The dynamics of surface acoustic wave‐driven scaffold cell seeding

Abstract

Flow visualization using fluorescent microparticles and cell viability investigations are carried out to examine the mechanisms by which cells are seeded into scaffolds driven by surface acoustic waves. The former consists of observing both the external flow prior to the entry of the suspension into the scaffold and the internal flow within the scaffold pores. The latter involves micro-CT (computed tomography) scans of the particle distributions within the seeded scaffolds and visual and quantitative methods to examine the morphology and proliferation ability of the irradiated cells. The results of these investigations elucidate the mechanisms by which particles are seeded, and hence provide valuable information that form the basis for optimizing this recently discovered method for rapid, efficient, and uniform scaffold cell seeding. Yeast cells are observed to maintain their size and morphology as well as their proliferation ability over 14 days after they are irradiated. The mammalian primary osteoblast cells tested also show little difference in their viability when exposed to the surface acoustic wave irradiation compared to a control set. Together, these provide initial feasibility results that demonstrate the surface acoustic wave technology as a viable seeding method without risk of denaturing the cells.

Effect of surface acoustic waves on the viability, proliferation and differentiation of primary osteoblast-like cells

“…The nature of the SAW substrate and the IDTs was described in our previous studies. 13,15 Figure 1͑a͒ ͑model 10W1000C, 0.5-1000 MHz, Amplifier Research, USA͒ were used to generate the electrical signal input via bus bars to the IDT electrodes to efficiently convert the electrical signal into a traveling SAW propagating away from the IDT along the x axis. For SAW-driven cell seeding, a scaffold was first placed on the surface of the SAW device.…”

“…However, the work used particles, not live cells, let alone the kinds of cells that would be typically used in tissue engineering, a distinct shortcoming as the deleterious effect of ultrasound on cells is well known. Though in a later work 15 we reported the infusion of yeast cells with some cursory results on the viability of primary-like osteoblast cells postexposure to the SAW radiation, we did not consider their viability in detail, nor did we consider the far more important issue of whether such cells remain functional postexposure and are able to form useful tissue. This is the focus of this work.…”

Cytocentrifugation: a convenient and efficient method for seeding tendon-derived cells into monolayer cultures or 3-D tissue engineering scaffolds

“…A number of approaches have been used to address this problem all with some degree of success. These include the use of magnetic particles (Shimizu et al 2006(Shimizu et al , 2007, perfusion (Dai et al 2009;Maidhof et al 2010), acoustic waves (Bok et al 2009;Li et al 2007) and, similar to the approach of this laboratory, centrifugation (Godbey et al 2004;Roh et al 2007;Ng et al 2010). All of these have demonstrated an improved ability to deliver cells to the centre of 3-D cell culture scaffolds and the choice of method would probably be dependent on other factors including cost, simplicity, selectivity and sterility.…”

Ultrasound assisted particle and cell manipulation on-chip

“…One relevant application of ultrasound is for enhancing the seeding of tissue engineering scaffolds. Surface acoustic waves can be used to generate acoustic streaming within a cell-containing droplet, to drive that droplet to a porous scaffold, and then use the acoustically induced flow to improve the penetration of the cells within the scaffold [88,89].…”