Objective: Poor prognosis, drug resistance, and lower drug loading capacity of the delivery systems lead to therapeutic failures of breast cancers. Herein, we functionalized sodium caseinate nanomicelles (NaCNs) with the divalent calcium (Ca2+) and the glucose (Glc) to increase the loading capacity of micelles for higher cellular uptake and cytotoxicity against breast cancer cells.

Methodology: Modification of casein micelles was confirmed through Fourier transform infrared spectra (FTIR). Triple quadrupole liquid chromatography-mass spectrometry (TQOF-LCMS/MS) was utilized as a simple, rapid, and sensitive method for protein corona quantification around casein through SwissProt.Mus_musculus database and through de novo sequencing. Un-modified and modified casein micelles were further characterized through field emission scanning electron microscope (FESEM), high resolution-transmission electron microscope (HR-TEM), and energy-dispersive X-ray (EDX). Whereas, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used for protein separation and analysis during micelles formation.

Results: Calcium divalent modified sodium caseinate nanomicelles (Ca-NaCNs) and glucose-modified sodium caseinate nanomicelles (Glc-NaCNs) were successfully developed, demonstrating a significantly improved micellar stability. Glc-NaCNs-DOX showed a zeta size of 297.13 ± 15.66 nm with an improved zeta potential of -13.73 ± 0.579 with a drug loading efficiency (DLE) of 86% as compared to our previously published casein formulations since the modified versions involved more soluble casein in the protein micelle matrix, Whereas, Ca-NaCNs-DOX also showed an IC50 value of approximately 197.1 nm as compared to IC50 of free DOX (341.8 nm) and when compared to unmodified DOX loaded formulations (p < .001).

Conclusion: Modified NaCNs exhibit the potential to be investigated further as a novel delivery system for similar active moieties to maximize their therapeutic effects.