Graphene Oxide Reinforcement Enhances the Piezoelectric and Mechanical Properties of Poly(3-hydroxybutyrate-co-3-hydroxy valerate)-Based Nanofibrous Scaffolds for Improved Proliferation of Chondrocytes and ECM Production.

Abstract

The discovery of piezoelectricity in natural cartilage has inspired the development of piezoelectric biomaterials for its repair and regeneration using tissue engineering approaches. In the present work, piezoelectric scaffolds composed of poly(3-hydroxybutyrate-co-3-hydroxy valerate) (PB) and graphene oxide (GO) have been successfully fabricated by the electrospinning technology. The fabricated scaffolds were examined for their morphological, physical, chemical, piezoelectric, and biological characterizations. The fiber diameter was found to be in the range of 600-800 nm appropriate for chondrogenic growth. Reinforcement of 1.5% GO enhanced the tensile strength of PB to 2.08 ± 0.33 MPa compared to PB alone (0.59 ± 0.12). Reinforcement of GO significantly enhances the piezoelectric coefficient (d33), and for 0.5, 1, and 1.5% GO in PB, it was found to be 0.12 ± 0.015, 0.57 ± 0.19, and 0.94 ± 0.03 pC/N, respectively, and corresponding voltages of 11.84 ± 1.4, 54.69 ± 18.29, and 100.2 ± 3.2 mV, respectively, were generated. The biological activity of the smart piezo scaffolds was also evaluated on freshly isolated goat chondrocytes. The GO-reinforced scaffold showed higher cell proliferation and cell adhesion as confirmed by alamarBlue assay and field emission scanning electron microscopy imaging. The GO-reinforced scaffold has demonstrated significantly higher extracellular matrix production compared to PB as confirmed by histochemistry and real-time polymerase chain reaction. Hence, the GO-based piezoelectric PB electrospun scaffold can be a better alternative for cell-free and growth factor-free approach for cartilage tissue engineering.