Rat 3D Printed Induction Device (RAPID-3D): A 3D-Printed Device for Uniform and Reproducible Scald Burn Induction in...

Scald burns are common thermal injuries in clinical settings, yet existing animal models lack standardization in burn size, exposure time, and severity control. Traditional burn induction methods, such as manual immersion or heated metal contact, suffer from high variability, limited reproducibility, and are operator-dependent, reducing their translational relevance. This study presents RAPID-3D (rat printed induction device-3D), a novel 3D-printed system designed to induce uniform and reproducible scald burns in a rat model, ensuring precise exposure control and minimal variability.

RAPID-3D features four burn exposure windows (10 × 20 mm each, 10 mm spacing), allowing for controlled boiling water (100 °C, 8 s) exposure while immobilizing the anesthetized rat's dorsum. N = 10 female Wistar rats were subjected to eight controlled burns per animal. Internal unburned control areas were used in each rat for intra-animal comparison. Burn evolution was assessed using digital planimetry, histological evaluation, and real-time microvascular perfusion analysis via laser Doppler line scanning (LDLS) at 1 h, which was repeated on day 4, 9 and 21 post-burn.

RAPID-3D generated highly consistent burn sizes (198 ± 3.54 mm²) across all rats, with low inter-animal variability. Histological analysis confirmed full-thickness epidermal necrosis and deep partial-thickness dermal damage (600-900 µm depth). Microvascular Trends: Perfusion dropped immediately post-burn, remained low at day 4, and gradually increased from day 9 onward, suggesting progressive neovascularization and vascular remodeling. RAPID-3D provides a standardized, reproducible, and clinically relevant scald burn model, eliminates operator-induced variability, enhances experimental consistency, and offers strong translational relevance for burn treatment development and wound healing research.