Music for cells? Rhythmic mechanical stimulations of cell cultures

Abstract

This dissertation investigates how acoustic parameters and musical elements can be generated and manipulated to induce beneficial mechanical stimulations and alterations in cell cultures. The research has been conducted as part of a life science convergence environment, and the theoretical framework and experimental method in this dissertation are derived from three different disciplines: biology, music technology, and physics. The theoretical discussions centre around biological cell sensing mechanisms, the physical limitations and potentiality of audible sound to be used as mechano-acoustic cellular stimuli, and the concept of rhythm from biology and music technology perspectives. The methods include audio signal processing, physical characterisation of the experimental setup, various biological assays, and microscopic image feature extraction. Such a radically interdisciplinary approach culminated in laboratory experiments involving sound vibrations of human cell cultures using a vertical vibration system controlled by synthesized audio signals. The experimental variables included: No Vibration (NV, control), Continuous Vibration (CV), Regular Pulse (RP), and Variable Pulse (VP). The CV condition was categorised as non-rhythmic in this dissertation, while RP and VP were categorised as rhythmic conditions. The results demonstrate alterations in F-actin filament structure (length, thickness, angle) and the tendency of increased levels of cells in the G1-phase cell cycle in vibrated cell cultures. The “effect” was more apparent under the non-rhythmic (CV) condition than rhythmic conditions (RP and VP). The results also show that F-actin filament structural properties are negatively correlated (r < -.9), and the number of cells in the G1-phase cycle is positively correlated (r > .9) in relation to the magnitudes of mechanical parameters (RMS acceleration and shear stress). Nevertheless, the biological mechanism(s) responsible for the observed effects has yet to be characterised. The results from this dissertation inspire further studies on the effects of rhythmic mechanoacoustic stimulation on cellular biological rhythms (e.g., regulation of CLOCK, PER, and CRY genes).