Minipig skin is one of the most widely used non‐rodent animal skin models for dermatological research. A thorough characterization of minipig skin is essential for gaining deeper understanding of its structural and functional similarities with human skin. In this study, three‐dimensional (3‐D) in vivo images of minipig skin was obtained non‐invasively using a multimodal optical imaging system capable of acquiring two‐photon excited fluorescence (TPEF) and fluorescence lifetime imaging microscopy (FLIM) images simultaneously. The images of the structural features of different layers of the minipig skin were qualitatively and quantitatively compared with those of human skin. Label‐free imaging of skin was possible due to the endogenous fluorescence and optical properties of various components in the skin such as keratin, nicotinamide adenine dinucleotide phosphate (NAD(P)H), melanin, elastin and collagen. This study demonstrates the capability of optical biopsy techniques, such as TPEF and FLIM, for in vivo non‐invasive characterization of cellular and functional features of minipig skin, and the optical image‐based similarities of this commonly utilized model of human skin. These optical imaging techniques have the potential to become promising tools in dermatological research for developing a better understanding of animal skin models, and for aiding in translational pre‐clinical to clinical studies.

Sanitation guidelines for animal research facilities state that disinfection is achieved by application of high-temperature water (143 to 180 °F [62 to 82 °C]) or detergents and disinfectants. However, these guidelines are based on requirements for pasteurization, which may be unnecessarily stringent for the sanitation of nonfood items and do not address the theoretical sanitation potential of water at temperatures below 143 °F (62 °C). Recent literature indicates that water temperatures below 143 °F (62 °C) can also provide effective sanitation. In this study, we compared cagewash cycles at low (100 °F [38 °C] and 120 °F [49 °C]) and high (standard) (180 °F [82 °C]) temperatures and evaluated sanitation efficacy by using ATP swabs and RODAC plates. Low-temperature loads were washed either with or without prior treatment of a chemical disinfectant (10% bleach). The 100 °F (38 °C) cycle was not sufficient for sanitization without bleach pretreatment. However, the 120 °F (49 °C) cycle effectively sanitized cages without bleach pretreatment. Validation of effective sanitation at a lower water temperature (120 °F [49 °C]) can improve cagewash logistics and reduce costs as compared with standard (180 °F [82 °C]) high-temperature cycles.

No abstract