Evidence map›Paper›PMID 41822977›Full record

ArticleAnalytical chemistry2026

POx-Lipids as an Alternative to PEG-Lipids? Multimethod Assessment of Chemistry and Structure.

Ekaterina Tsarenko, Ilya Anufriev, Caroline T Holick, Tobias Klein, Stephanie Schubert, Nicole Fritz, Stephanie Hoeppener, Ulrich S Schubert, Ivo Nischang

Abstract read
In one paragraph

Article in Analytical chemistry, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Ekaterina TsarenkoLaboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany.
Ilya AnufrievLaboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany.
Caroline T HolickLaboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany.
Tobias KleinLaboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany.ORCID 0000-0001-9404-7739
Stephanie SchubertLaboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany.ORCID 0000-0001-9527-7763
Nicole FritzLaboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany.
Stephanie HoeppenerLaboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany.ORCID 0000-0002-5770-5197
Ulrich S SchubertLaboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany.ORCID 0000-0003-4978-4670
Ivo NischangLaboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstraße 10, 07743 Jena, Germany.ORCID 0000-0001-6182-5215

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The characterization of polymer-lipid conjugates is essential for their successful application in pharmaceutical formulations, particularly in lipid nanoparticles (LNPs). While poly(ethylene glycol) (PEG) lipids are widely used in LNPs, growing concerns over PEG immunogenicity have prompted the search for alternatives. Here, we investigate a series of poly(2-ethyl-2-oxazoline) (PEtOx) lipids as promising PEG substitutes featuring biocompatibility, tunable hydrophilicity, and stealth-like properties. We apply a comprehensive, multimethod approach utilizing liquid chromatography (LC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to assess end group homogeneity, sample purity, and information about overall hydrophobicity/hydrophilicity of PEtOx-lipids compared to benchmark PEG-lipids used in COVID vaccines. We also demonstrate that under conditions of high sample purity only, hydrodynamic techniques such as analytical ultracentrifugation (AUC) become robust tools for analyzing conformational properties, aggregation behavior, and hydration of the polymers in aqueous environments. Though PEtOx-lipid analogues form micelles with lower aggregation numbers than PEG-lipids, they feature the same hydrodynamic size and values of hydration. The large levels of hydration of PEtOx-lipid micelles cannot be explained by hydrogen bonded water. Water present in the micelles constitutes a major part of their overall hydrodynamic volume and is located between the extended chain conformation of assembled polymers. Our study, with a unique multimethod approach, shows the importance of sample purity in high-end hydrodynamic analysis and paves the way for a quantitative replacement of PEG-based lipid conjugates by PEtOx-based lipid conjugates through a distinct set of properties to be considered for a particular application.

Indexed as

LipidsPolyaminesPolyethylene GlycolsHydrophobic and Hydrophilic InteractionsNanoparticlesPolyether CompoundsSpectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationLipidspoly(2-ethyl-2-oxazoline)PolyaminesPolyether CompoundsPolyethylene Glycols

Identifiers

PMID41822977
PMCPMC13019425

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.