The effect of combined cyclic mechanical stretching and microgrooved surface topography on the behavior of fibroblasts

Abstract

Under the influence of mechanical stress, cultured fibroblasts have a tendency to orient themselves perpendicular to the stress direction. Similar cell alignment can be induced by guiding cells along topographical clues, like microgrooves. The aim of this study was to evaluate cell behavior on microgrooved substrates, exposed to cyclic stretching. We hypothesized that cellular shape is mainly determined by topographical clues. On basis of earlier studies, a 10-microm wide square groove, and a 40-microm wide V-shaped groove pattern were used. Smooth substrates served as controls. Onto all substrates fibroblasts were cultured and 1-Hz cyclic stretching was applied (0, 4, or 8%) for 3-24 h. Cells were prepared for scanning electron microscopy, immunostaining of filamentous actin, alignment measurements, and PCR (collagen-I, fibronectin, alpha1- and beta1-integrins). Results showed that cells aligned on all grooved surfaces, and fluorescence microscopy showed similar orientation of intracellular actin filaments. After 3 h of stretch, cellular orientation started to commence, and after 24 h the cells had aligned themselves almost entirely. Image analysis showed better orientation with increasing groove depth. Statistical testing proved that the parameters groove type, groove orientation, and time all were significant, but the variation of stretch force was not. Substrates with microgrooves perpendicular to the stretch direction elicit a better cell alignment. The expression of beta1-integrin and collagen-I was higher in the stretched samples. In conclusion, we can maintain our hypothesis, as microgrooved topography was most effective in applying strains relative to the long axis of the cell, and only secondary effects of stretch force were present.

The effect of combined hypergravity and microgrooved surface topography on the behaviour of fibroblasts

“…The interaction between forces however remains poorly understood [Wang et al, 2003;Loesberg et al, 2005]. Therefore, the two aforementioned parameters, topography and (hyper)gravity, will be investigated in this study.…”

Remodeling of Engineered Tissue Anisotropy in Response to Altered Loading Conditions

“…In particular, a number of investigators have shown that the organization of most anchorage dependent cells may be impacted by principles of contact guidance, in which cells orient themselves in alignment with topographical cues from the substrate or other neighboring cells 23,33 . It has also been demonstrated that mechanical loading constraints can be used to guide cell and matrix alignment 2,13,14,21 . However, in most cases the loading and topographical cues are concomitant factors that act synergistically.…”

Mechanical Regulation of Fibroblast Migration and Collagen Remodeling in Healing Myocardial Infarcts

“…We obtained cell alignment data from 8 studies that plated cells on substrates with micro-ridges of varying height and pitch (Clark et al, 1990;Sutherland et al, 2005;Loesberg et al, 2005Kim et al, 2009;Pot et al, 2010;Sun et al, 2010;. The axis of cell alignment (mean angle) was parallel to the axis of ridge alignment.…”

“…Cells were either exposed to cyclic uniaxial stretch (Wang & Grood, 2000;Neidlinger-Wilke et al, 2001;Loesberg et al, 2005;Kaunas & Hsu, 2009) or plated on substrates etched with arrays of parallel micro-ridges (Clark et al, 1990;Sutherland et al, 2005;Kim et al, 2009;Pot et al, 2010;Sun et al, 2010). A handful of studies measured the alignment of cells plated on micro-ridged substrates and subjected to cyclic uniaxial stretch (Wang & Grood, 2000;Wang et al, 2004Wang et al, , 2005Loesberg et al, 2005), but only one of these studies examined a range of conditions sufficient for useful analysis . Due to the scarcity of studies that reported sufficiently quantitative data, we included data for any cell type.…”

“…We obtained cell alignment data from 5 studies that applied 1Hz cyclic uniaxial strain at varying strain amplitudes to cells plated on elastic membranes (Wang & Grood, 2000;Neidlinger-Wilke et al, 2001;Loesberg et al, 2005;Kaunas & Hsu, 2009;. The axis of cell alignment (mean angle) was perpendicular to the axis of applied strain.…”