Simultaneous Delivery of Oxali-palladium and Iron Nanoparticles by β-Casein

Abstract In the present study, Beta-Casein (β-CN) was employed for the drug delivery to diminish the Oxali-palladium (OX) side effects and enhanced its efficiency as an anti-cancer drug. Indeed, OX and iron nanoparticles (NP) interactions and binding states were investigated individually and competitively in an aqueous phase, while they are entrapped within β–CN. For this purpose, the distinct spectroscopic methods of fluorescence and Circular Dichroism (CD) were applied at two different temperatures of 25 and 37 °C. Moreover, the results of the fluorescence spectra of β–CN indicated that OX and NP could decrease the fluorescence intensity of β-CN in a dose-dependently via a dynamic quenching mechanism. Moreover, the examination of fluorescence quenching results in both temperatures indicated that there is one independent binding site on β-CN for binding to OX and another one for NP as well. Furthermore, the competitive binding parameters indicated no variations for any ligands due to the different degrees of binding sites on β–CN. Furthermore, analyzing thermodynamic parameters indicated that Van der Waals and hydrogen-bond interactions are significantly involved in binding the OX and NP to β-CN, respectively. Subsequently, it showed the decrement in β-CN solidity and its α-helical structure, significant change through its regular structure, and an enhancement in this protein’s structure of β-sheet with rising concentration OX and NP were confirmed by the examination of CD spectra. Based on the results, it is concluded that OX and NP's chemotherapeutic medicine can form a superb bind with β-CN protein using independent binding sites, which leads to considering β-CN to have a carrier role in synchronic delivery of both ligands.