Poly(l-Lactic Acid) Nanofiber-Based Multilayer Film for the Electrical Stimulation of Nerve Cells

Poly(l-lactic acid) (PLLA) films have excellent piezoelectric properties, but the strong hydrophobicity of the surface makes it difficult for cells to attach there. PLLA nanofibers have good biocompatibility, but the weak piezoelectric coefficient limits the ability of the nanofibers to stimulate cell growth. Therefore, the PLLA piezoelectric film is combined with the PLLA nanofibers to make a multilayer film. In our tests, the piezoelectric output of the multilayer film approximate to 260 mV. In the biological experiments section, without piezoelectric stimulation, the cell length on the nanofibers is approximately twice that of the cells in the blank control group. The length of cells cultured on piezoelectric-based stimulated nanofibers is more than twice that of cells cultured on nanofibers without piezoelectric stimulation. Therefore, it is confirmed that under the dual action of nanofiber guidance and piezoelectric stimulation, the growth rate of cells is four times faster than that in ordinary Petri dishes. Intracellular calcium imaging experiments confirmed that the concentration of Ca2+ in electrically stimulated cells is approximately twice that of ordinary cells. It is also confirmed that piezoelectric materials can complete electrical stimulation of cells in indirect contact with cells.