Gustavo Oliveira de Meira Gusmão

In this study, we report on the structural, electronic, and vibrational properties of the sodium titanate nanotubes (NaTiNTs) modified with cerium tungstate (CeW), which were synthesized via a single-step hydrothermal procedure, resulting in the nanocomposite (TiNTs@CeW). Structural and spectroscopic characterizations confirmed the preservation of the nanotube morphology after modification, while XPS and STEM analyses indicated the deposition of Ce- and W-containing species on the nanotube surface. Optical properties were investigated by UV–vis absorption spectroscopy and photoluminescence. For the TiNTs@CeW sample, a significant reduction in the band gap from (3.23 ± 0.04) eV to (2.52 ± 0.03) eV was observed, as well as an increase in the Urbach energy from (0.316 ± 0.003) eV to (0.444 ± 0.001) eV, compared to NaTiNTs. These effects are associated with a higher concentration of oxygen holes and localized electronic states, which act as emission centers and temporary charge traps. The TiNTs@CeW showed significantly superior photocatalytic performance, promoting 73.84% degradation of tetracycline in high-concentration solution and exhibiting good stability and reusability. NaTiNTs achieved only 26.28% degradation under the same experimental conditions. These results highlight the potential of nanocomposite TiNts@CeW as effective materials in environmental remediation through their good photocatalytic performance in the degradation of the drug tetracycline.

The use of bioactive materials, such as Ximenia americana L., to stimulate the bone repair process has already been studied; however, the synergistic effects of its association with light emitting diode (LED) have not been reported. The present work aims to evaluate the effect of its stem bark extract incorporated into methacrylate gelatin hydrogel (GelMA) on the bone repair process using pure hydrogel and hydrogel associated with LED therapy. For this purpose, the GelMA hydrogel loaded with Ximenia americana L. extract (steam bark) was produced, characterized and applied in animal experiments. The tests were performed using 50 male Wistar rats (divided into 5 groups) submitted to an induced tibia diaphyseal fracture. The therapy effects were verified for a period of 15 and 30 days of treatment using histological analysis and Raman spectroscopy. After 15 days of induced lesion/treatment, the new bone formation was significantly higher in the GXG (GelMA + X. americana L.) group compared to the control group (p < 0.0001). After 30 days, a statistically significant difference was observed when comparing the GXLEDG (GelMA + X. americana L. + LED) and the control group (p < 0.0001), the GXG and the control group (p < 0.001), and when comparing the GG, GXG (p < 0.005) and GXLEDG (p < 0.001) groups. The results shows that the Ximenia americana L. stem extract incorporated into GelMA hydrogel associated with LED therapy is a potentiator for animal bone repair.