A novel technique for the fabrication of 3D nanofibrous scaffolds using simultaneous positive voltage electrospinning and negative voltage electrospinning

Electrospinning is a very attractive technology for fabricating nanofibrous structures. However, for potential tissue engineering applications, the conventional eleetrospinning technique can only produce 2D nanofibrous membranes with limited thickness. In this investigation, a novel technique, which involved simultaneous positive voltage electrospinning (PVES) and negative voltage electrospinning (NVES), was developed for constructing 3D nanofibrous scaffolds with greatly increased thickness. Using a specially designed electrospinning device, the problem of attraction and agglomeration of oppositely charged fibers in mid-air during simultaneous PVES and NVES could be avoided. As a demonstration and for comparison, two types of polymers, polyvinyl alcohol and poly(D,L-lactic acid), were processed into fibrous scaffolds using conventional and novel electrospinning techniques, respectively. For each polymer, the novel technique rendered the formation of 3D fibrous scaffolds that could not be achieved via conventional electrospinning. The polymer type, applied voltage and scaffold fabrication technique were critical factors affecting the thickness of nanofibrous scaffolds. The mechanism for 3D scaffold formation was proposed. (C) 2012 Elsevier B.V. All rights reserved.