Antibody-decorated Magnetic Nanoparticles For Enhancing The Antitumor Efficacy Of Natural Killer Cells

In recent years,immunotherapy had made great progress in anti-tumor treatment.Among immune cells,natural killer cells(NK cells)are indispensable in the process of anti-tumor therapy.Compared with T cells and B cells,NK cells killing tumor cells was independent of antigen processing and presentation.Therefore,the preparation of anti-tumor drugs based on NK cells has the potential of clinical transformation.It is known that NK cell infiltration into tumor was beneficial to enhance the therapeutic effect.However,the existing strategies for using NK cells for anti-tumor therapy were faced with some unavoidable shortcomings,such as the low efficiency of cell expansion in vitro,mismatch between infused NK cells and the host killer-cell immunoglobulin-like receptors(KIRs),and impaired NK cell viability.Therefore,in order to avoid the aforementioned risk,we planned to develop a strategy to promote the enrichment of NK cells in tumor sites in situ.This work was divided into the following two parts:(1)In order to achieve the in vivo binding between magnetic particles and NK cells,anti-mouse NK1.1 antibody has been modified on the surface of Fe₃O₄ nanoparticles.Through the antigen-antibody reaction,Fe₃O₄ nanoparticles have been effectively bond to NK cells.(2)It was verified that the enrichment of NK cells in the tumor site can significantly inhibit the growth of melanoma through in situ model treatment experiments of mouse melanoma.This work provided a method to modify NK cells in vivo and endow them with tumor enrichment ability,providing a new idea for the tumor enrichment strategy of NK cells.