Open access to novel dual flow chamber technology for in vitro cell mechanotransduction, toxicity and pharamacokinetic studies

Abstract

Background: A major stumbling block for researchers developing experimental models of mechanotransduction is the control of experimental variables, in particular the transmission of the mechanical forces at the cellular level. A previous evaluation of state of the art commercial perfusion chambers showed that flow regimes, applied to impart a defined mechanical stimulus to cells, are poorly controlled and that data from studies in which different chambers are utilized can not be compared, even if the target stress regimes are comparable.

Mechanical modulation of osteochondroprogenitor cell fate

“…shear stress τ) predicted to occur in the embryo at the time that mesenchymal stem cells commit to a specific lineage [Anderson and Knothe Tate 2007a]. In addition, recent studies address the disparity between target and actual stresses imparted by devices that use fluid flow to impart shear stresses to cells seeded within [Anderson et al 2004, Anderson et al 2006, Anderson and Knothe Tate 2007b, introducing a further element of variability into experimental design. Finally, interpretation of data from studies designated to elucidate the role of mechanical signals in modulating fate is further confounded by inclusion of biochemical factors in the growth media, which introduces an additional independent extrinsic variable into the study design (Table 1).…”

“…Mechanical signals can be used to transduce biophysical forces as well as to define gradients of biochemical factors with the aim to modulate their mesenchymal stem cell differentiation and the subsequent formation of targeted tissue types. Mechanical signals can be controlled and delivered either within a perfusion chamber [Anderson and Knothe Tate 2007b] and/or within a scaffold structure [Anderson and Knothe Tate 2007a]. Application of shear stress via fluid drag over primary embryonic osteochondroprogenitor cells dissociated from the murine limb bud at E11.5 demonstrates a key role for β-catenin in transduction of mechanical signals during condensation [Falls 2007].…”

“…A body of literature documents the role of biochemical signals in determining cell fate during embryonic development [Thompson 1917, Turing 1952, Katagiri et al 1990, Schofield and Wolpert 1990, Chen et al 1991, Izumi et al 1992, Freeman and Gurdon 2002, Shea et al 2003, Derfoul et al 2004, Bielby et al 2004, Vogel and Sheetz 2006, Kawakami et al 2006. However, neither the biophysical signals experienced by multipotent progenitor cells during development nor the specific nature of biophysical signals conducive to guiding these cells toward specific cell lineages is well characterized [Anderson and Knothe Tate 2007a, Anderson and Knothe Tate 2007b, Falls 2007. For more than a century, scientists have hypothesized that biophysical signals including mechanical stimuli modulate cell lineage commitment and the formation of specific tissue types during development [Thompson 1917, Carey et al 1922, Pauwels 1960, Oster et al 1983, Oster et al 1985, Carter and Wong 1988, Estes et al 2004.…”

“…In the past few decades, computational models have predicted the role of mechanical [Oster et al 1983, Oster et al 1985, Carter and Wong 1988 and biophysical forces [Oster et al 1983, Oster et al 1985 on morphogenesis, yet the mechanism by which these stimuli drive uncommitted stem cells to differentiate into specific cell lineages remains a conundrum. Recent studies have demonstrated that embryonic stem cells are more mechanosensitive than differentiated cells from the same species [Oberhofer 2005, Falls 2007, McBride 2007, Anderson and Knothe Tate 2007a, Anderson and Knothe Tate 2007b. Furthermore, studies have demonstrated that biophysical mechanisms modulating fate decisions occur much earlier than previously thought [Hall and Miyake 2000].…”

“…in the sea urchin, a subset of mesenchymal cells "inserts between the cells of the ectodermal wall in order to firmly anchor" and provide an absolute reference point for the skeletal template during differentiation [Spiegel and Spiegel 1992]. Such absolute reference points would provide pivotal positional information to multipotent mesenchymal cells during prenatal vertebrate development, when biophysical cues arising from ground reaction forces are not yet relevant Knothe Tate 2007a, Anderson andKnothe Tate 2007b].…”