Search results for "Cationic liposome"

1984

Alkaline hydrolyses of anionic phenyl esters such as 4-acetoxy-3-nitrobenzoic acid and 4-butyryloxy-3-nitrobenzoic acid were examined in the presence of cationic and polymeric liposomes, liposomes of low molecular weight compounds, and micelles. All the additives accelerate the reaction due to the hydrophobic interaction between substrates and additives and the electrostatic interaction both between substrates and additives and between OH− and additives. In the Arrhenius plots of the reactions catalyzed by the liposomes, discontinuous regions were observed due to the phase transition of liposomes from the gel state to the liquid crystal state. Activation parameters ΔH≠, ΔS≠ and ΔV≠ for thes…

Effect of the surface charge of liposomes on their uptake by angiogenic tumor vessels

2003

Recently, cationic liposomes have been shown to preferentially target the angiogenic endothelium of tumors. It was the aim of our study to investigate the influence of liposomal surface charge on the uptake and kinetics of liposomes into solid tumors and tumor vasculature. Experiments were performed in the amelanotic hamster melanoma A-Mel-3 growing in the dorsal skinfold chamber preparation of male Syrian golden hamsters. Fluorescently labeled liposomes with different surface charge were prepared. Accumulation of i.v. injected liposomes was assessed by quantitative intravital fluorescence microscopy of tumor and surrounding host tissue. The histological distribution of liposomes was analyz…

Cationic Supramolecular Vesicular Aggregates for Pulmonary Tissue Selective Delivery in Anticancer Therapy

2016

The biopharmaceutical properties of supramolecular vesicular aggregates (SVAs) were characterized with regard to their physicochemical features and compared with cationic liposomes (CLs). Neutral and cationic SVAs were synthesized using two different copolymers of poly(aspartyl hydrazide) by thin-layer evaporation and extrusion techniques. Both copolymers were self-assembled in pre-formulated liposomes and formed neutral and cationic SVAs. Gemcitabine hydrochloride (GEM) was used as an anticancer drug and loaded by a pH gradient remote loading procedure, which significantly increased drug loading inside the SVAs. The resulting average size of the SVAs was 100 nm. The anticancer activity of …

Long-term expression of the human alpha1-antitrypsin gene in mice employing anionic and cationic liposome vector.

1997

The complete process of gene therapy involves three important steps: targeting, delivery, and gene expression. Since each step can be related to the pharmacological concept of affinity, bioavailability, and intrinsic capacity, this commentary examines, from this perspective, the efficiency of anionic and cationic liposomes as vectors for the in vivo gene transfer of the human alpha1-antitrypsin gene. Small liposomes represent the first generation of liposomes destined for the liver parenchymal cell. Although the final efficiency of gene transfer is low, we found that small liposomes are a kind of high-affinity hepatocyte-destined vector because the dose range for mediating the response is t…

Asialofetuin Liposomes for Receptor-Mediated Gene Transfer into Hepatic Cells

2003

Publisher Summary The liver is an excellent organ for gene transfer in treating a wide variety of diseases that affect liver function. It is an ideal organ for a high amount of expression of therapeutic genes and efficient systemic distribution of the resulting therapeutic proteins secreted into the bloodstream. For strategies of liver-destined gene therapy, the liver sinusoid endothelium contains pores with a mean diameter of 100 nm, which allow small vectors to leave the blood circulation and reach the hepatocytes. The preparation of asialofetuin–liposomes targeted to hepatocytes can be made by covalent coupling of asialofetuin glycoprotein (ASF) onto the liposome surface, by the use of h…

Heparin modulates the cellular uptake of nanomedicines

2021

Liposomal formulations are used to improve the safety and cellular absorption of conventional drugs by limiting their interaction with phagocytes. The uptake behaviour of these nanocarriers is affected by the blood composition, and accordingly the presence of an anticoagulant in the blood could have a critical impact on the efficiency of nanomedicines. For the negatively charged liposomes, such as AmBisome®, no significant change in the uptake could be observed when co-incubated with heparin and primary phagocytes. Yet, we observed that a peak of the uptake extent of cationic liposomes was reached at a clinically relevant concentration of heparin for phagocytes and cancer cells. Hence, we r…