Conclusion
This study demonstrated that losartan-induced fibroblasts ablation increased the penetration of MPNs into tumors. Enhanced penetration allowed PTT to kill more tumor cells and synergistically activate immune cells, leading to ICD, indicating the great promise of the strategy for treating neuroblastoma in vivo.
Methods
In this study, we investigated the application and potential mechanism of the combination of mesoporous platinum nanoparticles (MPNs) and losartan in the PTT of neuroblastoma by establishing neuroblastoma models in vitro and in vivo.
Results
Compared to the MPNs group without 808 nm laser irradiation, Neuro-2a cells pretreated with PTT and losartan showed lower survival rates, increased surface calreticulin, and higher release of HMGB1 and ATP. The group also exhibited the highest anti-tumor efficacy in vivo, with a tumor suppression ratio of approximately 80%. Meanwhile, we found that CD3+ T cells, CD4+ T cells and CD8+ T cells from the peripheral blood of experimental group mice were significantly higher than control groups, and CD8+PD-1+ cells were significantly lower than those in MPNs + Los group and Los + laser group. And the expression of PD-1 and α-SMA in Neuro-2a tumors tissue was reduced. Furthermore, losartan could reduce damage of liver function caused by MPNs and laser treatment.