Preclinical characterization of alginate-Poly-L-Lysine encapsulated
HepaRG for extracorporeal liver supply
Abstract
We recently demonstrated that HepaRG cells encapsulated into 1.5%
alginate beads are capable of self-assembling into spheroids. They
adequately differentiate into hepatocyte-like cells, with hepatic
features observed at day 14 post-encapsulation required for external
bioartificial liver applications. Preliminary investigations performed
within a bioreactor under shear stress conditions and using a culture
medium mimicking acute liver failure (ALF) highlighted the need to
reinforce beads with a polymer coating. We demonstrated in a first step
that a Poly-L-Lysine coating improved the mechanical stability, without
altering the metabolic activities necessary for bioartificial liver
applications (such as ammonia and lactate elimination). In a second
step, we tested the optimized biomass in a newly-designed perfused
dynamic bioreactor (PDB), in the presence of the medium model for
pathological plasma for 6 hours. Performances of the biomass were
enhanced as compared to the steady configuration, demonstrating its
efficacy in decreasing the typical toxins of ALF. This type of
bioreactor is easy to scale up as it relies on the number of
micro-encapsulated cells, and could provide an adequate hepatic biomass
for liver supply. Its design allows it to be integrated into a hybrid
artificial/bioartificial liver setup for further clinical studies
regarding its impact on ALF animal models.