Modulating Active Living Cell Networks with focused ultrasound

Focused ultrasound (FUS) has emerged as a precise, non-contact physical modality for neuromodulation, cancer mechanotherapy, and mechanobiology at sub-thermal intensities. However, current in vitro platforms that provide repeatable acoustomechanical loading to standard cultureware are still limited or expensive. In this context, we present an economical, portable "lid-style" FUS generator that can be capped to 35 mm culture dishes, maintains the transducer–cell distance with sub-millimeter precision, and couples through a thin fluid layer to prevent flow artifacts. No microbubbles were utilized, and an on-off pulsing control is used to minimize thermal drift. 

Utilizing GL261 murine glioma monolayers as an example, we investigated whether low-intensity FUS influences injury-evoked intercellular Ca²⁺ waves during scratch-wound assays. Calcium activity was monitored using Calbryte fluorescence at video rate and quantified as ΔF/F₀. By adjusting the intensity and frequencies of FUS, a more comprehensive map of calcium signal modulation is revealed.

These findings suggest that low-intensity FUS provides a tunable, non-invasive method for modulating collective Ca²⁺ signaling in glioma sheets while preserving network excitability. The lid-style actuator reduces barriers to systematically mapping parameter–response relationships (pressure, PRF, duty) in standard cell-culture formats.

Keywords: focused ultrasound; intercellular calcium waves; mechanotransduction; portable actuator