Piezoelectric PDMS/AlN Film for Osteogenesis in Vitro

Bone defect and nonunion are complex diseases which aredifficultto treat due to insufficient bone regeneration. Electrical stimulationhas attracted attention as a promising strategy to induce and enhancebone regeneration. Self-powered and biocompatible materials have beenwidely explored and used in biomedical devices, owing to their abilityto produce electrical stimulation without an external power source.We aimed to prepare a piezoelectric polydimethylsiloxane (PDMS)/aluminumnitride (AlN) film with excellent biocompatibility and osteoconductiveability for the growth of murine calvarial preosteoblast MC3T3-E1cells. By applying vibration to stimulate body movement, the PDMS/AlNfilm demonstrated a current density of 2-6 & mu;A cm(-2), and the generated continuous alternating current(AC) effectively promoted MC3T3-E1 cell growth, viability, and osteoblasticrelated gene expression (genes runt-related transcription factor 2[RUNX2], osteocalcin [OCN], alkalinephosphatase [ALP]) and exhibited higher mineralization.Compared to blank plates and nonvibrated PDMS/AlN films, the vibratedPDMS/AlN film showed rapid and superior osteogenic differentiation.The design of the biocompatible and flexible piezoelectric PDMS/AlNfilm overcame the poor processability, brittleness, and instabilityof electrical stimulation of traditional electroactive materials,demonstrating great potential in the application of electrical stimulationfor bone tissue engineering.