Recombinant Human Albumin in Weekend-Free hiPSC Culture – ISSCR Poster

Published on 30 July 2026

Poster

Recombinant Human Albumin Supports Weekend-Free hiPSC Culture and Protein-Free Cardiac Differentiation

Presented at ISSCR by Davi Lyra-Leite (BMEM Bio), Mark Stathos and Elliott Renft (InVitria), and Paul W. Burridge (Northwestern University Feinberg School of Medicine).

The Problem

Weekend-free hiPSC media change schedules save labor, but they have been reported to reduce subsequent differentiation efficiency. This study asked whether adding chemically defined recombinant human albumin (Optibumin) to chemically defined BMEM could close that gap and whether albumin could also replace the ROCK inhibitor step after passaging.

Key Findings

Higher purity than plasma-derived albumin. Native CE analysis showed significantly lower aggregate content in Optibumin rHSA lots than in plasma-derived HSA lots (p < 0.05).

A viable ROCK inhibitor alternative. Optibumin at 2 mg/mL provided cell survival benefit comparable to Chroman 1, and the two were additive when combined (four hiPSC lines, n = 8).

Pluripotency maintained over 10 passages. Growth, morphology, and POU5F1/NANOG expression were preserved across the weekend-free cadence in two hiPSC lines.

Enhanced cardiac differentiation. The combination of 2 mg/mL recombinant human albumin and 2x media volume during the weekend-free step produced the highest troponin T (TNNT2) positivity by flow cytometry, with more beating areas observed.

Why It Matters

For labs running weekend-free hiPSC schedules, chemically defined recombinant albumin offers a way to simplify the protocol by removing a separate ROCK inhibitor addition while recovering downstream cardiomyocyte differentiation efficiency. As an animal-origin-free, chemically defined supplement, Optibumin fits defined workflows without introducing plasma-derived variability.

Download the Poster

Get the full data set, including growth curves, pluripotency marker expression, morphology images, and TNNT2 flow cytometry across all albumin concentrations and media volumes.