Functional characterization of liver spheroids
After spheroids were cultured with functionalized MPs, levels of
albumin
were determined using a commercially available kit (QuantiChrom™ BCP
Albumin, BioAssay Systems, cat# DIAP-250) as a measure of liver cells’
function. The experiment was performed according to the manufacturer’s
instructions. Briefly, the medium was collected on days 5 and 10. A 20
µl aliquot was used to measure albumin secretion into the medium. 200 μL
of working reagent was added and after 5 min incubation at room
temperature, the optical density at 590-630 nm (peak absorbance at 610
nm) was read by a plate reader (Tecan Infinite M200, Tecan Austria GmbH,
Austria). Urea was also measured by the QuantiChrom™ Urea Assay Kit
(BioAssay Systems, cat# DIUR-100,) using a similar procedure to the
albumin kit. 5 μL of sample was mixed with 200 μL of working reagent,
incubated for 20 min, and absorbance was read at 520 nm by plate reader.