Doxorubicin-loaded methoxy-intercalated kaolinite as a repackaging of doxorubicin for an enhanced breast cancer treatment: in vitro and in vivo investigation

Abstract Doxorubicin is one of the most common wide-spectrum chemotherapeutics. However, its efficacy is limited due to off-target accumulation and selectivity issues. In this study, we compared the anti-cancer effect and biocompatibility of KaoliniteMeOH-Dox, a doxorubicin repackaging, to doxorubicin monotherapy. The formulation was extensively tested using transmission electron microscopy, dynamic light scattering, zeta potential, Fourier transform infrared, x-ray diffraction, and in vitro drug release. The MTT assay measured MCF-7 cell growth inhibition in vitro. In vivo testing involved 20 naïve mice and 40 Ehrlich solid tumor-inoculated mice. The tumor size was monitored for 18 days. In all experimental groups, tumor and cardiac tissues were evaluated for cytotoxicity and genotoxicity by addressing oxidative stress, histopathology, and comet assay. We found that kaoliniteMeOH-Dox has many advantages in terms of size, charge, shape, high loading efficiency (90.16%), and pH-dependent release. The MTT assay showed that the formulation outperformed doxorubicin in growth inhibition and selectivity. In vivo, research showed that kaoliniteMeOH-Dox suppressed tumors by 86.075% compared to 60.379% for free doxorubicin. Histological analysis showed that kaoliniteMeOH-Dox reduced tumor size, metastasis, and carcinogenic oxidative stress and inflammation in mice without harming naive mice. Based on the obtained data, the kaoliniteMeOH-Dox formulation holds promise for breast cancer treatment and warrants further investigation.