Biotin−Pyrene Conjugates with Poly(ethylene glycol) Spacers Are Convenient Fluorescent Probes for Avidin and Streptavidin

1997 ◽  
Vol 8 (4) ◽  
pp. 560-566 ◽  
Author(s):  
Markus Marek ◽  
Karl Kaiser ◽  
Hermann J. Gruber

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 119
Author(s):  
David Milićević ◽  
Jan Hlaváč

A new concept for simultaneous detection of two model proteases based on immobilized fluorescently labelled peptides was developed and evaluated. Each probe was composed of a carrier modified by poly(ethylene glycol) (PEG) chains, a specifically cleavable linker, and a fluorescent dye incorporated in the peptide tail. Based on a single excitation–double emission fluorescence response of liberated fluorophores caused by enzymatic cleavage, the presence of a single or both proteases in a mixture was unambiguously determined in an experimentally established concentration range. Among the tested solid supports, Rink Amide PEGA resin was recognized as the most suitable choice from the perspective of on-resin enzyme assays.



1987 ◽  
Vol 88 (3) ◽  
pp. 389-398
Author(s):  
Q.F. Ahkong ◽  
J.P. Desmazes ◽  
D. Georgescauld ◽  
J.A. Lucy

It has been claimed that purified poly(ethylene glycol) (PEG) is able only to aggregate cells and not to fuse them. In our hands, purified PEG 6000 (recrystallized/dialysed) induces both aggregation and fusion of human erythrocytes, and the mechanism of fusion by the purified polymer has been investigated with fluorescent probes. No movement of a carbocyanine probe or of octadecyl rhodamine B chloride from labelled to unlabelled cells occurred in the absence of PEG or with cells treated with concanavalin A, protamine or spermine. With 40% PEG, however, both probes immediately started to diffuse into the membranes of unlabelled cells. This indicates that continuity between the phospholipid bilayer membranes of adjacent erythrocytes (i.e. membrane fusion) is established within seconds in concentrated solutions of the polymer, and precedes the cell fusion event that is induced by purified PEG. These observations are consistent with the idea that micro-regions of shared phospholipid bilayer may be formed in the membranes of cells when they are forced together as a consequence of the dehydrating action of PEG. Intact erythrocytes were cytoplasmically labelled with 6-carboxyfluorescein to avoid the possibility that loading the cells with a cytoplasmic marker by hypotonic haemolysis might modify their response to PEG. Unlike the lipid probes, carboxyfluorescein did not diffuse from labelled to unlabelled cells in the presence of 40% PEG, and there was little diffusion on subsequent dilution of the polymer solution to 13%. However, after the PEG solution had been replaced by an isotonic buffer, a rapid transfer of the cytoplasmic fluorophore to unlabelled cells often occurred. This is considered to be more consistent with the osmotic rupture of a membranous barrier, such as a shared bilayer, between the labelled and unlabelled cells than with the return of cytoplasmic viscosity to normal when the PEG is removed. Possible reasons are discussed for the reported inability of purified PEG to fuse fibroblasts with hypotonically loaded human erythrocytes.



2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Anton Bonartsev ◽  
Vera Voinova ◽  
Elizaveta Akoulina ◽  
Andrey Dudun ◽  
Irina Zharkova ◽  
...  


2007 ◽  
Vol 32 (5) ◽  
pp. 431-446 ◽  
Author(s):  
Tahar Bartil ◽  
Mahmoud Bounekhel ◽  
Cedric Calberg ◽  
Robert Jerome


2019 ◽  
Author(s):  
Alex Khang ◽  
Andrea Gonzalez Rodriguez ◽  
Megan E. Schroeder ◽  
Jacob Sansom ◽  
Emma Lejeune ◽  
...  


2019 ◽  
Vol 14 (3) ◽  
pp. 280-291 ◽  
Author(s):  
Jaleh Varshosaz ◽  
Farshid Hassanzadeh ◽  
Batool Hashemi-Beni ◽  
Mohsen Minaiyan ◽  
Saeedeh Enteshari

Background: Due to the low water solubility of Docetaxel (DTX), it is formulated with ethanol and Tween 80 with lots of side effects. For this reason, special attention has been paid to formulate it in new drug nano-carriers. Objective: The goal of this study was to evaluate the safety, antitumor activity and tissue distribution of the novel synthesized Raloxifene (RA) targeted polymeric micelles. Methods: DTX-loaded RA-targeted polymeric micelles composed of poly(styrene-maleic acid)- poly(amide-ether-ester-imide)-poly(ethylene glycol) (SMA-PAEE-PEG) were prepared and their antitumor activity was studied in MC4-L2 tumor-bearing mice compared with non-targeted micelles and free DTX. Safety of the micelles was studied by Hematoxylin and Eosin (H&E) staining of tumors and major organs of the mice. The drug accumulation in the tumor and major organs was measured by HPLC method. Results: The results showed better tumor growth inhibition and increased survival of mice treated with DTX-loaded in targeted micelles compared to the non-targeted micelles and free DTX. Histopathological studies, H&E staining of tumors and immunohistochemical examination showed the potential of DTX-loaded RA-targeted micelles to inhibit tumor cells proliferation. The higher accumulation of the DTX in the tumor tissue after injection of the micelles compared to the free DTX may indicate the higher uptake of the targeted micelles by the G-Protein-Coupled Estrogen Receptors (GPER). Conclusion: The results indicate that RA-conjugated polymeric micelles may be a strong and effective drug delivery system for DTX therapy and uptake of the drug into tumor cells, and overcome the disadvantages and side effects of conventional DTX.



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