The objective of this study was to investigate the effect of crystalline state and a formulation of self-nanoemulsifying drug delivery system (SNEDDS) on oral bioavailability of 6-benzyl-1-benzyloxymethyl-5-iodouracil (W-1), a novel non-nucleoside reverse transcriptase inhibitor, in rats. The crystalline states of W-1 were characterized by scanning electron microscope (SEM), differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD). The SNEDDS was formulated by medium-chain lipids, characterized by droplet particle size.
View Article and Find Full Text PDFThe integrity of poly(ethylene glycol)-co-poly(ε-caprolactone) (PEG-PCL) micelles transcellular transported across madin-darby canine kidney(MDCK) epithelial cells was investigated. Fluorescein isothiocyanate isomer I(FITC) was conjugated to PEG-PCL and the product PEG-PCL-FITC was identified by fluorescence spectra. Two micelles were prepared using the thin-film hydration method: 3,3’-dioctadecyloxacarbocyanine perchlorate (DiO) and 1,1’-dioctadecyl-3,3,3’,3’-tetramethylindocarbocyanine perchlorate (DiI) co-loaded PEG-PCL micelles (DiO-DiI-M), DiI loaded and PEG-PCL-FITC contained micelles(FITC-DiI-M).
View Article and Find Full Text PDFThe purpose of this study was to characterize the disposition, distribution, excretion and plasma protein binding of 6-benzyl-1-benzyloxymethyl-5-iodouracil (W-1) in rats. Concentrations of W-1 within biological samples were determined using a validated high performance liquid chromatography method. The plasma protein binding of W-1 was examined by equilibrium dialysis method.
View Article and Find Full Text PDFThe aimed of this study was to prepare stabilized thiomers to overcome the poor stability character of traditional thiomers. Poly(acrylic acid)-cysteine (PAA-Cys) was synthesized by conjugating cysteine with poly(acrylic acid) and poly(acrylic acid)-cysteine-6-mercaptonicotinic acid (PAA-Cys-6MNA, stabilized thiomers) was synthesized by grafting a protecting group 6-mercaptonicotinic acid (6MNA) with PAA-Cys. The free thiol of PAA-Cys was determined by Ellmann's reagent method and the ratio of 6MNA coupled was determined by glutathione reduction method.
View Article and Find Full Text PDFYao Xue Xue Bao
September 2013
The transcellular process of coumarin 6 (C6) loaded poly(ethyl ethylene phosphate)-co-poly (epsilon-caprolactone) (PEG-PCL) micelles on Madin-Darby Canine Kidney (MDCK) epithelial cells was investigated. C6 loaded PEG-PCL micelles were prepared using the thin-film hydration method. The size of the micelles was characterized by dynamic light scattering analysis using a Malvern Zetasizer Nano ZS.
View Article and Find Full Text PDFBackground: Nanocarriers represent an attractive means of drug delivery, but their biosafety must be established before their use in clinical research.
Objectives: Four kinds of amphiphilic polymeric (PEG-PG-PCL, PEEP-PCL, PEG-PCL and PEG-DSPE) micelles with similar hydrophilic or hydrophobic structure were prepared and their in vitro and in vivo safety were evaluated and compared.
Methods: In vitro nanotoxicity evaluations included assessments of cell morphology, cell volume, inflammatory effects, cytotoxicity, apoptosis and membrane fluidity.
iRGD-modified sterically stabilized liposomes loaded doxorubicin (iRGD-SSL-DOX) were prepared and their cellular toxicity and anti-tumor efficacy were evaluated, comparing to doxorubixin loaded sterically stabilized liposomes (SSL-DOX) and RGD modified doxorubixin loaded sterically stabilized liposomes (RGD-SSL-DOX). The iRGD peptide, with both tumor targeting and cell penetrating functions, was conjugated to DSPE-PEG-NHS and DSPE-PEG-iRGD was obtained. DSPE-PEG-RGD was gained in the same way.
View Article and Find Full Text PDFThe interaction of nanocarriers with cells including their transcellular behavior is vital not only for a drug delivery system, but also for the safety of nanomaterials. In an attempt to clarify how the structures of polymers impact the transport mechanisms of their nanocarriers in epithelial cells, three amphiphilic polymers (PEEP-PCL, PEG-PCL and PEG-DSPE) with different hydrophilic or hydrophobic blocks were synthesized or chosen to form different micelle systems here. The endocytosis, exocytosis, intracellular colocalization, paracellular permeability and transcytosis of these micelle systems were compared using Förster resonance energy transfer analysis, real-time confocal images, colocalization assay, transepithelial electrical resistance study, and so on.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
October 2012
Purpose: To enhance drug uptake in RPE cells, improve efficacy for choroidal neovascularization (CNV), and reduce drug toxicity, an EphA2-targeted nanocarrier loaded with doxorubicin (DOX) was developed by conjugation with a homing peptide YSA.
Methods: The YSA was coupled to PEGylated lipid. Then, YSA-modified DOX stealth liposomes (YSA-SSL-DOX) were prepared and characterized.