Why reducing DMSO could improve CAR-T cell preservation

Researchers want to reduce DMSO in CAR-T cell preparations to limit potential cell toxicity and patient exposure while preserving the cells’ ability to fight cancer. In protocols that remove DMSO after thawing, reducing it could also avoid processing steps that lose or damage cells. But simply using less is not enough: the replacement freezing method must still protect the cells and preserve their function. A review of T- and natural-killer-cell cryopreservation describes this central trade-off.

Here, DMSO means dimethyl sulfoxide, a solvent used as a cryoprotectant—a substance that helps cells survive freezing. It is part of the preservation formulation, not the cancer-targeting genetic modification.

Why use DMSO in the first place?

CAR-T therapy uses T cells engineered to recognize cancer targets. Freezing allows manufacturers to store and ship those living cells and gives treatment centers flexibility in scheduling infusions.

DMSO crosses cell membranes and helps protect cells from ice formation and the stresses associated with freezing. That effectiveness explains its widespread use. Without adequate cryoprotection, reducing DMSO can leave fewer viable, functional cells after thawing. Preservation methods therefore need to be optimized for the particular cell product—not judged by DMSO concentration alone. Cryopreservation review

What researchers hope to improve

There are three distinct reasons to reduce DMSO:

• Protect the therapeutic cells. Prolonged exposure to high DMSO concentrations can interfere with cellular enzyme activity and growth. Researchers assess not just whether cells are alive immediately after thawing, but whether they can subsequently expand and retain cancer-killing activity. Original SAFE study
• Reduce a potential source of infusion reactions. The U.S. prescribing information for Kymriah warns that serious hypersensitivity reactions, including anaphylaxis, may be due to DMSO or dextran 40 in the product. That supports investigating lower exposure; it does not prove that a particular reduced-DMSO method lowers reactions in patients. FDA prescribing information
• Avoid unnecessary post-thaw handling. Where a protocol removes cryoprotectants, the extra manipulation can compromise cell recovery or function. A formulation suitable for use without removal could simplify that workflow. Original SAFE study

DMSO removal is not required for every CAR-T product. Although MIT’s news report describes removal as necessary, Kymriah’s FDA-hosted prescribing information, revised June 2025, explicitly says not to wash, spin down, or resuspend it in new media before infusion. Handling must follow the specific product’s instructions. Nor should all CAR-T adverse effects be attributed to DMSO: the label separately warns about cytokine release syndrome and neurological toxicities. FDA prescribing information

What the 2026 sugar-based study actually showed

In research reported by MIT on August 19, 2026, investigators used trehalose and sucrose as protective sugars. Because these sugars do not readily enter cells, they used electroporation: brief electrical pulses that temporarily open pores in cell membranes.

The resulting strategy, called SAFE, was serum-free and DMSO-reduced—not DMSO-free. The researchers still needed a small amount of DMSO. The study reported improved post-thaw cell viability, expansion, and functional measures compared with conventional preservation approaches. Because SAFE changes both the formulation and intracellular delivery of cryoprotectants, these findings should not be read as proof that lowering DMSO alone produces the same benefits. Original study

The animal findings also need to be separated by model. The paper describes a survival advantage with human anti-CD19 CAR-T cells in a mouse lymphoma model, but similar tumor reduction with mouse anti-EGFRvIII CAR-T cells in a mouse glioblastoma model. It does not establish better survival for human patients or superior outcomes across all cancers. Original study

At the time of MIT’s report, hospital integration and a possible small patient trial were future steps. Easier distribution and better patient outcomes were potential benefits, not demonstrated clinical results.

This is cell-preservation research, not a DMSO cancer remedy

DMSO helps preserve the cells that deliver treatment; that does not make DMSO itself an anticancer treatment. Memorial Sloan Kettering states that there is no evidence DMSO treats cancer in humans. Nothing in this preservation study establishes a benefit from taking DMSO or MSM supplements. MSK’s DMSO review

For someone receiving CAR-T therapy, the useful question is: “How is my specific product preserved, and what infusion precautions apply?” The research is a reason to improve validated manufacturing methods—not a reason to request improvised washing or alteration of an approved cell product. For the broader distinction between clinical applications and consumer claims, see established DMSO uses in humans.