Banca de QUALIFICAÇÃO: DIEGO GONZALEZ VIVAS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : DIEGO GONZALEZ VIVAS
DATE: 12/03/2025
TIME: 16:00
LOCAL: Google meet
TITLE:

Clinicopathological and microbiological evaluations of the healing of contaminated skin wounds treated with hydrogel based on Melaleuca alternifolia essential oil and Aloe vera extract

KEY WORDS:

Wound; Aloe vera; Tea tree; Healing; Bactericide

PAGES: 25
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

Healing is a complex process that involves cellular, molecular and biochemical mechanisms; and aims to restore the integrity of the skin. The optimization of the healing process is due to veterinary medical knowledge in indicating accurate therapeutic approaches, using appropriate and rational drugs; avoiding adverse drug reactions, poisoning and especially bacterial resistance, leading to higher treatment costs and delayed tissue repair. There are increasing financial and academic investments in pre-clinical and clinical studies in the lines of research in pharmacology and biomaterials, aiming to create new types of dressings, such as hydrogels and calcium alginate. Also following this line of thought, more and more research is being carried out using medicinal plants as alternative treatments for wound healing due to their antiseptic, bactericidal and healing properties. In this category, Aloe vera (Aloe vera) and Melaleuca alternifolia (Tea tree) stand out. The objective of the present study was to evaluate the clinicopathological and microbiological picture of the healing of contaminated skin wounds treated with hydrogel based on M. alternifolia essential oil and A. vera extract. The experiment was carried out at Estácio de Sá University and the project was approved by CEUA (001/2023) of that institution. Twenty-four Wistar rats (Rattus norvegicus) were used for the study. Two surgical wounds were made in each animal (cranial and caudal) and the incisions were contaminated with a multidrug-resistant strain of Staphylococcus aureus. The animals were divided into two groups and treated openly: G1G2 with twelve animals (G1 - cranial wound treated with 0.9% saline twice a day and G2 - caudal wound treated with collagenase ointment with chloramphenicol twice a day ) and G1G3 with twelve animals (G1 - cranial wound treated with 0.9% saline twice a day and G3 - caudal wound treated with hydrogel extract A. vera with M. alternifolia essential oil twice a day. In both groups, four animals were euthanized on the third day of treatment, four were euthanized on the seventh day and four were euthanized on the fourteenth day. The animals were euthanized with 5% isoflurane until hypnosis was induced and then thiopental was administered at a dose of 120mg/kg intraperitoneally.  The processing of the material, as well as the staining and preparation of the histological slides were carried out in the Histopathology laboratory of the Pathological Anatomy Sector at UFRRJ. Fragments of two surgical skin wounds (cranial and caudal) from each rat, received in 10% buffered formalin, were processed, in addition to the liver, spleen and kidneys. After cleaving, the fragments were dehydrated in a series of ethyl alcohol concentrations in increasing dilutions until absolute alcohol, clarified in xylene and embedded in previously heated paraffin. Histological sections were obtained using a microtome adjusted to four micrometers in thickness and subjected to Hematoxylin-eosin (HE) techniques, in addition to Masson's Trichrome staining (skin fragments). The analyzes were carried out under an optical microscope. Crust formation, inflammatory infiltrate, extracellular matrix deposition, neovascularization and re-epithelialization were evaluated, according to the protocol published by Estevão et al. (2019). The analysis consisted of a description of the slide and comparative analysis of the groups, qualitatively differentiating scores from 0 to 3 for each parameter evaluated: zero (0) representing absence of the tested parameter (intact skin); 1, discreet; 2, moderate; and 3, intense or complete training. Regarding the histology of the wounds, it was observed that G3 wounds showed greater collagen deposition and re-epithelialization area than G2 wounds. Morphologically, the G3 wounds produced less crust than the G2 wounds and, despite maintaining a drier appearance, the crust produced a barrier that protected the loss of electrolytes, fluids and extrinsic entry of harmful agents. Regarding inflammatory infiltrate, wounds treated with commercial ointment presented a lower rate when compared to those treated with herbal hydrogel and, in the microbiological control, a reduction in the rate of microorganisms of 25% was observed in G2 wounds and, in G3 wounds, reduction of 17%. Therefore, it can be suggested that the herbal hydrogel proposed in the present study presented satisfactory results compared to the ointment, as it demonstrated good healing capacity, despite its low bactericidal potential.

COMMITTEE MEMBERS:
Presidente - 2606155 - VIVIAN DE ASSUNCAO NOGUEIRA CARVALHO
Interna - 6387102 - MARILENE DE FARIAS BRITO QUEIROZ
Interno - 2929022 - SAULO ANDRADE CALDAS
Externa à Instituição - MARIANA CORREIA OLIVEIRA - UES