Surgical removal of brain tumors necessitates a high degree of accuracy in safeguarding healthy tissue, particularly eloquent regions. In addition to existing neuronavigational techniques, quantum sensing technologies, which employ highly sensitive magnetic sensors based on nitrogen vacancies (NV) in diamonds, can be used. However, concerns have been raised regarding the safety of the sensor's application, which relies on the usage of additional microwave (MW) frequencies, particularly with the use of 2.86GHz. Further investigation is essential to evaluate the potential impact of MW on human neural tissue.

A tailor-made configuration comprised of a millimeter-wave (MMW) antenna situated beneath in-vitro cultures (Microglia, Astrocytes, and GBM cells) at 1 mm. The cultures were exposed to MW at 2.86 GHz at 15 watts, selected based on a dosing curve, with exposure durations of 5/30 mins, followed by a 24-hour post-incubation period to investigate long-term effects. Functional changes to cells and network architecture were assessed using an established calcium imaging pipeline. A customized cell segmentation and analysis pipeline facilitated morphometric analysis and lactate dehydrogenase (LDH) cytotoxicity assays were conducted to assess the potential cytotoxic effects.

Morphometric analysis revealed no significant changes in morphology or cellular distribution post-MW exposure. Functional calcium signaling analysis revealed no changes in signaling activity nor network architectures due to exposure to MW. Our results reveal that exposure to MW at the chosen settings did not lead to a significant change in cytotoxicity across all studied cell types.

The overall results of our study allowed us to determine safe MW limits for brain-based applications, with multimodal measurements including cellular motility, morphology, signaling, and cytotoxicity.