Fast investigations from biological matrices using CE – Test of a blood–brain barrier model

Abstract

In order to adopt a general workflow for complex biological matrices with respect to a new blood-brain barrier (BBB) model, a micellar electrokinetic chromatography method has been developed. The cells forming the BBB have been cultivated in a special cell growth medium in which six drugs (acetaminophen, caffeine, carbamazepine, cimetidine, indometacin and propranolol) have been dissolved and tested for their penetration properties. The results showed good to very good accordance to the reference values. Samples were directly injected onto the capillary without any pretreatment (fused silica capillary, id: 50 μm, L: 48 cm, l: 40 cm). After method development, separations were carried out using a 60 mM borate buffer containing 200 mM of SDS at 30 kV, leading to an analysis time of less than 10 min. Between two runs the capillary was rinsed with a mixture of equal parts of running buffer and isopropanol (70% v/v), which proved to be very effective to remove matrix compounds. An appropriate choice of the detection wavelength (220 or 254 nm) could avoid major interferences between analytes and matrix. The typical RSD% for migration times was approximately 2%, for peak areas, it ranged from 2 to 6%, which was very well acceptable for the generic method used in this study and the low concentrations investigated. The LODs ranged from 10 to 30 ng/mL.

Capsule Contributes to Transmigration of Streptococcus pneumoniae Serotype 7F Meningitis Isolates through Complex Blood Brain Barrier Models

“…Our barrier model systems employed in this study combined the advantage of multicellular complexity with functional specificity. The ECV304-C6 system has already successfully established as an experimental model for analysis of BBB penetration by African trypanosomes causing human trypanosomiasis and has been confirmed as reliable analytical method for the quantification of drug penetration properties [25,26]. In addition to this multicellular model we employed a second system based on a Brain Derived Endothelial Cells (HBMEC) in our assays in order to elucidate transmigration efficiencies with this brain-tissue specific barrier system.…”

“…Our recently designed and evaluated BBB models designated as ECV304-C6 BBB and HBMEC-BBB allow the analysis of transmigration mechanisms of bacterial and parasitical pathogens including streptococci and African trypanosomes [25,26] causing inflammatory CNS diseases like bacterial meningitis [27] and human African trypanosomiasis [28]. In this study we have used these models to investigate the role of pneumococcal polysaccharide capsule in bacterial transmigration of BBB using a highly invasive serotype 7F isolate from a meningitis patient.…”

Recent advances in capillary electrophoretic migration techniques for pharmaceutical analysis

“…CE techniques demonstrated successful applications for analysis of small analytes from biological matrices usually using proper IS without tedious sample preparation . However, in order to guarantee the accuracy of a main assay and to reliably control all degradation products of pharmaceuticals or biopharmaceuticals, orthogonal assays with different separation efficiency are indispensable .…”

“…The analysis of compounds from biological media or the use of pharmaceutical drugs for the demonstration of the feasibility of a given separation technique will not be considered here. For a summary on the determination of drugs in biological fluids such as plasma or urine, the reader is referred to recent articles . CE has also been used for the characterization of herbal drugs including preparations of traditional Chinese medicine or the detection of adulterants in such preparations.…”

Recent advances in capillary electrophoretic migration techniques for pharmaceutical analysis (2013–2015)

“…The analysis of drugs in biological media or the use of pharmaceutical drugs for the demonstration of the feasibility of a certain separation technique will not be considered. The determination of drugs in biological fluids such as plasma or urine has been summarized . CE has also been used for the characterization of herbal drugs including preparations of traditional Chinese medicine or the detection of adulterants in such preparations.…”