Nanocomposite of reduced nanographene oxide with β-lactoglobulin protein (rNGO/β-Lg) as a carrier of the anticancer drug oxaliplatin (Eloxatin)

In this study, reduced nanographene oxide (rNGO) together with β-lactoglobulin (β-Lg) protein is used for better and more effective encapsulation, loading and release of oxaliplatin (OXP) drug in colon tumor cells. Drug distribution, loading and encapsulation on graphene oxide/reduced β-lactoglobulin (rNGO/β-Lg) nanocomposite is investigated and confirmed by IR, Uv-Vis, fluorescence and zeta sizer analysis. The rNGO/β-Lg nanocomposite shows a promising loading capacity. So that the percentage of encapsulation and loading for the anticancer drug oxaliplatin is 70 % and 55 %, respectively, and the results show that the penetration and diffusion mechanism is non-Fickian diffusion. Due to the electronic stereo resonance of the drug with the nanocomposite, rNGO/β-Lg@OXP has low toxicity in healthy tissues and higher toxic effects on colon cancer cells than the free oxaliplatin drug. The interaction mechanism of β-Lg with rNGO, drug loading and release on nanocomposite (rNGO/β-Lg@OXP) will be simulated and discussed by DFT method based on M06-2×/aug-cc-pVDZ-PP calculations. The calculation results show that β-Lg reacts on the rNGO surface by forming a π-π bond. The adsorption energy (Eads = −25.99 kcal.mol-1) and the calculated thermodynamic functions indicate a favorable interaction between them, which causes the formation of rNGO/β-Lg nanocomposite at ambient temperature. By encapsulating the drug by nanocomposite, the softness of the chemical structure of the drug and its reactivity have decreased and the synthetic stability has increased. The value of charge transfer (ΔNmax = −0.16)) calculated for rNGO/β-Lg@OXP indicates the transfer of electrons from the drug to the nanocomposite and the creation of stereo electronic resonance, hardening and stabilization of their geometric structure. It reduces the release rate of the drug and reduces its accumulation and toxicity in the body.