Process control of electrospinning artificial fenestrated capillary vessels

Abstract

Rapid fabrication of capillary vessels is important for tissue engineering because local perfusion and oxygen exchange within the tissue depend on the network of capillaries which have diameters ranging from 5 to 10 µm. Fenestrated capillaries are microvessels that have surface pores of 80 to 100 nm in diameter. These capillaries are essential for many organs, such as small intestines, endocrine glands, and kidneys. In this paper, we presented a wet coaxial electrospinning technique for the rapid fabrication of porous microtubes as artificial fenestrated capillaries using polycaprolactone and polyethylene oxide. We characterized the effects of process parameters on the morphological features of these microtubes by regression modeling. Our study shows that the flow rate ratio of the core/sheath solutions and the viscosity of the sheath solution play a significant role in the outside diameter, wall thickness, and hollow area of the microtubes. In addition, the formation of surface pores is dominated by the humidity during the electrospinning. At the same humidity level, the size of the surface pores is positively correlated with the viscosity of the sheath solution and the outside diameter of the microtubes. Overall, this study established the process-property relationship for wet coaxial electrospinning of artificial fenestrated capillaries.