Improving Offset Electrospinning for the Tendon-Bone Junction

The tendon-bone junction, also known as the enthesis, is crucial for properly transferring mechanical loadings during physical activity. During injury, current restoration procedures are insufficient for properly restoring tissue function. Thus, it is paramount to design alternative tissue engineered scaffolds to act as a template to the injured region and a regenerative response for tendon-bone repair. Thus, we utilized an offset electrospinning technique to fabricate a scaffold that mimics the native biochemical gradients present within the tendon-bone junction. To improve chemical gradient resolution, we implemented both insulating and conductive shields during offset electrospinning. Polycaprolactone fibers with either rhodamine or fluorescein were used to measure the scaffold fluorescent strength with distance. Without shields, at an offset of 4 cm, the chemical gradient resolution for rhodamine and fluorescein were 2.5 cm and 6.0 cm, respectively. During implementation of insulating shields, the gradient resolution for rhodamine and fluorescein improved to 2 cm and 0.5 cm, respectively. Lastly, grounded conductive shields improved gradient resolution for rhodamine and fluorescein to 1.0 cm and 1.5 cm, respectively.