Vesicular Lipid Nanoparticles (Liposomes) for the Treatment of Medical Device Infections

2011 ◽  
Vol 1316 ◽  
Author(s):  
Erik Taylor ◽  
Anubhav Kaviratna ◽  
Rinti Banerjee ◽  
Thomas J. Webster

AbstractLiposomes (a phospholipid bi-layer which can be formulated to contain drugs or other reagents) composed of endogenous phospholipid dipalmitoylphosphatidylcholine (DPPC) in combination with dioleoylphosphatidylethanolamine (DOPE), lauric acid, and silver sulfadiazine were made into vesicular nanoparticles in this study using an optimized extrusion technique. Liposomes were then tested for antibacterial activity against a range of bacteria species including Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Bacillus subtilis (all are relevant human pathogens known to infect implants) and were also challenged to prevent the growth of adherent biofilms (a robust slimy extracellular matrix) through an in vitro assay relevant to device related infections. It was found that all liposomes reduced bacterial growth, and, most importantly, liposomes containing DPPC and DOPE reduced biofilm formation better than the commercially available antibiotic silver sulfadiazine. These results indicated for the first time that such liposomes might be a better approach to prevent device related infections.

1996 ◽  
Vol 135 (5) ◽  
pp. 1229-1237 ◽  
Author(s):  
G L Bush ◽  
D I Meyer

Ssa1/2p, members of one of the yeast cytosolic hsp70 subfamilies, have been implicated in the translocation of secretory proteins into the lumen of the ER. The involvement of these hsp70s in translocation was tested directly by examining the effect of immunodepleting Ssa1/2p from yeast cytosol and subsequently testing the cytosol for its ability to support co- and post-translational translocation of prepro-alpha-factor. Depletion of Ssa1/2p had no effect on the efficiency of translocation in this in vitro assay. The system was used to examine the effect of the absence of Ssa1/2p on two other putative hsp70 functions: cotranslational folding of nascent luciferase and refolding of denatured luciferase. Depletion of Ssa1/2p had no effect on the ability of the yeast lysate to synthesize enzymatically active luciferase, but had a dramatic effect on the ability of the lysate to refold chemically denatured luciferase. These results demonstrate, for the first time, the refolding activity of Ssa1/2p in the context of the yeast cytosol, and define refolding activity as a chaperone function specific to Ssa1/2p, aprt from other cytosolic hsp70s. They also suggest that Ssa1/2p do not play a significant role in chaperoning the folding of nascent polypeptides. The implications of these findings for Ssa1/2p activity on their proposed role in the process of translocation are discussed.


2020 ◽  
Vol 58 (5) ◽  
pp. 533
Author(s):  
Nguyen Phi-Hung

From the whole plant of Isodon ternifolius collected in Vietnam, four triterpens including ursaldehyde (1), ursolic acid (2), b-sitosterol (3) and b-sitosteryl ferulate (4) were purified. Their chemical structures were determined by interpretation of NMR and MS data and comparison with the literatures. Compounds 1-4 were evaluated for their inhibitory activity against PTP1B enzyme activity using in vitro assay. Compounds 1 and 2 displayed potential activities with IC50 values of 16.92 ± 0.12 and 3.42 ± 0.45 μM, respectively. This is the first time that compounds 1 and 4 have been isolated from the Isodon genus and I. ternifolius has been evaluated for the PTP1B inhibitory activity.


2001 ◽  
Vol 183 (8) ◽  
pp. 2700-2703 ◽  
Author(s):  
Cheryl Galvani ◽  
Jefferson Terry ◽  
Edward E. Ishiguro

ABSTRACT The direct interaction of the Escherichia colicytotoxin RelE with its specific antidote, RelB, was demonstrated in two ways: (i) copurification of the two proteins and (ii) a positive yeast two-hybrid assay involving the relB andrelE genes. In addition, the purified RelE protein exhibited ribosome-binding activity in an in vitro assay, supporting previous observations suggesting that it is an inhibitor of translation.


2018 ◽  
Vol 65 (1) ◽  
pp. 1
Author(s):  
A. P. Liyanage ◽  
M. R. C. K. Mallawa ◽  
I. D. Silva

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