Three new flavonoid glycosides from Urena lobata.

Three new flavonoid glycosides, kaempferol-3-O-ß-D-apiofuranosyl(1 → 2)-ß-D-glucopyranosyl-7-O-α-L-rhamnopyranoside (1), kaempferol-4'-O-ß-D-apiofuranosyl-3-O-ß-D-glucopyranosyl-7-O-α-l-rhamnopyranoside (2), and 5,6,7,4'-tetrahydroxy-flavone-6-O-ß-D-arabinopyranosyl-7-O-α-L-rhamnopyranoside (3), were isolated from the aerial parts of Urena lobata L., along with 10 known compounds (4-13). Their structures were determined based on spectroscopic methods including 1D and 2D NMR spectroscopy as well as HR-ESI-MS.

New tumor-targeted nanosized delivery carrier for oligonucleotides: characteristics in vitro and in vivo.

BACKGROUND: The purpose of this study was to investigate the in vitro and in vivo characteristics of a new tumor-targeted nanosized delivery carrier for antisense oligonucleotide (ASON). METHODS: Polyethylenimine (PEI) was used to condense ASON to form nanosized complexes (PEI/ASON), which were then modified using asparagine-glycine-arginine (NGR) peptide to obtain a tumor-targeted nanosized delivery carrier (NGR/PEI/ASON). The conditions required to form PEI/ASON were investigated. RESULTS: A linear correlation between the natural logarithm of the N/P ratio (PEI to ASON) and the zeta potential of the PEI/ASON complexes was found, ranging from 1.5 to 5.0. The pH of the solution strongly influenced the zeta potential of the PEI/ASON complexes. PEI/ASON and NGR/PEI/ASON were stable in RPMI-1640 culture medium in the presence of Dextran 70. Incorporation of ASON into PEI/ASON and NGR/PEI/ASON complexes prevented degradation of ASON by DNase I. CONCLUSION: Both ASON/PEI and NGR/PEI/ASON complexes enhanced the uptake of ASON by EC9706 cells in vitro. In vivo, NGR/PEI/ASON complexes had the ability to target tumor tissues effectively.

Preparation and characterization of freeze-dried 2-methoxyestradiol nanoparticle powders.

Poorly water-soluble compounds are difficult to develop as drug products using conventional formulation techniques and are frequently abandoned early in discovery. In the present study, a nanoprecipitation-high-frequency ultrasonication technique was adapted to produce drug nanosuspensions. The formulation of 2-methoxyestradiol (2-ME) as nanosuspension, either in the form of lyophilized powder or granules, was very successful in enhancing dissolution rate, more 45 times than bulk 2-ME being dissolved in the first 10 min. The increase in vitro dissolution rate may favourably affect bioavailability. The nanosuspension produced was then characterized using particle size determination, zeta potential measurement, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray analysis. Results showed that freeze-dried nanosuspension composed of amorphous particles with a mean particle size of 244 +/- 10.6 nm (polydispersity index of 0.21 +/- 0.02) was obtained. Physical stability studies showed that 2-ME nanosuspension remained homogeneous with slight increase in mean particle size and polydispersity index over a 3-month period.

Preparation, characterization and in vivo evaluation of 2-methoxyestradiol-loaded liposomes.

This study systematically investigated the intravenous injection formulation of liposomes loaded with 2-methoxyestradiol (2-ME), a poor water soluble anti-tumor drug. The objective of this study was to design passive targeting nanoliposome which could improve therapeutic efficacy and liver first pass effect. Based on the optimized conditions of single-factor and orthogonal design, 2-ME-loaded liposomes were prepared by the aether injection method. The formulated liposomes were found to be relatively uniform in size with a negative zeta potential. The average drug entrapment efficiency and loading were 85% and 8%, respectively. The overall targeting efficiency (TE(C)) of the 2-ME-loaded liposomes was enhanced from 40.29% to 88.32% in the lung. The lung damage caused by liposomes was less severe than that by solution. These results indicated that 2-ME liposomes could mainly deliver the drug to the lungs and make the drug accumulate in the lungs, which changed the disposition behavior in vivo, decreased the toxic and side effects on other tissues and reduced the severity of damage to lungs following intravenous injection.