Overcoming therapeutic limitations in glioblastoma treatment: A nanocomposite inducing ferroptosis and oxeiptosis via Photodynamic therapy

Photodynamic therapy (PDT) is an effective treatment for glioblastoma (GBM) that activates photosensitizers to produce reactive oxygen species (ROS) while minimizing harm to normal tissues. However, the therapeutic outcomes of PDT are often unsatisfactory. This limitation arises partly from the challenges posed by the blood-brain barrier (BBB) in transporting photosensitizers and partly from the excessive levels of glutathione (GSH) in the tumor microenvironment (TME), which can neutralize ROS. Hypericin (HYP) has emerged as a promising photosensitizer for PDT due to its excellent photosensitizing properties and antitumor activity. Dysregulated iron metabolism is a hallmark of numerous cancers, including GBM. In this study, biodegradable tetrasulfide-bound dendritic mesoporous organosilicas nanocomposite (NCs) modified with bovine serum albumin (BSA) were synthesized. NCs penetrates the BBB and selectively targets GBM by binding to secreted acidic protein acidic and rich in cysteine (SPARC), an albumin-binding receptor that is prominently expressed in both the BBB and GBM. Upon degradation in response to high GSH concentrations in the TME, the NCs release their payload while concurrently depleting GSH. Under laser irradiation, the ROS-generating agent HYP, loaded within the NCs, is combined with the ferroptosis inducer erastin to achieve a synergistic anti-GBM effect via PDT/ ferroptosis. Additionally, the NCs induces oxeiptosis by regulating KEAP1/PGAM5/AIFM1 pathway. Consequently, NC inhibits GBM growth by inducing ferroptosis and oxeiptosis through excessive ROS production. This study demonstrates the potential of NCs to enhance the effectiveness of PDT, offering a promising therapeutic strategy for GBM patients.