Annealing temperature influences the cytocompatibility, bactericidal and bioactive properties of green synthesised TiO2 nanocomposites

Abstract

Annealing is a crucial functional parameter relevant to the green synthesis and bactericidal properties of TiO 2 nanocomposites (TiO 2 -NPs). In this work, the effect of the annealing temperature on the physicochemical and bactericidal properties of TiO 2 -NPs obtained from Calotropis gigantea was comprehensively studied. The synthesised TiO 2 -NPs were characterised using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energydispersive X-ray spectroscopy, UV-Vis spectrophotometer and FTIR spectroscopy. The bactericidal properties were determined via the minimum inhibitory concentration (MIC) and Kirby-Bauer disc diffusion methods. The cytocompatibility of green TiO 2 was further investigated using broblast cells lines model.Results indicated that amorphous-phase TiO 2 -NPs were transformed into the anatase phase at 500 °C with a crystallite size of 40.9 nm and MIC of 100 mg/mL towards S. aureus (colony count reduction from 4.3 log 10 to 1.01 log 10 ). Whereas TiO 2 -NPs annealed at 400 °C demonstrated no bacterial reduction, TiO 2 -NPs annealed at 500 °C showed a moderate zone of inhibition of 6.33-6.83 mm towards Escherichia coli and Pseudomonas aeruginosa. Findings from this study found that TiO-500C nanocomposites concentration at 100 mg/mL is cytocompatible to the broblast cells lines with proliferation rate/activity higher than 116% after 24 h treatment. The plant-mediated nano-sized cubic and spherical anatase TiO 2 -NPs encapsulated bioactive green elements, such as carbon, sodium, magnesium, chlorine, potassium, calcium and sulphur, from the C. gigantea extract, ultimately leading to versatile and eco-friendly bactericidal agents with wound-healing properties. Further studies are necessary to support the ndings of this work.

Physical characterization, biocompatibility, and antimicrobial activity of polyvinyl alcohol/sodium alginate blend doped with TiO2 nanoparticles for wound dressing applications

“…This stimulated research on green-synthesized nanoparticles with different morphologies as a bactericidal agent to overcome open wound ulcers. Several studies have investigated the use of different types of green synthesized metal oxide NPs, such as TiO 2 , ZnO, CuO, and ZnO/CuO, in various applications 22 – 26 .…”