Establishment of a Bama miniature pig burn model with different burn depths

The skin morphological characteristics of the Bama miniature pig are very similar to those of humans; thus, the Bama miniature pig is an ideal choice for establishing a skin burn model.

In this study, 6 ordinary, male, Bama miniature pigs (weight: 23-28 kg and length: 71-75 cm) were used to establish burn models. A mixture of 1 mg of Ketamine and Sumianxin II was used for Bama miniature pigs anesthetizing, and 1 mg of Pentobarbital sodium was added as necessary. The different burn depths were made using a continuous pressure of 1 kg and contact times of 0 s, 10 s, 15 s, 20 s, 25 s, 30 s, 35 s, 40 s, and 45 s by the newly invented electronic burn instrument. The burned tissues were collected and examined with hematoxylin and eosin (H&E) and Masson staining.

Burning for 10-15 s caused a first-degree burn; the blood vessels in the superficial dermis were dilated and congested, and necrosis occurred above the basal layer of the epidermis. Burning for 20-25 s caused a superficial partial-thickness burn; the whole epidermal layer was necrotic, and the collagen fibers were slightly deformed. Burning for 30-35 s caused a deep partial-thickness burn; the whole epidermal layer and dermal layers were necrotic with leukocyte infiltration zones, and the collagen fibers were disordered, degenerated, and necrotized. Burning for 40-45 s caused a third-degree burn; the skin layers and adipose tissues were necrotic, and the thick blood vessels in the skin adipose tissues were full of disintegrated and agglutinated red blood cells.

Stable burn depth models of Bama miniature pigs were constructed using a new and innovative electronic burn instrument. Our findings provide a basis for further research on the burn mechanism and evaluations of therapeutic drugs.