Light-responsive hyaluronic acid nanomicelles co-loaded with an IDO inhibitor focus targeted photoimmunotherapy against “immune cold” cancer

. Meanwhile, the IDO1-mediated immunosuppression was effectively reprogrammed to an immunostimulatory phenotype, which was accompanied by an enhanced cytotoxic T cell response as well as reduced Treg infiltration in tumour bed. Ultimately, the 4T1 tumour was synergistically suppressed by NLG919@HA-Ce6 due to the outcome of focused PDT, obvious ICD post PDT and IDO1 blockade. This study suggests the promise of NLG919@HA-Ce6 as an alternative simple, stimulative and targeted nanoagent to enable the whole-body photo-immune therapy against "immune cold" cancer.