Nanotechnology deals with the development of nanosized structures, which present enticing new properties, compared to their macrosized counterparts. Nanoparticles have been actively investigated as carrier systems for drugs, especially in the treatment with chemotherapeutics, because they allow a reduction in the administered dose, and consequently a decrease in the side effects caused by the drugs. Moreover, they can be actively targeted and accumulate in the tumor tissue, increasing the efficacy of the drug. Recently, the introduction of the therapy with check-point inhibitors (a form of immunotherapy based on the administration of antibodies) has shown outstanding results, particularly in the treatment of cancers characterized by high mortality rates (e.g., melanoma and lung cancer). Active immunotherapy relies on the patient’s immune system, providing the instruments and/or the activation switch to recognize and eliminate cancer cells.
Nanotechnology offers promising new possibilities in this field: nanosystems can load and efficiently deliver the components of a vaccine (antigen, the fingerprint of the cancer cells that needs to be recognized by the immune system; and adjuvant, an activation signal for immune cells) to the cells, stimulating their activation and priming against cancer. Furthermore, they can act as adjuvant themselves based on the intrinsic properties displayed by the material. Finally, traditional chemotherapy can be combined with immunotherapy to fight the tumor cells from multiple standpoints. A wide range of synthetic and natural polymers, together with liposomes, metallic and inorganic nanosystems, co-loaded with antigens and adjuvants, have achieved control or elimination of the cancer, while biomimetic structures, vesicles derived from the membrane of cancer cells have recently been investigated as they can act as personalized sources of antigens for each patient.
A recent review by F. Fontana, D. Liu, J. Hirvonen, and H.A. Santos discusses this new approach in the fight against cancer, presenting examples of different materials and their applications in vitro and in vivo. Read it in WIREs Nanomedicine and Nanobiotechnology.