The compatibility of swine BMDC-derived bile duct endothelial cells with a nanostructured electrospun PLGA material.

PURPOSE: To investigate the production of bile duct endothelial cells via directed differentiation of porcine bone marrow mesenchymal stem cells (BMSCs) down the hepatic lineage in vitro and the biocompatibility of differentiated bile duct endothelial cells with electrospun nanofibers. METHODS: Porcine BMSCs were differentiated in vitro into bile duct endothelial cells, which were identified by morphology and RT-PCR. PLGA nanofiber membranes were prepared by electrospinning. The morphology was detected by scanning electron microscopy and the short-term (two weeks) in vitro degradation rate was determined. Adhesion and proliferation of the bile duct endothelial cells on the nanofiber surface were analyzed by calculating the cell adhesion rate and MTT assay, respectively. Cell growth, morphology and distribution on the material surface were observed by fluorescence staining and scanning electron microscopy, respectively. RESULTS: After four weeks of directed differentiation of BMSCs in vitro, cells showed the typical morphology of dendritic bile duct endothelial cells and had the expression of CK19. Scanning electron micrographs showed that electrospun materials were continuous nanofibers with diameters between 200 and 500 nm. No significant degradation of the PLGA nanofibers was observed within two weeks. Based on the measured cell adhesion rate, MTT assay, fluorescence staining, and scanning electron microscopy, the differentiated cells possess a good proliferative capacity on PLGA nanofibers. CONCLUSIONS: BMSCs can be differentiated into the bile duct endothelial cells in vitro. Materials prepared by the electrospinning method have a nanofiber structure, which does not significantly degrade within two weeks. Differentiated cells exhibit good biocompatibility with the nanofibers.

Development and validation of a nylon6 nanofibers mat-based SPE coupled with HPLC method for the determination of docetaxel in rabbit plasma and its application to the relative bioavailability study.

A simple and sensitive HPLC method was established and validated for the determination of docetaxel (DTX) in rabbit plasma. Biosamples were spiked with paclitaxel (PCX) as an internal standard (I.S.) and pre-treated by solid-phase extraction (SPE). The SPE procedure followed a simple protein digestion was based on nylon6 electrospun nanofibers mats as sorbents. Under optimized conditions, target analytes in 500 microL of plasma sample can be completely extracted by only 2.5mg nylon6 nanofibers mat and eluted by 100 microL solvent. The HPLC separation was obtained on C18 column and UV detector was used to quantify the target analytes. The extraction recovery was more than 85%; the standard curve was linear over the validated concentrations range of 10-5000 ng/mL and the limit of detection was 2 ng/mL. The inter-day coefficient of variation (CV%) of the calibration standards was below 5.0% and the mean accuracy was in the range of 92.8-113.4%. Moreover, analysing quality control plasma samples in 3 days, the results showed that the method was precise and accurate, for the intra- and inter-day CV% within 10% and the accuracy from 96.0% to 114.0%. The developed and validated method was successfully applied to relative bioavailability study for the preclinical evaluation of a new injectable DTX-sulfobutyl ether beta-cyclodextrin (DTX-SBE-beta-CD) inclusion complex freeze-dried powder (test preparation), compared with the reference preparation (DTX injection, Taxotere) in healthy rabbits. On the basis of the mean AUC(0-t) and AUC(0-infinity), the relative bioavailability of the test preparation was found to be 113.1%.

Analysis of phthalate migration from plastic containers to packaged cooking oil and mineral water.

The migration of phthalates (PAEs), a class of typical environmental estrogen contaminants in food, from food packaging to packaged food attracts more and more attention worldwide. Many factors will affect the migration processes. The purpose of this study was to evaluate PAE migration from plastic containers to cooking oil and mineral water packed in authentic commercial packaging and stored under various conditions (different storage temperatures, contact times, and storage states (static or dynamic state)) and to identify a potential relationship between the amount and type of PAEs migrated and the lipophilic character of the food matrix. The samples were analyzed by a novel method of liquid chromatography combined with solid-phase extraction by an electrospun nylon 6 nanofibers mat, with PAE detection limits of 0.001 µg/L in mineral water and 0.020 µg/L in cooking oil, respectively. The results demonstrated that the cooking oil was a more suitable medium for the migration of PAEs from packages into foodstuffs than mineral water. Scilicet, the migration potential of the PAEs into foodstuffs, depends on the lipophilic characteristics of the food matrix. The results also demonstrated that migrations were more significant at higher temperature, longer contact time, and higher dynamic frequency; thus, the migration tests should be evaluated with consideration of different storage temperatures and contact times. Mathematical models with good logarithmic relationships were established to demonstrate the relationship between the PAE migration and food/packaging contact time for different storage temperatures. These established mathematical models would be expected to become a set of practical tools for the prediction of PAE migration.