Banca de QUALIFICAÇÃO: NIZYARA COSTA DA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : NIZYARA COSTA DA SILVA
DATE: 19/08/2026
TIME: 09:00
LOCAL: Departamento de Biofisica e farmacologia
TITLE:

Biological evaluation of a chitosan triamcinolone acetonide nanogel in an experimental model of traumatic ulcer

KEY WORDS:

chitosan; triamcinolone acetonide; traumatic ulcer; nanoemulsion; oxidative stress.

PAGES: 91
BIG AREA: Ciências da Saúde
AREA: Odontologia
SUMMARY:

Oral traumatic ulcers represent a common clinical condition that often resolves spontaneously but is associated with pain and discomfort, requiring effective and low-cost therapeutic approaches. The present study evaluated the biological effects of a chitosan–triamcinolone acetonide (TA) nanogel system in an experimental model of traumatic ulcer induced in the buccal mucosa. A total of 108 male Wistar rats were used and allocated into five experimental groups: Negative Control/SHAM (n=8), consisting of animals without ulcer induction and treatment; Positive Control/ULC (n=24), consisting of animals with ulcers and no treatment; Standard Triamcinolone Acetonide/STA (n=24), consisting of animals with ulcers treated with standard triamcinolone acetonide gel; Chitosan/CHI (n=24), consisting of animals with ulcers treated with chitosan gel alone; and Chitosan–Triamcinolone Acetonide Nanogel/CHI+TA (n=24), consisting of animals with ulcers treated with the nanogel. The animals were evaluated and euthanized at two experimental time points, 3 and 7 days. Traumatic ulcers were induced using a 5-mm punch biopsy in the left buccal mucosa, followed by application of the respective treatments. Behavioral analyses were performed using the Open Field test and the Rat Grimace Scale. The animals were also evaluated for macroscopic parameters, including body weight and lesion size at the different experimental time points. After euthanasia, hematological and blood biochemical analyses were performed. The buccal mucosa was subjected to histopathological analysis using hematoxylin and eosin staining, considering inflammation, fibrosis, and ulcer extent. Special stains were used to evaluate collagen, including Picrosirius Red and Masson's trichrome. Immunohistochemical analyses were also performed, as well as quantification of the inflammatory cytokines IL-1β and IL-6 on day 3 and assessment of GILZ and TGF-β gene expression on day 7. The data were statistically analyzed using GraphPad Prism 5.0 software, with the Kruskal–Wallis test followed by Dunn's post hoc test, adopting a significance level of 5%. In the Rat Grimace Scale analysis, the STA group showed the largest area under the curve, differing significantly from the SHAM group, whereas the CHI+TA group showed the smallest area under the curve among the ulcerated groups, with a significant difference compared with the STA group (p<0.01). Morphometric analysis demonstrated a greater percentage of lesion contraction in the CHI+TA group on day 7 (96.67%), which was significantly higher than that observed in the STA group (63.71%; p<0.05). Histopathological analysis on day 7 showed that the ULC group had a higher histopathological score compared with the SHAM group (p<0.01), whereas the STA and CHI+TA groups showed a significant reduction in this score compared with the ULC group (p<0.05). Regarding inflammatory cytokines, on day 3, the ULC group showed higher IL-1β levels, differing significantly from the SHAM and CHI+TA groups (p<0.05). For IL-6, the ULC group showed significantly higher levels than those observed in the STA and CHI+TA groups (p<0.05) and the CHI group (p<0.01).

COMMITTEE MEMBERS:
Presidente - 2374605 - AURIGENA ANTUNES DE ARAUJO
Interno - 3486175 - CIRO DANTAS SOARES
Interna - 2492713 - ERICKA JANINE DANTAS DA SILVEIRA