The physical properties of a fibrillar fibronectin-fibrinogen material with potential use in tissue engineering

Previous work has shown that orientated fibrous fibronectin-based materials can be useful in tissue repair and tissue engineering. The aim here was to characterise the basic material properties of a comparable orientated fibr onectin-rich aggregate which is amenable to large scale production. Fine pr otein cables, diameter 150-200 mu m, consisting of both fibronectin and fib rinogen in an approximately 2:1 molar ratio may be drawn from a cryoprecipi tate-derived protein solution. The composition of the cables was found to d epend on the ratio of the two proteins in the starting solution. The cable formation was associated with a reduction in the pH of the solution to betw een 4.0 and 4.5. Scanning electron microscopy of the cables showed that eac h one was composed of micron-diameter fibrils giving the material ultrastru ctural orientation. The cables possess moderate tensile strength (61 N/mm(2 )) and displayed hygroscopic properties. Due to their natural composition, strict fibre alignment and the cell adhesive properties of fibronectin thes e cables form an effective template to orientate cells during tissue repair . Their properties and method of formation show promise for the scale-up of production.