How can nanoparticles be used for immunotherapy?

Nanoparticles are ultrafine particles between 1-100 nm in size. They are capable of being transported in whole organisms without rapid degradation, and their interfacial layer can incorporate surface ligands or be used to carry cargo such as drugs. Nanoparticulate immunotherapy is gaining traction as an efficient platform for targeting antigen presenting cells with tumor-associated antigens as well as co-stimulatory molecules. Additionally, nanoparticles can also be used as artificial antigen presenting cells that can bind to T-cell receptors and produce co-stimulatory molecules to activate T-cells. Nanoparticles that can be used in this context includes polypropylene sulfide, gold, poly(lactic-co-glycolic acid) [PLGA], and artificial exosomes.1 Previous studies have attempted delivering conventional chemotherapeutic drugs to cancer cells, but using nanoparticles to provide immunostimulatory chemicals to dendritic or antigen-presenting cells may provide the additional immune-system boost necessary for an impact on this disease. Surface modifications and material composition are especially critical in selectively targeting nanoparticles to tumor cells and immune cells. The use of nanocarriers for improving cancer immunotherapy requires more investigations before it can be applied to clinical settings.2

1. X. Zang et al, "Nanoparticles for Tumor Immunotherapy," Eur J Pharm Biopharm 115(6): 243-256, 2017.
2. P. Velpurisiva et al, "Nanoparticle Design Strategies for Effective Cancer Immunotherapy," J Biomed 2(2): 64-77, 2017.