Dual ligand functionalized pH-sensitive liposomes for metastatic breast cancer treatment: in vitro and in vivo assessment

This research demonstrates the design and development of a novel dual-targeting, pH-sensitive liposomal (pSL) formulation of 5-Fluorouracil (5-FU), i.e., (5-FU-iRGD-FA-pSL) to manage breast cancer (BC). The motivation to explore this formulation is to overcome the challenges of systemic toxicity and non-specific targeting of 5-FU, a conventional chemotherapeutic agent. The proposed formulation also combines folic acid (FA) and iRGD peptides as targeting ligands to enhance tumor cell specificity and penetration, while the pH-sensitive liposomes ensure the controlled drug release in the acidic tumor microenvironment. The physicochemical characterization revealed that 5-FU-iRGD-FA-pSL possesses optimal size, low polydispersity index, and favorable zeta potential, enhancing its stability and targeting capabilities. In vitro studies demonstrated significantly enhanced cellular uptake, cytotoxicity, and inhibition of cell migration in MCF-7 BC cells compared to free 5-FU and non-targeted liposomal formulations. DAPI staining revealed significant apoptotic features, including chromatin condensation (CC) and nuclear fragmentation (NF), with 5-FU-iRGD-FA-pSL inducing more pronounced apoptosis compared to 5-FU-pSL. Furthermore, in vivo analysis in a BC rat model showed superior anti-tumor efficacy, reduced systemic toxicity, and improved safety profile of the 5-FU-iRGD-FA-pSL formulation. This dual-targeting pSL system presents a promising approach for enhancing the therapeutic index of 5-FU, offering a potential strategy for more effective BC treatment.