Affiliation: Department of Biological Sciences, Kharazmi University, Tehran, Iran.
We developed a drug-delivery system comprising a novel platinum drug (Pt(II) complex) entrapped within β-Casein (β-CN) nanoparticles referred to as nano-vehicles. Fluorescence spectroscopy, UV-Vis spectrometry, dynamic light scattering (DLS), and scanning electron microscopy (SEM) were used to characterize the β-CN-Pt(II) complex . What was apparent in this study was that the solubility of Pt (II) complex increased in the presence of β-CN. Furthermore, fluorescence spectroscopy results revealed the binding of the β -CN micelle to the platinum complex at pH 7.0. The tryptophan fluorescence intensity further revealed that the optimal loading molar ratio of β-CN: Pt (II) complex was 1:3 (with β-CN at 1 mg/mL). Under these conditions, the optimal nano-vehicle was formed based on the DLS results. Results from the DLS and SEM analyses are proof for the formation of the β-CN-Pt(II) complex nanoparticles with a very good colloidal stability and an average particle size of 250 nm. Finally, the cytotoxicity of free- and encapsulated-Pt (II) complex was evaluated using colorectal carcinoma HCT116 cells, as a cancer model cell line, because platinum drugs have been used mostly for treatment of Gastrointestinal cancers. Results indicated that the cytotoxicity and cellular uptake of the drug was enhanced when entrapped in β -CN nanoparticles. Polymeric micelles are internalized into the cells via fluid-state endocytosis. These findings suggest that β-CN is an excellent nano-vehicle for targeted delivery of platinum drugs, which are generally recognized as safe (GRAS) and potentially useful in pharmaceutical industries.