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Labouchère A, Haselbach D, Michetti M, Pythoud C, Raffoul W, Applegate LA, Hirt-Burri N, de Buys Roessingh A. A New Ex Vivo Human Skin Burn Model. J Burn Care Res 2024; 45:308-317. [PMID: 37202124 PMCID: PMC10911692 DOI: 10.1093/jbcr/irad071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Indexed: 05/20/2023]
Abstract
Currently, most burn models for preclinical testing are on animals. For obvious ethical, anatomical, and physiological reasons, these models could be replaced with optimized ex vivo systems. The creation of a burn model on human skin using a pulsed dye laser could represent a relevant model for preclinical research. Six samples of excess human abdominal skin were obtained within one hour after surgery. Burn injuries were induced on small samples of cleaned skin using a pulsed dye laser on skin samples, at varying fluences, pulse numbers and illumination duration. In total, 70 burn injuries were performed on skin ex vivo before being histologically and dermato-pathologically analyzed. Irradiated burned skin samples were classified with a specified code representing burn degrees. Then, a selection of samples was inspected after 14 and 21 days to assess their capacity to heal spontaneously and re-epithelize. We determined the parameters of a pulsed dye laser inducing first, second, and third degree burns on human skin and with fixed parameters, especially superficial and deep second degree burns. After 21 days with the ex vivo model, neo-epidermis was formed. Our results showed that this simple, rapid, user-independent process creates reproducible and uniform burns of different, predictable degrees that are close to clinical reality. Human skin ex vivo models can be an alternative to and complete animal experimentation, particularly for preclinical large screening. This model could be used to foster the testing of new treatments on standardized degrees of burn injuries and thus improve therapeutic strategies.
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Affiliation(s)
- Ania Labouchère
- PlasticReconstructive, and Hand Surgery Service, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- Regenerative Therapy Unit, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- Lausanne Burn Center, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Daniel Haselbach
- PlasticReconstructive, and Hand Surgery Service, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Murielle Michetti
- Regenerative Therapy Unit, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- Lausanne Burn Center, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Catherine Pythoud
- Regenerative Therapy Unit, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Wassim Raffoul
- PlasticReconstructive, and Hand Surgery Service, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- Lausanne Burn Center, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Lee Ann Applegate
- Regenerative Therapy Unit, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- Lausanne Burn Center, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland
| | - Nathalie Hirt-Burri
- Regenerative Therapy Unit, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- Lausanne Burn Center, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Anthony de Buys Roessingh
- Lausanne Burn Center, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- Children and Adolescent Surgery Service, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
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Rodgers KE, Tan A, Kim L, Espinoza T, Meeks C, Johnston W, Maulhardt H, Donald M, Hill C, diZerega GS. Development of a guinea pig cutaneous radiation injury model using low penetrating X-rays. Int J Radiat Biol 2016; 92:434-43. [PMID: 27258737 DOI: 10.1080/09553002.2016.1186302] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
PURPOSE A guinea pig skin model was developed to determine the dose-dependent response to soft X-ray radiation into the dermis. MATERIALS AND METHODS X-ray exposure (50 kVp) was defined to a 4.0 × 4.0 cm area on the lateral surface of a guinea pig using lead shielding. Guinea pigs were exposed to a single fraction of X-ray irradiation ranging from 25-79 Gy via an XRAD320ix Biological Irradiator with the collimator removed. Gross skin changes were measured using clinical assessments defined by the Kumar scale. Skin contracture was assessed, as well as histological evaluations. RESULTS Loss of dermal integrity was shown after a single dose of soft X-ray radiation at or above 32 Gy with the central 2.0 × 2.0 cm of the exposed site being the most affected. Hallmarks of the skin injury included moist desquamation, ulceration and wound contracture, as well as alterations in epithelium, dermis, muscle and adipose. Changes in the skin were time- and radiation dose-dependent. Full-thickness injury occurred without animal mortality or gross changes in the underlying organs. CONCLUSIONS The guinea pig is an appropriate small animal model for the short-term screening of countermeasures for cutaneous radiation injury (CRI).
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Affiliation(s)
- Kathleen E Rodgers
- a School of Pharmacy, University of Southern California , Los Angeles , CA , USA
| | - Alick Tan
- a School of Pharmacy, University of Southern California , Los Angeles , CA , USA
| | - Lila Kim
- a School of Pharmacy, University of Southern California , Los Angeles , CA , USA
| | - Theresa Espinoza
- a School of Pharmacy, University of Southern California , Los Angeles , CA , USA
| | - Christopher Meeks
- a School of Pharmacy, University of Southern California , Los Angeles , CA , USA
| | | | | | | | - Colin Hill
- c Keck School of Medicine at USC , Los Angeles , CA , USA
| | - Gere S diZerega
- b US Biotest , San Luis Obispo , CA , USA ;,c Keck School of Medicine at USC , Los Angeles , CA , USA
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Dai T, Yaseen MA, Diagaradjane P, Chang DW, Anvari B. Comparative study of cryogen spray cooling with R-134a and R-404a: implications for laser treatment of dark human skin. JOURNAL OF BIOMEDICAL OPTICS 2006; 11:041116. [PMID: 16965144 DOI: 10.1117/1.2338001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Cutaneous laser treatment in dark skin patients is challenging due to significant light absorption by the melanin at the basal layer of epidermis, which can result in irreversible nonspecific thermal injury to the epidermis. Cryogen spray cooling (CSC) with R-134a (boiling point approximately -26.2 degrees C at 1 atm), which is currently used during cutaneous laser treatment, has shown poor efficacy in protecting dark human skin. We investigated the potential of CSC with R-404a (boiling point approximately -46.5 degrees C at 1 atm), which has a lower boiling point than R-134a, for improved therapeutic outcome in dark human skin at three levels: in vitro (epoxy resin skin phantom), ex vivo (normal dark human skin sample), and in vivo (skin of the rabbit external ear). The skin phantom was used to acquire the surface and internal temperature profiles in response to CSC with R-134a or R-404a at various spurt durations, based upon which CSC-induced heat removal from the skin phantom was estimated using an algorithm that solved a one-dimensional inverse heat conduction problem. CSC with R-404a increased the temperature reductions within the phantom and subsequently the amount of heat removal from the phantom in comparison to that with R-134a. Normal ex vivo Fitzpatrick types V-VI human skin samples were used to investigate the thermal response of dark human skin epidermis to CSC (R-134a or R-404a) at various spurt durations in conjunction with 595-nm pulsed dye laser irradiation at various radiant exposures. Cryogen R-404a increased the threshold radiant exposures for irreversible thermal injury to the epidermis in dark pigmentation skin. No obvious CSC-induced morphological changes to human skin was observed when sprayed with R404-a spurts using durations up to 300 ms. In vivo rabbit ear vasculature was used as a model of cutaneous anomalies to assess the influences of CSC (with R-134a or R-404a) on the photothermolysis of dermal blood vessels. CSC (R-134a or R-404a) with the spurt durations of 100 to 300 ms increased the most superficial depth of thermally damaged dermal blood vessel compared with the sites without CSC, implying possible nonspecific cooling of superficial dermal blood vessels by the cryogen spurts with the settings applied.
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Affiliation(s)
- Tianhong Dai
- Rice University, Department of Bioengineering, MS 142, P.O. Box 1892, Houston, Texas 77251, USA
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