Two poly(ethylene glycol) (PEG)-peptides were synthesized and tested for their ability to bind to plasmid DNA and form soluble DNA condensates with reduced spontaneous gene expression. PEG-vinyl sulfone or PEG-orthopyridyl disulfide were reacted with the sulfhydryl of Cys-Trp-Lys(18) (CWK(18)) resulting in the formation of nonreducible (PEG-VS-CWK(18)) and reducible (PEG-SS-CWK(18)) PEG-peptides. Both PEG-peptides were prepared on a micromole scale, purified by RP-HPLC in >80% yield, and characterized by (1)H NMR and MALDI-TOF. PEG-peptides bound to plasmid DNA with an apparent affinity that was equivalent to alkylated (Alk)CWK(18), resulting in DNA condensates with a mean diameter of 80-90 nm and zeta (zeta) potential of +10 mV. The particle size of PEG-peptide DNA condensates was constant throughout the DNA concentration range of 0. 05-2 mg/mL, indicating these to be approximately 20-fold more soluble than AlkCWK(18) DNA condensates. The spontaneous gene transfer to HepG2 cells mediated by PEG-VS-CWK(18) DNA condensates was over two orders of magnitude lower than PEG-SS-CWK(18) DNA condensates and three orders of magnitude lower than AlkCWK(18) DNA condensates. PEG-VS-CWK(18) efficiently blocked in vitro gene transfer by reducing cell uptake. The results indicate that a high loading density of PEG on DNA is necessary to achieve highly soluble DNA condensates that reduce spontaneous in vitro gene transfer by blocking nonspecific uptake by HepG2 cells. These two properties are important for developing targeted gene delivery systems to be used in vivo.
Pharmacology, Toxicology and Pharmaceutical Science
1
8%
Agricultural and Biological Sciences
1
8%
Unknown
6
46%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 9. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 19 August 2025.
All research outputs
#4,215,144
of 27,774,969 outputs
Outputs from Journal of Pharmaceutical Sciences
#392
of 6,486 outputs
Outputs of similar age
#4,576
of 44,960 outputs
Outputs of similar age from Journal of Pharmaceutical Sciences
#26
of 437 outputs
Altmetric has tracked 27,774,969 research outputs across all sources so far. Compared to these this one has done well and is in the 83rd percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 6,486 research outputs from this source. They receive a mean Attention Score of 4.9. This one has done well, scoring higher than 87% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 44,960 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 84% of its contemporaries.
We're also able to compare this research output to 437 others from the same source and published within six weeks on either side of this one. This one has done well, scoring higher than 83% of its contemporaries.
