LncRNA-targeting bio-scaffold mediates triple immune effects for postoperative colorectal cancer immunotherapy.

Colorectal cancer (CRC) recurrence after surgical resection results in poor clinical outcomes. Long noncoding RNAs (lncRNAs) are emerging new targets for mediating tumorigenesis and immunosuppression within tumor microenvironment. We develop a bio-scaffold encapsulating lncRNA-targeting biomimetic nanosystems for mediating triple immune effects against postoperative CRC recurrence. Liposome (termed as "D")-decorated CRC cells' membrane (CM) envelops a plasmid encoding a short hair-pinned RNA (shRNA) against plasmacytoma variant translocation 1 (Pvt1), forming the shPvt1-CM-D nanosystem. This nanosystem and the chemodrug Oxaliplatin (Oxa) are embedded in a hyaluronic acid and alginate-based bio-scaffold for postoperative implantation. (1) ShPvt1-CM-D-mediated Pvt1 knockdown strengthens Oxa-induced immunogenic cell death (ICD). (2) Such tumor antigens released from enhanced ICD and the CM from shPvt1-CM-D act as dual vaccines of dendritic cells. (3) Pvt1 knockdown by shPvt1-CM-D within granulocytic myeloid-derived suppressor cells (G-MDSCs) ameliorates G-MDSC-mediated immunosuppression. The nanosystem-carrying bio-scaffold significantly suppresses perioperative CRC local recurrence by 97.8% with survival rate (SR) of 62.5%. The bio-scaffold generates robust immune memory responses for completely suppressing tumor ectopic rechallenging and metachronous metastasis (SR: 100%). Additionally, the bio-scaffold reduces synchronously distant metastasis by 70.8%. This work presents a potent nanotechnology-facilitated lncRNA-targeting immunotherapy for postoperative CRC treatments.