Sprayable gel for postsurgical immunotherapy

Surgery remains the first option to treat most solid tumors. However, despite the development of surgical techniques, the elimination of tumor recurrence after surgery remains a challenge.

In a recent study published in Nature Nanotechnology, we described an in-situ-sprayed gel for local delivery of bioresponsive and immunotherapeutic calcium carbonate nanoparticles encapsulated with anti-CD47 antibodies (aCD47@CaCO₃) to the surgical site after surgery. CaCO₃ nanoparticles react with H⁺ in the surgical wound site, eliciting an immunosupportive tumor microenvironment after surgery. Meanwhile, the subsequently released aCD47 blocks the 'don't eat me' signal expressed on cancer cells to increase the phagocytosis of cancer cells by macrophages and activate T-cell-mediated antitumor immune responses.

The engineered immunotherapeutic gel could activate both innate and adaptive immune responses systemically after local treatment, effectively destroying the remaining cancer cells and reducing tumor recurrence.