Purpose: Therapy for triple-negative breast cancer (TNBC) is a global problem due to lack of specific targets for treatment selection. Cancer stem cells (CSCs) are responsible for tumor formation and recurrence but also offer a promising target for TNBC-targeted therapy. Here, zirconium-89 (⁸⁹Zr)-labelled multifunctional liposomes (MLPs) surface-decorated with chitosan (CS) were fabricated to specifically target and trace cluster of differentiation 44⁺ (CD44⁺) TNBC CSCs specifically.
Patients and Methods: The biological basis of CS targeting CD44 for cancer therapy was investigated by detecting the expression of CD44 in TNBC CSCs and TNBC tissues. Molecular docking and dynamics simulations were performed to investigate the molecular basis of CS targeting CD44 for cancer therapy. Gambogic acid (GA)-loaded, ⁸⁹Zr@CS-MLPs (⁸⁹Zr-CS-GA-MLPs) were prepared, and their uptake and biodistribution were observed. The anti-tumor efficacy of ⁸⁹Zr@CS-GA-MLPs was investigated in vivo.
Results: CD44 is overexpressed in TNBC CSCs and tissues. Molecular docking and dynamics simulations showed that CS could be stably docked into the active site of CD44 in a reasonable conformation. Furthermore, ⁸⁹Zr@CS-GA-MLPs were able to bind specifically to CD44⁺ TNBC stem-like cells and accumulated in tumors of xenograft-bearing mice with excellent radiochemical stability. ⁸⁹Zr@CS-GA-MLPs loaded with GA showed remarkable anti-tumor efficacy in vivo.
Conclusion: The GA-loaded, ⁸⁹Zr-labelled, CS-decorated MLPs developed in this study represent a novel strategy for TNBC imaging and therapy.
Keywords: radionuclide, PET, CS, CD44, molecular docking, molecular dynamics simulation