On-site microfluidic analysis of combined and individual drug effects on breast cancer spheroids

Objective Investigate the synergistic cytotoxic effects of doxorubicin (DOX) and paclitaxel (PXT), as well as lactate dehydrogenase (LDH) release, in MCF-7 breast cancer spheroids cultured in an integrated microfluidic system.Significance This study highlights the potential of microfluidic 3D tumor models to identify synergistic chemotherapy combinations under physiologically relevant conditions, supporting their application in preclinical drug screening and personalized oncology.Methods A modular microfluidic device with reversible sealing was developed to culture MCF-7 spheroids under continuous flow. Outlet reservoirs enabled direct analysis of glucose consumption and LDH activity. Spheroids were treated with DOX or PXT alone (0.025–0.1 mg·mL−1) or in combination (DOX 0.050 or 0.070 mg·mL−1 with PXT 0.025 mg·mL−1). Cell viability and death mechanisms were evaluated after 180 minutes using Live/Dead fluorescence imaging and metabolic assays.Results Single-drug treatments showed limited cytotoxicity, whereas combined DOX and PXT reduced spheroid viability by approximately 80–85%, predominantly through apoptosis.Conclusion This microfluidic platform enhances physiological relevance and analytical efficiency in 3D tumor drug testing, representing a promising tool for preclinical chemotherapy evaluation.