Comparative study between lactose-silk fibroin conjugates and extracellular matrices as a substrate for the culture of human induced pluripotent stem cell-derived hepatocytes

BACKGROUND: Human induced pluripotent stem cell (hiPSC)-derived hepatocytes are an attractive alternative cell source to primary human hepatocytes for tissue regeneration. OBJECTIVES: This study presents an application of lactose-silk fibroin conjugates (Lac-CY-SF) bearing..-galactose residues as a substrate for culture of hiPSC-derived hepatocytes. A comparison of hiPSC-derived hepatocytes cultured on three different substrates; Lac-CY-SF conjugates, Matrigel and type I collagen was performed. METHODS: Cell morphology, viability, maturation and albumin secretory function were assessed by phase-contrast microscopy, tetrazolium-based colorimetric assay, immunofluorescence staining and enzyme-linked immunosorbent assay. RESULTS: Morphological characteristics of the cells cultured on the conjugates resembled those on Matrigel throughout the 6-day culture period. The number of viable cells cultured on the conjugates was comparable to that on Matrigel at day 2 and 6. The protein expression of mature hepatocyte markers, asialoglycoprotein receptor 1 and albumin, by the cells cultured on the conjugates resembled that by the cells cultured on collagen at day 2 and 6. Albumin secretory function per cell cultured on the conjugates was higher than that on collagen and comparable to that on Matrigel. CONCLUSIONS: These limited results suggest that Lac-CY-SF conjugates may be as useful as Matrigel and collagen for cultivation of hiPSC-derived hepatocytes.