Electrospun nanofibrils embedded hydrogel composites for cell cultivation in a biomimetic environment

Abstract

Hybrid composites composed of nanofibrils and hydrogels were fabricated for cell cultivation in a cell-friendly environment mimicking the extracellular matrix. Electrospun fibrous mats composed of polycaprolactone (PCL) were digested to nanofibrils (NF) under optimized conditions and subsequently incorporated into hydrogels composed of gelatin and alginate. The hydrogel hybrids containing nanofibrils (NF/hydrogel) were calcium-crosslinked and solidified with or without cells. The mechanical properties of the cell-incorporated NF/hydrogels were dramatically increased in proportion to the NF content in the NF/hydrogels after 7 days of cultivation. Mass erosion of the NF/hydrogel was significantly attenuated when NF content increased. Confocal microscopy revealed that fibroblasts cultivated in NF/hydrogels showed superior adhesion behavior onto the matrix compared to those without NF, and the formation of spindle and stress fibers was distinct in NF/hydrogels with a high NF content. Cells on NF/hydrogels showed higher levels of collagen synthesis as NF content increased. Thus, NF/hydrogels are expected to serve as a cell culture matrix facilitating cell–matrix interactions by combining supportive nanofibrils and hydrogels.