PXB-cells® are ~95% pure fresh human hepatocytes isolated from PXB-mouse®
24-well plates, 96-well plates and T75 flasks are available from KMT Hepatech location
Why use PXB-cells®?
PXB-cells® are used for in vitro studies in drug metabolism, enzyme induction / inhibition, safety assessment, transporter evaluation, anti-HBV therapeutics efficacy testing and other studies which require the use of primary human hepatocytes (PHH)
Stable supply on demand of PXB-cells® allows reproducible experiments with the same source of donor hepatocytes
High human specific enzymes and transporters activity in PXB-cells® can be maintained for a long term (over three weeks)
High cell adhesion allows using PXB-cells® as planar or spheroid culture
Hepatitis B virus (HBV) can persistently infect PXB-cells®
Direct comparison between in vitro and in vivo data is possible, as PXB-cells® and PXB-mouse® have the same source of donor hepatocytes
PXB-cells® show human-type enzyme activity
Figure shows the comparison of CYP3A activity of commercially sourced donor hepatocytes and PXB-cells® produced with the same source of hepatocytes. PXB-cells® show equivalent to or better CYP3A activity than the original human hepatocytes for 21 days
Gene expression of drug metabolizing enzymes in PXB-cells®
CYP2C9: The expression level of human CYP2C9 is lower than immediately after isolation (before plating), but it is maintained for 21 days
CYP3A4: Human CYP3A4 expression decreased immediately after plating, but later it is maintained at higher level than immediately after isolation
UGT1A1: Human UGT1A1 maintains 21 days of expression equivalent to or better than immediately after isolation (before plating)
OATP1B1: The expression of human OATP1B1 is maintained for 21 days at lower than the initial post-isolation level (before plating)
BSEP: Human BSEP is reduced immediately after separation, but it is maintained for 21 days
MRP2: Human MRP2 maintains the same or higher expression level for 21 days
Case Study II: PXB-cells® in metabolite identification
PXB-cells® were used as a model in vitro system for the prediction of the in vivo metabolism of new drugs of abuse.
A powerful synthetic opioid fentanyl and its analogue acetylfentanyl were studied. Major and minor metabolites were detected with PXB-cells®. The metabolite profiles in PXB-cells® was consistent with the in vivo metabolite profiles of drug users reported previously.
Overall, higher amounts of metabolites were formed in PXB-cells® as compared to other source of commercially available primary human hepatocytes (PHH). Some metabolites were detected only in the medium of PXB-cells®. The difference is attributed to the faster decrease in activity of metabolizing enzymes in PHH versus PXB-cells® after the start of incubation.
Metabolites detected with the PXB-cells®
Methods
Seeding was performed at PhoenixBio (Japan) facility. 24-well plates were delivered to study facility 2 days later (at Day 0). Drug was added at Day 4 or Day 11 at a final concentration of 10 µM. PXB-cells® were cultured with the drug for 24-48 hours. Media were collected and analyzed by liquid chromatography/ mass spectrometry (LC/MS). The performance of PXB-cells® was compared to the regularly purchased primary human hepatocytes (PHH).