Piezoelectric Stimulation Induces Osteogenesis in Mesenchymal Stem Cells Cultured on Electroactive Two-Dimensional...

Area of Science:

• Biomaterials Science
• Stem Cell Biology
• Tissue Engineering

Background:

• Physical cues are effective inducers of osteogenic differentiation in mesenchymal stem cells (MSCs).
• Bone's extracellular matrix possesses electroactive properties, suggesting piezoelectric stimulation as a biomimetic approach.
• Combining piezoelectric polymers with magnetostrictive components enables cell stimulation via external magnetic fields.

Purpose of the Study:

• To investigate piezoelectric stimulation using magnetic fields as an osteogenic cue for MSCs.
• To develop and characterize piezoelectric films (PVDF and PVDF-CFO) for electromechanical stimulation.
• To evaluate the initial response and osteogenic differentiation of MSCs under stimulation.

Main Methods:

• Fabrication of poly(vinylidene fluoride) (PVDF) and PVDF-cobalt ferrite oxide (CFO) films using an ionic liquid ([Bmim][Cl]) for enhanced β-phase crystallization.
• Characterization of film properties, including phase percentage and crystalline content.
• Assessment of MSC biocompatibility, adhesion, proliferation, and cytoskeleton changes in response to static and stimulated conditions using a bioreactor.

Main Results:

• PVDF and PVDF-CFO films exhibited high percentages of the electroactive β-phase.
• Films were biocompatible and supported MSC adhesion and proliferation.
• Electromechanical stimulation of MSCs on PVDF-CFO films for 3 days resulted in longer focal adhesions and decreased vimentin density, indicative of early osteogenic differentiation.
• MSCs rearranged their energy metabolism towards an osteogenic phenotype after 7 days of stimulation.

Conclusions:

• Piezoelectric stimulation, particularly with PVDF-CFO films activated by magnetic fields, effectively induces osteogenic differentiation in MSCs.
• The developed material and method are biocompatible and demonstrate potential for bone tissue engineering applications.
• Electromechanical stimulation via magnetic fields offers a promising strategy for mimicking bone's electroactive properties to guide cell fate.