Low intensity mechanical signals promote proliferation in a cell-specific manner:Tailoring a non-drug strategy to enhance biomanufacturing yields

Biomanufacturing relies on living cells to produce biotechnology-based therapeutics,tissue engineering constructs,vaccines,and a vast range of agricultural and industrial products.With the escalating demand for these bio-based products,any process that could improve yields and shorten outcome timelines by accelerating cell proliferation would have a significant impact across the discipline.While these goals are primarily achieved using biological or chemical strategies,harnessing cell mechanosensitivity represents a promising–albeit less studied–physical pathway to promote bioprocessing endpoints,yet identifying which mechanical parameters influence cell activities has remained elusive.We tested the hypothesis that mechanical signals,delivered non-invasively using low-intensity vibration(LIV;<1 g,10–500 Hz),will enhance cell expansion,and determined that any unique signal configuration was not equally influential across a range of cell types.Varying frequency,intensity,duration,refractory period,and daily doses of LIV increased proliferation in Chinese Hamster Ovary(CHO)-adherent cells(t79%in 96 hr)using a particular set of LIV parameters(0.2 g,500 Hz,330 min/d,2 hr refractory period),yet this same mechanical input suppressed proliferation in CHO-suspension cells(13%).Another set of LIV parameters(30 Hz,0.7 g,260 min/d,2 hr refractory period)however,were able to increase the proliferation of CHO-suspension cells by 210%and T-cells by 20.3%.Importantly,we also reported that T-cell response to LIV was in-part dependent upon AKT phosphorylation,as inhibiting AKT phosphorylation reduced the proliferative effect of LIV by over 60%,suggesting that suspension cells utilize mechanism(s)similar to adherent cells to sense specific LIV signals.Particle image velocimetry combined with finite element modeling showed high transmissibility of these signals across fluids(>90%),and LIV effectively scaled up to T75 flasks.Ultimately,when LIV is tailored to the target cell population,it's highly efficient transmission across media represents a means to noninvasively augment biomanufacturing endpoints for both adherent and suspended cells,and holds immediate applications,ranging from small-scale,patient-specific personalized medicine to large-scale commercial biocentric production challenges.