A Review on Different Approaches for Improving Cell Infiltration in Electrospun Nanofibrous Scaffolds

In recent years, electrospinning with capability to form polymeric nano /micro fibers has gained substantial attention to fabricate tissue engineering scaffolds. The morphological resemblance to native extracellular matrix (ECM), high surface to volume ratio, high porosity and pore interconnectivity are amongst the most brilliant features of electrospun structures. The high surface area to volume ratio and interconnected pores of these fibrous meshes confer desirable cell attachment and growth. However, due to small pore sizes and high packing density of electrospun nanofibers, cell penetration into a conventional electrospun mat is completely restrained. Scarce cell infiltration in turn prohibits cell migration into internal parts of scaffold, causes inhomogeneous cell distribution throughout the structure, limits vascularization and impedes tissue ingrowth. In fact, traditional electrospun nanofibrous scaffolds in practice act as two-dimensional (2D) surfaces, rather than 3D microenvironments. So far, a number of approaches have been employed to solve the mentioned problem ranging from simple variations in electrospinning parameters to intricate post-processing modifications. Some efforts directly manipulate the electrospun mat characteristics to enhance cell penetration, while others combine cells with scaffolds or encourage cells to migrate into internal parts with different stimuli. In present study, we have tried to provide an overview of different approaches offered for improving cell infiltration in electrospun scaffolds.