The impact of rheology of human fibronectin-fibrinogen solutions on fibre extrusion for tissue engineering

Fibronectin-fibrinogen composite materials form a basis for natural constructs for applications in soft tissue engineering including skin repair, blood vessel replacement and nerve regeneration. Scaleable methods for the preparation of such scaffolds are a prerequisite for their widespread use. Here, we report data on the extrusion of fibronectin-based constructs in the form of fibres. The results suggested that events occurring in the extrusion head and coagulation bath were critical in determining the ultimate mechanical strength of the extruded fibres. These events were controlled by interaction between the theology of the dope, the geometry of the extrusion device and the operating parameters of the extrusion process. The rheology of the dope was successfully controlled by incorporation of sodium alginate, and urea was added to the formulation to produce oriented fibres. We previously reported that oriented fibronectin fibres have the capacity to induce desirable cell responses. Measurements indicated that for a given formulation, the mechanical properties and morphological features depended on the diameter of the extruded fibre, the rate of shear in the extrusion pipe and the time of exposure to it. (C) 2002 Elsevier Science Ltd. All rights reserved.