38862-24-7Relevant academic research and scientific papers
Polymer vesicles containing small vesicles within interior aqueous compartments and pH-responsive transmembrane channels
Chiu, Hsin-Cheng,Lin, Yue-Wen,Huang, Yi-Fong,Chuang, Chih-Kai,Chern, Chorng-Shyan
, p. 1875 - 1878 (2008)
(Figure Presented) Multivesicle assemblies with pH-responsive transmembrane channels in the vesicle walls (see picture) were made by two-step double emulsion of copolymers comprising acrylic acid and acrylate of 1,2-distearoyl-rac-glycerol. These assemblies mimic eukaryotic cells, which contain functional organelles within the cell walls.
Affinity chromatography with collapsibly tethered ligands
Yamanaka, Hidenori,Yoshizako, Kimihiro,Akiyama, Yoshikatsu,Sota, Hiroyuki,Hasegawa, Yukio,Shinohara, Yasuro,Kikuchi, Akihiko,Okano, Teruo
, p. 1658 - 1663 (2003)
We introduce a novel affinity chromatography mode in which affinity ligands are secured to the media surface via collapsible tethers. In traditional affinity chromatography, the immobilized ligands act passively, and their local concentration is static. In collapsibly tethered affinity chromatography, the ligand can move dynamically in response to external stimuli, a design that enables marked changes in both the local concentration of the ligand and its surrounding environment without exchange of solvent. Using the thermoresponsive polymer poly(N-isopropylacrylamide) (PIPAAm) as a scaffold for ligand and hapten attachment, we were able to achieve controlled mobility and microenvironment alteration of the affinity ligand Ricinus communis agglutinin (RCA120). The glycoprotein target, asialotransferrin, was loaded onto a column in which PIPAAm was partially substituted with both RCA120 and lactose. At 5 °C, the column retained the glycoprotein, but released most (95%) of the asialotransferrin upon warming to 30 °C. This temperature-induced elution was much greater than can be explained by temperature dependency of sugar recognition by RCA120. The simplest explanation is that upon thermally induced dehydration and collapse of the PIPAAm chains, coimmobilized RCA120 ligand and lactose hapten are brought into closer proximity to each other, enabling immobilized lactose to displace affinity-bound asislotransferrin from the immobilized RCA120 lectin.
Elaboration of densely functionalized polylactide nanoparticles from N-acryloxysuccinimide-based block copolymers
Handke, Nadege,Trimaille, Thomas,Luciani, Elsa,Rollet, Marion,Delair, Thierry,Verrier, Bernard,Bertin, Denis,Gigmes, Didier
, p. 1341 - 1350 (2011)
Poly(N-acryloxysuccinimide) (PNAS) and poly(N-acryloxysuccinimide-co-N- vinylpyrrolidone) (P(NAS-co-NVP)) of adjustable molecular weights and narrow polydispersities were prepared by nitroxide-mediated polymerization (NMP) in N,N-dimethylformamide in the presence of free SG1 (N-tert-butyl-N-1- diethylphosphono-(2,2-dimethylpropyl) nitroxide), with MAMA-SG1 (N-(2-methylpropyl)-N-(1-diethylphosphono-2,2-dimethylpropyl) -O-(2-carboxylprop-2-yl)hydroxylamine) alkoxyamine as initiator. The reactivity ratios of NAS and NVP were determined to be rNAS = 0.12 and r NVP = 0, indicating a strong alternating tendency for the P(NAS-co-NVP) copolymer. NAS/NVP copolymerization was then performed from a SG1-functionalized poly(D,L-lactide) (PLA-SG1) macro-alkoxyamine as initiator, leading to the corresponding PLA-b-P(NAS-co-NVP) block copolymer, with similar NAS and NVP reactivity ratios as mentioned above. The copolymer was used as a surface modifier for the PLA diafiltration and nanoprecipitation processes to achieve nanoparticles in the range of 450 and 150 nm, respectively. The presence of the functional/hydrophilic P(NAS-co-NVP) block, and particularly the N-succinimidyl (NS) ester moieties at the particle surface, was evidenced by ethanolamine derivatization and zeta potential measurements.
Synthesis of Comblike Poly(butyl methacrylate) Using Reversible Addition-Fragmentation Chain Transfer and an Activated Ester
Vosloo, Johannes J.,Tonge, Matthew P.,Fellows, Christopher M.,D'Agosto, Franck,Sanderson, Ronald D.,Gilbert, Robert G.
, p. 2371 - 2382 (2004)
Comblike polymers of poly(n-butyl methacrylate) were prepared using an activated ester-type comonomer (N-acryloxysuccinimide, NAS) to generate branch points. The conventional solution free-radical copolymerization kinetics of n-butyl methacrylate (BMA) and NAS were first investigated by following individual monomer consumption rates by 1H NMR spectrometry and reactivity ratios of BMA and NAS determined using the terminal model. The reactivity ratios so obtained are both close to 0.2; the joint confidence interval is also determined. Reversible addition - fragmentation chain transfer (RAFT) was then used to grow polymers with controlled backbone and branch chain length. Because both reactivity ratios have similar values, this implies that the copolymer will have a random distribution of NAS and hence of branch points. RAFT-mediated polymerization was first used to synthesize linear poly(BMA-co-NAS) chains. Primary hydroxy-functionalized RAFT agents were then immobilized on this linear poly(BMA-co-NAS) through nucleophilic substitution on the activated ester units of the NAS. From these immobilized RAFT agents, branches were grown upon addition of a further aliquot of monomer (BMA) and initiator (AIBN). The amount of NAS in the starting BMA/NAS composition was varied without adversely affecting the uniformity of the NAS distribution along the resulting linear poly(BMA-co-NAS) backbone. This results in branched polymers whose molecular weight, branching density, and degree of polymerization of branches are all relatively narrow and controlled.
Thermo-responsive shell cross-linked PMMA-b-P(NIPAAm-co-NAS) micelles for drug delivery
Chang, Cong,Wei, Hua,Wu, De-Qun,Yang, Bin,Chen, Ni,Cheng, Si-Xue,Zhang, Xian-Zheng,Zhuo, Ren-Xi
, p. 333 - 340 (2011)
Thermo-responsive amphiphilic poly(methyl methacrylate)-b-poly(N- isopropylacrylamide-co-N-acryloxysuccinimide) (PMMA-b-P(NIPAAm-co-NAS)) block copolymer was synthesized by successive RAFT polymerizations. The uncross-linked micelles were facilely prepared by directly dissolving the block copolymer in an aqueous medium, and the shell cross-linked (SCL) micelles were further fabricated by the addition of ethylenediamine as a di-functional cross-linker into the micellar solution. Optical absorption measurements showed that the LCST of uncross-linked and cross-linked micelles was 31.0 °C and 40.8 °C, respectively. Transmission electron microscopy (TEM) showed that both uncross-linked and cross-linked micelles exhibited well-defined spherical shape in aqueous phase at room temperature, while the SCL micelles were able to retain the spherical shape with relatively smaller dimension even at 40 °C due to the cross-linked structure. In vitro drug release study demonstrated a slower and more sustained drug release behavior from the SCL micelles at high temperature as compared with the release profile of uncross-linked micelles, indicating the great potential of SCL micelles developed herein as novel smart carriers for controlled drug release.
Semiconductor nanocrystals with multifunctional polymer ligands
Potapova, Inga,Mruk, Ralf,Prehl, Sabine,Zentel, Rudolf,Basche, Thomas,Mews, Alf
, p. 320 - 321 (2003)
In this letter, we describe the preparation of a versatile polymer ligand, which can be attached to CdSe/ZnS semiconductor nanocrystals via a phase transfer reaction. The ligand is based on a chain of reactive esters, which can, in principle, be substituted by any compound containing amino-functionalities. The polymer/nanocrystal complexes are characterized in terms of structure and photostability. Copyright
Effective inhibitors of hemagglutination by influenza virus synthesized from polymers having active ester groups. Insight into mechanism of inhibition
Mammen,Dahmann,Whitesides
, p. 4179 - 4190 (1995)
Highly effective sialic acid-containing inhibitors of influenza virus X- 31 were synthesized using poly[N-(acryoyloxy)succinimide] (pNAS), a polymer preactivated by incorporation of active ester groups. Polymers containing two and three different components were prepared by sequential reaction of pNAS with two and three amines, respectively. This preparation of co- and terpolymers was synthetically more efficient than methods involving copolymerization of different monomers and gave polymers that were more easily compared than those generated by copolymerization. Polymers in this study (prepared from a single batch of pNAS) had a constant degree of polymerization (DP ? 2000) and probably had a distribution of components that was more random than analogous polymers prepared by copolymerization. Use of C-glycosides of sialic acid made it possible to investigate inhibition by different polymers at temperatures ranging from 4 to 36°C without artifacts due to the hydrolytic action of neuraminidase. The inhibitors were, in general, more effective at 36 °C than at 4 °C. The hemagglutination (HAI) assay was used to measure the value of the inhibition constant K(i)/(HAI) each polymer. The value of K(i)/(HAI) for the two-component polymer containing 20% sialic acid on a polyacrylamide backbone at 4 °C was 4 nM (in terms of the sialic acid moieties present in solution) and was approximately 50-fold more effective than the best inhibitors previously described and 25-fold more effective than the best naturally occurring inhibitor. The most effective inhibitor synthesized in this work contained 10% benzyl amine and 20% sialic acid on a polyacrylamide backbone, and its value of K(i)/(HAI) was 600 pM at 36 °C. Approximately 100 polymers that differed in one or two components were assayed to distinguish between two limiting mechanisms for inhibition of the interaction between the surfaces of virus and erythrocytes: high-affinity binding through polyvalency, and steric stabilization. The results suggest that both mechanisms play an important role. The system comprising polyvalent inhibitors of agglutination of erythrocytes by influenza provides a system that may be useful as a model for inhibitors of other pathogen-host interactions, a large number of which are themselves polyvalent.
Temperature-Switchable Glycopolymers and Their Conformation-Dependent Binding to Receptor Targets
Paul, Tanja J.,Strzelczyk, Alexander K.,Feldhof, Melina I.,Schmidt, Stephan
, p. 2913 - 2921 (2020)
The temperature-dependent binding of copolymers from poly(N-isopropylacrylamide) (PNIPAM) and mannose ligands to Escherichia coli and concanavalin A (ConA) is determined. Through polymer analogous reactions using poly(N-acryloxysuccinimide) and amine-linked mannose residues with different linkers, glycopolymers are prepared with the variation of the mannose density. Quantitative adhesion inhibition assays show the inhibitory potential of the glycopolymers as a function of the mannose/NIPAM ratio and linker type above and below their lower critical solution temperature (LCST). Intriguingly, opposite temperature effects on the binding to E. coli and ConA are observed. While the E. coli inhibition is stronger above the LCST, the ConA inhibition is, in overall, weaker at elevated temperatures. When going beyond the LCST, the polymers undergo a coil-to-globule transition, forming microphases with surface-enriched hydrophilic sugar moieties exhibiting increased E. coli inhibition through steric shielding. However, the formation of such microphases above the LCST renders a fraction of carbohydrate ligands inaccessible,and the polymers remaining in the solution phase then have coil sizes below the minimum binding site spacing of the ConA receptor, explaining reduced ConA inhibition. Overall, these results suggest that the coil-to-globule transition of glycopolymers may induce lower or higher inhibitory potentials due to the adverse effects of steric shielding and carbohydrate ligand accessibility.
Efficient Amino-Sulfhydryl Stapling on Peptides and Proteins Using Bifunctional NHS-Activated Acrylamides
Silva, Maria J. S. A.,Faustino, Hélio,Coelho, Jaime A. S.,Pinto, Maria V.,Fernandes, Adelaide,Compa?ón, Ismael,Corzana, Francisco,Gasser, Gilles,Gois, Pedro M. P.
supporting information, p. 10850 - 10857 (2021/04/15)
Widely used reagents in the peptide functionalization toolbox, Michael acceptors and N-hydroxysuccinimide (NHS) activated esters, are combined in NHS-activated acrylamides for efficient chemoselective amino-sulfhydryl stapling on native peptides and proteins. NHS-activated acrylamides allow for a fast functionalization of N-terminal cysteines (k2=1.54±0.18×103 M?1 s?1) under dilute aqueous conditions, enabling selectivity over other nucleophilic amino acids. Additionally, the versatility of these new bioconjugation handles was demonstrated in the cross-linking of in-chain or C-terminal cysteines with nearby lysine residues. NHS-activated acrylamides are compatible with the use of other cysteine selective reagents, allowing for orthogonal dual-modifications. This strategy was successfully applied to the late-stage functionalization of peptides and proteins with a PEG unit, fluorescent probe, and cytotoxic agent. The level of molecular control offered by NHS-activated acrylamides is expected to promote amino-sulfhydryl stapling technology as a powerful strategy to design functional bioconjugates.
Modified Polyvinylchloride Surface with Antibacterial and Antifouling Functions
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Paragraph 0021, (2020/08/12)
Disclosed are materials having an antifouling and a biocidal property. The materials include a polyvinylchloride plastic covalently linked to a polymer, where the polymer includes an antifouling component and a biocidal component.
