Biomolecular interactions and diffusion of curcumin-loaded carbon dots in live cells: implications for drug delivery

Abstract

Drug delivery systems for transporting hydrophobic drugs are of considerable importance for targeting molecules to specific sites of live cells. Carbon dots (CDs) are promising drug delivery systems because of their biocompatibility, low toxicity, and better stability for improved cellular uptake. The synthesis of drug-loaded CDs using a greener approach and their applications in biology are attracting considerable attention nowadays. Here, we report an eco-friendly method for the synthesis of CDs and their application to carry a hydrophobic drug, curcumin, in live cells. In addition, the molecular interactions of curcumin-loaded CDs (C-CDs) with partially unfolded BSA were demonstrated by steady-state and time-resolved fluorescence resonance energy transfer (FRET). The real-time diffusion dynamics and cellular uptake kinetics of C-CDs were studied by raster image correlation spectroscopy (RICS) and live-cell imaging, respectively. The antibacterial efficacy and cytotoxicity of C-CDs were determined via an MTT-based assay and minimum inhibitory concentration (MIC) analysis. Our findings provide a greater insight into the integrated application of C-CDs for drug delivery and bioimaging.