Figure 1.

Assembly of nanoparticles and delivery to natural killer cells. Chitosan–TPP nanoparticles are assembled via ionic gelation. CPAs (for example, trehalose) are loaded inside the nanocarriers and the nanoparticles are lyophilized, prior to being rehydrated in cell culture media. Delivery to NK cells occurs by incubating the CPA‐loaded nanoparticles with NK cells at 37 °C. This promotes internalization of the nanoparticles and the intracellular delivery of CPA cargo to NK cells. Following nanoparticle internalization, NK cells are able to be cryopreserved at subzero temperatures in liquid N₂ in the absence of DMSO. Thawed NK cells are then used for adoptive transfer immunotherapy.