共查询到20条相似文献,搜索用时 15 毫秒
1.
Fluorescence response of acridine orange to changes in pH gradients across liposome membranes 总被引:3,自引:0,他引:3
The influence that changes in proton distribution have on the fluorescence of acridine orange was examined using negatively charged liposomes. Our results indicate that at least two mechanisms are involved: distribution of the probe between the internal aqueous phase of the liposomes and the outside medium, and binding of the probe to the liposome membranes. 相似文献
2.
L Mattenberger-Kreber G Auderset M Schneider A Louis-Broillet M S Benedetti A Malno? 《Experientia》1976,32(12):1522-1524
Uptake of 14C-cholesterol or 3H-cholesterol labelled liposomes, stimulation of 14C-glucose oxidation, as well as ultrastructural and autoradiographical experiments have shown that liposomes are phagocytized by mouse peritoneal macrophages. Further results have shown that degradation of liposomes was not complete 2h after uptake. 相似文献
3.
L. Mattenberger-Kreber G. Auderset M. Schneider A. Louis-Broillet M. Strolin Benedetti A. Malnoë 《Cellular and molecular life sciences : CMLS》1976,32(12):1522-1524
Summary Uptake of14C-cholesterol or3H-cholesterol labelled liposomes, stimulation of14C-glucose oxidation, as well as ultrastructural and autoradiographical experiments have shown that liposomes are phagocytized by mouse peritoneal macrophages. Further results have shown that degradation of liposomes was not complete 2 h after uptake. 相似文献
4.
The ability of liposomes composed of different kinds of phospholipid materials to adhere to the surface of the cornea was studied in the rabbit. The liposomes were labelled with tracer amounts of an I125-labelled phosphatidylethanolamine derivative and were instilled in 10 microliters drops onto the cornea. The retention of radioactivity was monitored. The results show that liposomes containing positively charged phospholipids are better retained than an albumin control. Thus, it may be possible to develop a drug delivery liposome system which would permit long-term sustained release of ophthalmic drugs onto the cornea. 相似文献
5.
Enhanced heparan sulfate proteoglycan-mediated uptake of cell-penetrating peptide-modified liposomes
Marty C Meylan C Schott H Ballmer-Hofer K Schwendener RA 《Cellular and molecular life sciences : CMLS》2004,61(14):1785-1794
Protein transduction domains (PTDs) are used to enhance cellular uptake of drugs, proteins, polynucleotides
or liposomes. In this study, functionalized Antennapedia (Antp, aa 43–-58) and HIV Tat (aa 47–57)
peptides were coupled to small unilamellar liposomes via thiol-maleimide linkage. Modified liposomes showed higher
uptake into a panel of cell lines including tumor and dendritic cells than unmodified control liposomes. Liposome
uptake was time and concentration dependent as analyzed by flow cytometry and live-cell microscopy. At least 100
PTD molecules per small unilamellar liposome (100 ± 30 nm) were necessary for efficient translocation into
cells. Cellular uptake of PTD-modified liposomes was 15- to 25-fold increased compared to unmodified liposomes and
was inhibited by preincubation of liposomes with heparin. Glycosaminoglycan-deficient CHO cells showed dramatically
reduced cell association of PTD-modified liposomes, confirming the important role of heparan sulfate proteoglycans
in PTD-mediated uptake. Antp-liposomes used as carriers of the cytotoxic drug
N4-octadecyl-1--D-arabinofuranosylcytosine-(5- 5)-3-C-ethinylcytidine
showed a reduction of the IC50 by 70% on B16F1 melanoma cells compared with unmodified
liposomes. PTD-functionalized liposomes, particularly Antp-liposomes, represent an interesting novel carrier
system for enhanced cell-specific delivery of a large variety of liposome-entrapped molecules.Received 16 April 2004; received after revision 13 May 2004; accepted 25 May 2004 相似文献
6.
Summary The ability of liposomes composed of different kinds of phospholipid materials to adhere to the surface of the cornea was studied in the rabbit. The liposomes were labelled with tracer amounts of an I125-labelled phosphatidylethanolamine derivative and were instilled in 10 l drops onto the cornea. The retention of radioactivity was monitored. The results show that liposomes containing positively charged phospholipids are better retained than an albumin control. Thus, it may be possible to develop a drug delivery, liposome system which would permit long-term sustained release of ophthalmic drugs onto the cornea. 相似文献
7.
Shao K Hou Q Go ML Duan W Cheung NS Feng SS Wong KP Yoram A Zhang W Huang Z Li QT 《Cellular and molecular life sciences : CMLS》2007,64(4):506-515
Tenascin-C is an extracellular matrix glycoprotein, whose expression is highly restricted in normal adult tissues, but markedly
up-regulated in a range of tumors, and therefore serves as a potential receptor for targeted anticancer drug or gene delivery.
We describe here a liposomal carrier system in which the targeting ligand is sulfatide. Experiments with tenascin-C-expressing
glioma cells demonstrated that binding of liposomes to the extracellular matrix relied essentially on the sulfatide-tenascin-C
interaction. Following binding to the extracellular matrix, the sulfatide-containing liposomes were internalized via both
caveolae/lipid raft- and clathrin-dependent pathways, which would ensure direct cytoplasmic release of the cargoes carried
in the liposomes. Such natural lipid-guided intracellular delivery targeting at the extracellular matrix glycoproteins of
tumor cells thus opens a new direction for development of more effective anticancer chemotherapeutics in future.
K. Shao & Q. Hou: These authors contributed equally to this work.
Received 22 September 2006; received after revision 5 December 2006; accepted 9 January 2007 相似文献
8.
G. Palacios 《Cellular and molecular life sciences : CMLS》1978,34(5):653-655
Summary We have studied glomerular zone involution in the rat's adrenal gland after a period of hyperfunction brought about by a low-sodium diet. The changes observed in this zone affect those organoids that are more directly involved in steroid genesis; mitochondria, smooth endoplasmic reticulum and liposomes. The Golgi complexes appear very developed, often, showing, a positive acid phosphatase activity. Lysosomes suffered a considerable increase in their number, and carried out their digestive function on liposomes. All those changes discussed here are seen as an accomodation of this zone to the new normofunctional situation. 相似文献
9.
D Gerlier F Sakai J F Doré 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1978,286(5):439-442
The Gross virus associated cell surface antigen GCSAa was extracted from (C58NT)D cells by solubilization of membranes with detergent and partially purified. This antigen was entraped in liposomes. Absorption experiments of the cytotoxic activity towards EmaleG2 cells of a W/Fu anti (C58NT)D serum showed the presence of the antigen at the surface of sensibilized liposomes. 相似文献
10.
The distribution of fast, intermediate and slow renaturing fractions of Rhynchosciara americana DNA was examined in the polytene salivary gland chromosomes by in situ hybridization. Heterochromatic areas readily hybridized but hybrid formation in the euchromatin depended more on the repetitiveness of the RNA probe. 相似文献
11.
Asbestos-induced cell damage is initiated by a reaction at the plasma membrane. The effect of chrysotile (which is more hemolytic and releases more silicic acid than other types of asbestos) on permeability changes of liposomes has been investigated. The destabilizing effect rises when the amount of chrysotile is increased. Silicon dioxide is one major constituent which could be a hemolytic agent, and a cause of damage. It also caused an increase of permeability of liposomes. 相似文献
12.
Summary The distribution of calcium in the fine-fibred bone tissue of the human adult tibia is measured with the electron probe X-ray microanalyzer. Variations in the calcium concentration may be related to the stratified fine structure of the bone matrix. 相似文献
13.
S. P. Dufrane A. Poss E. Goormaghtigh J. M. Ruysschaert 《Cellular and molecular life sciences : CMLS》1981,37(5):524-525
Summary We present evidence that cholesterol mediates thyrotropin binding to liposomes containing GT1 ganglioside. Thyrotropin fixation is maximal at 22% of cholesterol. This result suggests that the gangliosides' organization in the lipid matrix modulates their interaction with the glycoprotein hormone. 相似文献
14.
Barratt G 《Cellular and molecular life sciences : CMLS》2003,60(1):21-37
Colloidal drug carriers such as liposomes and nanoparticles are able to modify the distribution of an associated substance.
They can therefore be used to improve the therapeutic index of drugs by increasing their efficacy and/or reducing their toxicity.
If these delivery systems are carefully designed with respect to the target and route of administration, they may provide
one solution to some of the delivery problems posed by new classes of active molecules such as peptides, proteins, genes,
and oligonucleotides. They may also extend the therapeutic potential of established drugs such as doxorubicin and amphotericin
B. This article discusses the use of colloidal, particulate carrier systems (25 nm to 1 μm in diameter) in such applications.
In particular, systems which show diminished uptake by mononuclear phagocytes are described. Specific targeting of carriers
to particular tissues or cells is also considered.
Received 8 April 2002; received after revision 25 June 2002; accepted 26 June 2002 相似文献
15.
Lonez C Legat A Vandenbranden M Ruysschaert JM 《Cellular and molecular life sciences : CMLS》2008,65(4):620-630
The inflammatory effect of unmethylated CpG DNA sequences represents a major obstacle to the use of cationic lipids for in vivo gene therapy. Although the mechanism of CpG-induced inflammatory response is rather well understood nowadays, few solutions
have been designed to circumvent this effect in gene therapy experiments. Our previous work has shown that a refractory state
towards inflammation can be elicited by preinjecting cationic liposomes. Here, we present evidence that diC14-amidine liposomes
confer new anti-inflammatory properties to phospholipids from low-density lipoprotein (LDL) and even to synthetic phospholipids
for which such an observation has not been reported so far. Whereas oxidation of LDL lipids was a prerequisite for any anti-inflammatory
activity, lipid oxidation is no longer required in our experiments, suggesting that cationic lipids transport phospholipids
through a different route and affect different pathways.This opens up new possibilities for manipulating inflammatory responses
in gene therapy protocols but also in a general manner in immunological experiments.
Received 12 November 2007; received after revision 4 December 2007; accepted 4 December 2007 相似文献
16.
Immunoadjuvant activity of synthetic N-acetyl muramyl dipeptide 总被引:1,自引:0,他引:1
K. Mašek M. Zaoral J. Ježek R. Straka 《Cellular and molecular life sciences : CMLS》1978,34(10):1363-1364
Summary The administration of phosphatidyl choline/cholesterol liposomes with entrapped N-acetyl muramyl dipeptide induced in guinea-pigs the development of delayed hypersensitivity to ovalbumin. 相似文献
17.
Direct evidence is provided for the transmembrane permeation of xanthomegnin across phospholipid bilayer membranes using ascorbate-loaded liposomes. This process may be associated with an uncoupling effect on the oxidative phosphorylation of mitochondria. 相似文献
18.
Summary Direct evidence is provided for the transmembrane permeation of xanthomegnin across phospholipid bilayer mebranes using ascorbate-loaded liposomes. This process may be associated with an uncoupling effect on the oxidative phosphorylation of mitochondria. 相似文献
19.
Treatment of cloned pituitary cells (GH3/B6) with cholesterol-enriched liposomes, which presumably increases membrane cholesterol content, affects the passive and active electrophysiological properties and stimulates the release of prolactin (PRL). 相似文献
20.
Conclusions Our results indicate that the choice of the probe for ELOSA is of major concern. In our panel we had seven sera which contained about 100 molecules/ml and further five sera which contained less than 1000 molecules/ml. Most of them were detected by the long probe but not by the short probe. When PCR for the S-or PreS-gene was included it was possible to detec all 24 HBV-positive sera (not shown) by ELOSA. The reliable lower quantification limit for the long probe is 250 molecules/ml and for the short probe 2500 molecules/ml. Surprisingly, chemiluminescence did not produce better qualitative or quantitative results. The data suggest that the usage of several replicates allows relative quantification in most cases. One possible drawback we see is the hybridization efficiency. Six of our positive samples showed great differences between the number of target molecules suggested by agarose gel electrophoreses or by hybridization (Southern blot or ELOSA). All of them contained more than 106 molecules/ml. For these cases and for the samples where the short probe and the long probe gave discordant result (2 cases) we think that competitive PCR will be the method of choice, but in most cases ELOSA with the long probe gives reliable results and is highly sensitive. 相似文献