title: Application of Electron Paramagnetic Resonance (EPR) Oximetry to Monitor Oxygen in Wounds in Diabetic Models.
abstract: A lack of oxygen is classically described as a major cause of impaired wound healing in diabetic patients. Even if the role of oxygen in the wound healing process is well recognized, measurement of oxygen levels in a wound remains challenging. The purpose of the present study was to assess the value of electron paramagnetic resonance (EPR) oximetry to monitor pO2 in wounds during the healing process in diabetic mouse models. Kinetics of wound closure were carried out in streptozotocin (STZ)-treated and db/db mice. The pO2 was followed repeatedly during the healing process by 1 GHz EPR spectroscopy with lithium phthalocyanine (LiPc) crystals used as oxygen sensor in two different wound models: a full-thickness excisional skin wound and a pedicled skin flap. Wound closure kinetics were dramatically slower in 12-week-old db/db compared to control (db/+) mice, whereas kinetics were not statistically different in STZ-treated compared to control mice. At the center of excisional wounds, measurements were highly influenced by atmospheric oxygen early in the healing process. In pedicled flaps, hypoxia was observed early after wounding. While reoxygenation occurred over time in db/+ mice, hypoxia was prolonged in the diabetic db/db model. This observation was consistent with impaired healing and microangiopathies observed using intravital microscopy. In conclusion, EPR oximetry using LiPc crystals as the oxygen sensor is an appropriate technique to follow wound oxygenation in acute and chronic wounds, in normal and diabetic animals. Nevertheless, the technique is limited for measurements in pedicled skin flaps and cannot be applied to excisional wounds in which diffusion of atmospheric oxygen significantly affects the measurements.
authors.affiliation: Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Céline M
authors.initials: CM
authors.lastname: Desmet
authors.affiliation: Endocrine Cell Therapy Unit, Center of Tissue/Cell Therapy, Institut de Recherche Expérimentale et Clinique, Cliniques Universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium.|Plastic and Reconstructive Surgery Unit, Cliniques Universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Aurore
authors.initials: A
authors.lastname: Lafosse
authors.affiliation: Endocrine Cell Therapy Unit, Center of Tissue/Cell Therapy, Institut de Recherche Expérimentale et Clinique, Cliniques Universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Sophie
authors.initials: S
authors.lastname: Vériter
authors.affiliation: Pole of Pharmacology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Paolo E
authors.initials: PE
authors.lastname: Porporato
authors.affiliation: Pole of Pharmacology, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Sonveaux
authors.affiliation: Endocrine Cell Therapy Unit, Center of Tissue/Cell Therapy, Institut de Recherche Expérimentale et Clinique, Cliniques Universitaires Saint-Luc, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Denis
authors.initials: D
authors.lastname: Dufrane
authors.affiliation: Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Philippe
authors.initials: P
authors.lastname: Levêque
authors.affiliation: Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Bernard
authors.initials: B
authors.lastname: Gallez
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D016022:Case-Control Studies; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000150:complications*; D004195:Disease Models, Animal; D004578:Electron Spin Resonance Spectroscopy; D000069416:Intravital Microscopy; D008297:Male; D051379:Mice; D008820:Mice, Obese; D010092:Oximetry; D010100:Oxygen / Q000378:metabolism*; D012871:Skin Diseases / Q000150:complications / Q000473:pathology; D014945:Wound Healing
chemical_list: D001786:Blood Glucose; D010100:Oxygen