Natural hydroxyapatite-based nanobiocomposites and their biomaterials-to-cell interaction for bone tissue engineering

Abstract

Hydroxyapatite (HA) is an extensively used biomaterial for dental and orthopaedic applications because of its biocompatibility and biomimetic nature. HA is extensively used as a bone-graft substitute. HA bone graft substitutes of bovine or synthetic origins have been extensively studied. However, caprine-based HA has not been explored. In this study, we aimed to determine the utilization of goat bone-derived HA for commercial applications. HA from caprine bone and teeth was isolated using thermal calcination. The developed HA can be used as a bone graft substitute. Chemical characterization of the isolated HA was carried out using Fourier transform infrared spectroscopy, X-Ray Diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. The biocompatibility and apatite formation of isolated HA were assessed using MG-63 cells, MC3T3-E1, L929 cells, MSCs, adipose derived stem cells, human dermal tissue derived fibroblast cells and osteoblast-like cell line, The studies demonstrate that HA support cell adhesion and osteogenic properties. To improve sheep, lamp, or caprine bone-derived HA, several other composites have been developed with MgO₂, ZrO_2, ZnO_2, and other polymeric substances. 3D printed technology was used to develop a bioink using sheep-derived HA and printed the composite scaffold as a bone graft substitute. Furthermore, the biomedical applications of sheep-derived HA been studied in terms of their antimicrobial activity, bone-forming ability, and wound healing applications. Sheep-, goat-, and caprine-derived HA are still underutilized and require further research to develop commercial possibilities and sustainable raw materials for HA-based bone graft substitutes.

Keywords: Bone-graft substitute; Caprine bone; Goat bone; Sheep bone; Thermal calcination.

Fig. 1

Livestock waste their value-added products. Figure adopted with permission from the [18]

Fig. 2

A The process flowchart for isolation of bioactive HA from caprine bone bio-waste and its characterization [64]. Figure adopted with permission from [64]. B Preparation process steps [93]. Figure adopted with permission from [93]

Fig. 3

SEM micrograph, EDS spectrum and EDS mapping of caprine bones calcined at (a, b) 900 °C, (c, d) 1000 °C, (e, f) 1100 °C, (g, h) 1200 °C and (i, j) 1300 °C [64]. Figure adopted with permission from [64]

Fig. 4

FT-IR spectrum and XRD spectrum of goat bone derived Hydroxyapatite and raw bones [65]. Figure adapted with permission from [65]

Fig. 5

(i) a–d Microscopic images of HAp1 to HAp4, respectively, calcined HA (900 °C), and f control and (ii) Cell viability profile for Hap at 0.5 and 1.0 mg/200 μl [110]. Figure adapted with permission from [110]

Fig. 6

Chemical characterization of sHA, X-Ray diffraction analysis, Thermogravimetric analysis, Raman spectra and Fourier transform infrared spectroscopy and scanning electron microscopy analysis [93]. Figure adapted with permission from [93]

Fig. 7

Pictures of DCP cement paste after injectability for different PLR a 3.4 g mL⁻¹, b 3.2 g mL⁻¹, c 3.0 g mL⁻¹, d 2.8 g mL⁻¹, e 2.6 g mL⁻¹ [102]. Figure adapted with permission from [107]

Fig. 8

FESEM image of DCP cement for PLR 3.0 g mL⁻¹ before and after immersion in SBF a before immersion b after 1 day of immersion c after 3 days of immersion d after 7 days of immersion [102]. Figure adapted with permission from [102]

Fig. 9

A–H Microbial plates showing evaluation of antibacterial activity of the formulations against Staphylococcus aureus (SA), Staphylococcus saprophyticus (SS), Klebsiella pneumonia (KP) and Escherichia coli (ES) and the graphical representation of inhibition of zones against the bacteria [107]. Figure adapted with permission from [102]

Fig. 10

Wounds images showing contraction as the treatment days elapsed and histological photomicrographs [107]. Figure adapted with permission from [107]

Fig. 11

Antimicrobial activity of caprine derived hydroxyapatite were evaluated against E. Coli [108]. Figure adapted with permission from [108]