We use two pore-forming proteins, alpha-hemolysin and aerolysin, to compare the polymer size-dependence of ionic current block by two types of ethyleneglycol polymers: 1) linear and 2) 3-arm star poly(ethylene glycol), both applied as a polydisperse mixture of average mass 1kDa under high salt conditions. The results demonstrate that monomer size sensitivity, as known for linear PEGs, is conserved for the star polymers with only subtle differences in the dependence of the residual conductance on monomer number. To explain this absence of a dominant effect of polymer architecture, we propose that PEG adsorbs to the inner pore wall in a collapsed, salted-out state, likely due to the effect of hydrophobic residues in the pore wall on the availability of water for hydration.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1140/epje/i2018-11687-6 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Unexpected Stress Overshoot in Extensional Flow of Star Polymer Melts.
ACS Macro Lett
July 2024
Polymer Research Institute, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China.
Previous studies have shown that the nonlinear rheological behavior of 3-arm star polymer melts in fast extensional flow is identical to that of linear polymers with the same span molecular weight, because the star polymers are highly aligned and have a similar conformation as the corresponding linear polymers. However, with more arms, it would be more difficult for the stars to be aligned like linear chains, and the nonlinear extensional rheology of star polymers with more arms under large deformations has not been investigated yet. Here we show that the star polystyrene (8-10 arms) melts behave differently from the linear polystyrenes.
View Article and Find Full Text PDFDevelopment, Characterization and Pharmacological Evaluation of Cannabidiol-Loaded Long Circulating Niosomes.
Pharmaceutics
October 2023
Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Pharmacy, Medical University of Sofia, 2 Dunav Str., 1000 Sofia, Bulgaria.
Cannabidiol (CBD) is a promising drug candidate with pleiotropic pharmacological activity, whose low aqueous solubility and unfavorable pharmacokinetics have presented obstacles to its full clinical implementation. The rational design of nanocarriers, including niosomes for CBD encapsulation, can provide a plausible approach to overcoming these limitations. The present study is focused on exploring the feasibility of copolymer-modified niosomes as platforms for systemic delivery of CBD.
View Article and Find Full Text PDFTailoring Writability and Performance of Star Block Copolypeptides Hydrogels through Side-Chain Design.
Small
December 2023
Department of Chemistry & Biochemistry, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
Shear-recoverable hydrogels based on block copolypeptides with rapid self-recovery hold potential in extrudable and injectable 3D-printing applications. In this work, a series of 3-arm star-shaped block copolypeptides composed of an inner hydrophilic poly(l-glutamate) domain and an outer β-sheet forming domain is synthesized with varying side chains and block lengths. By changing the β-sheet forming domains, hydrogels with diverse microstructures and mechanical properties are prepared and structure-function relationships are determined using scattering and rheological techniques.
View Article and Find Full Text PDFSynthesis of High Molecular Weight Polymers by Organocatalyzed Living Radical Polymerization and Self-Assembly Behavior.
Macromol Rapid Commun
April 2023
State Key Laboratory of Separation Membranes and Membrane Processes, School of Chemistry, Tiangong University, Tianjin, 300387, P. R. China.
A mild organocatalyzed living radical polymerization method is studied for high molecular weight polymers (HMWPs), yielding low-dispersity linear and star polymers (Đ = M /M = 1.03-1.28) up to M = 3.
View Article and Find Full Text PDFSTAR-TREC: An International Three-arm Multicentre, Partially Randomised Controlled Trial Incorporating an External Pilot.
Clin Oncol (R Coll Radiol)
February 2023
Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK. Electronic address:
Aim: Organ saving treatment for early-stage rectal cancer can reduce patient reported side effects compared to standard total mesorectal excision (TME) and preserve quality of life (QOL). An optimal strategy for achieving organ preservation and longer-term oncological outcomes are unknown, thus there is a need for high quality trials.
Method: Can we Save the rectum by watchful waiting or TransAnal surgery following (chemo)Radiotherapy versus Total mesorectal excision for early REctal Cancer (STAR-TREC) is an international 3-arm multi-centre, partially randomised controlled trial incorporating an external pilot.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!