4th Generation Biomaterials Based on PVDF-Hydroxyapatite Composites Produced by Electrospinning: Processing and Characterization

Abstract

Biomaterials that effectively act in biological systems, as in treatment and healing of damaged or lost tissues, must be able to mimic the properties of the body’s natural tissues in its various aspects (chemical, physical, mechanical and surface). These characteristics influence cell adhesion and proliferation and are crucial for the success of the treatment for which a biomaterial will be required. In this context, the electrospinning process has gained prominence in obtaining fibers of micro- and nanometric sizes from polymeric solutions aiming to produce scaffolds for tissue engineering. In this manuscript, poly(vinylidene fluoride) (PVDF) was used as a polymeric matrix for the manufacture of piezoelectric scaffolds, exploring the formation of the β-PVDF piezoelectric phase. Micro- and nanometric hydroxyapatite (HA) particles were incorporated as a dispersed phase in this matrix, aiming to produce multifunctional composite membranes also with bioactive properties. The results show that it is possible to produce membranes containing micro- and nanofibers of the composite by the electrospinning process. The HA particles show good dispersion in the polymer matrix and predominance of β-PVDF phase. Also, the composite showed apatite growth on its surface after 21 days of immersion in simulated body fluid (SBF). Tests performed on human fibroblasts culture revealed that the electrospun membranes have low cytotoxicity attesting that the composite shows great potential to be used in biomedical applications as bone substitutions and wound healing.

Hydroxyapatite-filled osteoinductive and piezoelectric nanofibers for bone tissue engineering

“…A comparable approach was taken by Tandon et al (2019), which fabricated HAp filled PVDF nanofibers with two distinct HAp concentrations (5% and 10%) and performed a physicochemical characterization of the generated scaffolds without addressing their biocompatibility [ 51 ]. More recently, dos Santos et al (2022) developed similar PVDF/HAp nanofibers with a wider range of HAp nanoparticle concentrations (0–20%) [ 52 ]. By using PVDF instead of PVDF-TrFE, however, the piezoelectricity of the resulting scaffolds is expected to be lower, as this PZP comprises an intrinsically higher α-phase and reduced β-phase content (more thermodynamically favorable) comparatively to its derivative PVDF-TrFE.…”

Biocompatible Piezoelectric PVDF/HA/AgNO3 Thin Film Prepared by the Solvent Casting Method

“…Due to the amorphous phases, the interpretation of the size of the nanocrystallites by X-ray diffraction was not possible, but in the SEM image for sample 1 and 2, the spherical HA with a diameter of ~25 and 5 µm, respectively, can be predicted compared to the pure PVDF. It is worth mentioning that by Cotica et al HA:PVDF composite was prepared based on an electrospinning process and the HA particles were nucleated on the PVDF, and HA played a role as reinforcement [ 50 ]. Furthermore, the similarity of the images of samples 1 and 2 is related to the similar composition of these composites.…”

Multi-Parametric Exploration of a Selection of Piezoceramic Materials for Bone Graft Substitute Applications

“…As possible candidates for designing macro-porous scaffolds based on piezoelectric composites, one can mention: collagen, silk, cellulose, chitosan, polyhydroxybutyrate (PHB), poly(L-lactide) (PLLA), polyamide-11, poly(vinylidene fluoride) (PVDF) and its co-polymers poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) and poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) [30,64,[88][89][90][91]. Amongst them, PVDF-based materials are perhaps the most promising, possessing the highest piezoelectric coefficients (i.e., situated in the range of 24-38 pC/N, depending on composition), and furthermore being already tested successfully in bone-related applications in both single form [30,88,92] and coupled with piezoelectric (e.g., BT [93][94][95][96][97]) or bioactive (e.g., hydroxyapatite [98][99][100]) ceramics, both in vitro [93][94][95][98][99][100][101] and in vivo [96,97,102,103].…”