Effects of Freezing on Cytoskeletal Structure of Fibroblasts in Engineered Tissues

Abstract

Successful preservation of functional cells and tissues are critical to cell/tissue engineering and regenerative medicines. One of the most reliable methods of cell/tissue preservation is cryopreservation; in which cells and tissues are frozen before storage and thawed when needed. Since the cellular viability and the microstructure of extracellular matrix (ECM) directly correspond to the functionality of a tissue, successful cryopreservation should maintain the extracellular matrix (ECM) microstructure as well as cellular viability post-thaw. A few recent studies [1,2] reported that complex cell-fluid-matrix interaction occurred during freezing of tissues, and this interaction might determine the post-thaw ECM microstructure and affect the cellular viability. These studies also suggested that the cells within tissues might exert or sense mechanical stress during freezing through the cytoskeleton connected to the ECM via cell-matrix adhesion complexes.

Role of intracellular poroelasticity on freezing-induced deformation of cells in engineered tissues

“…Then, we investigated the effect of the cytoskeletal structures on the cryoresponse of cells embedded in the ECM. For these experiments, dermal equivalents were prepared with fibroblasts and type I collagen so that the cytoskeletal structure of fibroblasts was modulated by embedding the cells on, between and in collagen matrices, as described previously [16,17]. These three different configurations were shown to generate different levels of stress fibre formation and cell morphologies [17,18].…”

“…For these experiments, dermal equivalents were prepared with fibroblasts and type I collagen so that the cytoskeletal structure of fibroblasts was modulated by embedding the cells on, between and in collagen matrices, as described previously [16,17]. These three different configurations were shown to generate different levels of stress fibre formation and cell morphologies [17,18]. The spatio-temporal deformation of the cells in the matrix was analysed, while the dermal equivalents were directionally frozen using a recently developed particle tracking deformetry [19].…”