Black phosphorus-based photothermal therapy with aCD47-mediated immune checkpoint blockade for enhanced cancer immunotherapy

Here, we describe a combination strategy of black phosphorus (BP)-based photothermal therapy together with anti-CD47 antibody (aCD47)-based immunotherapy to synergistically enhance cancer treatment. Tumour resistance to immune checkpoint blockades in most cancers due to immune escape from host surveillance, along with the initiation of metastasis through immunosuppressive cells in the tumour microenvironment, remains a significant challenge for cancer immunotherapy. aCD47, an agent for CD47/SIRP alpha axis blockade, induces modest phagocytic activity and a low response rate for monotherapy, resulting in failures in clinical trials. We showed that BP-mediated ablation of tumours through photothermal effects could serve as an effective strategy for specific immunological stimulation, improving the inherently poor immunogenicity of tumours, which is particularly useful for enhancing cancer immunotherapy. BP in combination with aCD47 blockade activates both innate and adaptive immunities and promotes local and systemic anticancer immune responses, thus offering a synergistically enhanced effect in suppression of tumour progression and in inducing abscopal effects for inhibition of metastatic cancers. Our combination strategy provides a promising platform in which photothermal agents could help to enhance the therapeutic efficacy of immunotherapy. Immunotherapy: enhancing the therapeutic effectiveness of photothermal cancer treatments By combining photothermal therapy and immunotherapy, scientists have improved cancer treatments. In cancer immunotherapy, the body's immune system is artificially boosted to fight cancer. Some cancers, however, can protect themselves from immunotherapies by stimulating immune checkpoint targets, which regulate the immune system and prevent it from attacking non-cancerous cells. Checkpoint blockade immunotherapy helps the immune system to recognise and attack cancer cells. However, it is ineffective in treating patients suffering from most solid tumour cancers like melanomas. Now, a team of scientists, led by Paras Prasad from the State University of New York, have used a combination of black phosphorus-based photothermal therapy and antibody immunotherapy to enhance the therapeutic efficiency of the treatment. By exerting a synergistically enhanced antitumor effect, the technique has proved effective in suppressing the proliferation and growth of cancer cells.