A new apparatus for standardization of experimental burn models

Experimental models for controlled burn injuries in rats: a systematic analysis of original methods and burn devices

AIM

Despite a wide variety of models found in literature, choosing the right one can be difficult as many of them are lacking precise methodology. This study aims to analyze and compare original burn models in terms of burn device and technique, parameters, and wound depth assessment.

METHODS

A systematic search was performed according to PRISMA guidelines on studies describing original experimental burn models in rats. The adapted PICO formula and ARRIVE checklist were followed for inclusion and assessment of quality of studies. Characteristics of animals, burn technique, burn parameters and method of histological confirmation of burn depth were recorded.

RESULTS

Twenty-seven studies were included in the final analysis. Most studies used direct contact with skin for burn infliction (n=20). The rat's dorsum was the most common site (n=18). Ten studies used manually controlled burn devices, while ten designed automatic burn devices with control over temperature (n=10), exposure time (n=5), and pressure (n=5). Most studies (n=7) used a single biopsy taken from the center of the wound to confirm burn depth immediately after burn infliction.

CONCLUSION

From the wide variety of burn models in current literature, our study provides an overview of the most relevant experimental burn models in rats aiding researchers to understand what needs to be addressed when designing their burn protocol. Models cannot be compared as burn parameters variate significantly. Assessment of burn depth should be done in a standardized, sequential fashion in future burn studies to increase reproducibility.

A Practical Noncontact Model to Create Standardized Experimental Burn Wounds of Any Thickness: Blue Beam Laser Pointer for Burn Induction

The objective of this study was to describe a predictable and easy-to-use model that can create standardized burn wounds. A 450-nm 1000-mW blue beam laser pointer was used to create burn wounds on the dorsal skin of 24 Sprague Dawley rats. Twelve distinct areas of dorsal skin were pulsed for 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, and 23 seconds with the help of a punched plastic card template. Three groups of 8 animals were killed immediately after on the third day and on the seventh day of the procedure and tissue samples were taken for histological evaluation and measurements. A second-degree burn was obtained in all animals with 3 and 5 seconds of laser application on the same day, third day, and seventh day measurements. Seven seconds of application resulted in a burn depth of 84.87% of dermis on the application day which deepened to involve the whole dermal layer on the third and seventh day. Nine seconds and longer application times resulted in third-degree burn wounds. Burn induction with blue beam laser pointer is an easy-to-use, predictable and safe model to create a standardized burn wound of desired thickness.

Design and Testing of an Experimental Steam-Induced Burn Model in Rats

Background

Most of the current models for experimental burns pose difficulties in ensuring consistency and standardization.

Aim of Study

We aimed to develop an automated, reproducible technique for experimental burns using steam-based heat transfer.

Methods

The system developed for steam exposure was based on a novel, integrated, computer-controlled design. Three groups of rats were exposed to steam for 1, 3, and 7 seconds. The lesions were evaluated after 20 minutes, 48 hours, and 72 hours after burn induction.

Results

One-second steam application produced a superficial second-degree burn; three-second application induced deep second-degree burn; and seven-second application led to a third-degree burn.

Conclusion

The high level of automation of our integrated, computer-controlled system makes the difference between our system and other models, by ensuring the control of the duration of exposure, temperature, and pressure and eliminating as many potential human generated errors as possible. The automated system can accurately reproduce specific types of burns, according to histological assessment. This model could generate the reproducible data needed in the study of burn pathology and in order to assess new treatments.