High Antimicrobial Activity and Low Human Cell Cytotoxicity of Core–Shell Magnetic Nanoparticles Functionalized with an Antimicrobial Peptide

2016 ◽  
Vol 8 (18) ◽  
pp. 11366-11378 ◽  
Author(s):  
Hajar Maleki ◽  
Akhilesh Rai ◽  
Sandra Pinto ◽  
Marta Evangelista ◽  
Renato M.S. Cardoso ◽  
...  
MedChemComm ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 896-900 ◽  
Author(s):  
Takashi Misawa ◽  
Chihiro Goto ◽  
Norihito Shibata ◽  
Motoharu Hirano ◽  
Yutaka Kikuchi ◽  
...  

Amphipathic helical peptideStripeshowed high antimicrobial activity, low hemolytic activity, and low human cell cytotoxicity.


2018 ◽  
Vol Volume 13 ◽  
pp. 3965-3973 ◽  
Author(s):  
Kamiar Zomorodian ◽  
Hamed Veisi ◽  
Mahmoud Mousavi ◽  
Mahmoud Ataabadi ◽  
Somayeh Yazdanpanah ◽  
...  

2006 ◽  
Vol 50 (4) ◽  
pp. 1522-1524 ◽  
Author(s):  
Jon-Paul S. Powers ◽  
Morgan M. Martin ◽  
Danika L. Goosney ◽  
Robert E. W. Hancock

ABSTRACT The horseshoe crab peptide polyphemusin I possesses high antimicrobial activity, but its mechanism of action is as yet not well defined. Using a biotin-labeled polyphemusin I analogue and confocal fluorescence microscopy, we showed that the peptide accumulates in the cytoplasm of wild-type Escherichia coli within 30 min after addition without causing substantial membrane damage.


Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 844
Author(s):  
Philip Storck ◽  
Florian Umstätter ◽  
Sabrina Wohlfart ◽  
Cornelius Domhan ◽  
Christian Kleist ◽  
...  

The increasing number of infections caused by multidrug-resistant bacteria requires an intensified search for new antibiotics. Pep19-4LF is a synthetic antimicrobial peptide (GKKYRRFRWKFKGKLFLFG) that was previously designed with the main focus on high antimicrobial activity. The hydrophobic motif, LFLFG, was found to be essential for antimicrobial activity. However, this motif shows several limitations such as aggregation in biological media, low solubility, and small yields in peptide synthesis. In order to obtain more appropriate peptide characteristics, the hydrophobic motif was replaced with fatty acids. For this purpose, a shortened variant of Pep19-4LF (Pep19-short; GKKYRRFRWKFKGK) was synthesized and covalently linked to saturated fatty acids of different chain lengths. The peptide conjugates were tested with respect to their antibacterial activity by microdilution experiments on different bacterial strains. The length of the fatty acid was found to be directly correlated to the antimicrobial activity up to an ideal chain length (undecanoic acid, C11:0). This conjugate showed high antimicrobial activity in absence of toxicity. Time–kill studies revealed a fast and bactericidal mode of action. Furthermore, the first in vivo experiments of the conjugate in rodents demonstrated pharmacokinetics appropriate for application as a drug. These results clearly indicate that the hydrophobic motif of the peptide can be replaced by a single fatty acid of medium length, simplifying the design of this antimicrobial peptide while retaining high antimicrobial activity in the absence of toxicity.


2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.


2020 ◽  
Vol 4 (3) ◽  
Author(s):  
C. Kons ◽  
Manh-Huong Phan ◽  
Hariharan Srikanth ◽  
D. A. Arena ◽  
Zohreh Nemati ◽  
...  

2021 ◽  
Vol 9 (6) ◽  
pp. 1249
Author(s):  
Johannes Koehbach ◽  
Jurnorain Gani ◽  
Kai Hilpert ◽  
David J Craik

According to the World Health Organization (WHO) the development of resistance against antibiotics by microbes is one of the most pressing health concerns. The situation will intensify since only a few pharmacological companies are currently developing novel antimicrobial compounds. Discovery and development of novel antimicrobial compounds with new modes of action are urgently needed. Antimicrobial peptides (AMPs) are known to be able to kill multidrug-resistant bacteria and, therefore, of interest to be developed into antimicrobial drugs. Proteolytic stability and toxicities of these peptides are challenges to overcome, and one strategy frequently used to address stability is cyclization. Here we introduced a disulfide-bond to cyclize a potent and nontoxic 9mer peptide and, in addition, as a proof-of-concept study, grafted this peptide into loop 6 of the cyclotide MCoTI-II. This is the first time an antimicrobial peptide has been successfully grafted onto the cyclotide scaffold. The disulfide-cyclized and grafted cyclotide showed moderate activity in broth and strong activity in 1/5 broth against clinically relevant resistant pathogens. The linear peptide showed superior activity in both conditions. The half-life time in 100% human serum was determined, for the linear peptide, to be 13 min, for the simple disulfide-cyclized peptide, 9 min, and, for the grafted cyclotide 7 h 15 min. The addition of 10% human serum led to a loss of antimicrobial activity for the different organisms, ranging from 1 to >8-fold for the cyclotide. For the disulfide-cyclized version and the linear version, activity also dropped to different degrees, 2 to 18-fold, and 1 to 30-fold respectively. Despite the massive difference in stability, the linear peptide still showed superior antimicrobial activity. The cyclotide and the disulfide-cyclized version demonstrated a slower bactericidal effect than the linear version. All three peptides were stable at high and low pH, and had very low hemolytic and cytotoxic activity.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chin-Wei Lin ◽  
Jian-Ming Chen ◽  
You-Jun Lin ◽  
Ling-Wei Chao ◽  
Sin-Yi Wei ◽  
...  

Abstract Recently, gold-coated magnetic nanoparticles have drawn the interest of researchers due to their unique magneto-plasmonic characteristics. Previous research has found that the magneto-optical Faraday effect of gold-coated magnetic nanoparticles can be effectively enhanced because of the surface plasmon resonance of the gold shell. Furthermore, gold-coated magnetic nanoparticles are ideal for biomedical applications because of their high stability and biocompatibility. In this work, we synthesized Fe3O4@Au core-shell nanoparticles and coated streptavidin (STA) on the surface. Streptavidin is a protein which can selectively bind to biotin with a strong affinity. STA is widely used in biotechnology research including enzyme-linked immunosorbent assay (ELISA), time-resolved immunofluorescence (TRFIA), biosensors, and targeted pharmaceuticals. The Faraday magneto-optical characteristics of the biofunctionalized Fe3O4@Au nanoparticles were measured and studied. We showed that the streptavidin-coated Fe3O4@Au nanoparticles still possessed the enhanced magneto-optical Faraday effect. As a result, the possibility of using biofunctionalized Fe3O4@Au nanoparticles for magneto-optical biomedical assays should be explored.


2014 ◽  
Vol 50 (11) ◽  
pp. 1-4 ◽  
Author(s):  
Galina V. Kurlyandskaya ◽  
Inaki Madinabeitia ◽  
A. M. Murzakaev ◽  
M. Belen Sanchez-Ilarduya ◽  
V. Beketov ◽  
...  

2003 ◽  
Vol 36 (4) ◽  
pp. 1069-1074 ◽  
Author(s):  
D. Eberbeck ◽  
A. Lange ◽  
M. Hentschel

Different very dilute suspensions of magnetic nanoparticles (magnetite surrounded by an organic shell) in water (ferrofluids) were investigated using small-angle X-ray scattering. It is shown that the scattering originates not only from noncorrelated core–shell nanoparticles, but also from larger structures. By modelling, these structures can be identified as close-packed clusters consisting of core–shell particles (core diameter ∼10 nm). The analysis of the radial distance distribution function, obtained by Fourier transformation of the scattered intensity, reveals a lower bound of the mean cluster size of about 40 nm. The formation of clusters is persistent, even in very dilute suspensions.


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