The Nano Function Packaging Protectant Of NK Cells

Natural killer(NK)cells could kill target cells without requiring priming or restriction by major histocompatibility complex(MHC)molecules.Morever,strong evidence supported that allogeneic donor NK cells could inhibit graft-versus-host disease(GVHD)and promote graft-versus-tumor effects.Thus,NK cells have attracted considerable attention in tumor immunotherapy,such as leukemia,lymphoma,breast cancer,etc.).After cultivation,qualified NK cells need to be transported to hospital.Therefore,it is vital that a high proportion of cells survive the entirety of the transportation process and maintain their cytolytic activity for downstream applications in their destination hospital.Typically,the most commonly used method for cell shipment is cryopreservation,freezing and storing cells below-80°C.The addition of CPAs is a common practice during cryopreservation to reduce the freezing and thawing–induced damage to the cells.However,NK cells are highly sensitive to freezing and thawing,while the use of DMSO during cryopreservation raises serious safety concerns.Unlike cryogenic and hypothermic preservation,normothermic preservation no longer depends on expensive refrigeration and insulation equipment and cumbersome freezing procedures,breaking the limitations of traditional cell transportation.It has become the preferred method for short-distance transportation of cells.Based on 3D polymer scaffolds,it could construct three-dimensional(3D)microenvironment in vitro,to maintain high rate of cell viability under ambient conditions.In this paper,a serum-free 3D preservation method of NK cells under ambient conditions was established based on nano-self-assembled peptide materials,and the function of NK cells after preservation were evaluated.First,for NK cells enrichment,we expanded peripheral blood mononuclear cells in vitro,cultivation in medium containing IL-2 and IL-15 for up to 2 weeks.Secondly,based on nano self-assembly peptide,NK cells uniformly distributed in the 3D microenvironment.Finally,this study detected the NK cell count,viability,apoptosis rate,the proportion of CD3~-CD56~+subsets and the function after NK cells were stored under ambient conditions.The results of the experiment confirmed that compared with normal saline(2D),the peptide scaffold material enhanced NK cell viability and reduced apoptosis rate of NK cells,maintaining the proportion of CD3~-CD56~+subsets at higher level.Meanwhile,the cytotoxicity of NK cells and the cytokine secretion ability(perforin,granzyme B,IFN-γ)improved in 3D preservation under ambient conditions.In conclusion,the novel method of 3D preservation under ambient conditions has been established based on the peptide scaffold material.Moreover,3D preservation of NK cells maintained the cell quality during normothermic preservation.