Vitamin C-driven epirubicin loading into liposomes

Area of Science:

• Nanomedicine
• Drug Delivery Systems
• Oncology

Background:

• Liposome encapsulation protects anticancer drugs, improving circulation and tumor accumulation.
• Conventional drug loading methods have limitations in efficiency and drug release kinetics.
• Vitamin C has shown potential synergistic effects with certain anticancer drugs.

Purpose of the Study:

• To develop and characterize a new active drug loading method for liposomes using a vitamin C pH/ion gradient.
• To evaluate the impact of this novel loading method on epirubicin (EPI) coencapsulation and anticancer activity.
• To compare the efficacy and pharmacokinetics of vitamin C gradient-loaded liposomes with conventional methods.

Main Methods:

• Characterization of liposome formulations for optimal external pH, loading time, drug-to-lipid ratio, and in vitro stability.
• Active drug loading of epirubicin (EPI) using a vitamin C pH/ion gradient.
• In vitro evaluation of anticancer activity against MCF-7 and 4T-1 breast cancer cells.
• In vivo testing in a murine 4T-1 breast cancer model.
• Cryogenic transmission electron microscopy for visualizing drug salt solubility and liposome structure.

Main Results:

• The vitamin C gradient method demonstrated efficient active loading of epirubicin (EPI).
• Coencapsulation of EPI with vitamin C potentially enhances anticancer activity through synergistic effects.
• Liposomes exhibited good stability and favorable pharmacokinetics with a half-life of 18.6 hours.
• Vitamin C gradient loading resulted in higher in vitro antitumor activity against breast cancer cells compared to ammonium sulfate gradient loading.
• In vivo studies confirmed significant tumor growth inhibition (>40%) with EPI liposomes, while free EPI showed no activity at the tested dose.

Conclusions:

• The novel vitamin C pH/ion gradient method offers an effective approach for active drug loading into liposomes.
• This method enhances anticancer drug efficacy and improves pharmacokinetic profiles.
• The vitamin C gradient system facilitates faster drug release at the tumor site, increasing overall therapeutic potential.