Evaluation of Doxorubicin-loaded Echogenic Macroemulsion for Targeted Drug Delivery

Background: The latest technology trend in targeted drug delivery highlights stimuliresponsive particles that can release an anticancer drug in a solid tumor by responding to external stimuli.Objective: This study aims to design, fabricate, and evaluate an ultrasound-responsive drug delivery vehicle for an ultrasound-mediated drug delivery system.Methods: The drug-containing echogenic macroemulsion (eME) was fabricated by an emulsification method using the three phases (aqueous lipid solution as a shell, doxorubicin (DOX) contained oil, and perfluorohexane (PFH) as an ultrasound-responsive agent). The morphological structure of eMEs was investigated using fluorescence microscopy, and the size distribution was analyzed by using DLS. The echogenicity of eME was measured using a contrast-enhanced ultrasound device. The cytotoxicity was evaluated using a breast cancer cell (MDA-MB-231) via an in vitro cell experiment.Results: The obtained eME showed an ideal morphological structure that contained both DOX and PFH in a single particle and indicated a suitable size for enhancing ultrasound response and avoiding complications in the blood vessel. The echogenicity of eME was demonstrated via an in vitro experiment, with results showcasing the potential for targeted drug delivery. Compared to free DOX, enhanced cytotoxicity and improved drug delivery efficiency in a cancer cell were proven by using DOX-loaded eMEs and ultrasound.Conclusion: This study established a platform technology to fabricate the ultrasound-responsive vehicle. The designed drug-loaded eME could be a promising platform with ultrasound technology for targeted drug delivery.