Submicron-sized nano-vaccines enhance lymphatic retention and antigen-presenting cell uptake.

The targeted delivery of therapeutic agents to lymphoid tissues or immune cells plays an important role in tumor vaccine efficacy. To investigate size-dependent immunological effects, we designed luminescent nanoparticles with three distinct sizes (RSNP-30, RSNP-150, and RSNP-600) and systematically evaluated their efficiency in lymphatic retention, antigen-presenting cell (APC) uptake, and in vivo vaccine performance. Our findings revealed that larger nanoparticles (RSNP-150 and RSNP-600) exhibited enhanced lymphatic accumulation 24 h post-administration and were more efficiently internalized by APCs. Notably, tumor inhibition efficacy correlated positively with increasing nanoparticle size (within the size range of 30-600 nm), demonstrating the advantages of submicron-scale vaccine delivery systems.Therefore, these results provide valuable insights for the design of nano-sized delivery systems for enhanced immunotherapeutic outcomes.