First Insights into Human Fingertip Regeneration by Echo-Doppler Imaging and Wound Microenvironment Assessment

• Published in: International journal of molecular sciences Vol. 18; no. 5; p. 1054
• Main Authors: Jafari, Paris, Muller, Camillo, Grognuz, Anthony, Applegate, Lee Ann, Raffoul, Wassim, di Summa, Pietro G, Durand, Sébastien
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13-05-2017; MDPI
• Subjects: Adult; Aged; Brain-derived neurotrophic factor; Brain-Derived Neurotrophic Factor - genetics; Burns - genetics; Burns - physiopathology; Cell Differentiation - genetics; Chemokines; Communication; Cytokines; Doppler effect; Elasticity; Exudates; Exudates and Transudates - immunology; Exudates and Transudates - metabolism; Exudates and Transudates - physiology; Exudation; Finger Injuries - genetics; Finger Injuries - physiopathology; Fingers & toes; Functional anatomy; Growth factors; Humans; Imaging; Immunoassay; Inflammation; Leukemia inhibitory factor; Leukemia Inhibitory Factor - genetics; Male; Mechanical properties; Medical dressings; Medical imaging; Mesenchymal Stromal Cells - metabolism; Mesenchymal Stromal Cells - physiology; Mesenchyme; Middle Aged; Neuroimaging; Occlusive Dressings; Platelet-derived growth factor; Platelet-Derived Growth Factor - genetics; Regeneration; Regeneration - genetics; Repair; Skeleton; Surface layers; Texture; Tissue engineering; Trauma; Vascular endothelial growth factor; Vascular Endothelial Growth Factor A - genetics; Vascularization; Wound healing; Wound Healing - genetics; Wound Healing - physiology; Doppler imaging; clinical assessment; angiogenesis; fingertip regeneration
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms18051054

Fingertip response to trauma represents a fascinating example of tissue regeneration. Regeneration derives from proliferative mesenchymal cells (blastema) that subsequently differentiate into soft and skeletal tissues. Clinically, conservative treatment of the amputated fingertip under occlusive dressing can shift the response to tissue loss from a wound repair process towards regeneration. When analyzing by Immunoassay the wound exudate from occlusive dressings, the concentrations of brain-derived neurotrophic factor (BDNF) and leukemia inhibitory factor (LIF) were higher in fingertip exudates than in burn wounds (used as controls for wound repair versus regeneration). Vascular endothelial growth factor A (VEGF-A) and platelet-derived growth factor (PDGF) were highly expressed in both samples in comparable levels. In our study, pro-inflammatory cytokines were relatively higher expressed in regenerative fingertips than in the burn wound exudates while chemokines were present in lower levels. Functional, vascular and mechanical properties of the regenerated fingertips were analyzed three months after trauma and the data were compared to the corresponding fingertip on the collateral uninjured side. While sensory recovery and morphology (pulp thickness and texture) were similar to uninjured sides, mechanical parameters (elasticity, vascularization) were increased in the regenerated fingertips. Further studies should be done to clarify the importance of inflammatory cells, immunity and growth factors in determining the outcome of the regenerative process and its influence on the clinical outcome.