In vitro characterization of hydroxyapatite and cobalt ferrite nanoparticles compounds and their biocompatibility in vivo

Cristiane C Vital Cintra,Sheila M C M Bicalho,Dayana A C Ferreira-Ermita,Fabrício L Valente,Iara M Ribeiro,Fabrícia H Loures,Fabiana R Araújo,Pascally M A G Araújo,Emily C Carlo Reis,Ana Cristina F M Costa,Andréa P B Borges

doi:10.1007/s10856-022-06640-z

Abstract

Bioactive materials in combination with antibiotics have been widely developed for the treatment of bone infection. Thus, this work aims to characterize six biomaterials formulated with different concentrations of hydroxyapatite and cobalt ferrite nanoparticles, in addition to the antibiotic ciprofloxacin, using X-ray diffraction (XRD), scanning electron microscopy (SEM), and the antibiotic diffusion test on agar. Furthermore, in vivo biocompatibility and the reabsorption process of these materials were analyzed. XRD showed that both hydroxyapatite and cobalt ferrite present high crystallinity. The photomicrographs obtained by SEM revealed that composites have a complex surface, evidenced by the irregular arrangement of the hydroxyapatite and cobalt ferrite granules, besides demonstrating the interaction between their components. The antibiotic-diffusion test showed that all biomaterials produced an inhibition halo in Staphylococcus aureus cultures. For the biocompatibility study, composites were surgically implanted in the dorsal region of rabbits. At 15, 30, 70, and 100 days, biopsies of the implanted regions were performed. The biomaterials were easily identified during histological analysis and no significant inflammatory process, nor histological signs of toxicity or rejection by the adjacent tissue were observed. We can conclude that the biomaterials analyzed are biocompatible, degradable, and effective in inhibiting the in vitro growth of Staphylococcus aureus.Graphical abstract

Highlights

Biomaterials are substances of natural or synthetic origin, used in biomedical applications and that interact with biological systems, treating, increasing, or replacing tissues, organs, or restoring functions compromised by degenerative processes or trauma [1]
The group of biomaterials that most resemble bone composition is the group of calcium phosphate ceramics [7, 8], among which the most widespread is hydroxyapatite (HAp) [4]
The methodology was approved by the Ethics Committee on Animal Use of Federal University of Viçosa (CEUA/UFV), under the protocol 67/2016

Summary

Introduction

Biomaterials are substances of natural or synthetic origin, used in biomedical applications and that interact with biological systems, treating, increasing, or replacing tissues, organs, or restoring functions compromised by degenerative processes or trauma [1]. The group of biomaterials that most resemble bone composition is the group of calcium phosphate ceramics [7, 8], among which the most widespread is hydroxyapatite (HAp) [4] It has been used because it is a bioactive, nontoxic substance that causes little tissue reaction [9,10,11] and is biocompatible with bone, once both have the same type of crystalline structure [3, 10, 11]. It has a porous structure, which is an advantage for bone ingrowth [12,13,14]

Objectives

Methods

Results

Discussion

Conclusion