The thermal polymerization of amino acids revisited; Synthesis and structural characterization of hyperbranched polymers from <scp>L</scp>‐lysine

Scholl, Markus; Nguyen, Tuan Q.; Bruchmann, Bernd; Klok, Harm‐Anton

doi:10.1002/pola.22295

Cited by 69 publications

(83 citation statements)

References 41 publications

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“…The hyperbranched polymers used in this study have been prepared by Zr(O n Bu) 4 catalyzed thermal polymerization of L-lysine monohydrochloride in the presence of 1 equiv of KOH. 36,37 This typically results in hyperbranched polylysines (HBPL) with a number-average molecular weight (M n ) of ∼ 6000 g/mol, a degree of branching (DB) of 0.35-0.45 and an average number of branches (ANB) of 0.15-0.25. For this study, samples with different molecular weights were obtained by dialyzing a sample with M n ) 3900 against membranes with different molecular weight cut-offs.…”

Section: Resultsmentioning

confidence: 99%

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Thermotropic Ionic Liquid Crystals via Self-Assembly of Cationic Hyperbranched Polypeptides and Anionic Surfactants

et al. 2007

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This work describes the dilute solution and solid-state structure of polyelectrolyte complexes generated from hyperbranched polylysine (HBPL) and various anionic, sodium alkyl sulfate surfactants. In dilute solution, the radius of gyration (R g ) of the HBPL and HBPL-surfactant complexes was determined in the Guinier regime in good solvent conditions by means of small-angle X-ray scattering (SAXS). With increasing molecular weight of the HBPL, an increase in R g up to a maximum of 3.7 and 4.2 nm was observed for the HBPLs and HBPL-surfactant complexes, respectively. In the solid state, HBPL-surfactant complexes were found to form liquid crystalline (LC) phases, whose thermal stability and structure depended both on the molecular weight of the HBPL as well as on the nature of the anionic surfactant. Depending on the surfactant alkyl chain length, liquid crystalline phases with short range liquid-like order, columnar hexagonal packing or lamellar ordering were observed. By combination of small-angle X-ray scattering, differential scanning calorimetry (DSC), and cross-polarized light optical microscopy (CPOM), the exact structure of the LC phases, as well as their region of thermal stability, could be identified. HBPL-sodium dodecyl sulfate LC phases showed thermotropic behavior and underwent two transitions with increasing temperature. First, at lower temperatures, an order-nematic transition was observed. Upon further temperature increase, a second transition from a nematic to an isotropic phase was observed. Structural models for these different LC phases are proposed.

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Section: Resultsmentioning

confidence: 99%

“…The results indicated a good agreement between the data obtained using light scattering and the "universal calibration" method. 37 Nuclear Magnetic Resonance (NMR). 1 H and 13 C NMR spectra were recorded at room temperature on a Bruker Avance 400 spectrometer.…”

Section: Methods Gel Permeation Chromatography (Gpc)mentioning

confidence: 99%

Thermotropic Ionic Liquid Crystals via Self-Assembly of Cationic Hyperbranched Polypeptides and Anionic Surfactants

et al. 2007

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“…The thermal polymerization of L-lysine hydrochloride was performed at 150°C in the presence of an alkaline metal base to neutralize the amine hydrochloride and to create the corresponding free amino acid base according to the procedure described by Scholl et al 27 Samples were purified by dialysis and gel filtration with a Sephadex column.…”

Section: Materials and Methods Synthesis Of Hpnpsmentioning

confidence: 99%

Nuclear entry of hyperbranched polylysine nanoparticles into cochlear cells

Zhang¹,

Pyykkö²,

Zou³

et al. 2011

IJN

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Background: Gene therapy is a potentially effective therapeutic modality for treating sensorineural hearing loss. Nonviral gene delivery vectors are expected to become extremely safe and convenient, and nanoparticles are the most promising types of vectors. However, infrequent nuclear localization in the cochlear cells limits their application for gene therapy. This study aimed to investigate the potential nuclear entry of hyperbranched polylysine nanoparticles (HPNPs) for gene delivery to cochlear targets. Methods: Rat primary cochlear cells and cochlear explants generated from newborn rats were treated with different concentrations of HPNPs. For the in vivo study, HPNPs were administered to the rats’ round window membranes. Subcellular distribution of HPNPs in different cell populations was observed with confocal microscope 24 hours after administration. Results: Nuclear entry was observed in various cochlear cell types in vitro and in vivo. In the primary cochlear cell culture, concentration-dependent internalization was observed. In the cochlear organotypic culture, abundant HPNPs were found in the modiolus, including the spiral ganglion, organ of Corti, and lateral wall tissues. In the in vivo study, a gradient distribution of HPNPs through different layers of the round window membrane was observed. HPNPs were also distributed in the cells of the middle ear tissue. Additionally, efficient internalization of HPNPs was observed in the organ of Corti and spiral ganglion cells. In primary cochlear cells, HPNPs induced higher transfection efficiency than did Lipofectamine ™ . Conclusion: These results suggest that HPNPs are potentially an ideal carrier for gene delivery into the cochlea.

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“…13 Briefly, L-lysine monohydrochloride monomer (2 g, 10.9 mmol) and KOH (0.61 g, 10.9 mmol) was introduced with Zr(OnBu) 4 catalyst (0.119 mL, 0.327 mmol) in a reactor and heated in an oven at 150 C under nitrogen flow without stirring during different times (5,10,15,20, and 25 h). The water formed during the polymerization was allowed to escape from the open reactor.…”

Section: Synthesis Of Pllmentioning

confidence: 99%

Syntheses of donor acceptor biobased photocurable water‐soluble resins based on poly‐l‐lysine

Koleilat

Giani

Joly‐Duhamel

et al. 2015

J. Polym. Sci. Part A: Polym. Chem.

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We report a new kind of coating using UV waterborne technique with a biobased poly(amino acid) resin. Firstly we performed the thermal polycondensation of L-lysine during 15 h at 150 C to synthesize water-soluble oligomers of poly-Llysine (PLL) with 5-6 monomer units. These oligomers were then transformed in mild conditions to give photocurable water-soluble resins. We grafted on the poly-L-lysine backbone, allyl and maleamic acid functional groups, with a grafting rate close to 65% thanks to allyl glycidyl ether and maleic anhydride respectively. The influence of the reaction time and the reagents ratio on the grafting rate was investigated. Hence, the donor/acceptor photopolymerization of the mixture of allyl ether-poly-L-lysine (PLL-g-AE) with maleamic acid-poly-L-lysine (PLL-g-MA) in aqueous solution gave yellow transparent films.The degree of conversion and other kinetic parameters have been studied and detailed. This work contributes to the development of materials based on renewable resources and cleaner processes. It opens a new pathway to both fundamental and applied-driven research.

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The thermal polymerization of amino acids revisited; Synthesis and structural characterization of hyperbranched polymers from L‐lysine

Cited by 69 publications

References 41 publications

Thermotropic Ionic Liquid Crystals via Self-Assembly of Cationic Hyperbranched Polypeptides and Anionic Surfactants

Thermotropic Ionic Liquid Crystals via Self-Assembly of Cationic Hyperbranched Polypeptides and Anionic Surfactants

Nuclear entry of hyperbranched polylysine nanoparticles into cochlear cells

Syntheses of donor acceptor biobased photocurable water‐soluble resins based on poly‐l‐lysine

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