Assessment of cell alignment by fibronectin multi-fibre cables capable of large scale production

The repair of damaged human tissue will be enhanced greatly by a capacity t o organise the arrangement of the cells. We have demonstrated an approach t o quantifying the capacity of fibronectin multi-fibre cables to align human cells. It is based on staining and subsequent image analysis of cells in t he neighbourhood of the cables, and the application of an Orientation Index (S), to give a quantitative measure of alignment of the cells. Alignment of human dermal fibroblasts, parallel to the fibronectin cable ax is, was observed by light microscopy after 3 days in culture. At 7 days, al ignment was determined by image analysis after hematoxylin and eosin staini ng. This showed that the lateral extent of cell alignment i.e. the number o f cell layers lined up beside a cable, termed the cell docking band width, was independent of cable diameter. Scanning electron microscopy confirmed c ell alignment and the deposition of fine collagen fibrils by the cells. Ori entation of cells to the cable, as measured by an orientation index (S), wa s S = 0.97 +/- 0.05 in cell docking bands denoting almost perfect alignment . Cell seeding levels ranging from 14 K cells/cm(2) up to 54 K cells/cm(2) resulted in cell docking band widths of aligned cells from 335 mu m to 890 mu m respectively, increasing as a function of cell seeding levels. This me thod represents a quantitative measure of quality for potential contact gui dance materials. The guidance system is capable of large-scale manufacture.