RU2472232C2 - Method for simulating thermal skin burn injury in laboratory animals - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: white laboratory rat's hair is shaved off, skin is processed with alcohol in an interscapular space under two-component anaesthesia. A copper plate of the area 400 mm² and thickness 1 mm is brought to skin. It is exposed to a contact end face of a laser guide (Lasermed 1001) at wave length 1064 nm in a continuous mode, end face power 7.8-8.2 Wt. The thermovision camera aided plate is heated to 220°C and kept on skin for another 2 seconds. It results in creating a sequential burn injury of all the skin layers to subcutaneous fat (degree IIIB burn). A burn injury area matches with a copper plate area.

EFFECT: method enables standardising the experiment, strictly observing the pre-set criteria of burn area and depth.

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Description

The invention relates to medicine, namely to experimental surgery and combustiology, and can be used to simulate skin burn wounds under experimental conditions in laboratory animals.

A well-known experimental model of creating a burn wound obtained using a household electric soldering iron (220 V) with a power of 100 W in the interscapular region of the back of a rat with complete damage to the entire thickness of the skin with an area of 320 mm ² (1).

The disadvantage of this method of modeling the burn is the inability to create a given area of the burn wound, the duration of the heating procedure and the uncontrolled depth of the burn.

Describes the creation of a burn wound of the skin of the lumbar region by exposure to water vapor for 5 seconds (2). A similar model of a burn wound in the interscapular region in rats was obtained using a flat-bottomed glass flask filled with boiling water with an exposure of 35 seconds (3).

The disadvantage of these methods is the use of steam as a heater, which does not allow to accurately calculate the depth and area of the burn wound.

Another modern way of modeling a burn wound of the skin, which allows you to quickly reproduce a burn wound of exactly the specified area and depth of skin lesion of an experimental animal, is the use of laser technology (4).

However, the disadvantage of this method is the insufficient area of laser exposure to the skin, because the laser fiber has a diameter of 2 mm, therefore, to obtain a given burn area requires multiple exposure to the skin. This method is taken as a prototype.

The aim of the invention is to expand the experimental capabilities of creating a thermal burn wound of the skin in laboratory animals.

This goal is achieved by the fact that a laser fiber nozzle, made in the form of a copper plate of the required shape and size, is applied to a selected area of the skin and is contacted by laser radiation.

Comparison of the proposed method with others known in the field of medicine, showed its compliance with the criteria of the invention.

The method is implemented as follows. Under a two-component anesthesia, a white shaving rat is shaved in the interscapular space of the back, the skin is treated with alcohol, the skin is marked and shaved, a nozzle is brought to the skin - a copper plate with an area of 400 mm and a thickness of 1 mm and through the end of the laser fiber (“Lasermed 10 01”) they are affected by radiation with a wavelength of 1064 nm in a constant mode, with a power of 7.8-8.2 W at the end of the fiber. Under the control of a thermal imager, the plate heats up to 220 ° C, after which it is kept on the skin for another 2 seconds. As a result, a burn wound is created sequentially of all skin layers to subcutaneous tissue (degree IIIB burn) with an area corresponding to the area of a copper plate.

The principal difference of the proposed method is the use of a laser nozzle for a thermal burn in the form of a copper plate of a given area and shape, heated with a laser under the control of a thermal imager to a predetermined temperature, which makes it possible to standardize the experiment. The advantage of the proposed method over the prototype lies in the single exposure of laser radiation to the region of the simulated wound, which allows to standardize and accelerate the process of experimental modeling of burn wounds.

Experimental example

The studied white laboratory rat was given two-component anesthesia (rometar, zoletil). The skin is shaved in the interscapular space and treated with 70% ethanol. A copper plate with an area of 400 mm ² and a thickness of 1 mm, a laser fiber (Lazermed 10 01) with a wavelength of 1064 nm, a radiation power at the end face of 8 W in a constant mode, and a fiber diameter of 1.2 mm were brought to the skin. Upon direct contact of the end of the laser fiber with the copper plate, it heats up and a burn wound (burn of the IIIB degree) is created, controlled by area and temperature, sequentially of all skin layers to the subcutaneous tissue (Figure 1). The exposure time of a plate heated to 220 ° C is 2 seconds. Consistently increasing the exposure to laser exposure, you can set the degree of depth of the burn, changing the shape and area of the plate - to create the corresponding burn wounds.

As can be seen from the above example, in comparison with similar methods of creating a burn wound using laser technology, the modeling process is significantly simplified, accelerated and standardized, while changing the size of the copper plate, it is possible to accurately create the necessary area and degree of burn. During morphological verification of histosections of the burn wound substrate, it was found that the obtained wound model corresponds to a degree of burn degree burn (Figure 2).

Thus, the proposed method for modeling burn wounds is simple in technical design, significantly reduces the time of laser exposure to the skin, is economically feasible and affordable, allows you to standardize the experiment, clearly comply with the set criteria for the area and depth of the burn, and can be used in experimental surgery and combustiology.

Sources of literature

1. F.E. Shin, P.I. Strelnikov, E.F. Stranadko. Photodynamic therapy of experimental burn wounds // Laser medicine. - 2009. - No. 13. S.55-60.

2. I.P. Bogatova, A.M. Panichev, V.P. Koksharova. The structure of endotheliocytes of the lymphatic capillaries of the skin under the conditions of correction of the wound process during thermal burn // Bulletin SB RAMS, No. 1 (115). - 2005. P.37-42.

3. V.V. Boltovskaya. Pathomorphology of the wound process in the area of a deep burn of the skin in the conditions of application of low-intensity electromagnetic radiation // Abstract. dis. Cand. medical sciences. - Saratov. - 2006. - 14 p.

4. "The method of modeling burn wounds in the experiment," application for invention No. 201043368 (priority from 10.22.10., V.V. Alipov et al.)

Claims (1)

A method for modeling a burn wound of skin of the IIIB degree in an experiment on a laboratory animal, characterized in that under the control of a thermal imager, a copper plate with a size of 400 mm ² and a thickness of 1 mm is installed on a specific area of the skin, with which the laser fiber has direct contact with a wavelength of 1064 nm and power radiation at the end of 8 W with a constant heating mode of 220 ° C for 2 s.

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