Polydopamine nanoparticles carrying tumor cell lysate as a potential vaccine for colorectal cancer immunotherapy
Polydopamine nanoparticles (PDA NPs) were prepared via dopamine self-polymerization, and then tumor cell lysate (TCL) was covalently attached onto PDA NPs. The TCL loading capacity was 480 μg per mg of PDA NPs, and the resulted TCL@PDA NPs (241.9 nm) had perfect storage stability and negligible cytotoxicity against APCs. The tumor-bearing mice vaccinated with TCL@PDA NPs experienced significant delay in tumor progression due to the sufficient amount of CTLs and M1-type TAM as well as the deficient number of immunosuppression-related cells in tumor tissues. Furthermore, empty PDA NPs had the ability to modulate DCs maturation, delayed the development of tumor by facilitating the production of activated T cells and reducing the subpopulation of MDSCs within the tumor microenvironment. Overall, PDA NPs were expected to be a promising candidate for application as antigen delivery carriers because of the facile antigen loading method as well as the simple and rapid preparation process.