Liposome uptake

RES-Avoiding Liposomes. Since intravenously administered liposomes tend to accumulate in the RES, liposomal drugs work effectively when the target site is the RES. On the other hand, when the target site is not the RES, liposomal uptake by RES should be avoided. Liposomes that are not recognized by the RES have... 

Liposomal size has a pivotal role in macrophage uptake as the size of the liposome increases, there is enhancement of liposome uptake by macrophages, as also reported by others previously (66,67). However, although the trend remains the same, the clearance of liposomes is affected to differing extents depending on the composition (75). 

Microscopic Investigations of Liposome Uptake by Dendritic Cells... 

Figure 3 Binding and internalization of different liposomal formulations by bone marrow-derived dendritic cells (BmDQ from mice. BmDC were incubated for one hour with liposomes at 37 C and liposome uptake was analyzed by confocal laser scanning microscopy.

Block dynamin dependent processes dynamin is not only involved in clathrin uptake (see section Dynamin Dependence on Liposome Uptake )... 

The calcineurin inhibitors tacrolimus (FK 506) and cyclosporin A block the function of dynamin and are thought to be specific for clathrin-mediated uptake (50). The smal guanosine triphosphate (GTP)ase dynamin is also involved in other processes and is therefore described in section Dynamin Dependence on Liposome Uptake. ... 

Because of the strict requirement for actin, the most commonly used inhibitors of macropinocytosis are the cytochalasins, especially cytochalasin D or toxin C. These substances also block phagocytosis and intracellular trafficking along actin filaments. Therefore, the results from these experiments are described in the trafficking section Actin Dependence on Liposome Uptake. ... 

Several aspects of intracellular trafficking should be kept in mind in the intracellular trafficking section. The first is the dependence of acidification of endosomes on the uptake of liposomes. This aspect is sometimes discussed when analyzing clathrin uptake. However, several other pathways are also in need of acidic compartments as a destination of uptake so, we list this factor as an individual aspect. Other aspects of intracellular trafficking that are of interest are the transport from early endosomes to late endosomes, the dependence of actin filaments and dynamin, and/or microtubules. Furthermore, the energy dependence of liposome uptake is discussed. 

Energy Dependence on Liposome Uptake and Fusion with Cell Membranes... 

Incubation at 4°C (see section Energy Dependence on Liposome Uptake and Fusion with Cell Membranes ) and a block of metabolic activity (see section Metabolic Activity ) might also be used to block endocytosis and to detect cellular association or fusion. 

Lymph system imaging I Liposome uptake in lymph Tc04"/Sn2+ incorporated in 639... 

Grammer, J.B., et al. 1996. Impregnation of collagen corneal shields with liposomes Uptake and release of hydrophilic and lipophilic marker substances. Curr Eye Res 15 815. 

Bonnekoh, B., Roding, J., Krueger, G.R. et al. Increase of lipid fluidity and suppression of proliferation resulting from liposome uptake by human keratinocytes in vitro. Br. J. Dermatol. 1991 124 333 10. 

The influence of incubation temperature on liposome uptake by CVl cells was examined. The cells were ineubated with either the pol5mier-modified or the unmodified EYPC liposomes containing a fluorescent lipid, NBD-PE, at 37 or 42°C for 3 h. The amount of liposomal lipid associated with the cells after the incubation was evaluated from the fluorescence intensity of NBD-PE in the cells (Fig. 6). For the unmodified liposome, approximately the same amount of liposome was taken up by the cell at both temperatures, indicating that temperature does not affect the liposome uptake in this temperature region. In the case of the polymer-modified liposome, the amount of liposome taken up by the cell at 37°C was slightly lower than that of the unmodified liposome at the same temperature. However, at 42°C the amount became two times higher than that of the unmodified liposome. In... 

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