Preparation and characterization of a piezoelectric poly (vinylidene fluoride)/nanohydroxyapatite scaffold capable of naproxen delivery

Abstract Piezoelectric polymers are of great interest because of their ability to produce temporary surface electric charge, which can have a positive impact on the growth, attachment and proliferation of osteoblastic cells. The aim of this study was to combine potential osteoinductive properties of piezoelectric PVDF with the excellent bioactivity of nHA. In this regard, PVDF/nHA composite scaffolds were fabricated via a solvent casting/particulate leaching (SC/PL) method. The composite scaffold at 5 wt% nHA was annealed for 5 h at 60 °C and 90 °C in order to induce α to β phase transformation. Naproxen (NAP) was chosen as a reference drug and was complexed with beta-cyclodextrin (βCD) to form an inclusion complex (NAP-βCD-IC). Both NAP and NAP-βCD-IC were incorporated into PVDF solution during the fabrication process. The results showed that pore size and porosity both increased with the addition of nHA up to 5 wt%. The compressive modulus and strength of the scaffolds was increased with increasing nHA content in the composite. Fourier transform infrared (FTIR) spectroscopy confirmed increased β phase content due to annealing, and a higher increment was achieved for samples annealed at 90 °C. Superior cell viability was observed in the sample with a higher amount of piezoelectric β phase compared with the as-prepared sample and the sample annealed at 60 °C. The release profile of NAP from the PVDF/nHA composite scaffold showed that the formation of NAP-βCD inclusion complexes increased the rate and amount of NAP release from the scaffold.