Effect of tension on collagen arrangement / 中华创伤杂志

ABSTRACT

Objective To study the effect of mechanical tension on collagen arrangement and illustrate the relationship between tissue architecture and tension properties. Methods Cell morphologies, orientation and collagen arrangement of fibroblasts cultured in three different types of collagen gels with variation of mechanical tension were observed by phase contrast photomicrographs, light microscopy and transmission electron microscopy. Expression and distribution of a-smooth muscle actin (α-SMA) were investigated by immunohistochemistry. Results Phase contrast photomicrographs, light microscopy and transmission electron microscopy showed high level of tension distributed anisotropically in the monolayer gels and the anchored collagen gels, with bipolar shape of the fibroblasts, obvious polarity, arrangement of exogenous collagen fibres parallel to the long axis of the fibroblasts, especially prominent in monolayer gels. Low level of tension distributed isotropically was observed in floating collagen gels, with stellate morphology and arrangement of exogenous collagen fibres in a reticular array. Immunofluorescence showed that fibroblasts expressed high level of α-SMA protein distributed along the long axis of fibroblasts in the monolayer gels and the anchored collagen gels, especially in former ones. In contrast, few expression of α-SMA protein was found in floating collagen gels. Cell morphologies and orientation, expression and distribution of α-SMA as well as collagen arrangement of fibroblasts in the monolayer gels and the anchored collagen gels were similar to those in granulation tissue, whereas floating collagen gels resembled normal dermis or remodelled tissues. Conclusions Tissue architecture or morphology of the dermis are corresponding to tension proporties. Different tissue architectures are closely correlated with particular tension proporties.