Anti-tumor response induced by immunologically modified carbon nanotubes and laser irradiation using rat mammary tumor model

The ideal treatment modality for metastatic cancer would be a local treatment that can destroy primary tumors while inducing an effective systemic anti-tumor response.To this end,we de-veloped laser immunotherapy,combining photothermal laser application with an immunoadju-vant for the treatment of metastatic cancer.Additionally,to enhance the selective photothermal effect,we integrated light-absorbing nanomaterials into this innovative treatment.Specifically,we developed an immunologically modified carbon nanotube combining single-walled carbon nanotubes(SWNTs)with the immunoadjuvant glycated chitosan(GC).To determine the ef-fectiveness of laser iradiation,a series of experiments were performed using two different irra-diation durations-5 and 10 min.Rats were inoculated with DMBA-4 cancer cells,a metastatic cancer cell line.The treatment group of rats receiving laser irradiation for 10 min had a 50%long-term survival rate without residual primary or metastatic tumnors.The treatment group of rats receiving laser irradiation for 5 min had no long-term survivors;all rats died with multiple metastases at several distant sites.Therefore,Laser+SWNT-GC treatment with 10 min of laser irradiation proved to be efective at reducing tumor size and inducing long-term anti-tumor immunity.