stearates and polyethylene-glycol-monostearate

The aim of this study was to investigate the cellular uptake of solid lipid nanoparticles (SLN) and cytotoxicity of its paclitaxel delivery system. The conjugate of octadecylamine-fluorescein isothiocyanate (ODA-FITC) was synthesized, and used as a marker to prepare fluorescent SLN. The cellular uptakes of fluorescent SLN with different lipid material were evaluated by fluorescence microscopy and the measurement of fluorescence intensity. The order of cellular uptake ability was glycerol tristearate SLN>monostearin SLN>stearic acid SLN>Compritol 888 ATO SLN (ATO888 SLN). The cellular cytotoxicities of paclitaxel were highly enhanced by the encapsulation of lipid matrix. Due to the lower drug entrapment efficiency of glycerol tristearate SLN, monostearin SLN was considered as the best lipid material to improve the cytotoxicity of drug. The polyethylene glycol monostearate (PEG-SA) and the synthesized conjugate of folic acid-stearic acid (FA-SA) were further introduced into monostearin SLN, respectively. The PEG and folate modified SLN could enhance the cellular uptake of SLN and the cellular cytotoxicity of drug by the membrane disturb ability of PEG chains on the SLN surface and the improved endocytosis mediated by folate receptor.

Topics: Amines; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cell Proliferation; Cell Survival; Fatty Acids; Fluorescein-5-isothiocyanate; Folic Acid; Glycerides; Humans; Inhibitory Concentration 50; Lipids; Nanoparticles; Paclitaxel; Particle Size; Polyethylene Glycols; Static Electricity; Stearates; Stearic Acids; Surface Properties; Triglycerides

The effect of synthetic amphiphiles, poly(ethyleneglycol) 6000 (PEG) esterified with saturated fatty acids (C2-C18), on the locomotion of polymorphonuclear leucocytes (PMNL) has been investigated. It was noticed that PEG-myristate (M-PEG; C14) stimulated the random locomotion of PMNL populations in concentrations up to about 1 g/l. By contrast, the esters with shorter aliphatic chains had negligible effects and those with longer chains, PEG-palmitate (P-PEG; C16) and PEG-stearate (S-PEG; C18) reduced the locomotion, irrespectively of concentration. The ability of the PMNL to be stimulated by an attractant liberated from normal human serum was slightly impaired with M-PEG, but not with P-PEG. The response to M-PEG of individual PMNL was heterogeneous in that some cells were stimulated and others were inhibited, but the average result was a reduction of the motility. This indicates that methods used for the study of the locomotion of cell populations do not always reproduce the true behaviour of the whole population, but rather of a selected subpopulation. It was also concluded that the different effects of M-PEG and P-PEG were probably not due to phagocytosis or selective binding of either substance, but rather due to dissimilar effects on the membrane structure of the PMNL, since (i) M-PEG perturbated the PMNL membrane more than P-PEG, as assayed by the release of superoxide anion (O2-) although the binding was smaller, and (ii) M-PEG and P-PEG increased and decreased the membrane fluidity, respectively, as measured with fluorescence bleaching and recovery after bleaching of labeled PMNL. The results indicate a subtle coupling between membrane structure and PMNL locomotion.

Topics: Cell Membrane; Cells, Cultured; Chemotaxis, Leukocyte; Humans; Membrane Fluidity; Myristates; Myristic Acids; Neutrophils; Palmitates; Polyethylene Glycols; Stearates; Stearic Acids

Topics: Glycols; Pharmacy; Polyethylene Glycols; Stearates