betadex and stearic-acid

This study aimed to evaluate the potential of solid lipid nanoparticles (SLNs) of paclitaxel (PTX) modified with a 2-hydroxypropyl-β-cyclodextrin system to enhance cellular accumulation of PTX into p-glycoprotein (p-gp)-expressing cells.. The PTX-loaded-SLNs consisted of lipid (stearic acid) and surfactants (lecithin and poloxamer 188) and were then modified with 2-hydroxypropyl-β-cyclodextrin by a sonication method.. In terms of cytotoxicity, PTX-loaded SLNs modified with 2-hydroxypropyl-β-cyclodextrin showed higher cytotoxicity than other formulations. In particular, the cellular uptake of PTX from PTX-loaded SLNs modified with 2-hydroxypropyl-β-cyclodextrin was about 5.8- and 1.5-fold higher than that from PTX solution and unmodified PTX-loaded SLNs in MCF-7/ADR cells, respectively. After a 4-h incubation, clear fluorescence images inside cells were observed over time. When PTX-loaded SLNs modified with 2-hydroxypropyl-β-cyclodextrin were incubated with MCF-7/ADR cells for 4 h, cellular uptake of PTX increased 1.7-fold versus that of PTX in the presence of verapamil.. These results suggest that optimized SLNs modified with 2-hydroxypropyl-β-cyclodextrin may have potential as an oral drug delivery system for PTX.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Antineoplastic Agents, Phytogenic; ATP Binding Cassette Transporter, Subfamily B; ATP Binding Cassette Transporter, Subfamily B, Member 1; beta-Cyclodextrins; Biological Transport; Breast Neoplasms; Calcium Channel Blockers; Cell Survival; Chemistry, Pharmaceutical; Drug Delivery Systems; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Excipients; Female; Humans; MCF-7 Cells; Nanoparticles; Neoplasm Proteins; Paclitaxel; Stearic Acids; Surface-Active Agents; Ultrasonics; Verapamil

This study investigates the role of lipid rafts and caveolae, a subclass of lipid raft microdomains, in the binding and uptake of long-chain fatty acids (LCFA) by 3T3-L1 cells during differentiation. Disruption of lipid rafts by beta-cyclodextrin (betaCD) or selective inhibition of caveolae by overexpression of a dominant-negative mutant of caveolin-3 (Cav(DGV)) resulted in disassembly of caveolae structures at the cell surface, as assessed by electron microscopy. While in 3T3-L1 fibroblasts, which express few caveolae, Cav(DGV) or betaCD had no effect on LCFA uptake, in 3T3-L1 adipocytes the same treatments decreased the level of [(3)H]oleic acid uptake by up to 55 +/- 8 and 49 +/- 7%, respectively. In contrast, cholesterol loading of 3T3-L1 adipocytes resulted in a 4-fold increase in the extent of caveolin-1 expression and a 1.7-fold increase in the level of LCFA uptake. Both the inhibitory and enhancing effects of these treatments were constantly increasing with the [(3)H]oleic acid incubation time up to 5 min. Incubation of 3T3-L1 adipocytes with [(3)H]stearate followed by isolation of a caveolin-1 positive detergent-resistant membrane (DRM) fraction revealed that [(3)H]stearate binds to caveolae. Fatty acid translocase (FAT/CD36) was found to be present in this DRM fraction as well. Our data thus strongly indicate a critical involvement of lipid rafts in the binding and uptake of LCFA into 3T3-L1 adipocytes. Furthermore, our findings suggest that caveolae play a pivotal role in lipid raft-dependent LCFA uptake. This transport mechanism is induced in conjunction with cell differentiation and might be mediated by FAT/CD36.

Topics: 3T3-L1 Cells; Adipocytes; Animals; beta-Cyclodextrins; Binding Sites; Caprylates; Caveolae; Caveolin 3; Caveolins; CD36 Antigens; Cholesterol; Cholic Acids; Cyclodextrins; Detergents; Fatty Acids; Membrane Microdomains; Mice; Oleic Acid; Stearic Acids

The individual influence of wet granulation and lubrication on the powder and tableting properties of codried product of microcrystalline cellulose (MCC) with beta-cyclodextrin (beta-CD) was examined in this study. Avicel PH 101 and 301 were included for comparison. The codried product, Avicel PH 101 and 301 were granulated with water, and the granules were milled to retain three different size fractions: 37-60 microm, 60-150 microm, and 150-420 microm. The original Avicels and codried product were lubricated with magnesium stearate in three different percentages (0.2, 0.5, and 1.0%). The results showed that the powder flowability and disintegration of codried product and Avicels were significantly improved after wet granulation. However, the compactibility of codried product and Avicels decreased with increasing particle size. Nevertheless, the compactibility of the codried excipient after granulation was still better than the non-granulated Avicel PH 101 and 301. On the other hand, codried product and Avicels were sensitive to lubrication and resulted in decreasing compactibility and increasing disintegration. Because of the rounder shape of particles, the codried excipient was more sensitive to magnesium stearate and produced weaker tablets than did Avicels.

Topics: Analysis of Variance; beta-Cyclodextrins; Cellulose; Cyclodextrins; Lubrication; Powders; Stearic Acids; Tablets

Inclusion complexes of hydrocortisone and progesterone were formed with beta-cyclodextrin or 2-hydroxypropyl-beta-cyclodextrin. The formation of the complexes was confirmed by differential scanning calorimetry (DSC). The inclusion complexes were incorporated in two types of solid lipid nanoparticles (SLN). In the presence of the complexes the sizes of SLN remained below 100 nm. DSC analysis showed that hydrocortisone and progesterone are dispersed in SLN in an amorphous state. Using the beta-cyclodextrin complexes the incorporation of the more hydrophilic drug, hydrocortisone, was higher than that of progesterone. Release of hydrocortisone and progesterone from SLN was lower when they were incorporated as inclusion complexes than as free molecules.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Anti-Inflammatory Agents; beta-Cyclodextrins; Calorimetry, Differential Scanning; Cyclodextrins; Drug Carriers; Excipients; Freeze Drying; Hydrocortisone; Kinetics; Lipids; Particle Size; Progesterone; Solubility; Stearic Acids; Water

Palmitic, palmitoleic and stearic acids were found in the extracted cellular lipids of virulent Bordetella pertussis as unesterified acids in confirmation of earlier taxonomic analyses. The same free fatty acids (FFAs) were found in the spent culture supernatant in concentrations higher than in the uninoculated medium, indicating that they are released into the extracellular medium. These long-chain fatty acids are known to inhibit the growth of B. pertussis at concentrations as low as 1 ppm. Measurement of palmitate cell-medium partitioning demonstrated a strong tendency of FFAs for cellular adsorption. Inhibition kinetics indicated that the cell-bound FFA was responsible for inhibition and that the specific cellular FFA concentrations actually found during growth were similar to those determined to be inhibitory. Autoinhibition by these endogenous FFAs provides an explanation of the low maximum cell concentrations currently attainable in liquid media. Addition of soluble dimethyl-beta-cyclodextrin (MebetaCD) to FFA-inhibited cultures resulted in a rapid reversal of the inhibition. A corresponding shift in the distribution of FFAs from the cells to the extracellular medium demonstrated that MebetaCD sequesters FFAs. Although MebetaCD did not increase final cell concentrations and even had an adverse effect on growth at concentrations above 1 g l-1, it did (at 1 g l-1 extend the initial period of high growth rate leading to shorter cultivation times.

Topics: beta-Cyclodextrins; Biotechnology; Bordetella pertussis; Cell Division; Culture Media; Cyclodextrins; Fatty Acids, Monounsaturated; Fatty Acids, Nonesterified; Growth Substances; Palmitic Acid; Stearic Acids