Lipid-Coated Iohexol-Carbon Dots for Sonodynamic Therapy of 4T1 Cancer Cells

Sonodynamic therapy is an emerging treatment method that involves non-invasive ultrasound (US) to locally generate lethal reactive oxygen species (ROS) in combination with sonosensitizers. Carbon dots (CDs) are in high demand for therapeutic applications due to their sonodynamic activity and intrinsic fluorescence imaging capabilities, making them well-suited for the generation of ROS. In this study, we synthesized red fluorescent carbon dots (RCDs) from Clitoria ternatea plant leaves using a hydrothermal technique. RCDs’ hydrophobic nature mainly leads to their rapid clearance and poor biodistribution, which limits their therapeutic potential. Further, Iohexol and RCDs were encapsulated in liposomes (LIRCDs) using the rotary evaporation method to improve their biodistribution and therapeutic efficiency. LIRCDs emit fluorescence at 674 nm with a shoulder peak at 725 nm. Hydrodynamic size, determined by dynamic light scattering (DLS), is around 178 nm. Transmission electron microscopy (TEM) analysis shows spherical RCDs with an average size of 10 nm and LIRCDs with an average size of 50 nm. In vitro analysis was also conducted to investigate the multimodal properties of the theranostics via cellular uptake, US-mediated ROS generation, and cell cytotoxicity study. In summary, we developed multifunctional LIRCDs for imaging and US therapy for 4T1 cancer cell treatment.