Nanotubos de TiO2 carregados com híbridos pirazol-tetrazólicos: um potencial sistema contra infecção bacteriana

Abstract

The implant failures present rate of 10% worldwide, causing losses of 20 billion dollars per year. The impact of this reality is socioeconomic, as it also harms patients with physical pain, psychological trauma and restricted mobility. Studies of surface modifications in titanium implants have been investigated to reduce the incidence of bacteria on the surface of biomaterials. Surface treatments coated with TiO2 nanotubes associated with antimicrobial compounds are a possible solution to reduce the rate of failures caused by bacteria. The objective of this work is to associate TiO2 nanotubes to two novel hybrid pyrazol-tetrazol compounds, the compound 5-[1-(3-chlorophenyl)-3-methyl-1H-pyrazol-4-yl)]-1H-tetrazol (JVS02 ) and 5-[1-(3,4-dichlorophenyl)-3-methyl-1H-pyrazol-4-yl)]-1H-tetrazol (JVS05), to reduce bacteria on the surface of pure titanium biomaterials for implants. The material was evaluated by scanning electron microscope (SEM), X-ray diffraction (XRD) and contact angle. The compounds associated with TiO2 nanotubes were characterized by drug release test and the biofilm test with Staphylococcus aureus bacteria of the HU25 strain. The results showed that the anodization resulted in TiO2 nanotubes on the surface of the anodized material with diameters of 50 nm, present in the rutile phase and the material became hydrophilic with an average contact angle of 7.81°. The release test showed that compound JVS02 has an immediate release and compound JVS05 has a gradual release with clear delimitation between phases. The biofilm test showed that the JVS05 compound has greater action against the formation of biofilm on the material's surface. With the results presented, we can conclude that there was loading of both compounds studied in TiO2 nanotubes on titanium substrates and among these, the compound 5-[1-(3,4-dichlorophenyl)-3-methyl-1H-pyrazol-4 -il)]-1H-tetrazol has more adequate characteristics for a drug delivery system due to its release time and antimicrobial action.