Effects of small and rapid temperature oscillations on adherent cell cultures: Exposure system, experimental method and a pilot study on human cancer cells

We present an original and simple system to aseptically incubate multiple adherent cell cultures simultaneously in a static and/or rapid oscillating temperature environment while monitoring the cell culture surface temperature in real-time. Additionally, in a pilot study, we show how exposure with this system to small (Temp _varying $$\le 2.5 ^{\circ}$$C _peak-to-peak ) and rapid (Freq = $$ \frac{1}{7} $$-$$ \frac{1}{25} $$ Hz) oscillations about a static temperature (Temp _static = $$37.0^{\circ} $$C) limits the growth rate of human fibrosarcoma cell cultures (HT1080), to the extent not seen by exposure to static temperatures in the same range and causing no apparent damage to cells. Additionally, the magnitude of the growth rate limitation depends on the thermal oscillation frequency, and its manifestation depends on specific experimental parameters such as culture seeding concentration and time point of observation. Although further scrutiny of the mechanism of action behind the effects here reported must be performed, we hypothesize that these effects may be due to the periodic stimuli affecting the functioning of cellular autonomous biochemical oscillators and processes. This experimental regime and initial findings may help expand on the current knowledge of the effects of small and rapid energy deposition regimes causing oscillatory thermal exposures on biological systems, with possible implications in therapeutic, cell culture and regulatory arenas.