Electrospun PVA/HAp nanocomposite nanofibers: biomimetics of mineralized hard tissues at a lower level of complexity

Abstract

Based on the biomimetic approaches the present work describes a straightforward technique to mimic not only the architecture (the morphology) but also the chemistry (the composition) of the lowest level of the hierarchical organization of bone. This technique uses an electrospinning (ES) process with polyvinyl alcohol (PVA) and hydroxyapatite (HAp) nanoparticles. To determine morphology, crystalline structures and thermal properties of the resulting electrospun fibers with the pure PVA and PVA/HAp nanocomposite (NC) before electrospinning various techniques were employed, including transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). In addition, FT-IR spectroscopy was carried out to analyze the complex structural changes upon undergoing electrospinning as well as interactions between HAp and PVA. The morphological and crystallographic investigations revealed that the rod-like HAp nanoparticles exhibit a nanoporous morphology and are embedded within the electrospun fibers. A large number of HAp nanorods are preferentially oriented parallel to the longitudinal direction of the electrospun PVA fibers, which closely resemble the naturally mineralized hard tissues of bones. Due to abundant OH groups present in PVA and HAp nanorods, they strongly interact via hydrogen bonding within the electrospun PVA/HAp NC fibers, which results in improved thermal properties. The unique physiochemical features of the electrospun PVA/HAp NC nanofibers prepared by the ES process will open up a wide variety of future applications related to hard tissue replacement and regeneration (bone and dentin), not limited to coating implants.

Influence of Glyoxal in the Physical Characterization of PVA Nanofibers

“…Pure PVA melting temperature (T m ) is about 220-225º C as literature reports [13,14,21,22]. Table 2 provides the results obtained from the preliminary analysis of our samples.…”

“…DSC curves were obtained using a DSC Where ΔH c represents the crystallization enthalpy and ΔH 100 is the heat of crystallization for a 100% crystalline PVA, ΔH 100 =138.6 J/g (from literature) [21,22].…”

Synthesis and character investigation of new collagen Hydrolysate/polyvinyl alcohol/hydroxyapatite Polymer-Nano-Porous Membranes: I. Experimental design optimization in thermal and structural properties

“…This shift might be attributed to the interactions between PVA molecules and HA particles (Asran et al 2010). Also the spectra of PVA adsorbed on HA clearly influence the recovering of the carbonyl-stretching region (Kim et al 2008). In CH-PVA/ HA nano porose membrane (Fig.…”

“…In CH-PVA/HA nano composites, the surface of HA nanoparticles will contact with the CH and PVA molecules to make a coordination bond between Ca 2? and RCOO -in CH molecules and a strong interact between the hydroxyl groups on the surface of HA and PVA hydrophilic molecules (Chang and Tanaka 2002a, b;Ficai et al 2009;Kim et al 2008;Peng and Kong 2007). These reactions were influenced on tertiary weight loss stage of CH-PVA blend materials.…”

“…PVA, as a safe component, has been cleared by the United States Food and Drug Administration (FDA) (Lindemann 1971). Also, preparation of PVA/HA blends has been reported to exploit the advantages of both materials (Kim et al 2008). COL-PVA/HA composite materials have been poorly studied in the literature (Asran et al 2010;Degirmenbasi et al 2006;Kobayashi et al 2004;Poursamar et al 2009).…”