From Differentiation toward Maturation

Human Pluripotent Stem Cell-derived Cardiomyocyte (PSC-CM) has emerged as a new platform for cardiac therapeutics, disease modeling, and drug screening. State of the art culturing techniques have moved away from a pathway with intermediary Embryoid Bodiesand cardiac progenitor cell stages toward the direct differentiation method, and the CM yields are mostly above 75% now.

After the successful generation of CM, the next tasks might include subtype specification such as to control the ratio of ventricular and atrial cells derived and the faster maturation of fetal-type PSC-CM, with regards to the phenotypes such as fetal gene expression, disorganized morphology, contractile characteristics, and the reliance on predominantly glycolytic metabolism instead of beta-oxidation of fatty acids. (ref. 1)

Albumin's function in CM

Albumin is considered critical in the first Chemical defined PSC-CM differentiation medium reported by Burridge et al. in 2014 (ref. 2), in which rHSA from rice is specified. In 2015, Lian et al. reported the neutralization of CHIR99021 by albumin, and Albumin-free medium formula (ref. 3).

However, later studies on PSC-CM maturation has indicated the benefit of albumin, or the albumin associated fatty acids in cell automaticity, and could induce CM hypertrophy and increase its force production (ref. 4 and ref. 5)

Cross Reference of Lipid content in Albumins

Owing to its history as a by-product in the plasma fractionation process and its stickiness toward other plasma molecules, Albumin has long been considered to have untenable lot-to-lot variations.

deAlbumin™ is the formulated recombinant rHSA derived from yeast, on which all small molecules associated are stripped and re-associated from a defined recipe of such small molecules. Therefore the lot-to-lot variation could be eliminated.

For users to optimize their CM differentiation protocols, we list below the fatty acid level cross-reference charts of various commercially available albumin products.