Electrospinning fabrication of high-trackable catheter tip with gradually graded or gradient flexibility

Increasing demand for a flexible catheter tip exists in the rapidly growing fields of vascular and interventional radiology. This article describes a fabrication technology producing a catheter tip with gradually graded or gradient flexibility. Based on deflection mechanics of a tubular construct, three models were incorporated into structural designs. The models included graded wall thickness, tapered shape, or graded Young's moduli. Electrospinning using elastomeric polymer [poly(L-lactide-co-epsilon-caprolactone), polyurethane] solutions on a transversely and rotationally moving mandrel enabled preparation of three prototype tubular tips by either regio-specific control of wall thickness, tapered mandrel, or regiospecific deposition of polyurethanes with different Young's moduli. All prototype tips exhibited high flexibility at tip ends, as verified using a bifurcated vessel model.