Biophysical and biological evaluation of free and liposomal doxorubicin and β-carotene reveals enhanced therapeutic selectivity in MCF-7 breast cancer cells

Breast cancer remains a major health challenge, highlighting the need for more effective and safer therapies. Although doxorubicin is widely used, its clinical utility is limited by oxidative stress–induced toxicity. This study investigated β-carotene and doxorubicin co-delivery in free and liposomal forms using multiple soy lecithin-based formulations. Physicochemical characterization was performed using FTIR spectroscopy, TEM, DLS, zeta potential analysis, and DSC. Biological evaluation was conducted in MCF-7 cells using cytotoxicity assay, apoptosis assay, cell cycle analysis, and comet assay.while cytotoxic selectivity was further assessed by IC50 determination in non-tumorigenic MCF-10A breast epithelial cells. The prepared liposomes showed a uniform spherical morphology, narrow size distribution, and favorable physicochemical stability. Free doxorubicin demonstrated potent anticancer activity against MCF-7 cells (IC50 = 2.46 µg/mL), but was associated with significant apoptosis and DNA damage. liposomal doxorubicin showed moderated cytotoxicity (IC50 = 4.73 µg/mL), consistent with a controlled release profile. Notably, the co-delivery of β-carotene and doxorubicin in liposomes reduced cytotoxic potency (IC50 = 9.98 µg/mL), associated with inducing G2/M cell cycle arrest and apoptosis while reducing genotoxic effects. Liposomal β-carotene and empty liposomes exhibited minimal cytotoxicity. In MCF-10A cells, all liposomal formulations and β-carotene showed negligible toxicity (IC50 > 100 µg/mL), whereas free doxorubicin was highly toxic (IC50 ≈ 5 µg/mL). This toxicity was partially reduced when combined with β-carotene (IC50 ≈ 20 µg/mL). Overall, these findings suggest that liposomal co-delivery of β-carotene and doxorubicin may enhance therapeutic efficacy while potentially reducing off-target toxicity.