Dextran-Based Hydrogel as a New Tool for BALB/c 3T3 Cell Cryopreservation Without Dimethyl Sulfoxide

Cryopreservation provides an efficient way to preserve cells for a broad range of medical applications, including cell therapy. In clinical practice, cells are frozen in solutions containing dimethyl sulfoxide (DMSO) cryoprotectant agents (CPAs) to reduce their damage during the cooling process. In the current cell preservation methods, polysaccharides such as dextran, a nonpenetrating CPA, are used. However, the cell viability decreases when the solution concentration in polysaccharides increases.

To overcome this limitation, we have developed a dextran-based hydrogel (PSH) as a new CPA. Three molecular weight PSHs (PSH₄₀, PSH₇₀, and PSH₅₀₀) were synthesized. The physicochemical characteristics of PSHs were studied. Then, their biocompatibility properties were studied in vitro in BALB/c 3T3 cells according to ISO standard 10993-5/12. Crystallization temperature (Tc), that is, ice-crystal formation, was determined using the thermocouple method. Finally, PSHs were used as CPAs in a slow freezing procedure of BALB/c 3T3 cells with Voluven^® (Fresenius Kabi, Sèvres, France), and were compared with the DMSO procedure.

Our results showed that PSHs were biocompatible and did not modify the osmolality of the Voluven cryopreservation solution. PSHs decreased the Tc when compared with the DMSO procedure. Furthermore, without adding DMSO, PSH₅₀₀ cryopreserved the viability of BALB/c 3T3 cells, and the result was similar to that of the control conditions.

PSH₅₀₀ could represent an alternative to DMSO. It could be used as a new medical device while avoiding DMSO side effects on patients.