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 (CaCO3) 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 TLRtriggering capacity resulting in immunogenic vaccine particles. We anticipate this strategy might hold potential to turn patientderived tumor tissue, comprising the patient’s own mutanome, into potent personalized anticancer vaccines.