skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Depleting Cationic Lipids Involved in Antimicrobial Resistance Drives Adaptive Lipid Remodeling in Enterococcus faecalis
Title: Depleting Cationic Lipids Involved in Antimicrobial Resistance Drives Adaptive Lipid Remodeling in Enterococcus faecalis
The cell membrane plays a pivotal role in protecting bacteria against external threats, such as antibiotics. Cationic phospholipids such as lysyl-phosphatidyglycerol (L-PG) resist the action of cationic antimicrobial peptides through electrostatic repulsion.  more » « less
Award ID(s):
1427621
PAR ID:
10506957
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ;
Editor(s):
Huebner, Johannes; Gilmore, Michael S.
Publisher / Repository:
American Society for Microbiology
Date Published:
Journal Name:
mBio
Volume:
14
Issue:
1
ISSN:
2150-7511
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; (, Polymer Chemistry)
    In this report we demonstrate methanol as an effective degenerative chain transfer agent to control the cationic polymerisation (initiated by triflic acid) of electron rich p -alkoxy-styrenes, such as p -methoxystyrene ( p -MOS). Kinetic analysis revealed that an induction period occurs initially during which free cationic polymerisation occurs at low monomer conversion before proceeding through the pseudo first order rate, analogous to the RAFT mechanism. Ethanol and isopropanol also demonstrated excellent control ( Đ > 1.30), however, with an apparent increase in experimental molecular weight. Furthermore, methanol controlled polymers were successfully chain extended upon sequential monomer addition, demonstrating the ‘livingness’ of the alcohol mediated cationic polymerisation. 
    more » « less
  2. ; ; ; (, Macromolecular Chemistry and Physics)
    Abstract The unique properties of cationic nanogels, such as their hydrophilicity and high loading capacity, make them a promising platform as drug delivery agents, particularly for the delivery of hydrophilic biomolecules. Although several synthetic methods exist for cationic nanogels, polymerization in dispersed media is advantageous due to its ability to provide control over composition and high monomer conversion. However, polymer droplets typically suffer from a significant increase in size during polymerization due to the Ostwald ripening process. Herein, the preparation of cationic nanogels by atom transfer radical polymerization under inverse microemulsion conditions of a hydrophilic inimer that prevents monomer diffusion and hence limits droplets’ growth during polymerization is reported. Additionally, the surface functionality of the nanogels can be modulated by the application of hydrophobic reactive surfactants or by grafting hydrophilic shells to form core‐shell cationic nanogels. The synthesized cationic nanogels are biocompatible, internalized to HEK 293 cells, and have a high complexation ability for plasmid DNA. 
    more » « less
  3. ; ; ; ; (, Nanomaterials)
    Anionic carboxylated cellulose nanofibers (CNF) are effective media to remove cationic contaminants from water. In this study, sustainable cationic CNF-based adsorbents capable of removing anionic contaminants were demonstrated using a simple approach. Specifically, the zero-waste nitro-oxidization process was used to produce carboxylated CNF (NOCNF), which was subsequently converted into a cationic scaffold by crosslinking with aluminum ions. The system, termed Al-CNF, is found to be effective for the removal of fluoride ions from water. Using the Langmuir isotherm model, the fluoride adsorption study indicates that Al-CNF has a maximum adsorption capacity of 43.3 mg/g, which is significantly higher than that of alumina-based adsorbents such as activated alumina (16.3 mg/g). The selectivity of fluoride adsorption in the presence of other anionic species (nitrate or sulfate) by Al-CNF at different pH values was also evaluated. The results indicate that Al-CNF can maintain a relatively high selectivity towards the adsorption of fluoride. Finally, the sequential applicability of using spent Al-CNF after the fluoride adsorption to further remove cationic contaminant such as Basic Red 2 dye was demonstrated. The low cost and relatively high adsorption capacity of Al-CNF make it suitable for practical applications in fluoride removal from water. 
    more » « less
  4. ; ; ; ; ; (, Progress in Polymer Science)
    Cationic polymerization is a powerful strategy for the production of well-defined polymers and advanced materials. In particular, the emergence of living cationic polymerization has enabled pathways to complex polymer architectures inaccessible before. The use of light and electricity as external stimuli to regulate cationic polymerization represents another advance with increasing applications in surface fabrication and patterning, additive manufacturing, and other advanced material engineering. The past decade also witnessed vigorous progress in stereoselective cationic polymerizations, allowing for the dual control of both the tacticity and the molecular weight of vinyl polymers towards precision polymers. In addition, in addressing the plastics pollution crisis and achieving a circular materials economy, cationic polymerization offers unique advantages for generating chemically recyclable polymers, such as polyacetals, polysaccharides, polyvinyl ethers, and polyethers. In this review, we provide an overview of recent developments in regulating cationic polymerization, including emerging control systems, spatiotemporally controlled polymerization (light and electricity), stereoselective polymerization, and chemically recyclable/degradable polymers. Hopefully, these discussions will help to stimulate new ideas for the further development of cationic polymerization for researchers in the field of polymer science and beyond. 
    more » « less
  5. ; ; ; ; ; ; ; ; ; ; et al (, Proceedings of the National Academy of Sciences)
    Adding a cationic helper lipid to a lipid nanoparticle (LNP) can increase lung delivery and decrease liver delivery. However, it remains unclear whether charge-dependent tropism is universal or, alternatively, whether it depends on the component that is charged. Here, we report evidence that cationic cholesterol-dependent tropism can differ from cationic helper lipid-dependent tropism. By testing how 196 LNPs delivered mRNA to 22 cell types, we found that charged cholesterols led to a different lung:liver delivery ratio than charged helper lipids. We also found that combining cationic cholesterol with a cationic helper lipid led to mRNA delivery in the heart as well as several lung cell types, including stem cell-like populations. These data highlight the utility of exploring charge-dependent LNP tropism. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email