Reduced malignant glioblastoma recurrence post-resection through the anti-CD47 antibody and Temozolomide co-embedded in-situ hydrogel system

Infiltrative glioma growth makes surgical excision incomplete, and the residual tumor cells proliferate rapidly. Residual glioma cells evade phagocytosis by macrophages through upregulating anti-phagocytosis molecule CD47, which binds to the signal regulatory protein alpha (SIRPα) of macrophages. Specifically, blocking the CD47-SIRPα pathway is a potential strategy for post-resection glioma treatment. In addition, the anti-CD47 antibody (α-CD47) in combination with temozolomide (TMZ) caused an enhanced pro-phagocytic effect due to the TMZ not only destroying DNA but also inducing endoplasmic reticulum stress response of glioma cells. However, the obstruction of the blood-brain barrier makes systemic combination therapy not ideal for post-resection glioma treatment. Herein, we designed a temperature-sensitive hydrogel system based on a moldable thermosensitive hydroxypropyl chitin (HPCH) copolymer to encapsulate both α-CD47 and TMZ as α-CD47&TMZ@Gel for in situ postoperative cavity administration. Through the in vitro and in vivo evaluations, α-CD47&TMZ@Gel significantly inhibited glioma recurrence post-resection through enhancement of pro-phagocytosis of macrophages, recruitment, and activation of CD8+ T cells and NK cells.