Cysteamine hydrochloride protected carbon dots as a vehicle for the efficient release of the anti-schizophrenic drug haloperidol†
The use of phenylalanine derived non-toxic carbon dots (C-dots) as a vehicle for the delivery of widely used anti-psychotic drug haloperidol (HaLO) is described in the present research work. The C-dots were found to have remarkable optical properties and to exhibit bright green fluorescence under UV light (λex = 365 nm). The UV-Vis spectrum of the C-dots exhibits peaks at 232 and 276 nm confirming their synthesis in solution. The size of the C-dots was found to be in the range of 5–10 nm, as confirmed by Field Emission Scanning Electron Microscopy (FE-SEM). Cysteamine hydrochloride (CysHCl) was used as a non-toxic linker to functionalize the purified C-dots before grafting HaLO on the surface to facilitate the controlled release under physiological conditions. A constant release of HaLO was achieved for more than 40 h, which followed the Hixson–Crowell model under standardized conditions. The C-dot–CysHCl–HaLO conjugate was found to have a much higher compatibility with MDCK cells at pH 7.2 in comparison to bare HaLO.