A Tumor-Homing Peptide Platform Enhances Drug Solubility, Improves Blood–Brain Barrier Permeability and Targets Glioblastoma
Cancers 2022, 14(9), 2207; https://doi.org/10.3390/cancers14092207
Choi-Fong Cho, Charlotte E. Farquhar, Colin M. Fadzen, Benjamin Scott, Pei Zhuang, Niklas von Spreckelsen, Andrei Loas, Nina Hartrampf, Bradley L. Pentelute and Sean E. Lawler.
Background: Glioblastoma (GBM) is the most common and deadliest malignant primary brain tumor, contributing significant morbidity and mortality among patients. As current standard-of-care demonstrates limited success, the development of new efficacious GBM therapeutics is urgently needed. Major challenges in advancing GBM chemotherapy include poor bioavailability, lack of tumor selectivity leading to undesired side effects, poor permeability across the blood–brain barrier (BBB), and extensive intratumoral heterogeneity. Methods: We have previously identified a small, soluble peptide (BTP-7) that is able to cross the BBB and target the human GBM extracellular matrix (ECM). Here, we covalently attached BTP-7 to an insoluble anti-cancer drug, camptothecin (CPT). Results: We demonstrate that conjugation of BTP-7 to CPT improves drug solubility in aqueous solution, retains drug efficacy against patient-derived GBM stem cells (GSC), enhances BBB permeability, and enables therapeutic targeting to intracranial GBM, leading to higher toxicity in GBM cells compared to normal brain tissues, and ultimately prolongs survival in mice bearing intracranial patient-derived GBM xenograft. Conclusion: BTP-7 is a new modality that opens the door to possibilities for GBM-targeted therapeutic approaches.