A novel combined strategy for the physical PEGylation of polypeptides

Ambrosio, Elena; Barattin, Michela; Bersani, Sara; Shubber, Saif; Uddin, Shahid; Walle, Christopher F. van der; Caliceti, Paolo; Salmaso, Stefano

doi:10.1016/j.jconrel.2016.02.009

Cited by 16 publications

(26 citation statements)

References 48 publications

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“…This is in agreement with the small increase in the association constant (K) for PEG-cholane:VIP-palm binding measured by calorimetry at higher pH. 27 It should be noted that the peptide has an isoelectric point of 10.04, therefore, as pH increases from 5 to 7.4, the net charge of VIP-palm decreases (from ca. +4 to +3) 27 and so favours interaction with the cholane moiety of the amphiphilic polymer.…”

supporting

confidence: 86%

“…Furthermore, the absence of any significant difference in the percentage of helix content for VIP-palm alone between pH 5.0 and 7.4 (Figure 4A) is in good agreement with previous experimental data. 27 The models of PEG-cholane:VIP-palm stoichiometries of 1:1 and 2:1 demonstrated a reduced peptide backbone exposure to water (~90% in the absence of polymer and ~50% in 2 mol. equiv.…”

Section: In Silico Simulations Capture Vip-palm Structural Change On Supramolecular Assemblymentioning

confidence: 97%

“…27 It should be noted that the peptide has an isoelectric point of 10.04, therefore, as pH increases from 5 to 7.4, the net charge of VIP-palm decreases (from ca. +4 to +3) 27 and so favours interaction with the cholane moiety of the amphiphilic polymer. The solution structure of VIP-palm at 25 °C, pH 5.0, is predominantly α-helical when either free or complexed with PEG-cholane (Figure S2 A-D), consistent with our previous data.…”

mentioning

confidence: 99%

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Control of Peptide Aggregation and Fibrillation by Physical PEGylation

Ambrosio

Podmore²,

Santos³

et al. 2018

Biomacromolecules

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Peptide therapeutics have the potential to self-associate, leading to aggregation and fibrillation. Noncovalent PEGylation offers a strategy to improve their physical stability; an understanding of the behavior of the resulting polymer/peptide complexes is, however, required. In this study, we have performed a set of experiments with additional mechanistic insight provided by in silico simulations to characterize the molecular organization of these complexes. We used palmitoylated vasoactive intestinal peptide (VIP-palm) stabilized by methoxy-poly(ethylene glycol)-cholane (PEG-cholane) as our model system. Homogeneous supramolecular assemblies were found only when complexes of PEG-cholane/VIP-palm exceeded a molar ratio of 2:1; at and above this ratio, the simulations showed minimal exposure of VIP-palm to the solvent. Supramolecular assemblies formed, composed of, on average, 9-11 PEG-cholane/VIP-palm complexes with 2:1 stoichiometry. Our in silico results showed the structural content of the helical conformation in VIP-palm increases when it is complexed with the PEG-cholane molecule; this behavior becomes yet more pronounced when these complexes assemble into larger supramolecular assemblies. Our experimental results support this: the extent to which VIP-palm loses helical structure as a result of thermal denaturation was inversely related to the PEG-cholane:VIP-palm molar ratio. The addition of divalent buffer species and increasing the ionic strength of the solution both accelerate the formation of VIP-palm fibrils, which was partially and fully suppressed by 2 and >4 mol equivalents of PEG-cholane, respectively. We conclude that the relative freedom of the VIP-palm backbone to adopt nonhelical conformations is a key step in the aggregation pathway.

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confidence: 86%

Section: In Silico Simulations Capture Vip-palm Structural Change On Supramolecular Assemblymentioning

confidence: 97%

mentioning

confidence: 99%

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Control of Peptide Aggregation and Fibrillation by Physical PEGylation

Ambrosio

Podmore²,

Santos³

et al. 2018

Biomacromolecules

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“…These stealth nanoparticles reduce the degree of opsonization via a steric hindrance or by increasing the hydrophilicity of the surface [ 20 , 21 , 22 ]. Physical PEGylation has several advantages over chemical attachment of PEG on the surface of the NPs including, in addition to simplicity, rapidness, and low cost, the absence of premature drug release during the conjugation step [ 23 ].…”

Section: Introductionmentioning

confidence: 99%

Optimized Polyethylene Glycolylated Polymer–Lipid Hybrid Nanoparticles as a Potential Breast Cancer Treatment

et al. 2020

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Purpose: The aim of this work is to optimize a polyethylene glycolated (PEGylated) polymer–lipid hybrid nanoparticulate system for the delivery of anastrozole (ANS) to enhance its biopharmaceutical attributes and overall efficacy. Methods: ANS loaded PEGylated polymer–lipid hybrid nanoparticles (PLNPs) were prepared by a direct emulsification solvent evaporation method. The physical incorporation of PEG was optimized using variable ratios. The produced particles were evaluated to discern their particle size and shape, zeta-potential, entrapment efficiency, and physical stability. The drug-release profiles were studied, and the kinetic model was analyzed. The anticancer activity of the ANS PLNPs on estrogen-positive breast cancer cell lines was determined using flow cytometry. Results: The prepared ANS-PLNPs showed particle sizes in the range of 193.6 ± 2.9 to 218.2 ± 1.9 nm, with good particle size uniformity (i.e., poly-dispersity index of around 0.1). Furthermore, they exhibited relatively low zeta-potential values ranging from −0.50 ± 0.52 to 6.01 ± 4.74. The transmission electron microscopy images showed spherical shape of ANS-PLNPs and the compliance with the sizes were revealed by light scattering. The differential scanning calorimetry DSC patterns of the ANS PLNPs revealed a disappearance of the characteristic sharp melting peak of pure ANS, supporting the incorporation of the drug into the polymeric matrices of the nanoparticles. Flow cytometry showed the apoptosis of MCF-7 cell lines in the presence of ANS-PLNPs. Conclusion: PEGylated polymeric nanoparticles presented a stable encapsulated system with which to incorporate an anticancer drug (ANS) with a high percentage of entrapment efficiency (around 80%), good size uniformity, and induction of apoptosis in MCF-7 cells.

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“…[16][17][18][19][20][21][22][23][24][25][26] Examples include polymer conjugation via: co-factor reconstitution, 16 the biotin-streptavidin complex, 18 supramolecular complexation with cucurbituril, 19 charge-charge 20 and metal affinity 21,24 interactions, as well as lectin-mediated complexation. 25,27,28 The advantage of noncovalent systems is that temporal control of conjugate assembly and disassembly can be asserted by the presence of competitor molecules.…”

Section: Introductionmentioning

confidence: 99%

Noncovalent PEGylation via Lectin–Glycopolymer Interactions

et al. 2016

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The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 2 AbstractPEGylation, the covalent modification of proteins with polyethylene glycol, is an abundantly used technique to improve the pharmacokinetics of therapeutic proteins. The drawback with this methodology is that the covalently attached PEG can impede the biological activity (e.g. reduced receptor-binding capacity). Protein therapeutics with "disposable" PEG modifiers have potential advantages over the current technology. Here, we show that a protein-polymer "Medusa complex" is formed by the combination of a hexavalent lectin with a glycopolymer. Using NMR spectroscopy, small angle X-ray scattering (SAXS), size exclusion chromatography and native gel electrophoresis it was demonstrated that the fucose-binding lectin RSL and a fucose-capped polyethylene glycol (Fuc-PEG) form a multimeric assembly. All of the experimental methods provided evidence of noncovalent PEGylation with a concomitant increase in molecular mass and hydrodynamic radius. The affinity of the protein-polymer complex was determined by ITCand competition experiments to be in the µM range, suggesting that such systems have potential biomedical applications.

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A novel combined strategy for the physical PEGylation of polypeptides

Cited by 16 publications

References 48 publications

Control of Peptide Aggregation and Fibrillation by Physical PEGylation

Control of Peptide Aggregation and Fibrillation by Physical PEGylation

Optimized Polyethylene Glycolylated Polymer–Lipid Hybrid Nanoparticles as a Potential Breast Cancer Treatment

Noncovalent PEGylation via Lectin–Glycopolymer Interactions

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