Improving the Hydrophilicity of the Drugs Paclitaxel, Violacein, and Tetrandrine Using Carbon-Based Quantum Dots

Carbon-based quantum dots and their nitrogen- and sulfur-doped derivatives were used as platforms to improve the aqueous solubility for Paclitaxel, Violacein and Tetrandrine, drugs with known high partition coefficients (Log P). Paclitaxel, Violacein and Tetrandrine showed a significant reduction in their partition coefficient values by coupling with the carbon-based quantum dots. Paclitaxel's partition coefficient value decreased from 3.96 to 0.2, Violacein's from 3.34 to 1.17, and Tetrandrine's from 2.5 to 1.57, thus demonstrating a significant reduction in their hydrophobicity without being encapsulated. The efficiency of each type of carbon-based quantum dot in lowering each drug's Log P varied and this behavior was correlated with the nature of the surface interaction between each drug and each of the carbon-based quantum dots.