Intelligent Nanoparticles With pH-Sensitive Co-Delivery of Temozolomide and siEGFR to Ameliorate Glioma Therapy

Glioblastoma (GBM) is one of the most lethal forms of human cancer, with very few long-term survivors. In addition to surgery, chemotherapy is still an important strategy. Unfortunately, GBM chemotherapy faces two main challenges: first, in GBM, epidermal growth factor receptor (EGFR) overexpression results in chemoresistance; second, temozolomide (TMZ) lacks target specificity, which can lead to a reduction in the concentration and side effects in GBM. Nowadays, with the development of nanomedicine systems for applications in tumor therapies, increasing anticancer efficacy and reducing side effects with multi-drug delivery are huge advantages. In this study, pH-sensitive and GBM-targeting nanovesicle (Tf-PEG-PAE(SS)) was fabricated. The chemotherapy drug (TMZ) and EGFR inhibitor (EGFR-siRNA) were co-encapsulated in the nanocarrier, and their anticancer outcomes were investigated in detail. In vitro experiments have shown that the nanocarrier transports TMZ and EGFR-siRNA efficiently into U87 cells, causing a vigorous apoptotic response by silencing the proliferative EGFR gene and increasing the drug concentration of TMZ simultaneously. An experimental study in mice bearing orthotropic glioma revealed that the accumulated nanocarriers in the tumor site could inhibit the tumor growth and prolong the mice survival remarkably through the intracranial injection of Tf-PEG-PAE(SS)/TMZ@siEGFR. The drug co-delivery system could extend the blood circulation time and offer a new strategy to treat glioblastoma.