Utilizing Magnetic Electrospinning to Create Gradients in Fiber Alignment for Interfacial Tissue Engineering

Heterogeneous tissues are composed of chemical and physical gradients responsible for transferring load from one tissue type to another, through the thickness or the length of the tissue. Musculoskeletal tissues include these junctions, such as the tendon-bone and ligament-bone, which consist of an alignment gradient through the length of the interfacial regions. These junctions are imperative for transferring mechanical loadings between dissimilar tissues. Engineering a proper scaffold that mimics the native architecture of these tissues to prompt proper repair after an interfacial injury has been difficult to fabricate within tissue engineering. Electrospinning is a common technique for fabricating nanofibrous scaffolds that can mimic the structure of the native extracellular matrix (ECM). However, current electrospinning techniques do not easily allow for the replication of the chemical and physical gradients present in musculoskeletal interfacial tissues. In this work, a novel magnetic electrospinning technique was developed to fabricate polycaprolactone (PCL) nanofibrous scaffolds that recapitulate the gradient alignment structure of the tendon-bone junction. When exposed to the natural magnetic field from a permanent magnet, PCL fibers innately aligned near the magnet with unalignment at distances further away from the magnetic field.