Electrospinning of low density PCL fibers on SLS scaffold

Abstract

It was gathered from various studies that bimodal fibers are beneficial for cell behavior. By electrospinning thin Poly-ε-caprolactone (PCL) fibers on Selective Laser Sintering (SLS) scaffold, a similar bimodal effect of having both large and small size fiber diameters is achieved. The bimodal scaffold is then stacked together to form a 3-dimensional film. This is novel from the aspect that alternating layers of myocardial tissues and human umbilical vein endothelial cells (HUVEC) can be stacked together to mutually support each other along with the bimodal effects. In this study, PCL fibers were spun on a spinning mandrel collector and investigated to examine the effects of electrospinning parameters- acceleration voltage and feed rate on fiber diameter. Hence both small (0.5-1um) and large (8-10um) fibers were attempted to be spun by varying acceleration voltage and feed rate. A direct relationship between fiber diameter and acceleration voltage was not observed. Furthermore it was found that increasing feed rate beyond a certain threshold value, instead of producing larger fiber diameter, the reverse was resulted. The parameters to produce low density PCL scaffold of 0.5-1um diameter fibers were established to be acceleration voltage= 25kV, feed rate= 0.5ml/h, rotational speed= 1500rpm and time= 1min. On the other hand, electrospinning with the same duration of 1min produces a higher density scaffold while varying acceleration voltage to 15kV and feed rate of 10ml/h; 8-10um fibers were obtained. Overall, the objectives of this study to fabricate a low density PCL scaffold and examine the relationship of fiber diameter with acceleration voltage and feed rate were achieved.