Biopolymer immune implants co-loaded with TMZ, R848 and IOX1 for perioperative therapy of glioblastoma.

Glioblastoma (GBM), a prevalent and aggressive brain tumor, poses significant treatment challenges due to its rapid progression and the difficulty in achieving complete surgical resection. The current treatment regime, primarily surgery followed by radiotherapy and chemotherapy, offers limited success, with a five-year survival rate of less than 10 %. For addressing the challenges faced in the treatment of GBM, an approach using a biopolymer implant constructed with dynamic reversible covalent bonds, was designed to achieve controlled and constant-rate release of chemotherapy drug (Temozolomide, TMZ), immune adjuvant (Resiquimod, R848) and checkpoint inhibitor (5-carboxy-8-hydroxyquinoline, IOX1). The safety evaluation demonstrated the biocompatibility of the implants, with no significant inflammatory response or adverse effects on various systemic organs. In vivo antitumor study showed that the local delivery of drug combination via this implant significantly inhibited tumor recurrence of orthotopic GBM. Immune analysis revealed that the combination of the three drugs effectively activated systemic antitumor immune responses and induced memory effects. The synergistic mechanism of the drug combination was further validated by RNA whole sequencing. The innovative approach of combining chemotherapy and immunotherapy in biopolymer immune implants for GBM treatment showed promising and opens new avenues for treating GBM, particularly in addressing postoperative recurrence. STATEMENT OF SIGNIFICANCE: Our research introduces a pioneering approach in treating orthotopic brain glioblastoma (GBM), characterized by inevitable tumor recurrence, poor immune infiltration and the restrictive nature of the blood-brain barrier. To break the impasse of ineffective treatment for GBM, the innovative use of dynamically reversible covalent bonds in polymer matrix ensures the controlled, stable and sustained release of drug combinations of the chemotherapeutic agent temozolomide, immune adjuvants and checkpoint inhibitors, which maintains the optimal concentration in the tumor, overcoming problems associated with conventional chemotherapy such as systemic toxicity and low tumor targeting. Empirical evidence from in vivo experiments on the rat GBM model demonstrates significant outcomes: 90 % tumor size reduction and prolonged survival with over 70 % tumor cure rate.