Cancer Cell Lysate Entrapment in CaCO₃ Engineered with Polymeric TLR-Agonists: Immune-Modulating Microparticles in View of Personalized Antitumor Vaccination

Here, we report on a strategy to encapsulate cancer cell lysate in immunomodulating microparticles in view of their potential use in personalized anticancer vaccination. In a first step, cancer cell lysate is entrapped into porous calcium carbonate (CaCO 3 ) microparticles by a coprecipitation reaction. Second, a polymer substituted with a small molecule TLR7/8-agonist is adorbed onto the surface of the microparticles. Relative to soluble cell lysate, microparticle encapsulation yielded higher uptake of cell lysate by dendritic cells in vitro. Also, microparticle-adsorbed polymeric TLR7/8-agonists retained their TLR-triggering capacity resulting in immunogenic vaccine particles. We anticipate this strategy might hold potential to turn patient-derived tumor tissue, comprising the patient’s own mutanome, into potent personalized anticancer vaccines.