Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society
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It is well established that auto/paracrine acetylcholine (ACh) is essential for wound epithelialization, and that the mechanisms include regulation of keratinocyte motility and adhesion via nicotinic ACh receptors (nAChRs). Keratinocyte nAChRs can be also activated by non-canonical ligands, such as secreted mammalian Ly-6/urokinase-type plasminogen activator receptor-related protein (SLURP)-1 and -2. In this study, we determined effects of recombinant (r)SLURP-1 and-2 on migration of human epidermal and oral keratinocytes under agarose and epithelialization of cutaneous and oral mucosal excisional wounds in mice, and also identified nAChRs mediating SLURP signals. ⋯ The biologic effects of rSLURPs required the presence of endogenous ACh, indicating that auto/paracrine SLURPs provide for a fine tuning of the physiologic regulation of crawling locomotion via the keratinocyte ACh axis. Since nAChRs have been shown to regulate SLURP production, cholinergic regulation of keratinocyte migration appears to be mediated by a reciprocally arranged network. The cholinergic peptides, therefore, may become prototype drugs for the treatment of wounds that fail to heal.
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In this study our objectives were (1) to investigate whether meticillin-resistant Staphylococcus aureus (MRSA) showed an increased tolerance to silver wound dressings compared with meticillin-sensitive S. aureus (MSSA); and (2) to evaluate the effects of bacterial phenotypic states of MRSA and MSSA, and pH, on the activity of silver wound dressings and two antibiotics, ampicillin and clindamycin. Twenty MRSA strains and 10 MSSA strains isolated from burns patients in South Africa were evaluated for their susceptibility to a silver alginate and a silver carboxymethyl cellulose wound dressing, employing a corrected zone of inhibition assay, conducted on Mueller Hinton agar and a poloxamer-based biofilm model. When exposed to the two silver dressings, all 30 S. aureus strains showed susceptibility. ⋯ Susceptibility to silver was overall higher for MRSA when compared with MSSA. This study showed that the effect of pH and bacterial phenotypic state must be considered when the antimicrobial activity of silver wound dressings is being investigated. It is evident from the data generated that both pH and the bacterial phenotypic state are factors that induce changes that affect both antimicrobial performance and bacterial susceptibility.
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The use of mammalian target of rapamycin inhibitors coincides with an increased incidence of surgical complications. In previous experiments, serious negative effects of postoperative everolimus on anastomotic strength were found. This study aims to investigate if delayed drug administration can prevent loss of wound strength. ⋯ In abdominal fascia, this was the case only if everolimus was withheld until day 4. In general, changes in wound hydroxyproline content showed similarities to changes in wound strength. Thus, delaying administration of everolimus for 2-4 days after operation can prevent a serious loss of wound strength, both in the intestine and in the abdominal fascia.
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Recent data support the involvement of stromal cell-derived factor 1 (SDF-1) in the homing of bone marrow-derived stem cells to wound sites during skeletal, myocardial, vascular, lung, and skin wound repair as well as some fibrotic disorders via its receptor CXCR4. In this study, the role of SDF-1/CXCR4 signaling in the formation of hypertrophic scar (HTS) following burn injury and after treatment with systemic interferon α2b (IFNα2b) is investigated. Studies show SDF-1/CXCR4 signaling was up-regulated in burn patients, including SDF-1 level in HTS tissue and serum as well as CD14+ CXCR4+ cells in the peripheral blood mononuclear cells. ⋯ Also, recombinant SDF-1 and lipopolysaccharide stimulated fibroblast-conditioned medium up-regulated peripheral blood mononuclear cell mobility. In the burn patients with HTS who received subcutaneous IFNα2b treatment, increased SDF-1/CXCR4 signaling was found prior to treatment which was down-regulated after IFNα2b administration, coincident with enhanced remodeling of their HTS. Our results suggest that SDF-1/CXCR4 signaling is involved in the development of HTS by promoting migration of activated CD14+ CXCR4+ cells from the bloodstream to wound sites, where they may differentiate into fibrocyte and myofibroblasts and contribute to the development of HTS.
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Abnormal scarring occurring after wounds and burns remains a major source of functional and cosmetic disorders. The dermal part of the skin is recognized as playing a major role in the contraction process. ⋯ On the opposite extreme, in wounds of extended depth, the loss of dermal component results in the absence of elasticity and fibroblastic cell proliferation, leading to hypertrophy and contracture. These phenomena may be explained either by differences in cell populations, by extracellular matrix reactions to different stimuli, or by chemical control of interactions between cells and matrix.