Abstract
Bone exhibits piezoelectric properties. Thus, electrical stimulations such as pulsed electromagnetic fields (PEMFs) and stimuli-responsive piezoelectric properties of scaffolds have been investigated separately to evaluate their efficacy in supporting osteogenesis. However, current understanding of cells responding under the combined influence of PEMF and piezoelectric properties in scaffolds is still lacking. Therefore, in this study, we fabricated piezoelectric scaffolds by functionalization of polycaprolactone-tricalcium phosphate (PCL-TCP) films with a polyvinylidene fluoride (PVDF) coating that is self-polarized by a modified breath-figure technique. The osteoinductive properties of these PVDF-coated PCL-TCP films on MC3T3-E1 cells were studied under the stimulation of PEMF. Piezoelectric and ferroelectric characterization demonstrated that scaffolds with piezoelectric coefficient d33 = −1.2 pC/N were obtained at a powder dissolution temperature of 100 °C and coating relative humidity (RH) of 56%. DNA quantification showed that cell proliferation was significantly enhanced by PEMF as low as 0.6 mT and 50 Hz. Hydroxyapatite staining showed that cell mineralization was significantly enhanced by incorporation of PVDF coating. Gene expression study showed that the combination of PEMF and PVDF coating promoted late osteogenic gene expression marker most significantly. Collectively, our results suggest that the synergistic effects of PEMF and piezoelectric scaffolds on osteogenesis provide a promising alternative strategy for electrically augmented osteoinduction. The piezoelectric response of PVDF by PEMF, which could provide mechanical strain, is particularly interesting as it could deliver local mechanical stimulation to osteogenic cells using PEMF.
Highlights
Bone is the second most transplanted organ worldwide
Piezoelectric polycaprolactone-tricalcium phosphate (PCL-tricalcium phosphate (TCP)) films with d33 = −1.2 pC/N were developed by incorporating polyvinylidene fluoride (PVDF) as conformal piezoelectric coatings using a modified breath-figure method
The self-poling approach developed in this study represents a versatile solution for PVDF polarization at a low temperature when coated on material with low melting temperatures or complex structures such as macroporous three-dimensional scaffolds
Summary
The global bone substitute market was valued at USD 2.9 billion in 2019 and is expected to expand at 3% annually until 2030. PCL materials have rheological properties that allow them to be produced in various forms such as films, nanofibers, and macroporous 3D-printed scaffolds, being versatile in a variety of culture conditions, including small-scale culture plates and lab-scale bioreactors [6,7]. Bioactive ceramics such as β-tricalcium phosphate (TCP) can be incorporated into PCL for better osteogenesis and improved mechanical properties [8]. The release of calcium and phosphate ions grants the scaffolds cell chemotaxis, recruiting cells to grow in the implanted site [9]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
