MIT freezes CAR-T cells with less DMSO in mouse study

A patient’s T cells can spend several weeks being engineered and multiplied before they are returned as a CAR-T treatment. Once ready, the cells are frozen and shipped from centralized laboratories to hospitals—an essential logistics step in a field where only about 5% of U.S. hospitals can generate and deliver CAR-T therapy.

Freezing is where the process becomes fragile. Hospitals use dimethyl sulfoxide, or DMSO, to prevent ice crystals from damaging cell membranes, but the chemical must be removed before the cells reach the patient. That extra step requires expertise and can itself reduce the number of viable, effective CAR-T cells.

MIT researchers tested trehalose and sucrose, sugars that help protect proteins and limit ice formation at low temperatures. Using electroporation—a brief electrical pulse that creates temporary openings in the cell membrane—the team moved the sugars inside CAR-T cells. A small amount of DMSO was still needed, but not enough to require removal after thawing.

The approach produced higher survival after freezing and thawing in both CAR-T cells and mesenchymal stem cells than preservation based mainly on DMSO. In mouse models of non-Hodgkin’s lymphoma and glioblastoma, mice treated with the sugar-preserved CAR-T cells had higher survival rates than those treated with conventionally preserved cells. The study was published in Trends in Biotechnology; its evidence remains in cells and mice, not patients.

So what changes in practice? If hospitals can reproduce the results and fit the method into their workflows, treatment centers could potentially thaw and use the cells without an additional DMSO-removal step. That could reduce a technical bottleneck for centers that currently depend on centralized manufacturing. MIT’s researchers now hope to work with hospitals to examine whether the process is easy to integrate; no clinical deployment is reported yet.