Nitric-oxide propelled nanomotors sensitize tumors to ferroptosis immunotherapy via cholesterol depletion-induced tumor cells stiffening.

Despite the tremendous therapeutic promise of activating immunogenic ferroptosis, it can prime robust de novo T cell responses, biomechanically mediated immune suppression desensitizes the cytotoxicity of T cells against tumor cells. Herein, we developed a nitric oxide (NO)-propelled nanomotor (GFS@CAF) that co-delivers a ferroptosis inducer (GFS) and a cholesterol scavenger (β-cyclodextrin) to increase the sensitivity of tumors to ferroptosis immunotherapy by targeting deep penetration into tumor and depleting cholesterol to stiffen tumor cells. GFS@CAF nanomotors utilize the high level of H2O2 in the tumor microenvironment to generate NO, enabling self-propulsion and deep penetration into tumor by chemotaxis. GFS@CAF elevates reactive oxygen species levels and inactivate glutathione peroxidase 4, thereby promoting lipid peroxide accumulation to trigger immunogenic ferroptosis and initiate T cell responses. Meanwhile, membrane-anchored cyclodextrin depletes cholesterol to overcome the mechanical softness of cancer cell, which further enhances cytotoxic T lymphocyte-mediated cytotoxicity. In Hepa1-6 subcutaneous tumor-bearing mouse model, we successfully demonstrated that GFS@CAF led to significant tumor regression and established a durable immunological memory, with these mice surviving for two months. This study highlights the mechano-immunotherapeutic potential of combining cholesterol depletion and immunogenic ferroptosis for tumor treatment. Overall, our work presents a feasible approach for initiating robust T-cell-mediated anti-tumor killing in cancer immunotherapy.