In vivo characterization of minipig skin as a model for dermatological research using multiphoton microscopy

Abstract

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.

Label-free metabolic and structural profiling of dynamic biological samples using multimodal optical microscopy with sensorless adaptive optics

“…We had previously demonstrated in vivo FLIM imaging of murine skin using a typical TCSPC-based setup which took 51 s per frame, compared to the 2.5 s (and real-time processing) for FOCALS microscopy 54 . FOCALS microscopy also compares favorably against commercial FLIM imaging systems previously used for in vivo skin imaging 55 , 56 with a 5–6 × improvement in imaging speed, respectively.…”

In vivo two-photon imaging of topically applied care cosmetics and pharmaceuticals in human skin

“…It thus provides more information that may help to understand topically applied exogenous molecules diffusion, intradermal distribution, and penetration depth (25,26). FLIM tomography can be used for the investigation of their impact on the metabolism of skin cells directly in vivo (27)(28)(29).…”

How is depth of anaesthesia assessed in experimental pigs? A scoping review

“…No information has been found in minipigs, despite their increasing use in different branches of translational medicine [140][141][142][143]. Further specific studies should be performed characterizing the effects induced by anaesthetic drugs in these animals, also considering that most of them are used as adult.…”