Piezoelectric biomaterials are considered to be able to mimic the electrophysiological microenvironment of natural bone tissue, thus enhancing the bone regeneration. However, the effects of heterogeneous electric potential gradient of piezoelectric biomaterials on their osteogenic performance still remain elusive, largely because of the challenge of harassing the distribution of electric potential gradient on the surface of piezoelectric biomaterials. This study controls the heterogeneous electric potential gradient on the CoFe 2 O 4 /poly(vinylidene fluoride-trifluoroethylene (CFO/P(VDF-TrFE)) membrane by using an alternatively positive–negative polarization processing on microscaled straight-stripe patterned indium tin oxide coated glass (ITO) electrodes. The potential gradient (Δ ζ ) on membranes can be controlled by the stripe width and polarization parameters. Interestingly, Δ ζ shows a significant influence on the cellular osteogenic potential of mesenchymal stem cells (MSCs) and the bone regeneration performance in vivo. The Δ ζ of 0.672 pm/(V*µm) shows the optimal osteogenic performance both in vitro and in vivo, which can be attributed to the boost of integrins α 5 β 1 expression as well as the orientated arrangement and contractility of the cytoskeletons via mechanotransduction signaling cascades. This work therefore shows the importance of heterogeneous electric potential and provides a novel strategy to accelerate the osteogenic performances of piezoelectric biomaterials.
Yan Xu,Mingwei Cheng,Peijun Zhu,Shuo Yang,Chunhua Lai,Shulan Xu
During bone tissue regeneration, neovascularization is critical, and the formation of a blood supply network is crucial for bone growth stimulation and remodeling. Previous studies suggest that bioelectric signals facilitate the process of angiogenesis. Owing to their biomimetic electroactivity, piezoelectric membranes have garnered substantial interest in the field of guided bone regeneration. Nevertheless, the knowledge of their influence due to varying surface potentials on the progression of angiogenesis remains ambiguous. Therefore, we proposed the preparation of an electroactive material, P(VDF-TrFE), and investigated its effects on the activity and angiogenic functions of human umbilical vein endothelial cells (HUVECs). The HUVECs were directly cultured on P(VDF-TrFE) membranes with different surface potentials. Subsequently, cell viability, proliferation, migration, tube formation, and expressions of related factors were assessed through appropriate assays. Our results revealed that the negative surface potential groups exerted differential effects on the modulation of angiogenesis in vitro. The P(VDF-TrFE) membranes with negative surface potential exhibited the greatest effect on cellular behaviors, including proliferation, migration, tube formation, and promotion of angiogenesis by releasing key factors such as VEGF-A and CD31. Overall, these results indicated that the surface potential of piezoelectric P(VDF-TrFE) membranes could exert differential effects on angiogenesis in vitro. We present a novel approach for designing bioactive materials for guided bone regeneration.