Nanotherapeutics approaches to improve the efficacy of CAR-T cells in solid tumors

Adoptive cell therapy and Immune Checkpoint Blockade Inhibitors have recently revolutionized the field of oncology.However,these types of immunotherapeutic approaches have limited success in treating solid tumors.In particular,chimeric antigen receptor(CAR)-T cells efficacy is hampered by immunosuppressive signals in the tumor microenvironment(TME)and by a limited infiltration of re-infused T cells to the tumor site.The field of nanobiotechnology applied to oncology is also rapidly expanding.Nanoparticles-based delivery systems can be employed to modulate the activity of immune cells present in the TME enhancing the efficacy of CAR-T cells.Interestingly,nano-backpacks can be attached to CAR-T cells prior to re-infusion to support their homing to the tumor site and to slowly release immunopotentiators directly in the TME.Furthermore,nanovaccines can also be employed to support the in vivo expansion of CAR-T cells with consequent enhancement of their therapeutic potential.In this viewpoint,recent advancement in the field of nanobiotechnology to support CAR-T cell therapy will be discussed.The development of novel therapeutic CAR-T cells protocols together with nanotherapies is warranted in order to take full advantage of the high therapeutic potential of CAR-T cell therapy.