Preparing substrates encoding cell patterning and localized intracellular magnetic particle stimulus for high-throughput experimentation

Magnetic particles, beyond the simple cell sorting and drug delivery applications for which they are typically known, have become a powerful tool in permitting remote control of biological activity. While this functionality is traditionally accomplished by linking particles to extracellular, membrane localized moieties (such as ion channels and integrins), the intracellular stimulation of cells via magnetic nanoparticles has recently shown to be a unique and powerful method by which to spatially polarize cell behavior. More traditional magnetic stimulation approaches, whereby single magnetic tweezers or permanent magnets are placed in proximity to cells growing on substrates lack resolution, control, and scalability. Conventional single cell-patterning approaches, while having large precision and scalability, typically allow the evaluation of the response of cells to only their immediate extracellular, protein environment. Here, we detail the protocol combining the above approaches to resolve the problems hampering many biomagnetic studies. By integrating the scalability and resolution of traditional silicon microfabrication with modern surface patterning capabilities, we demonstrate a method of conducting thousands of biomagnetic experiments in parallel, whereby individual cells with designed, patterned matrix are subjected to controlled, repetitive magnetic stimulus introduced by electroplated, micromagnetic elements.