Fate of systemically and locally administered adipose-derived mesenchymal stromal cells and their effect on wound healing

There is increasing interest in the use of adipose-derived mesenchymal stromal cells (ASCs) for wound repair. As the fate of administered cells is still poorly defined, we aimed to establish the location, survival, and effect of ASCs when administered either systemically or locally during wound repair under physiological conditions. To determine the behavior of ASCs, a rat model with wounds on the dorsal aspect of the hind paws was used and two treatment modes were assessed: ASCs administered systemically into the tail vein or locally around the wound. ASCs were transduced to express both firefly luciferase (Fluc) and green fluorescent protein to enable tracking by bioluminescence imaging and immunohistological analysis. Systemically administered ASCs were detected in the lungs 3 hours after injection with a decrease in luminescent signal at 48 hours and signal disappearance from 72 hours. No ASCs were detected in the wound. Locally administered ASCs remained strongly detectable for 7 days at the injection site and became distributed within the wound bed as early as 24 hours post injection with a significant increase observed at 72 hours. Systemically administered ASCs were filtered out in the lungs, whereas ASCs administered locally remained and survived not only at the injection site but were also detected within the wound bed. Both treatments led to enhanced wound closure. It appears that systemically administered ASCs have the potential to enhance wound repair distally from their site of entrapment in the lungs whereas locally administered ASCs enhanced wound repair as they became redistributed within the wound bed.The Swiss National Science Foundation Project (#310030_170132), Medical Faculty of University of Geneva, the South African Medical Research Council University Flagship Program (SAMRC-RFA-UFSP-01-2013/STEM CELLS), the SAMRC Extramural Unit for Stem Cell Research and Therapy, and the Institute for Cellular and MolecularMedicine (ICMM) of the University of Pretoria. The Fonds National Suisse de la Recherche Scientifique (FNSNF) and the Faculty of Medicine of the University of Geneva for contributing to the funding in Geneva and the South African Medical Research Council (Flagship and Extramural Unit awards), the National Research Foundation (Scarce Skills Doctoral Scholarship, Grant UID: 88799), Ernst & Ethel Eriksen Trust (Doctoral Scholarship), University of Pretoria Bursary Office (Postgraduate Bursary), and the Institute for Cellular and Molecular Medicine (ICMM) of the University of Pretoria for contributing to the funding in South Africa.https://stemcellsjournals.onlinelibrary.wiley.com/journal/21576580am2020Immunolog

Circular abdominoplasty after massive weight loss: Is it a risky procedure?

Most post-bariatric patients seek body contouring procedures to correct skin excess after massive weight loss. Among these procedures, some surgeons are still wary of circular abdominoplasty, mainly because it is considered a major intervention associated with a high complication rate. The aim of this study was to assess the complication rate of circular abdominoplasty performed on patients presenting with massive weight loss, with a particular emphasis on patient selection and surgical technique

Case Report Multisite Infection with Mycobacterium abscessus after Replacement of Breast Implants and Gluteal Lipofilling

Introduction. Medical tourism for aesthetic surgery is popular. Nontuberculous mycobacteria (NTM) occasionally cause surgicalsite infections. As NTM grow in biofilms, implantations of foreign bodies are at risk. Due to late manifestation, infections occur when patients are back home, where they must be managed properly. Case Report. A 39-year-old healthy female was referred for acute infection of the right gluteal area. Five months before, she had breast implants replacement, abdominal liposuction, and gluteal lipofilling in Mexico. Three months postoperatively, implants were removed for NTM-infection in Switzerland. Adequate antibiotic treatment was stopped after seven days for drug-related hepatitis. At entrance, gluteal puncture for bacterial analysis was performed. MRI showed large subcutaneous collection. Debridement under general anaesthesia was followed by open wound management. Total antibiotic treatment was 20 weeks. Methods. Bacterial analysis of periprosthetic and gluteal liquids included Gram-stain plus acid-fast stain, and aerobic, anaerobic and mycobacterial cultures. Results. In periprosthetic fluid, Mycobacterium abscessus, Propionibacterium, and Staphylococcus epidermidis were identified. The same M. abscessus strain was found gluteally. The gluteal wound healed within six weeks. At ten months' follow-up, gluteal asymmetry persists for deep scarring. Conclusion. This case presents major complications of multisite aesthetic surgery. Surgical-site infections in context of medical tourism need appropriate bacteriological investigations, considering potential NTM-infections

Reactive Oxygen Species and NOX Enzymes Are Emerging as Key Players in Cutaneous Wound Repair

Our understanding of the role of oxygen in cell physiology has evolved from its long-recognized importance as an essential factor in oxidative metabolism to its recognition as an important player in cell signaling. With regard to the latter, oxygen is needed for the generation of reactive oxygen species (ROS), which regulate a number of different cellular functions including differentiation, proliferation, apoptosis, migration, and contraction. Data specifically concerning the role of ROS-dependent signaling in cutaneous wound repair are very limited, especially regarding wound contraction. In this review we provide an overview of the current literature on the role of molecular and reactive oxygen in the physiology of wound repair as well as in the pathophysiology and therapy of chronic wounds, especially under ischemic and hyperglycemic conditions

Hyperbaric oxygen therapy promotes wound repair in ischemic and hyperglycemic conditions, increasing tissue perfusion and collagen deposition

The treatment of chronic wounds remains inconsistent and empirical. Hyperbaric oxygen therapy (HBOT) is a promising method to improve wound repair but there is still a lack of understanding of its mechanisms of action and its indications are not yet clearly defined. We studied the effects of HBOT in four different wound conditions by inflicting bilateral wounds on the dorsal aspect of the feet of nonischemic or ischemic limbs in normoglycemic or hyperglycemic rats. To create an ischemic condition, arterial resection was performed unilaterally. Forty-four animals received HBOT five times a week until complete wound closure. Wound repair was compared with 44 rats receiving standard dressing only. HBOT increased blood flow and accelerated wound closure in ischemic and hyperglycemic wounds, most significantly when the two conditions were combined. Wound contraction and reepithelialization were similarly stimulated by HBOT. The acceleration of wound contraction was not associated with increased myofibroblasts expression, nor fibroblast recruitment or higher cell count in the granulation tissue. Of note, we observed a significant increase in collagen deposition in early time points in ischemic wounds receiving HBOT. This data emphasizes that an early application of HBOT might be crucial to its efficacy. We concluded that wounds where ischemia and hyperglycemia are combined, as it is often the case in diabetic patients, have the best chance to benefit from HBOT

Local shockwave-induced capillary recruitment improves survival of musculocutaneous flaps

BACKGROUND: Shockwave (SW) application has been shown to limit flap necrosis. However, the underlying microhemodynamic mechanisms remain unclear. Therefore, the objective of this study was to analyze the effect of SW application on a microcirculatory level. METHODS: We treated 12 C57BL/6 mice with local SW application (500 shockwave impulses at 0.15 mJ/mm(2)) either 24 h before (preconditioning [PRE]) or 30 min after (postconditioning [POST]) flap elevation. Animals with an untreated flap (CON) or without a flap served as controls. We applied dorsal skinfold chambers to the animals and performed epifluorescence microscopy over a 10-d period to assess microcirculatory parameters (arteriolar diameter, red blood cell velocity, blood flow, functional capillary density, and intercapillary distance) as well as inflammation, apoptotic cell death, and necrosis. RESULTS: SW application significantly decreased tissue necrosis independently of the application time point (PRE: 29% ± 7%; POST: 25% ± 7% versus CON: 47% ± 2%; day 10, P < 0.05). Arteriolar diameter, red blood cell velocity, and blood flow were not statistically significantly different among the 3 flap groups. However, SW (PRE and POST) resulted in an early and persistent increase in functional capillary density and consequently decreased intercapillary distance compared with CON and the group without a flap (P < 0.05). Also, SW resulted in a significantly decreased inflammatory response (P < 0.05) and induced an angiogenic response, as indicated by new functional microvessel formation observed 5 d after therapy. CONCLUSIONS: Local SW application improved tissue survival by recruitment of sleeping capillaries within the non ischemic tissue and maintenance of capillary perfusion within the critically perfused tissue after induction of ischemia, which was independent of the application time point. Neoangiogenesis occurred beyond the ischemic tolerance of the tissue, and therefore does not seem to contribute to improved tissue survival

Twenty-Five Years of Experience with the Submental Flap in Facial Reconstruction

The submental flap is a pedicled island flap with excellent colour match for facial reconstruction. The flap can be raised with muscle, submandibular gland or bone and can be transposed to reach defects up to two thirds of the face. We report the primary author's experience of 25 years using the submental flap from its original description to most recent technical evolutions in both Europe and Africa