The effect of fiber alignment and heparin coating on cell infiltration into nanofibrous PLLA scaffolds

Biodegradable nanofibers simulate the fibril structure of natural extracellular matrix, and provide a cell-friendly microenvironment for tissue regeneration. However, the effects of nanofiber organization and immobilized biochemical factors on cell infiltration into three-dimensional scaffolds are not well understood. For example, cell infiltration into an electrospun nanofibrous matrix is often limited due to relatively small pore size between the fibers. Here we showed that biophysical and biochemical modification of nanofibrous scaffolds facilitated endothelial cell infiltration in three-dimensional scaffolds in vitro and in vivo. Aligned nanofibers significantly enhanced cell infiltration into the nanofibrous matrices in vitro. In a full-thickness dermal wound model, the nanofiber scaffolds enhanced epidermal skin cell migration across the wound when compared to a control group without scaffold. Aligned nanofibers promoted the infiltration of endothelial cells into the scaffolds. Furthermore, heparin-coated nanofibers also increased cell infiltration significantly. These results shed light on the importance of biophysical and biochemical properties of nanofibers in the regulation of cell infiltration into three-dimensional scaffolds and tissue remodeling.