Cascade-Responsive Nanoparticles for Efficient CRISPR/Cas9-Based Glioblastoma Gene Therapy.

CRISPR/Cas9 (CRISPR, clustered regularly interspaced short palindromic repeats) gene editing technology represents great promise for treating glioblastoma (GBM) due to its potential to permanently eliminate tumor pathogenic genes. Unfortunately, delivering CRISPR to the GBM in a safe and effective manner is challenging. Herein, a glycosylated and cascade-responsive nanoparticle (GCNP) that can effectively cross the blood-brain barrier (BBB) and activate CRISPR/Cas9-based gene editing only in the GBM is designed. The GCNP possesses a cationic polyplex core and a glycosylated polymer layer that is capable of cascading response to low pH and high GSH concentration, so that the release of CRISPR/Cas9 only takes place after crossing the BBB and entering the GBM where the acidic tumor microenvironment and high concentration of glutathione (GSH) are present. By targeting the programmed death-ligand 1 (PD-L1) in GBM, GCNP effectively inhibited the tumor growth and greatly prolonged the survival time of GBM-bearing mice when combined with temozolomide (TMZ).