ANTI-TUMOR RESPONSES INDUCED BY LASER IRRADIATION AND IMMUNOLOGICAL STIMULATION USING A MOUSE MAMMARY TUMOR MODEL

Anti-tunor immunological response induced by local intervention is ideal for treatment of metastatic tumors.Laser immunot herapy was developed to synergize photot hermal interaction with immunological stimulation for cancer treatment.Using an infrared laser,indocyanine green(ICG,as a light abeorbing agent),and glycated chitosan(GC,as an immunostimulant),.laser imm unot herapy has resulted in tumor suppression and anti-tumor responses in pre-clinical as well as clinical studies.To further understand the mechanism of laser immunotherapy,the efects of laser and GC treatment without specifc enhancement of laser absorption were studied.Passive adoptive immunity transfer was perfomed using splenocytes as immune cells.Spleen cells harvested from tumor-bearing mice treated by laser+GC provided 60%immunity in naive recipients.Furthermore,cytotoxicity and TNF-ar secretion by splenocytes from treated mice also indicated that laser+GC induced immunity was tumor-specific.The high level of infiltrating T cells in tumors after laser+GC treatment furt her confirned a specific anti-tumor immune response.Therefore,laser+GC could prove to be a promisi ng selective local trea tment modality that induces a systemic anti-tumor response,with appropriate laser parameters and GC doses.

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.