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

Abstract

The repair of damaged human tissue will be enhanced greatly by a capacity to organise the arrangement of the cells. We have demonstrated an approach to quantifying the capacity of fibronectin multi-fibre cables to align human cells. It is based on staining and subsequent image analysis of cells in the 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 axis, was observed by light microscopy after 3 days in culture. At 7 days, alignment was determined by image analysis after hematoxylin and eosin staining. This showed that the lateral extent of cell alignment i.e. the number of cell layers lined up beside a cable, termed the cell docking band width, was independent of cable diameter. Scanning electron microscopy confirmed cell alignment and the deposition of fine collagen fibrils by the cells. Orientation of cells to the cable, as measured by an orientation index (S), was S = 0.97 ± 0.05 in cell docking bands denoting almost perfect alignment. Cell seeding levels ranging from 14 K cells/cm2 up to 54 K cells/cm2 resulted in cell docking band widths of aligned cells from 335 μm to 890 μm respectively, increasing as a function of cell seeding levels. This method represents a quantitative measure of quality for potential contact guidance materials. The guidance system is capable of large-scale manufacture.