Synergistic anticancer effect of Doxorubicin and Tamoxifen in chitosan nanoparticles for ER-positive breast cancer

Abstract

Chemotherapeutics/preventive nanomedicines such as Doxorubicin (DOX) (a DNA-intercalating topoisomerase II inhibitor), and Tamoxifen (TAM) (a selective estrogen receptor modulator (SERM)), are among the commonly used therapeutics to eradicate cancer. The non-specificity of DOX towards non-cancerous cells, systemic toxicity, and drug resistance have made researchers look for alternative modes of chemotherapy. This research focuses on the development and evaluation of dual drug (DOX and TAM) loaded chitosan (Chi) nanoparticles (Chi-Dox-Tam Nps) and a hybrid dual nanoparticles-in-alginate microsphere system (DNM) synthesized using a facile ultrasonic atomization-led spray-ionic gelation method. The functional and morphological characterization of Chi-Dox-Tam Nps and DNM was performed using various techniques including dynamic light scattering (DLS), zeta potential measurement, scanning electron microscopy (SEM), absorption spectroscopy, in-vitro drug release, and confocal laser scanning microscopy (CLSM). Particle sizing results indicated the size of Chi-Dox-Tam Nps to be ∼150 nm, whereas the DNM had a size of ∼5 μm. The DOX and TAM release from the Chi-Dox-Tam Nps was found to be 100 % and 60 % of the loaded drugs, respectively, at the end of 7 days. However, the release profile of DOX and TAM from DNM was recorded to be 80 % and 62 % of the loaded drugs, respectively, at the end of 14 days, highlighting prolonged sustained release of drugs suitable for chronic nature of cancer treatment. The in-vitro efficiency of the synthesized nanoparticles against MCF-7 cells were assessed by cellular uptake study, cytotoxicity assay, nuclear-cytoskeleton morphology assessment, live/dead cellular assay, ROS generation potential, and apoptosis assay. The Chi-Dox-Tam Nps substantially inhibited the growth of MCF-7 cells in 48 h, whereas DNM showed no significant cytotoxicity during the same incubation period owing to its slow-release profile. Moreover, the Chi-Dox-Tam Nps encapsulated with DOX and TAM (2:1) demonstrated better synergistic effects in comparison to the other ratios. This study demonstrates that the dual drug nanoparticle constructs enhance the anticancer efficacy in comparison with mono-drug therapy. The study addresses the escalating concern of efficacy, drug resistance and systemic toxicity by providing an innovative strategy for sustained dual drug delivery in a biocompatible carrier. © 2025 Elsevier B.V.