Surface-Acoustic-Wave (SAW)-Driven Device for Dynamic Cell Cultures

Abstract

In the last few decades, new types of cell cultures have been introduced to provide better cell survival and development, with micro- and nanoenvironmental physicochemical conditions aimed at mimicking those present in vivo. However, despite the efforts made, the systems available to date are often difficult to replicate and use. Here, an easy-to-use surface-acoustic-wave (SAW)-based platform is presented for realizing dynamic cell cultures that is compatible with standard optical microscopes, incubators, and cell-culture dishes. The SAW chip is coupled to a standard Petri dish via a polydimethylsiloxane (PDMS) disc and consists of a lithium niobate (LN) substrate on which gold interdigital transducers (IDTs) are patterned to generate the SAWs and induce acoustic streaming in the dish. SAW excitation is verified and characterized by laser Doppler vibrometry, and the fluid dynamics is studied by microparticle image velocimetry (μPIV). Heating is measured by an infrared (IR) thermal camera. We finally tested this device with the U-937 monocyte cell line for viability and proliferation and cell-morphological analysis. The data demonstrate that it is possible to induce significant fluid recirculation within the Petri dish while maintaining negligible heating. Remarkably, cell proliferation in this condition was enhanced by 36 ± 12% with respect to those of standard static cultures. Finally, we show that cell death does not increase and that cell morphology is not altered in the presence of SAWs. This device is the first demonstration that SAW-induced streaming can mechanically improve cell proliferation and further supports the great versatility and biocompatibility of the SAW technology for cell manipulation.

Vibration enhanced cell growth induced by surface acoustic waves as in vitro wound-healing model

“…After the successful verification of the positive impact of SAWs on cell growth in previous studies (14,20), we now elucidate adjustment parameters of the observed effect. In the first approach, we identified an increased cell growth of SaOs-2 cells up to 15.2 ± 1.7% using RWs at λ SAW = 25 μm and P IN = 4 mW (14).…”

High Frequency Sonoprocessing: A New Field of Cavitation‐Free Acoustic Materials Synthesis, Processing, and Manipulation

“…Besides providing a means for enhancing flow perfusion and hence cell culture, the ability of the SAW‐induced streaming, [ 147 ] and, in particular, microcentrifugation flow discussed previously in Section 2.2.1 can also be exploited to selectively concentrate (or, conversely, disperse) cells in a suspension (Figure 6c). This effect was employed for the assembly of embryoid bodies leading to the formation of cell spheroids (Figure 6d)—3D spherical cell aggregates displaying cell–cell and cell–matrix interactions, which more closely mimic in vivo avascular tumor structure and functionality—whose size can be tuned through the input SAW power and hence the flow intensity.…”

The waves that make the pattern: a review on acoustic manipulation in biomedical research

“…Acoustic streaming describes a steady flow of particles within a fluid that can be observed as continuous movement through the medium rather than an assembly in defined positions. The streaming strongly depends on the applied frequency and amplitude, as well as the particle size and fluid depth [ 16 , 35 ]. Specifically, acoustic streaming can be reduced by diminishing the chamber height [ 36 ] and scales negatively with the particle size [ 37 ].…”

“…Using a conventional IDT-LiNbO 3 setup to induce SAW, Greco et al. [ 35 ] stimulated suspension growing monocyte cells (U-937) for 48 ​h at 50 ​MHz. Different from many other studies, the authors highlight the importance of studying side-effects (wanted or non-wanted) that acoustic waves might have.…”