Sub-Normothermic Storage Of Hek293t Cells Using A “Novel” Biopreservation Medium, Aqix® Rs-I

Background: Cell based therapies are an exciting and rapidly developing technology. However, there are logistical problems related to cell storage and shipment. Recently, Coventry University and Life Science Group Ltd were awarded Knowledge Transfer Partnership (KTP) funding via Innovate UK to further develop AQIX® RS-I and its applications. AQIX® RS-I is a physiological solution based on human interstitial fluid, developed to maintain viability of isolated mammalian tissues and organs. Additionally, AQIX® RS-I may also have cell culture applications. As such, one of the areas that the KTP project is focusing on is the development of a novel, xeno-free medium suitable for sub-normothermic non-frozen cell storage. Being xeno-free maintains the principles of the 3R’s by being free of animal products, such as foetal bovine serum (FBS). Additionally, development of a xeno-free storage medium will address logistical issues associated with cell-based therapies. Methods: HEK293T cells were plated at 1.5 x 106 cells per T25 in 5 ml complete DMEM + 10% FBS with antibiotic-antimycotic and were cultured at 37°C, 5% CO2 for 24 h. Media was replaced with the storage medium; DMEM/HEPES or AQIX® RS-I. Cells were then stored at ambient temperature, in darkness for 96 h. To recover the cells, the storage medium was replaced with complete DMEM + 10% FBS with antibiotic-antimycotic and cells were cultured at 37°C in 5% CO2 for 72 h. Cells were then dissociated and viability was assessed using trypan blue. Results: Following 72 h recovery, cells stored in AQIX® RS-I showed a 2.3 fold increase in cell number compared to the number of cells seeded and were 99% viable. Whereas, half of the original number of cells remained, following storage in DMEM/HEPES with only 73% viability. Conclusion: Preliminary work indicates that following 96 h storage in AQIX® RS-I at ambient temperatures, HEK293T cells recover well and demonstrate excellent viability and proliferation. These initial results are promising, and further research will evidence that AQIX® RS-I is an optimal base on which to develop a transport and storage medium suitable for cell-based applications.