ORCID Profile
0000-0002-8792-7030
Current Organisations
University of Potsdam
,
Universität Potsdam
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Publisher: Wiley
Date: 22-04-2003
Publisher: American Chemical Society (ACS)
Date: 09-11-2017
Abstract: Antimicrobial polymers appear as a promising alternative to tackle the current development of bacterial resistance against conventional antibiotics as they rely on bacterial membrane disruption. This study investigates the effect of segmentation of hydrophobic and cationic functionalities on antimicrobial polymers over their selectivity between bacteria and mammalian cells. Using RAFT technology, statistical, diblock, and highly segmented multiblock copolymers were synthesized in a controlled manner. Polymers were analyzed by HPLC, and the segmentation was found to have a significant influence on their overall hydrophobicity. In addition, the amount of incorporated cationic comonomer was varied to yield a small library of bioactive macromolecules. The antimicrobial properties of these compounds were probed against pathogenic bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis), and their biocompatibility was tested using hemolysis and erythrocyte aggregation assays, as well as mammalian cell viability assays. In all cases, diblock and multiblock copolymers were found to outperform statistical copolymers, and for polymers with a low content of cationic comonomer, the multiblock showed a tremendously increased selectivity for P. aeruginosa and S. epidermidis compared to its statistical and diblock analogue. This work highlights the remarkable effect of segmentation on both the physical properties of the materials as well as their interaction with biological systems. Due to the outstanding selectivity of multiblock copolymers toward certain bacteria strains, the presented materials are a promising platform for the treatment of infections and a valuable tool to combat antimicrobial resistance.
Publisher: Oxford University Press (OUP)
Date: 06-2004
Publisher: Royal Society of Chemistry (RSC)
Date: 2017
DOI: 10.1039/C7PY00630F
Abstract: A flexible, robust and time-efficient scale-up of multiblock copolymers with low dispersity and high livingness.
Publisher: Oxford University Press (OUP)
Date: 2014
DOI: 10.1095/BIOLREPROD.113.114694
Abstract: Objectives were to evaluate the effects of administering either one or two low doses of slow-release recombinant bovine somatotropin (bST) on hormone concentrations, conceptus development, and fertility in dairy cows. Cows from two farms were detected in estrus on or after 50 days postpartum (n = 1483), inseminated, and enrolled in the study (Day 0). Within farm, cows were blocked by parity and assigned randomly to receive a single placebo injection at insemination (control), a single injection with 325 mg of bST at insemination (S-bST), or two injections with 325 mg of bST administered on Days 0 and 14 (T-bST). From a subset of cows, blood was collected twice weekly from Day 0 to 42 for determination of hormone concentrations and on Day 19 for isolation of leucocytes and analysis of transcript abundance of selected interferon-stimulated genes. Pregnancy was diagnosed on Days 31 and 66, and ultrasonographic morphometry of the conceptus was performed on Days 34 and 48 in a subset of cows. Cows that received T-bST had increased plasma concentrations of GH and IGF1 for 4 wk, increased mRNA expression of ISG15 and RTP4 in leukocytes, earlier rise in the pregnancy-specific protein B in plasma of pregnant cows, increased conceptus size, and enhanced fertility. Cows that received S-bST had increased concentrations of GH and IGF1 for only 2 wk and it was insufficient to alter conceptus development and fertility. In conclusion, supplementation with low doses of bST during the pre- and peri-implantation periods enhanced conceptus development, reduced embryonic losses, and improved fertility in dairy cows.
Location: United Kingdom of Great Britain and Northern Ireland
Location: Germany
Location: United States of America
No related grants have been discovered for Duane Keisler.