Evaluation of hepatocyte phenotype for different micro-aggregate sizes.

(A) Gene expression of albumin. Gene expression levels of albumin were determined for different micro-aggregation conditions and compared to cells cultured on tissue culture plastic (TCP). (B) Albumin secretion at day 3 after isolation for different micro-aggregation conditions. Data are mean ± SD, n = 3, **p<0,01; compared to cells cultivated as monolayers (TCP). (C) Gene expression of CypA3. Gene expression levels of Cyp3A for different aggregate dimensions compared to cells cultured on tissue culture plates (TCP). Gene expression of Cyp3A was determined after 72 hours of cultivation in the micro-wells. Data are mean RQ ± SD, n = 3. *p<0.05; **p<0.01 (D) Induced cytochrome 3A4 activity in aggregates of different diameter versus cells cultured on tissue culture plastic. Cyp3A4 activity was quantified after treatment with an inducing agent (hydrocortisone) using a luciferase based assay after 3 days of isolation. Data are mean ± SEM, n = 3. *p<0,05; **p<0,01; ***p<0,001 compared to cells cultured as monolayers (TCP). (E–F) Live/dead stain of micro-aggregates with diameters of 200 µm (E) and 100 µm (F). Dead cells are stained red, while viable cells are stained green. scale bar = 50 µm.