2022 年 11 巻 p. 33-36
Cell-based regenerative medicine entails culturing an abundance of cells outside of the body and then transfusing or injecting live cells back into the body. Our cancer immunotherapy uses multivalent Dendritic Cell (DC) vaccines and activated Natural Killer (NK) cells to increase the immune response against cancerous cells.
In our protocol, live cellular treatments are given to patients subcutaneously or intravenously every two weeks as soon as the cells are cultured for optimal results. However, patient health complications or concurrent treatment schedules can cause a delay in the treatment schedule. In these circumstances, the cellular treatment is cryopreserved.
Since the Covid-19 pandemic, lockdowns and travel restrictions have necessitated patient delays in getting care and as a result, the long-term cryopreservation of cells are needed. Due to concerns of cellular degradation and safety, we have limited the use of cellular treatments that have been cryopreserved for over one year. To address whether this safety precaution is warranted, we examined the viability of cells that have undergone prolonged cryopreservation. Our results show that DC vaccines and NK immune cells that had been preserved for over two years maintained high cell number and viability rates post-thaw. Our findings suggest that long-term cryopreserved DC and NK cells may be safely applied for clinical applications following further investigations on cell viability, quality and establishing biosafety profiles.
