Effect of Different Biomimetic Fiber Density on Cellular Responses

In the field of tissue regeneration, electrospun fibers with the characteristics of biomimicking fibrous structure of the native ECM (extracellular matrix) could provide an ideal platform for exploring the dynamic remodeling process of cells in their residing microenvironment. However, the compactness of conventional electrospun fibrous mats with the nanoscaled fibers crisscrossing and entangling with each other, eventually leads to a topological phenomenon similar to that of the nanofiber-like topography embossed on the surface of a solid matter. Therefore, it is impossible to accurately determine the remodeling effect of cells on the biomimicking fibrous microenvironment. In this study, electrospun fibrous matrices of GT/PCL (gelatin/polycaprolactone) with varied fiber densities were prepared by varying the collecting time of the GT/PCL fibers deposited on prior-silanized glass slides. Then, the effects of fiber-density on the cytomorphology, proliferation, ECM secretion, and matrix degradation of the C3H/10T1/2 cells were examined by performing CCK-8 assay, cytoskeleton staining, SEM imaging, qRT-PCR, ELISA, and immunofluorescence staining. The results showed that the cell viability was correlated with the fiber-density, and there existed a suitable fiber-density (103.0±13.2) μg/cm2 from which cells remodeled the fibrous microenvironment effectively. This study paved the way for the precise design of biomimetic fibrous matrix for tissue regeneration and laid a foundation for furthering our understanding of cell-fiber interactions.