[Background]
The successful application of Natural Killer (NK) cell therapies depends heavily on the availability of specialized culture media that can support high-yield expansion without compromising cellular potency. While various xeno-free formulations are commercially available, many fail to achieve sufficient expansion rates without the aid of feeder cells. In this study, we developed novel xeno-free, feeder-free NK cell culture media and evaluated their performance against leading commercial formulations to verify their clinical utility.
[Methods]
NK cells isolated from PBMCs were cultivated for 14 days in the newly developed xeno-free media supplemented with human serum and recombinant cytokines, without feeder cells. The performance of these media was benchmarked against several industry-standard formulations. We evaluated the impact of the media on expansion, purity, and functional maturation through immunophenotyping and standardized cytotoxicity assays.
[Results]
The newly developed media demonstrated superior proliferative capacity, achieving a significantly higher fold expansion by Day 14 compared to all reference media tested. High cell viability and exceptional NK cell purity (CD3⁻CD56⁺ > 95%) were consistently maintained without the use of feeder cells. Furthermore, NK cells expanded in these media exhibited a robust functional profile, characterized by elevated intracellular levels of Perforin and Granzyme B. Functional assays confirmed that the media yield NK cells with potent cytotoxic activity against K562 tumor targets, showing comparable or sufficient efficacy to leading competitor products across multiple donors.
[Conclusion]
The results demonstrate that these new xeno-free, feeder-free media are highly effective solutions for producing functional NK cells. By providing superior expansion and enhanced effector potency, these media serve as ideal candidates for the clinical-scale manufacturing of standardized NK cell-based immunotherapies.