Synthesis, characterization, and verification of the antibacterial and osteoblastic activity of an unpublished coating of ²-AgVO3 and chitosan on titanium surfaces

Abstract

There is no consensus in the literature regarding the best pro-osteogenic antibacterial surface treatment for dental implants. This project proposes three outcomes: (1) to develop an unprecedented coating of nanostructured silver beta vanadate decorated with silver nanoparticles (²-AgVO3) and chitosan on titanium (Ti) surfaces treated by plasma electrolytic oxidation (PEO) or not. The coating is composed of ²-AgVO3, a nanomaterial whose chemical elements silver (Ag) and vanadium (V) are antimicrobial, and V stimulates bone mineralization, associated with chitosan (QS), a natural polymer that has intrinsic antibacterial and pro-osteoblastic activity. (2) physical, chemical, and mechanical characterization, and (3) antibacterial and osteoblastic activity verification. After the synthesis of ²-AgVO3, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) will be determined against Streptococcus mutans, the main primary colonizer responsible for synthesizing the biofilm matrix. Eight groups will be analyzed: G1=Ti; G2= Ti + PEO; G3=Ti + ²-AgVO3 at the concentration determined by CBM + QS; G4= Ti + ²-AgVO3 X 5 CBM + QS; G5= Ti + ²-AgVO3 X 10 CBM + QS; G6=Ti + PEO + ²-AgVO3 at the concentration determined by CBM + QS; G7= Ti + PEO + ²-AgVO3 X 5 CBM + QS; G8= Ti + PEO + ²-AgVO3 X 10 CBM + QS. The secondary outcome will be evaluated by means of scanning electron microscopy, energy dispersive x-ray spectroscopy, photoelectron x-ray spectroscopy, surface and linear roughness by laser confocal microscopy, infrared spectroscopy by Fourier transform in the attenuated total reflection, quantification and release of ²-AgVO3 by inductively coupled plasma mass spectrometry, wettability, surface free energy, coating degradation by nuclear magnetic resonance, and coating adhesion strength by shear test; and the tertiary outcome of verification of antibacterial activity through colony forming units and metabolic activity by XTT of S. mutans, after contact of the discs with unstimulated human saliva, the microbial profile and microbial diversity will be verified by sequencing the bacterial 16S rDNA gene, and, verification of the osteoblastic activity of MC3T3-E1 through cell viability by MTT, expression of genes related to osteogenesis by polymerase chain reaction (PCR) in real time and mineralization of the extracellular matrix by colorimetric assay. The results will be submitted to parametric or non-parametric tests according to the data distribution (±=0.05).