Comparing them to control vaccines that lacked PEI but had all the other components, the team found them considerably more efficient in activating DC populations, stimulating interactions with T cells in nearby lymph nodes and driving the generation of circulating killer T cells that recognize tumor-specific peptides. Impressively, a single injection of the vaccine led to rapid and complete eradication of HPV tumors in mice, with 80 percent of the animals living longer than 150 days. Even six months after the injection, the animals vaccinated with the PEI formulation could still destroy tumor cells, showing that they had formed a robust immunological memory of the tumors. Each antibody (immune response) is specifically produced by the immune system to match an antigen after cells in the immune system come into contact with it; this allows a precise identification or matching of the antigen and the initiation of a tailored response. The large surface area of the pores allows the particles to be filled with a drug or a cytotoxin.

Harvard researchers describe a vaccine approach that uses an injectable scaffold loaded with a selection of tumor-expressed peptides. Comparing them to control vaccines that lacked PEI but had all the other components, the team found them considerably more efficient in activating DC populations, stimulating interactions with T cells in nearby lymph nodes and driving the generation of circulating killer T cells that recognize tumor-specific peptides. Impressively, a single injection of the vaccine led to rapid and complete eradication of HPV tumors in mice, with 80 percent of the animals living longer than 150 days. Even six months after the injection, the animals vaccinated with the PEI formulation could still destroy tumor cells, showing that they had formed a robust immunological memory of the tumors. Impressively, a single injection of the MSR–PEI vaccine using an E7 peptide completely eradicated large, established TC-1 tumors in about 80% of mice and generated immunological memory.