A novel therapeutic vaccine based on graphene oxide nanocomposite for tumor immunotherapy

With an intensive understanding of the mechanism of immune system,developing a therapeutic tumor vaccine is one of the most perspective strategy of cancer immunotherapy.In this study,we report a facile approach to prepare graphene oxide(GO)-based therapeutic cancer-nanovaccine.The model antigen(ovalbumin,OVA)and adjuvant(CpG ODN),are conjugated with GO-PEI nanosheet through electrostatic interaction.The addition of PEG can improve biocompatibility and prevent nanoparticle aggregation.The prepared GO-based nanovaccine,GO-PEI-OVA-PEG-CpG,exhibits good biocompatibility and low toxicity both in vivo and in vitro.More importantly,it can efficiently induce the maturation of dendritic cells(DCs),the enhancement of antigen cross-presentation ability,and the amplification of cytokine production of immune cells.Impressively,this nanovaccine shows a remarkable therapeutic effect against preestablished B16-OVA-melanoma tumors,which can significantly inhibit tumor growth and prolong the survival time of the OVA-expressed tumor-bearing mice.Moreover,combining GO-PEI-OVA-PEG-CpG with NLG919,an IDO-1(indoleamine-2,3-dioxygenase)inhibitor which can regulate the tumor microenvironment,displays a synergistic therapeutic effect.These findings indicate the GO-PEI-OVA-PEG-CpG nanovaccine actively induces an antigen-specific antitumor immune response and it combined with NLG919 could achieve better therapeutic outcomes.