Promoting Cell Migration and Neurite Extension along Uniaxially Aligned Nanofibers with Biomacromolecular Particles in a Density Gradient

A simple method based upon masked electrospray is reported for directly generating both unidirectional and bidirectional density gradients of biomacromolecular particles on uniaxially aligned nanofibers. The method has been successfully applied to different types of biomacromolecules, including collagen and a mixture of collagen and fibronectin or laminin, to suit different types of applications. Collagen particles in a unidirectional or bidirectional gradient are able to promote the linear migration of bone marrow stem cells or NIH-3T3 fibroblasts along the direction of increasing particle density. In the case of particles made of a mixture of collagen and fibronectin, their deposition in a bidirectional gradient promotes the migration of Schwann cells from two opposite sides toward the center, matching the scenario in peripheral nerve repair. As for a mixture of collagen and laminin, the particles in a unidirectional gradient promote the extension of neurites from embryonic chick dorsal root ganglion in the direction of increasing particle density. Taken together, the scaffolds featuring a combination of uniaxially aligned nanofibers and biomacromolecular particles in density gradient can be applied to a range of biological studies and biomedical applications.