Photosynthetic Bacteria‐Hitchhiking 2D iMXene‐mRNA Vaccine to Enable Photo‐Immunogene Cancer Therapy

Abstract Therapeutic mRNA vaccines have become powerful therapeutic tools for severe diseases, including infectious diseases and malignant neoplasms. mRNA vaccines encoding tumor‐associated antigens provide unprecedented hope for many immunotherapies that have hit the bottleneck. However, the application of mRNA vaccines is limited because of biological instability, innate immunogenicity, and ineffective delivery in vivo. This study aims to construct a novel mRNA vaccine delivery nanosystem to successfully co‐deliver a tumor‐associated antigen (TAA) encoded by the Wilms' tumor 1 (WT1) mRNA. In this system, named PSB@Nb1.33C/mRNA, photosynthetic bacteria (PSB) efficiently delivers the iMXene‐WT1 mRNA to the core tumor region using photo‐driven and hypoxia‐driven properties. The excellent photothermal therapeutic (PTT) properties of PSB and 2D iMxene (Nb1.33C) trigger tumor immunogenic cell death, which boosts the release of the WT1 mRNA. The released WT1 mRNA is translated, presenting the TAA and amplifying immune effect in vivo. The designed therapeutic strategy demonstrates an excellent ability to inhibit distant tumors and counteract postsurgical lung metastasis. Thus, this study provides an innovative and effective paradigm for tumor immunotherapy, i.e., photo‐immunogene cancer therapy, and establishes an efficient delivery platform for mRNA vaccines, thereby opening a new path for the wide application of mRNA vaccines.


Figure S2 .
Figure S2.A) The polydispersity index and B) DLS analysis of the Nb1.33C/mRNA within 14 days.

Figure S9 .
Figure S9.A) Typical CLSM images and B) corresponding fluorescence intensity and confocal imaging study of 4T1 cells co-staining with lysotracker Green and Cy3-labled Nb1.33C/mRNA (without laser).C) Typical CLSM images and D) corresponding fluorescence intensity and confocal

Figure S10 .
Figure S10.A) Typical CLSM images of GFP mRNA vaccine in 4T1, CAF and RAW 264.7 cells and B) the corresponding fluorescence intensity of GFP (n = 3).C) Typical FCM of GFP + 4T1 cells and D) quantitative analysis following the different treatments (n = 3).

Figure S15 .
Figure S15.HE staining of histological sections of various organs in healthy mice after the PSB@Nb1.33C/mRNAinjection within one month (1, 3, 7 and 30 days), Control without any treatment.

Figure S26 .
Figure S26.A) Representative flow cytometric and B) the quantitative analysis of Tregs in the primary 4T1 tumor tissue after the first different treatments (n = 3).C) Representative flow cytometric and D) the quantitative analysis of M2 macrophages in the primary 4T1 tumor tissue after the first different treatments (n = 3).Control (G1), PSB@Nb1.33C/mRNA(G2), laser (G3),

Figure S28 .
Figure S28.A) Flow cytometry gating strategy for the analysis of Tetramer + CD8 + T cells.B) Flow cytometry gating strategy for the analysis of CD11c + SIINFEKL + presenting DCs.C) Flow cytometry gating strategy for the analysis of DCs in tumor.

Figure S29 .
Figure S29.A) Flow cytometry gating strategy for the analysis of CD4 + and CD8 + T cells in primary tumor tissue.B) Flow cytometry gating strategy for the analysis of Tregs in tumor tissue.C) Flow cytometry gating strategy for the analysis of M2 macrophages in tumor.

Figure S30 .
Figure S30.Flow cytometry gating strategy for the analysis of T cells of CD4 + and CD8 + T cells in the lymph nodes.

Figure S31 .
Figure S31.A) Different channels of immunofluorescence images of CD3 + CD4 + and B) CD3 + CD8 + proliferating CTLs in the primary tumor tissue sections after various treatments.C) Corresponding positive area quantification of CD3 + CD4 + and D) CD3 + CD8 + proliferating CTLs in the primary

Figure S32 .
Figure S32.A) Different channels of immunofluorescence images of CD3 + CD4 + and CD3 + CD8 + proliferating CTLs for the distant tumor tissue sections after various treatments.C) Corresponding positive area quantification of CD3 + CD4 + and D) CD3 + CD8 + proliferating CTLs in the distant tumor

Figure S33 .
Figure S33.Representative photographs of lung metastatic nodules in the back for different groups (Control, Treated) (n = 3).