Study of physico-chemical properties and in vitro antimicrobial activity of hydroxyapatites obtained from bone calcination

Cássio M Resmim,Filipe Q Mariani,Mirian M Caetano,Marcelo M Tusi,Mariane Dalpasquale,Nilce I C Vielmo,Juan C Villalba,Fauze J Anaissi

doi:10.1007/s40204-018-0105-2

Abstract

Hydroxyapatite was obtained by bone calcinations. To study the calcination process, bovine and porcine bones were first autoclaved to remove fat and other non-bone tissues. They were then heated in an alumina pan in an oxidizing atmosphere of air, where simultaneous thermal analysis curves were recorded. To prepare the hydroxyapatites, bone samples were calcined at 850 °C and 1000 °C using a muffle furnace for 1 h. The obtained materials were powdered using mortar and pestle, and sifted in a sieve (60 mesh) without any additional purification or chemical treatment. The materials obtained were characterized by energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The antimicrobial properties of these materials were determined through direct contact tests against Staphylococcus aureus. The natural hydroxyapatites obtained by bone calcination inhibited S. aureus growth, with the material obtained by calcination of bovine bones at 1000 °C, showing the best antimicrobial activity. These results indicated that bone wastes can be used to obtain hydroxyapatites with antimicrobial activity.

Highlights

Bones of vertebrate animals are composed of hydroxyapatites (30–70 wt%), collagen, Na+, Mg+2, and CO−3 2 ions, and other minor compounds
The obtained materials were characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), energy-dispersive spectroscopy (EDX), Fourier-transform infrared (FTIR), and the antimicrobial properties were evaluated against S. aureus
The materials obtained from bovine bones at 850 and 1000 °C showed a growth inhibitory effect of 30% and 81%, respectively, while the hydroxyapatites obtained by calcination of porcine bones at 850 and 1000 °C were able to inhibit 38% and 56% of the bacterial cells, respectively

Summary

Introduction

Bones of vertebrate animals are composed of hydroxyapatites (30–70 wt%), collagen, Na+, Mg+2, and CO−3 2 ions, and other minor compounds. The use of calcination (Mkukuma et al 2004; Figueiredo et al 2010; Fara and Abdullah 2016) and chemical treatment to obtain hydroxyapatite (Barakat et al 2008) has been reported. In this work, nanostructured hydroxyapatites were obtained by calcination of bovine and porcine bones at two different temperatures. The obtained materials were characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), energy-dispersive spectroscopy (EDX), Fourier-transform infrared (FTIR), and the antimicrobial properties were evaluated against S. aureus. The bone samples (about 25 g) were calcined at 850 and 1000 °C (at a rate of 10 °C/min) for 1 h using a Jung (model 0812) muffle furnace and static atmosphere (Miyahara et al 2007; Figueiredo et al 2010; Fara and Abdullah 2016). Where IF stands for the inhibitory effect, Ccontrol is the arithmetic average of the colony-forming units grown on control plates, and Ctest is the arithmetic average of the colony-forming units grown on test plates

Results and discussion

Conclusions

Compliance with ethical standards