The control of cell orientation using biodegradable alginate fibers fabricated by near-field electrospinning

For spatially controlling cell alignment, near field electrospinning (NFES) was developed to direct-write alginate fiber patterns. Compared to randomly electrospun fibers, NFES fibers guided the extension of HEK 293T cells and the levels of cell alignment increased with decreasing fiber distances. However, these guiding fibers were unfavorable for cell adhesion and limited cell growth. To preserve cell alignment ability and improve biocompatibility, the stability of patterned alginate fibers was adjusted by regulating the level of ion crosslinking. These partially crosslinked NFES fibers demonstrated parallel line-patterns in the initial stage while gradually degraded with time. The reduction of fiber density increased the available area for cell growth and enhanced cell viability. On the other hand, aligned cells were still found on these degraded patterns, suggesting that cell morphologies were mainly guided during cell seeding. This dynamically controlled fiber pattern system fulfilled the need of controlling cell orientation and biocompatibility, thus was potential to modify scaffold surfaces for tissue engineering application.