Two- and three-dimensional piezoelectric scaffolds for bone tissue engineering.

The incidence of bone disorders worldwide is increasing. For this reason, new and more effective strategies for bone repair are needed. The most common strategy used for cell regeneration relies in biochemical stimulation while biophysical stimulation using mechanical, and electrical cues is a promising, however, still under-investigated field. This work reports on the development of piezoelectric 2D and 3D porous scaffolds for bone tissue regeneration strategies. While the porous scaffolds mimic the bone's structure, the piezoelectric activity of the scaffolds mimics the bone mechano-electric microenvironment. The piezoelectric activity is related to the electroactive β-phase of poly(vinylidene fluoride) (PVDF) in the scaffolds and was dynamically stimulated by cell culture in a custom-made mechanical bioreactor. These two factors combined provide an effective biomimetic environment for the proliferation of preosteoblasts. The electromechanically-responsive scaffolds are found to promote the enhancement of proliferation rate of MC3T3-E1 osteoblastic cells in about 20 % as well as an improved adhesion and proliferation over the materials, mainly when dynamically stimulated. These results prove that local piezoelectric effect, as the one existing in bone tissue, allows effective cell proliferation, which could be further translated in more efficient strategies for bone tissue regeneration.