A simple approach for synthesis, characterization and bioactivity of bovine bones to fabricate the polyurethane nanofiber containing hydroxyapatite nanoparticles

Abstract

In the present study, we had introduced polyurethane (PU) nanofibers that contain hydroxyapatite (HAp) nanoparticles (NPs) as a result of an electrospinning process. A simple method that does not depend on additional foreign chemicals had been employed to synthesize HAp NPs through the calcination of bovine bones. Typically, a colloidal gel consisting of HAp/PU had been electrospun to form nanofibers. In this communication, physiochemical aspects of prepared nanofibers were characterized by FE-SEM, TEM and TEM-EDS, which confirmed that nanofibers were well-oriented and good dispersion of HAp NPs, over the prepared nanofibers. Parameters, affecting the utilization of the prepared nanofibers in various nano-biotechnological fields have been studied; for instance, the bioactivity of the produced nanofiber mats was investigated while incubating in simulated body fluid (SBF). The results from incubation of nanofibers, indicated that incorporation of HAp strongly activates the precipitation of the apatite-like particles, because of the HAp NPs act as seed, that accelerate crystallization of the biological HAp from the utilized SBF.

Keywords: biocompatible polymers; nanomaterials.

Figure 1

Schematic diagram of a simple electrospinning spinning apparatus: (a) dc power supply (b) Syringe (e) Rotating collector (d) Electric motor

Figure 2

FE-SEM images for nanofibers that contain different amounts of HAp: 0% (a), 3% (b), 5% (c) and 7% (d) at low magnification. Corresponding figures containing 0% (e), 1% (f), 3% (g) and 7% (h) at high magnification from the encircled areas of low magnification images are also included.

Figure 3

XRD results for the standard (the vertical base lines) and prepared hydroxyapatite (calcined). Also, the spectra of pristine PU and the prepared hydroxyapatite/PU nanofiber mat with different concentrations of hydroxyapatite.

Figure 4

FE-SEM equipped with EDS images from one of the nanofibers containing HAp NPs. Area EDS of the nanofiber mat from the encircled area and its corresponding EDS scan results (a). Point EDS of the nanofiber mat from the point area that contains HAp NP and its corresponding EDS scan results (b).

Figure 5

TEM of an individual nanofiber prepared from HAp/PU colloid (7 wt%): (a) high resolution transmission electron microscope (HR TEM) for the encircled area; (b) the (upper inset) selected area diffraction pattern (SAED) for the encircled area and the (lower inset) fast Fourier transformation (FFT) image

Figure 6

TEM of an individual nanofiber prepared from HAp/PU colloid (7 wt%), the inset figure shows selected area diffraction ring pattern from the edge of HAp NP

Figure 7

TEM-EDS image of nanofibers prepared from a HAp/PU colloid (7 wt%) (a); the linear EDS analysis along the line appearing in the figure (b); results of line mapping for two compounds analyzed as in (c) and in (d).

Figure 8

FT-IR spectra of pure PU nanofiber: (A) Calcined bones; (B) PU nanofiber containing 3% HAp; (C) PU nanofiber containing 5% HAp; and (D) PU nanofiber containing 7% HAp; (E)

Figure 9

FE-SEM images for the PU nanofibers containing different amounts of hydroxyapatite: 0% (a), 3% (b), 5% (c) and 7% (d) with respect to polymer solution after incubation in SBF at 37°C for 10 days

Figure 10

The EDS results from one of the modified nanofiber combination after incubation in SBF

Figure 11

Thermal behavior and gain in residual weight of the PU nanofibers containing different amounts of hydroxyapatite before and after incubation in SBF at 37°C for 10 days

Figure 12

The systematic presentation for this novel strategy