Evidence map›Paper›PMID 42891191›Full record

ArticleACS polymers Au2026

Free Polymers Skew Polyplex Solution Properties and Confound the Interpretation of Structure-Function Relationships.

Jessica L Lawson, Kaitlin C Lesco, Ram Prasad Sekar, Grant Wheeler, S Kim Ratanathanawongs Williams, Ramya Kumar

Abstract read
In one paragraph

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

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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

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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

6 authors.

Jessica L LawsonMaterials Science, Colorado School of Mines, Golden, Colorado 80401, United States.ORCID https://orcid.org/0009-0009-7668-2419
Kaitlin C LescoBioenergy Science and Technology Directorate, National Laboratory of the Rockies, Golden, Colorado 80401, United States.
Ram Prasad SekarChemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States.ORCID https://orcid.org/0000-0003-3890-6230
Grant WheelerQuantitative Biosciences and Engineering, Colorado School of Mines, Golden, Colorado 80401, United States.
S Kim Ratanathanawongs WilliamsDepartment of Chemistry, Colorado School of Mines, Golden, Colorado 80401, United States.ORCID https://orcid.org/0000-0003-3894-478X
Ramya KumarChemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States.ORCID https://orcid.org/0000-0002-8725-0023

Funding

Machine-guided design of chaperone-mimetic polymeric carriers for ribonucleoprotein deliveryR21EB036183 · NIBIB · COLORADO SCHOOL OF MINES · PI RAMYA KUMAR · 2025 to 2026
$403k
NIBIB NIH HHS R21 EB036183
6 · The paper itself

Abstract

Structure-function relationships for polymeric gene carriers are derived from crude, heterogeneous mixtures of free polymers and polymer-pDNA complexes (polyplexes). Recognizing that our current understanding of polyplex solution properties may be erroneous, we separated free polymers from crude polyplexes to gain important, previously inaccessible perspectives into polymer-mediated pDNA delivery. Free polymers, the numerically dominant species in crude polyplexes, impose characterization and quality control challenges similar to empty viral capsids and lipid nanoparticles. Polyplexes are frequently formed at large stoichiometric excesses of cationic groups in polymers relative to phosphates in pDNA resulting in nitrogen-to-phosphorus ratios between 5-100. Most polymers exist as "free polymers" in dynamic equilibrium with pDNA-bound polymers. For the first time, we quantified the contributions of free polymers to polyplex solution properties and biological performance. We separated free polymers from polyplexes by applying asymmetrical flow field-flow fractionation (AF4), which removes free polymers under gentle laminar flow, minimizing shear stress and keeping polyplexes intact. While batch light-scattering analysis of unfractionated crude polyplexes severely underestimates polyplex size and pDNA loading by 2-4×, AF4-aided removal of free polymers sharpened measurements by eliminating background light-scattering contributions. Polyplexes with 78% free polymers aggravated inflammatory responses in macrophages by 2-20× compared to polyplexes devoid of free polymers. Removing free polymers depressed transfection efficiency by 50% while improving cell viability by 30%; reintroducing free polymers abrogated these contrasts. By separating and quantifying free polymers using AF4, we corrected systematic biases in structure-function trends gleaned from crude polyplexes. For instance, microstructure-dependent trends in pDNA loading reported in our earlier work originated from differences in free polymer content rather than the polymer microstructure itself. Our study establishes that free polymers skew measurements of polyplex properties and biological performance and offers design guidance to navigate trade-offs between transfection efficiency, immunogenicity, and toxicity.

Indexed as

AF4-MDblock copolymersfield-flow fractionationgradient copolymersnucleic acid deliverypolyplexesstatistical copolymers

Identifiers

PMID42891191
PMCPMC13673885

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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.