An Implantable Double-Layered Spherical Scaffold Depositing Gene and Cell Agents to Facilitate Collaborative Cancer Immunotherapy.

Gene therapies and adoptive cell therapy (ACT) are promising strategies for cancer immunotherapy. Referring to their different mechanisms, the combination of these two might result in a strategy with potential collaborative and compensatory effects. However, it is challenging to combine gene therapies and ACT that work in a proper logical order. Here, we developed a double-layered spherical scaffold (DLS) to codeliver mRNA and T cells and constructed an implantable hydrogel formulation, named the GD-920 scaffold. With a diameter of 7 mm, this scaffold loaded primary T cells in the inner layer and the Bim mRNA nanocomplex in the outer layer. While maintaining their bioactivities, GD-920 released gene and cell payloads in a controllable and sequential manner. The mRNA complex from the outer layer was first released and induced immunogenic tumor cell death. The produced antigens then migrated into the scaffold with dendritic cells, triggering a tumor-specific immune response. Finally, activated T cells released by the inner layer attacked the tumor tissue via massive infiltration. We showed that in situ implantation of the GD-920 scaffold is capable of effectively inhibiting tumor growth and is far more potent than that of control scaffolds containing a single payload. Our results demonstrated the outstanding potential of this DLS in combining gene and cell therapeutic approaches to cancer immunotherapy.