methacryloyl-D-galactopyranose)-b-poly(4-(4-methoxyphenylazo)phenoxy methacrylate) [P(DMAEMA-co-MAGP)-b-PMAZO]. The composition, moleculer weight, and moleculer weight distribution of the resultant polymers were characterized by 1H NMR and gel permeation chromatography. The micelles formed in aqueous solutions were simulated by various chemical and physical stimuli and characterized by dynamic light scattering, transmission electron microscopy, and UV-vis spectroscopy. It was found that the glycopolymer is responsive to three different types of stimulus (light, temperature, and pH). The poly(2-(dimethylamino) ethyl methacrylate) segments give thermo- and pH-responsiveness. The presence of the azobenzene moiety endows the block copolymer to exhibit light-responsiveness due to its reversible trans-cis isomerization conversion. The triple stimuli-responsive glycopolymer micelles can simulate biomacromolecues in vivo/in vitro environment and can be expected to open up new applications in various fields. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 2131–2138

Silk protein-based materials are promising biomaterials for application as tissue scaffolds, due to their processability, biocompatibility, and biodegradability. The preparation of films composed of an engineered spider silk protein (eADF4(C16)) and their functionalization with glycopolymers are described. The glycopolymers bind proteins found in the extracellular matrix, providing a biomimetic coating on the films that improves cell adhesion to the surfaces of engineered spider silk films. Such silk-based materials have potential as coatings for degradable implantable devices.

Wei Lu, Wenjuan Ma, Jiawei Lu, Xiao Li, Yun Zhao,* Gaojian Chen* ––––––––– W. Lu, J. Lu, X. Li, Prof. G. Chen Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou, 215006, P. R. ChinaCollege of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P. R China E-mail: gchen@suda.edu.cn W. Ma, Prof. Y. Zhao Cyrus Tang Hematology Center, Soochow University, Suzhou, 215123, P. R. China E-mail: zhaoy@suda.edu.cn Wei Lu and Wenjuan Ma contributed equally in this work. ––––––––– Copolymers of 2-(methacrylamido)glucopyranose (MAG) and methacrylic acid (MAA) were synthesized by RAFT polymerization and then used as templates to prepare the glycopolymer-functionalized Ag nanoclusters (Gly-Ag NCs) through microwave irradiation. Polymers and the resulting nanoclusters were characterized by NMR, GPC, UV-Vis, SEM, TEM and fluorescence spectroscopy. The bio-activity of the fluorescent Gly-Ag NCs were further examined using GLUT-1 over-expressing cancer cells K562. Gly-Ag NCs showed efficient binding ability toward K562 cells and inhibited the cell viability in a dose dependent manner (IC50 = 0.65 μg/mL), indicating their potential biological applications for both cancer imaging and targeted cancer therapy.

Searching for vaccines (antigen and adjuvant) with easy preparation and strong T-cell response are crucial for antitumor immunity. In this work, to design lymphoseek-inspired vaccine possessing the abilities of promoting vaccine internalization and enhancing CD8+ T-cell responses, a simple multicomponent strategy is successfully utilized to fabricate lymph node and dendritic cell dual-targeting glycoadjuvant@AuNPs in one pot, where three different components, catechol-containing glycopolymer, HAuCl4 , and amine-terminal CpG (CpG-NH2 ) can react in a single step to generate target adjuvant. It is found that hetero-glycoadjuvant@AuNPs could increase adjuvant internalization and enhance the activation of bone-marrow-derived dendritic cells. Critically, lymphoseek-inspired vaccine potentiates antigen-specific CD8+ T-cell immune responses.

One-pot system combining multi-reactions is used to synthesize novel porphyrin-glycopolymer conjugates. Sodium mercury amalgam is used to catalyze the reactions: 1) reduction of RAFT polymerized poly(2-(methacrylamido) glucopyranose) (PMAG), 2) converting protoporphyrin to protoporphyrinogen, 3) thiol-ene coupling reaction of PMAG and protoporphyrinogen. The product is oxidized in the same pot to generate the final porphyrin-PMAG conjugates. The resulting conjugates are characterized by NMR, GPC, UV-Vis, and fluorescence spectroscopy. Glycoparticles (≈ 200 nm) bearing glucose units are formed by dissolving the conjugates in water. Glycoparticles show enhanced binding ability toward Con A, bind K562 cells efficiently and kill these cells under light irradiation in dose and light treatment length dependent manners, illustrating the potential biological applications of the conjugates as photosensitizer for cancer imaging and photodynamic therapy.

Summary A straightforward route to glycopolymers bearing pendent gluconic residues is presented. The functionalization of poly(allylamine) by gluconolactone in water gives rise to gluconamide-substituted polymers within minutes at room temperature. The resulting polymers are characterized by 1H NMR. The grafting reaction is limited by competition with hydrolysis of gluconolactone, which is favoured when the pH increases. In presence of borax a hydrogel is obtained, which is attributed to the complexation of boron by the multivalent glycopolymer. In consequence these modified polymers could be used as rheology additives for aqueous formulations.

The creation of biomaterials with aligned fibers offers broad applications in tissue regeneration, guiding cell organization and physiological cues, and providing appropriate mechanical properties for many biomedical applications. Herein, for the first time, highly aligned electrospun membranes are designed and developed using glycopolymers. The membranes retain the strong mechanical properties of polycaprolactone, and fiber alignment facilitates the creation of anisotropic mechanical properties, enabling failure stress to be manipulated by an order of magnitude relative to randomly ordered fibers. Biocompatibility and cell attachment in these materials are characterized using tenocytes as a cell model. Both random and aligned fiber glycopolymers show promising biocompatibility, but aligned glycopolymer fibers additionally offer patterning to guide cell organization. These materials potentially provide a novel platform for tissue regeneration studies, demonstrating that the sugar-lectin interaction can produce materials capable of managing cell guidance.

Stimuli-responsive spherical brushes composed of 6-O-methacryloyl-1,2:3,4-di-O-isopropylidene-D-galactopyranose (MAIGal) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) are prepared via atom transfer radical polymerization (ATRP) using cross-linked polystyrene nanoparticles covered with a thin layer of 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM) as ATRP initiator by the "grafting from" approach. The stimuli-responsive behavior of the deprotected spherical PMAGal-b-PDMAEMA block copolymer brushes is investigated by dynamic light scattering and cryogenic transmission electron microscopy. A brush with arms containing 160 MAGal and 170 DMAEMA monomer units shows a significant contraction of the hydrodynamic radius from 20 to 70 °C at pH = 8 with a cloud point at ≈40 °C, whereas no LCST is detected at pH = 6 and 7 due to the protonation of the DMAEMA units. Aggregates occur at low temperatures and pH 8 due to intermolecular interactions between the chains of different brushes, which disappear above LCST, when the PDMAEMA chains fold back to the core of the brushes, exposing the glycopolymer chains to the outside.

Glycopolymer-corona-based micelles are obtained in a one-pot procedure, through reaction of D-mannosamine or D-glucosamine with the N-succinimidyl (NS) esters of a poly(D,L-lactide)-block-poly(N-acryloxysuccinimide-co-N-vinylpyrrolidone) (PLA-b-P(NAS-co-NVP)) amphiphilic copolymer (presenting quasi-alternating NAS/NVP units) in dimethyl sulfoxide (DMSO), followed by nanoprecipitation and dialysis against water. The glycopolymer micelles exhibit a higher CMC and size than those obtained from unmodified copolymer, due to increased hydrophilicity of the external block as a result of sugar derivatization, and the availability of the sugars at the micelle surface is evidenced through interactions with Concanavalin A (Con A) lectin, as attested by turbidimetric measurements and enzyme-linked lectin assay (ELLA). Interestingly, the glycopolymer micelles can be further used for hydrophobic molecule encapsulation and release, as shown with imiquimod, while keeping their interactions with con A intact. It is concluded that the PLA-based amphiphilic/reactive copolymer represents a versatile platform for glycopolymer-based micelle constructs for drug/vaccine delivery.

Polysaccharide synthesis is hampered by many factors. These problems can be circumvented by the crystal-to-crystal azide–alkyne cycloaddition polymerization of an unprotected monosaccharide, which gives a crystalline glycopolymer regiospecifically in quantitative yield.

Synthetic glycopolymers are important natural oligosaccharides mimics for many biological applications. To develop glycopolymeric drugs and therapeutic agents, factors that control the receptor-ligand interaction need to be investigated. A library of well-defined glycopolymers has been prepared by the combination of copper mediated living radical polymerization and CuAAC click reaction via post-functionalization of alkyne-containing precursor polymers with different sugar azides. Employing Concanavalin A as the model receptor, we explored the influence of the nature and densities of different sugars residues (mannose, galactose, and glucose) on the stoichiometry of the cluster, the rate of the cluster formation, the inhibitory potency of the glycopolymers, and the stability of the turbidity through quantitative precipitation assays, turbidimetry assays, inhibitory potency assays, and reversal aggregation assays. The diversities of binding properties contributed by different clustering parameters will make it possible to define the structures of the multivalent ligands and densities of binding epitopes tailor-made for specific functions in the lectin-ligand interaction. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2588-2597.

Glycopolymers are becoming more and more important in understanding biological interactions due to their unique recognition properties. Macromolecules with different chain lengths, compositions and architectures provide enormous diversity in the formation of primary and secondary structures that have a major effect on multivalent binding to lectins. It is crucial to control the precise structure of macromolecules to achieve specific and selective carbohydrate-lectin binding. The use of advanced synthesis techniques to prepare well-defined glycopolymers and selected advanced analytical techniques to study multivalent interactions are highlighted in this Feature Article.

Soluble hyperbranched glycopolymers were prepared by copolymerization of glycan monomers with reversible addition-fragmentation chain transfer polymerization (RAFT) inimers in a simple one-pot reaction. Two novel RAFT inimers, 2-(methacryloyloxy)ethyl 4-cyano-4-(phenylcarbonothioylthio)pentanoate (MAE-CPP) and 2-(3-(benzylthiocarbonothioylthio)propanoyloxy)ethyl acrylate (BCP-EA) were synthesized and used to prepare hyperbranched glycopolymers. Two types of galactose-based saccharide monomers, 6-O-methacryloyl-1,2:3,4-di-O-isopropylidene-D-galactopyranose (proGal-M) and 6-O-(2′-acrylamido-2′-methylpropanoate)-1,2:3,4-di-O-isopropylidene-D-galactopyranose (proGal-A), containing a methacrylate and an acrylamide group, respectively, were also synthesized and polymerized under the mediation of the MAE-CPP and BCP-EA inimers, respectively. In addition, hyperbranched poly(proGal-M), linear poly(proGal-A), and hyperbranched poly(proGal-A) were generated and their polymerization kinetics were studied and compared. An unexpected difference was observed in the kinetics between the two monomers during polymerization: the relationship between polymerization rate and concentration of inimer was totally opposite in the two monomer–inimer systems. Branching analysis was conducted by using degree of branching (DB) as the measurement parameter. As expected, a higher DB occurred with increased inimer content. Furthermore, these polymers were readily deprotected by hydrolysis in trifluoroacetic acid solution resulting in water-soluble polymers. The resulting branched glycopolymers have potential as biomimetics of polysaccharides. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Glycocalyx mimicking glycopolymer brushes presenting mannose, galactose and glucose residues in the pyranose form, similar to those present on cell surfaces, were synthesized on planar substrates (Si wafer, gold chip) and monodispersed polystyrene (PS) particles, and the interaction of blood to these surfaces were studied using various methods with the goal of producing a hemocompatible surface. Surface plasmon resonance (SPR) spectroscopy and gel analyses showed that the total protein adsorption from plasma was greatly reduced, as low as 24.3 ng/cm(2) from undiluted plasma on the glucose carrying brush. The protein adsorption decreased with increasing grafting density of the brushes. It was also found that the protein adsorption varied with the anticoagulant used for blood collection; much higher amount of protein was adsorbed from heparinzied plasma than citrated plasma. Proteomics protein identification analysis revealed that protein adsorption from plasma depended on the type of sugar residue present on the surface as well as the type of anticoagulant. All the three types of glycopolymer brushes showed similar level of platelet activation as that of buffer control irrespective of the nature of carbohydrate residue. However, the number of adhered platelet and their morphology depended on the type of carbohydrate residue present on the brush. On glucose brush, the extent of platelet adhesion and spreading was significantly lowered compared to other brushes. All the glycopolymer brushes were neutral to blood coagulation as indicated by thromboelastography analysis. The glucose brush gave a slightly longer initial coagulation time suggesting that this surface may be more biocompatible. Our data demonstrate that the structure of carbohydrate residue is an important factor in the design of synthetic blood contacting surface based on glycopolymer.

In this article, the synthesis and the functionalization of well-defined, narrow polydispersity (polydispersity index < 1.2) star polymers via reversible addition-fragmentation chain transfer polymerization is detailed. In this arm first approach, the initial synthesis of a poly(pentafluorophenyl acrylate) polymer, and subsequent, cross-linking using bis-acrylamide to prepare star polymers, has been achieved by reversible addition fragmentation chain transfer polymerization. These star polymers were functionalized using a variety of amino functional groups via nucleophilic substitution of pentafluorophenyl activated ester to yield star polymers with predesigned chemical functionality. This approach has allowed the synthesis of star glycopolymer using a very simple approach. Finally, the core of the stars was modified via thiol-ene click chemistry reaction using fluorescein-o-acrylate and DyLigh 633 Maleimide. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

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.

Thermoresponsive double hydrophilic diblock copolymers poly(2-(2′-methoxyethoxy)ethyl methacrylate-co-oligo(ethylene glycol) methacrylate)-b-poly(6-O-methacryloyl-D-galactopyranose) (P(MEO2MA-co-OEGMA)-b-PMAGP) with various compositions and molecular weights were obtained by deprotection of amphiphilic diblock copolymers P(MEO2MA-co-OEGMA)-b-poly(6-O-methacryloyl-1,2:3,4-di-O-isopropylidene-D-galactopyranose) (P(MEO2MA-co-OEGMA)-b-PMAlpGP), which were prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization using P(MEO2MA-co-OEGMA) as macro-RAFT agent. Dynamic light scattering and UV–vis studies showed that the micelles self-assembled from P(MEO2MA-co-OEGMA)-b-PMAlpGP were thermoresponsive. A hydrophobic dye Nile Red could be encapsulated by block copolymers P(MEO2MA-co-OEGMA)-b-PMAGP upon micellization and released upon dissociation of the formed micelles under different temperatures. The galactose functional groups in the PMAGP block have specific interaction with HepG2 cells, and P(MEO2MA-co-OEGMA)-b-PMAGP has potential applications in hepatoma-targeting drug delivery and biodetection. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

In this work the synthesis of poly(butyl acrylate)-b- poly(2-{((D-glucosamin-2-N-yl)carbonyl)oxy}ethyl methacrylate) (PBA-b-PHEMAGl) diblock glycopolymer and poly(2-{((D-gluco- samin-2-N-yl)carbonyl)oxy}ethyl methacrylate)-b-poly(butyl acrylate)-b-poly(2-{((D-glucosamin-2-N-yl)carbonyl)oxy}ethyl methacrylate) (PHEMAGl-b-PBA-b-PHEMAGl) was performed via atom transfer radical polymerization. Monofunctional and difunctional poly(butyl acrylate) macroinitiators were used to synthesize the well-defined diblock and triblock glycopolymers by chain extension reaction with the glycomonomer HEMAGl. The self-assembly of these glycopolymers in aqueous solution was studied by dynamic light scattering and transmission elec- tron microcopy, showing the coexistence of spherical micelles and polymeric vesicles. In addition, the biomolecular recogni- tion capacity of these micelles and vesicles, containing glucose moieties in their coronas, was investigated using the lectin Concanavalin A, Canavalia Ensiformis, which specifically inter- acts with glucose groups. The binding capacity of Concanava- lin A with glycopolymer is influenced by the copolymer composition, increasing with the length of HEMAGl glycopoly- mer segment in the block copolymer. V C 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 2627-2635, 2011

Original carbohydrate-based acrylamides bearing one azide group in C-2 or C-6 position namely, 2-[(2-deoxy-2-azido-alpha-D-mannopyranosyloxy)ethanamidol-ethyl acrylamide (II) and 24(6-deoxy-6-azido-alpha-D-glucopyranosyloxy)ethanarnido]-ethyl acrylamide (III), and their azide-free analogue, 2-((alpha-D-glucopyranosyloxy)ethanamidol-ethyl acrylamide (I), have been designed. Whereas the reversible addition fragmentation chain transfer (RAFT) process ensured the preparation of well-defined glycopolymers from I, the polymerization of moanomers II and III proved to be challenging at temperatures compatible with a thermally initiated radical process, due to the presumed concomitant 1,3-cycloaddition reactions between the azide and the acrylamide moieties. In contrast to III, for which no polymer could be obtained under any conditions, performing the RAFT polymerization of II at 30 C clearly favored the radical polymerization and conferred a controlled character to the process, affording well-defined azide-functionalized glycopolymers and block copolymers. The presence of numerous azide moieties was finally exploited to introduce carbohydrates onto the glycopolymer backbone through copper catalyzed azide-alkyne cycloaddition.

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

Statistical glycopolymers based on gluconolactone have been prepared by classical radical polymerization and followed by 1H NMR in situ. The kinetic behavior of this system in terms of global rate constant has been qualitatively studied. The variation of cumulative feed and copolymer composition with conversion has also been analyzed, showing a diminishment of both as the reaction progresses. The monomer reactivity ratios have been estimated using the Mayo-Lewis terminal model and extended Kelen–Tudos equation, being rHEMAG = 1.41 ± 0.06 and rMA = 0.42 ± 0.05. The thermal properties have been examined by differential scanning calorimetry and thermogravimetric analysis. The glass transition and the thermal degradation temperatures of glycopolymers increase as hydrophilic component decreases. In addition, the solution properties of the water-soluble glycopolymers have been investigated, observing the formation of small micelles. Finally, the potential of these glycopolymers as polymeric surfactants has been proved by the performance of emulsion polymerization of methyl acrylate. The resulting particles are stable and with low polydispersity, decreasing the particle size as the methyl acrylate content increases in the glycopolymer surfactant. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

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.

The synthesis of amphiphilic dextran-g-poly(methyl methacrylate) glycopolymers (Dex-g-PMMA) is studied using “grafting from” concept and atom transfer radical polymerization. Two strategies have been examined to control the macromolecular parameters of such glycopolymers. One is involving four steps including a protection/deprotection approach and the second one only two steps. The introduction of initiators group onto a protected acetylated dextran (and directly onto dextran) was achieved resulting in protected DexAcBr (and in unprotected DexBr). These two types of polysaccharidic macroinitiators differ in term of solubility (hydrophilic DexBr vs. hydrophobic DexAcBr) and of position of the initiators groups on the glucosidic units (which are the sites of the future grafts). When evaluated as macroinitiators for ATRP of MMA, control was achieved in both cases but DexBr gave much faster polymerization and lower average grafting efficiency compared with DexAcBr or model initiator. Advantages and drawbacks of both pathways have finally been discussed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

A new 2-oxazolines containing S-galactosyl substituents linked to alkyl chains of different lengths; (S-glycooxazoline) were prepared relatively in high yields. By using a 1:1 adduct of 2-methyl-2-oxazoline and methyl triflate, as the initiator, the monomer was polymerized via ring-opening polymerization (ROP) to give products with relatively narrow molecular weight distributions. Homo- and copolymerization were performed, and the kinetics of these new S-glycooxazolines in the ROP are investigated. After a quantitative deprotection, poly(2-oxazoline)s having pendant carbohydrate were obtained. The interaction of the poly(S-glycooxazoline) with RCA120 lectin was investigated, the binding constant between glycopolymer and lectin was increased by 102 times compared with that of the monosaccharide (D-galactose). The in vivo expression of green fluorescent protein using the synthesized poly(S-glycooxazoline)s as polymeric inducers in Escherichia coli host were performed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

Phosphorescent conjugated polymers consisting of alternating p-phenylene-ethynylene and 'para-' or 'meta-type' Pt(II)-salphen luminophore units have been synthesized. Side-arms bearing different substituents (n-alkoxy and acetylated-sugar) have afforded contrasting emission properties that are attributed to the polymer conformation, extent of π-stacking interactions and differences in chemical structure. Intriguing selectivity in luminescent sensing of metal ions has been observed.

Vesicles composed of self-assembled lipids or amphiphilic polymers have significant potential in applications such as delivery of cargo for therapeutics. However, they are fragile under physiological conditions such as inside living cells or the bloodstream, in which a vast number of other molecules are present in high concentrations. This is because vesicles are in dynamic equilibrium between unimers and vesicles. Therefore, the development of more robust vesicles by covalent cross-linking of the shell was focused on. Cross-linked polymer vesicles were prepared by the self-assembly of maltopentaose-b-poly(propylene glycol) followed by the reaction between divinyl sulfone and the hydroxyl group in a maltopentaose unit. It was found that two equivalents of DVS to the polymer is an optimal condition for the cross-linking without changing in size. The bilayer structures were retained after the cross-linking reactions. Importantly, the cross-linked polymer vesicles retained their size and polydispersity even in 50:50 v/v methanol/water solution. This work highlights the potential of the divinyl sulfone shell cross-link as a promising tool for stabilization of glycopolymer vesicles.

The atom transfer radical polymerization of an unprotected glycomonomer, 2-{[(D-glucosamin-2N-yl)carbonyl]oxy}ethyl methacrylate (HEMAGl) is firstly reported. Controlled polymerizations were performed with the CuBr/N,N,N′,N′,N′-pentamethyldiethylene triamine catalytic system with ethyl 2-bromoisobutyrate and 1,2-bis(bromoisobutyryloxy) ethane as mono and difunctional initiators in DMF solutions (80% w/w) at 40 and 50 °C, respectively. The polymerization of HEMAGl resulted in a controlled polymerization with linear kinetics, molecular weights which increase with conversion and narrow polydispersity indexes. Mono and difunctional PHEMAGl macroinitiators were used to synthesize the amphiphilic di and triblock glycopolymers with n-butyl acrylate, verifying their living character. The self-assembly of these glycopolymers in distilled water and in 0.1M NaCl solutions was studied by dynamic light scattering, showing the role of hydrogen bonds and the hydrophobic parts. In addition, their interaction with Concanavalin A lectin was examined, demonstrating the influence of molecular weight and copolymer composition. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3623–3631, 2010

pH-Sensitive block glycopolymers of poly(2-(diethylamino)ethyl methacrylate) (PDEAEMA) and poly(3-O-methacryloy-α,β-D-glucopyranose) (PMAGlc) were synthesized via reversible addition–fragmentation chain transfer (RAFT) radical polymerization based on protected glycomonomer 3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-D-glucofuranose (MAIpGlc). It was found that RAFT homopolymerization of MAIpGlc proceeded in a controlled fashion with 4-cyanopentanoic acid dithiobenzoate as chain transfer agent. Using the dithioester-capped PDEAEMA as macro-RAFT agent, block copolymerization of MAIpGlc was in good control as indicated by the linear pseudo first-order kinetic plot, the linear increment of number-average molecular weights as well as narrow and symmetrical gel permeation chromatography peaks, and low polydispersities. Well-defined diblock copolymers of DEAEMA and MAIpGlc were prepared successfully through the chain extension of PDEAEMA. The deprotection of MAIpGlc units in trifluoroacetic acid/H2O solution afforded PDEAEMA-b-PMAGlc block glycopolymer. The self-assembly behavior of PDEAEMA-b-PMAGlc in aqueous solution was investigated by using 1H NMR, UV-vis spectroscopy, dynamic light scattering, and transmission electron microscopy. The results demonstrated that spherical micelles with PDEAEMA as the hydrophobic cores and PMAGlc as the hydrophilic shells were formed in alkaline aqueous solution. These glucose-installed micelles had specific recognition with Concanavalin A. The combination of pH-sensitivity of PDEAEMA and biomolecular recognition of PMAGlc in one micellar system may create a multifunctional platform for targeted delivery, biomimetics, and biodection. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3350–3361, 2010