Antibacterial properties and regenerative potential of Sr2+ and Ce3+ doped fluorapatites; a potential solution for peri-implantitis

Abstract

Scaffolds and implants in orthopaedics and regenerative dentistry usually fail because of bacterial infections. A promising solution would be the development of biomaterials with both significant regenerative potential and enhanced antibacterial activity. Working towards this direction, fluorapatite was synthesised and doped with Sr2+ and Ce3+ ions in order to tailor its properties. After experiments with four common bacteria (i.e. E. Coli, S. Aureus, B. Subtilis, B. Cereus), it was found that the undoped and the Ce3+ doped fluorapatites present better antibacterial response than the Sr2+ doped material. The synthesised minerals were incorporated into chitosan scaffolds and tested with Dental Pulp Stem Cells (DPSCs) to check their regenerative potential. As was expected, the scaffolds containing Sr2+-doped fluorapatite, presented high osteoconductivity leading to the differentiation of the DPSCs into osteoblasts. Similar results were obtained for the Ce3+-doped material, since both the concentration of osteocalcin and the RUNX2 gene expression were considerably higher than that for the un-doped mineral. Overall, it was shown that doping with Ce3+ retains the good antibacterial profile of fluorapatite and enhances its regenerative potential, which makes it a promising option for dealing with conditions where healing of hard tissues is compromised by bacterial contamination.

Cerium and Its Oxidant-Based Nanomaterials for Antibacterial Applications: A State-of-the-Art Review

“…The results have shown that both undoped and Ce 3+ -doped fluorapatites present better antibacterial effect than the Sr 2+ -doped ones. Importantly, high osteoconductivity leading to the differentiation of the dental pulp stem cells into osteoblasts was detected in Ce 3+ -and Sr 2+ -doped fluorapatites (Anastasiou et al, 2019).…”

“…However, it was found that CeO 2 NPs at low concentrations (1 mg/L) could not destroy the bacterial biofilms (Hou et al, 2015). Therefore, various cerium-and cerium oxide-based nanomaterials including doping metal ions (Atif et al, 2019), antibacterial element Au/Ag decorations (Babu et al, 2014;Wang et al, 2014), nanocontainers (Gagnon et al, 2015), dopants (Bomila et al, 2018), and a component of blend (Pandey et al, 2018a) were developed to optimize antimicrobial performance as well as physical and biological properties (Anastasiou et al, 2019;Bharathi and Stalin, 2019;Liu et al, 2019).…”

Novel CaF2 Nanocomposites with Antibacterial Function and Fluoride and Calcium Ion Release to Inhibit Oral Biofilm and Protect Teeth

“…Therefore, the composite with calcium fluoride nanoparticles would enhance remineralization and form fluorapatite that is able to resist future acidic challenges. Several studies have demonstrated the ability of forming fluorapatite using nanotechnology [ 15 , 16 ]. In one study, they manufactured fluorapatite nanoparticles and examined its doping with silver ion nanoparticles and evaluated its physical and antimicrobial effects.…”

“…In another study, fluorapatite was incorporated into chitosan scaffolds. Fluorapatite maintained its structure, granted antimicrobial effects, and showed osteoconductive capability [ 16 ].…”

Cryogel biocomposite containing chitosan-gelatin/cerium–zinc doped hydroxyapatite for bone tissue engineering

“…This downside prompts the danger of bacterial adherence to implants covered with pristine HA ( Arcos and Vallet-Regí, 2020 ). Normally happening to follow components in bones (Magnesium, Zinc, Manganese, Strontium, Ag, Cerium, Copper) could be utilized as doping in HA to forestall microbial infections ( Arcos and Vallet-Regí, 2020 , Anastasiou et al, 2019 ). Zn is one of the significant follows components present in normal bone.…”