Synergistic Effect of PVDF-Coated PCL-TCP Scaffolds and Pulsed Electromagnetic Field on Osteogenesis

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.

Harnessing electromagnetic fields to assist bone tissue engineering

“…Their results showed that both the PVDF scaffold and PVDF/PANI scaffold had improved cell attachment and osteogenic differentiation under EMFs exposure, while the combination of EMFs and PVDF/PANI scaffold had a more significant effect [ 168 ]. Similar results were obtained by Dong et al [ 47 ], and they speculated that the mechanical stimulation resulting from the interplay between EMFs and PVDF-coated PCL-TCP scaffolds contributed to the well cellular response. The prominent effect of a combination of PVDF-based material and EMFs is inspiring and holds promises in the field of BTE.…”

“…Moreover, PEMF amplified the surface potential gradient of titanium implant [ 42 ]. Therefore, cations (mainly Ca 2+ ) and proteins/peptides with positive charges would adhere to the negatively charged surface owing to the electrostatic interaction [ 47 ]. Subsequently, integrin on cell membrane, the main mediator in cell–matrix adhesion, recognizes and binds to cell adhesion-mediated motifs such as arginine-glycine-aspartic acid (RGD), which are embedded in adsorbed proteins [ 48 , 49 ].…”

The Efficacy of Pulsed Electromagnetic Fields on Pain, Stiffness, and Physical Function in Osteoarthritis: A Systematic Review and Meta-Analysis

“…Pulsed electromagnetic field (PEMF) is viewed as a safe, noninvasive, and effective physical medicine and is a potential treatment for multiple diseases, including delayed wound healing and OA [ 9 ]. A recent study indicated that PEMF not only provides electrical stimulation piezoelectric scaffolds to transport partial mechanical impulses but also provides other functions of long-instance electrical impulses of cell proliferation and differentiation without partial potential of hydrogen alteration or reactive oxygen species creation [ 10 ].…”

Accelerated Degradation of Poly-ε-caprolactone Composite Scaffolds for Large Bone Defects

“…A similar trend was observed for the PCL scaffolds (showing an 11.64% weight loss at day 5 for scaffolds with a 200 μm pore size and a 13.37% weight loss at day 5 for scaffolds with a 500 μm pore size), which exhibited the lowest degradation kinetics. This can be explained by the increase in the surface area exposed to the NaOH that accelerates the hydrolytic degradation and the release into the liquid medium of the ceramic particles previously bonded with the polymeric material [ 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 ]. Results also indicate that, for the same material composition, bone bricks degrade slower compared with rectangular scaffolds.…”