Abstract P4-01-15: A high-throughput three-dimensional cell migration assay (BiO assay) for toxicity screening for breast cancer applications

Abstract

Abstract Common in vitro assays for drug toxicity screening are not accurate predictors of human in vivo toxicity as they are performed on two-dimensional (2D) surfaces that do not mimic native cellular environments. Three-dimensional (3D) cell culture systems, like magnetic levitation, offer representative culture environments, with spatial control to design assays for drug toxicity applications. In this study, a label-free 3D in vitro assay for high-throughput toxicity screening (BiO Assay) of breast cancer cells was developed. Confluent flasks of cancerous and non-cancerous mammary gland epithelial cells (MDA-231 and MCF-10A) were incubated overnight with a magnetic nanoparticle assembly, to which they bind. The next day, these cells were detached from the flask, and with the external application of a magnetic field, levitated to the air-liquid interface, where cells aggregated and interact to form larger 3D structures. These 3D structures were levitated for 24 hours to induce extracellular matrix formation. Afterwards, the structures were mechanically disrupted and patterned into rings using ring-shaped magnets. The magnetic field was removed, drugs, like doxorubicin, were added at varying concentrations, and the rings were allowed to close. This assay was validated against a 2D viability assay. A mobile device was programmed to capture the rings at specified timepoints, and image analysis was performed to track ring closure as a function of drug concentration and time. MDA-231s and MCF10As were successfully formed into 3D cultures using magnetic levitation, and patterned into rings. We found significantly different results in drug sensitivity between cells grown in 2D and 3D. In conclusion, the BiO Assay is a simple assay that measures drug toxicity in a culture system similar to the native cellular environment. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-01-15.