241: DMSO in Cell Therapy: Why Viability Scores Hide the Real Toxicity with Steve Oh - Part 1

Arctic fish survive in waters that would freeze most life solid. Not because they tolerate ice, but because their biology prevents crystals from forming in the first place. That same principle, translated into synthetic peptide chemistry, is now showing performance data that DMSO cannot match. Part 2 is where the science becomes practical.

Steve Oh spent 22 years at Singapore's A*STAR accumulating 43 patents across stem cell bioprocessing, microcarrier technologies, and serum-free media. He now advises XTherma, where he has been stress-testing their DMSO-free cryopreservation solution across T cells, MSCs, organoids, and beyond. In Part 2, he brings the data.

Key topics discussed:

• How antifreeze protein-inspired peptide chemistry reduces ice crystal size and protects cells during freezing and thawing (00:23)
• T cell and MSC performance data comparing XT Thrive to DMSO and CryoStor CS10, including a 2.5-fold increase in cell yield on microcarriers post-thaw (02:23-05:00)
• Why ice crystal formation causes more damage during thawing than freezing, and how XT Thrive addresses this (05:32)
• Elimination of the post-thaw wash step and what that means for contamination risk and manufacturing simplicity (07:00)
• Hold time extended to 24 hours and storage performance across 4°C, -80°C, and -196°C (08:01)
• Applicability beyond single cells: organoids, islets, and potential implications for organ preservation (09:50)
• How to transition from DMSO to XT Thrive: GMP grade, Drug Master File, same concentration, no protocol overhaul required (10:49)
• Broader cell therapy challenges: differentiation time, cell population consistency, and cost of goods (12:03)

Smart insight:

The transition away from DMSO is more accessible than most scientists assume. XT Thrive is GMP-grade, carries a Drug Master File, and is used at the same 5-10% concentration as DMSO, making it a plug-and-play substitution for most cell types. The manufacturing implications go further: no wash step, extended hold times, and storage stability across all standard temperature ranges simplify both production workflows and cold-chain logistics to remote treatment sites.

If you’re interested in this topic, check out these episodes, where we explore how Minnesota’s frozen forests inspired a new wave of biotech innovation, transforming how life-saving cells are frozen, stored, and shipped.

• Episodes 161 - 162: How to Achieve 85%+ Cell Recovery Without DMSO's Toxic Side Effects with Jeffrey Allen

This is Steve’s second appearance on the podcast. You can also catch his earlier conversation with David, where they explored the challenges and opportunities of cell and gene therapy.

• Episodes 11 - 12: From Lab to Patient: Steve Oh’s Guide to Mastering Cell Therapy Process Development.

Connect with Steve Oh:

Email: skwohso@gmail.com

LinkedIn: www.linkedin.com/in/steve-oh-4946261/

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