Evaluation of micro-aggregates after encapsulation in a gelatin hydrogel.

(A) Live/dead stain of aggregates encapsulated in gelatin hydrogel at day 10. scale bar = 50 µm (B) Stainings of the immobilized micro-aggregates at day 10 after isolation. The pictures represent stainings for albumin and HNF4α and PAS staining to visualize glycogen storage. Pictures were recorded at 20 x magnification at day 10, scale bar = 50 µm. (C) Cummulative albumin secretion deterimend by ELISA. Albumin secretion of the immobilized cells was evaluated during 21 days of cultivation by ELISA. Data are mean ± SD, n = 3. (D) Real-time PCR for gene expression analysis after immobilization in the hydrogel. Gene expression levels of HNF4α, Cyp3A4, Cyp1A2, E-cadherin and connexin 32 (Cx32) were determined for not immobilized (white bars, not encapsulated) and immobilized micro-aggregates (black bars, encapsulated) at day 3, 6, 10 and 15 after isolation. The expression values were normalized using GAPDH as stable housekeeping gene and compared to aggregate values before encapsulation (day 3, value = 1). Data are mean RQ ± SD, n = 3. *p<0.05; **p<0.01