Effect of piezoelectricity of nanocomposite electrospun scaffold on cell behavior in bone tissue engineering

Piezoelectric materials can generate electrical activity under deformation. Various types of these materials have been used for tissue regeneration, especially in bone repair, in which the charges caused by mechanical stress can increase bone formation. Designing polymeric scaffolds with mechanical and biological properties similar to the extracellular matrix is an important approach in tissue engineering. Therefore, developing nanofiber scaffolds that mimic the extracellular matrix is a positive step toward the formation of new functional tissue. In the present study, we aimed to fabricate a nanofiber scaffold with piezoelectric properties, containing hydroxyapatite particles. Initially, the optimum conditions for electrospinning of the composite fibers were determined from the combination of poly-capro-lactone (PCL), poly-vinylidene fluoride (PVDF) and hydroxyapatite (HA). Then, the effect of mechanical strain on voltage generation was investigated and the piezoelectric property of the scaffolds was calculated. Finally, the behavior of cells (MG63) on the scaffolds was evaluated. The PVDF/PCL/HA scaffold showed an approximate 20% increase in piezoelectric properties compared to a PCL scaffold. Similarly, the three-component scaffold (PVDF/PCL/HA) revealed significant improvement in cell adhesion and function compared to the PCL counterpart and presented almost 12% growth in alkaline phosphatase activity and mineralization. Overall, the results showed that the PVDF/PCL/HA scaffold has the features to induce the proper function of bone cells and satisfy the necessities of bone tissue engineering. To the best of the authors’ knowledge, the simultaneous effect of PVDF and PCL with HA nanoparticles in the form of nanofibers has not yet been investigated and it is considered a novelty in this aspect, in which the presence of poly-capro-lactone as a companion polymer seems to improve the degradation of scaffolds. Graphical abstract