EXPERIMENTAL MODELS OF WOUND HEALING: SURGICAL APPROACHES

BERENGENO, ANDREA; SALINAS, FACUNDO; DIAZ, PABLO URIEL; REBELINDO, ENRIQUE; GARCÍA LÁZARO, ROCÍO; ALONSO, DANIEL F.; SALVETTI, NATALIA R.; FARINA, HERNAN G. ; ORTEGA, HUGO H.

Rosario

Congreso; II REUNIÓN CIENTÍFICA INTERNACIONAL VII REUNIÓN CIENTÍFICA REGIONAL VI CONGRESO NACIONAL DE CIENCIA Y TECNOLOGÍA DE ANIMALES DE LABORATORIO; 2021

Asociación Argentina de Ciencia y Tecnología de Animales de Laboratorio (AACyTAL)

Normal wound healing is a complex biological process that takes place in all tissues and all organs of the body. Although in vitro models have been important in identifying critical repair mechanisms in specific cell types, in vivo models are necessary to obtain a more comprehensive understanding of human wound healing, under physiological and pathological conditions. A wide variety of models have been developed for examining different aspects of the repair response thus many animal models are used for the evaluation of wound healing activities. However, some discrepancies exist with the wound and types of wound models that can be used along with the topics like wound location, wound size as well as anesthetics and analgesics and analytical measures that are used in wound healing studies. The aim of this study was to develop two experimental models for wound healing evaluation in rabbit and rat using different surgical approaches. All procedures were approved by the Institutional Ethics and Security Committee of Faculty of Veterinary Sciences, Universidad Nacional del Litoral, Argentina (336/16- rabbits and 513/19- rats). Forty-two New Zealand rabbits (2000-2500 g) of both sexes were anesthetized and standardized ventral midline laparotomies and uniform-length gastrotomies were performed. A 30 mm long incision was made in the anterior gastric wall parallel to the greater curvature. Stomach wounds were immediately closed with absorbable sutures. Gastrotomy wounds were assessed for wound healing through Power Doppler ultrasonography at 1st, 3rd, 7th, 15th days after surgery. The excisional full thickness skin wound model with splinting was employed for wound healing activity in thirty-four healthy adult male Wistar/Cmedc rats (300-350 g). A full skin thickness excisional wound of 5 mm diameter was made on the dorsal area of each anesthetized animal. Silicone rings were used as splints to hold the wound margins in place. Digital images of the wounds were taken at 0th, 1st, 4rd, 7th, 10th, 13th, 16th, 19th, 22nd and 25th days after wound creation. Images from rabbit and rat models were analyzed by Image-ProPlus 6.0 software to obtain quantitative data. The quantification of Power Doppler images in rabbit gastrotomy model show that the highest signal of blood flow velocity was obtained at 24 h after surgery and then decreased on day 3 maintaining practically the same values until day 15 post wounding. Healing pattern in rat excisional full thickness skin wound model was observed from the 1st day. The wound closure percentage was 20 %, 60 % and 80 % on day 4, 7 and 16 post wounding respectively. A complete wound closure was observed after 25 days of wound creation. Significant differences (p < 0.001) were obtained for all times analyzed except for 7th, 10th, 13th days after wounding. The results of this study demonstrated that these experimental animal models can be fundamental tools for the development of new treatments to wound therapy for translational applications.