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Repair and regeneration of craniofacial tissues is particularly challenging because they comprise a complex structure of hard and soft tissues involved in intricate functions. This study combined collagen scaffolds and human adipose stem cells (hASCs) for oral mucosal and calvarial bone regeneration by using resveratrol (RSV), which affects the differentiation of mesenchymal stem cells. We have evaluated the effect of collagen scaffold‐containing RSV (collagen/RSV) scaffolds both in vitro and in vivo for their wound healing and bone regeneration potential. Scanning electron microscopy and immunostaining results reveal that hASCs adhere well to and proliferate on both collagen scaffolds and collagen/RSV scaffolds. Oral mucosal lesion experiments demonstrated that the collagen/RSV scaffold is more effective in wound closure and contraction than the collagen scaffold. The micro‐computed tomography (μCT) images of calvarial bone display regenerating bone in defects covered with hASCs on collagen/RSV scaffolds that are more visible than that in defects covered with hASCs on a collagen scaffolds. RSV was more effective at inducing hASC differentiation on the collagen scaffold, suggesting that collagen/RSV scaffolds can provide useful biological cues that stimulate craniofacial tissue formation. [ABSTRACT FROM AUTHOR]

Objectives: The lack of real-time assessment of vascular perfusion changes remains a major weakness in assessing the efficacy of bone marrow stromal cells (BMSC) therapeutic ischemia reperfusion (I/R) injury. This study provides for the first time the real-time in vivo perfusion monitoring in I/R mice with BMSC therapy.Study Design: Animal model.Methods: Surgically created cutaneous flaps perfused by the inferior epigastric vessels were subjected to 3.5 hours of ischemia/reperfusion. Wound healing and vascular perfusion were assessed by Image-J and laser speckle contrast analysis (LSCA) in three groups (sham, I/R, and I/R + BMSC). BMSC tracking was quantified in an additional two groups (with/without I/R) using intravital fluorescent microscopy. The histopathology of skin flaps was examined by hematoxylin and eosin stain. Infiltrated macrophages were analyzed by confocal immunofluorescent microscopy.Results: Postischemic tissues treated with BMSC demonstrated significantly greater survival than I/R control. On days 3 to 7 postreperfusion, both proximal and distal areas in BMSC-treated flaps demonstrated greater levels of perfusion than untreated I/R flaps (P < 0.05). Intravital fluorescent microscopy revealed that numbers of labeled BMSC were significantly increased in the distal area compared to the proximal area in both with and without ischemic mice. Histological examination showed lower necrosis and infiltrated inflammatory cells in I/R + BMSC-treated mice versus I/R controls.Conclusion: BMSC accumulated in I/R flaps and exerted beneficial effects including: 1) improving vascular perfusion and 2) attenuating inflammatory cell infiltration. LSCA facilitates monitoring of the real-time restitution of perfusion during flap wound healing in experimental animals and could also similarly applied in clinical investigations.Level Of Evidence: NA. Laryngoscope, 128:E198-E205, 2018. [ABSTRACT FROM AUTHOR]

Blood supply is the most important factor determining the survival of a skin flap. Botulinum toxin-A (Botox-A) is used as pharmacologic agent not only for aesthetic purposes, but also for its vasomotor actions. This study was conducted to establish whether local application of Botox-A increased survival of random pattern skin flaps in rats by changing the expression of neurotransmitters. Forty adult Sprague-Dawley rats with a caudally-based random pattern skin flap were divided into two groups: Botox-A group and saline group. Surviving flap area and cutaneous blood flow in the flap were evaluated on postoperative days 3 and 7. After injection of Botox-A, changes in vessels were analyzed using immunohistochemical staining. Levels of norepinephrine, neuropeptide-Y, nitric oxide, and endothelial nitric oxide synthase were analyzed quantitatively by high performance liquid chromatography, Western blot, and colorimetric assay. The survived area in the Botox-A group was significantly higher than that in the control group on postoperative days 3 and 7. Blood flow in the Botox-A group was significantly high in the proximal and middle areas immediately after the operation. The number of CD31-positive vessels in the Botox-A group was significant greater than that in the control group. Norepinephrine level in the Botox-A group decreased significantly immediately after flap elevation and at postoperative day 3. There were no significant differences in neuropeptide-Y level between the two groups. Nitric oxide level did not change significantly in either group despite the increase in endothelial nitric oxide synthase immediately after flap elevation and at 3 days postoperatively. In conclusion, Botox-A increased vascular blood flow and viable flap area in rats by reducing norepinephrine level. In contrast, neuropeptide-Y, another vasoconstrictor, was not affected by Botox-A. Nitric oxide, a vasodilator, was also not affected by Botox-A, despite the significant increase in endothelial nitric oxide synthase expression in the flaps. [ABSTRACT FROM AUTHOR]

Relaxin ( RLX) has multiple vascular actions, including vasodilation and angiogenesis, which occur via induction of vascular endothelial growth factor ( VEGF) expression. We generated a RLX-expressing ( dE1- RGD/ lacZ/ RLX) adenovirus and investigated whether it enhances skin flap survival. Thirty Sprague-Dawley rats were divided into three groups: RLX-expressing adenovirus group, control virus group, and phosphate-buffered saline ( PBS) group. Two days before surgery and immediately after flap elevation, the caudally based flap that was 3 × 9 cm in size was subdermally injected with the dE1- RGD/ lacZ/ RLX virus (107 PFU), dE1- RGD/ lacZ virus (107 PFU), or PBS. The surviving area of the flap and the amount of blood flow were measured. On postoperative day 10, CD31-positive vessels and VEGF protein expression were examined. We observed a significant increase in the survival area of the flap in the RLX group. Doppler measurement also showed significantly increased blood flow immediately after the operation and on postoperative days 7 and 10. CD31-positive vessels and VEGF protein expression were significantly greater in the RLX group. Thus, administration of RLX-expressing adenovirus into elevated skin flaps increased VEGF expression, the number of capillaries, and blood flow to the flap, thereby improving skin flap survival. [ABSTRACT FROM AUTHOR]

The article offers information on the guidelines developed by the Wound Healing Society (WHS) for wound treatment. These include guidelines to decrease the impediment to acute wound healing caused by inadequate wound perfusion, nonviable tissue, hematoma or seroma, an increased tissue bacterial bioburden, and mechanical factors during wound repair.

The aim of the present study was to experimentally evaluate whether topical fibrin-mediated administration of a vascular endothelial growth factor (VEGF)-A plasmid to the wound bed can protect skin flaps from necrosis. A plasmid expression vector containing the VEGF-A cDNA was constructed. The plasmid was then administered to the wound bed of rat abdominal skin flaps in a fibrin sealant. The percentage of viable, ischemic and necrotic tissue was assessed postoperatively as a baseline and after 3 and 7 days using digital surface area morphometry. Laser Doppler imaging of the flaps and VEGF-A Western blot analysis of flap tissue were performed to assess angiogenesis and VEGF-A tissue levels. Flaps treated with VEGF plasmids in the presence of uptake enhancing Lipofectamine transfection reagent increased flap survival 7 days postoperatively significantly associated with markedly elevated tissue perfusion and enhanced tissue VEGF-A protein expression. Our results indicate that topical fibrin-mediated administration of a VEGF-A plasmid may serve as an alternative to previous strategies in treating ischemic skin flaps. The suggested therapeutic approach is easily applicable and inexpensive in preparation. Thus, this protocol may also enhance wound healing in posttrauma skin lacerations or in skin grafts. [ABSTRACT FROM AUTHOR]

To facilitate bone healing in difficult circumstances, and to replace conventional therapeutic modalities, highly purified bone marrow-derived human mesenchymal stem cells (hMSCs) were investigated for induction of their osteogenic lineage upon provision of cytokine cues in vitro and in the cranial defect model in vivo. Alkaline phosphatase-expressing cells were most frequently observed when the hMSCs were treated with 2.5 ng/ml of basic fibroblast growth factor (bFGF) and 50 ng/ml of bone morphogenetic protein (BMP)-2 for 4 days in culture after a 6-day incubation in osteogenic medium containing dexamethasone, ascorbic acid-2-phosphate, and β-glycerophosphate. Four-millimeter full-thickness cranial defect wounds were made in male nude rats (F344/NJCl-rnu), whose deficit in the T cell compartment prevented T-cell–mediated cellular rejection. The animals were treated for 4 weeks with hMSCs and application of 10 µg each of bFGF and BMP-2 that had been soaked into a gelatin sponge carrier. Significant bone mineral density was observed by dual X-ray absorptiometry and this treatment also produced histologically mature osteocytes surrounded by both osteoblasts and osteoclasts expressing alkaline phosphatase and osteocalcin. The bone mineral densities and histological structures were matched at 8 weeks post-transplantation. Therefore, human bone marrow-derived mesenchymal stem cells are able to differentiate into an osteogenic lineage upon cytokine stimulation and accelerate healing in a nude rat cranial bone healing model. [ABSTRACT FROM AUTHOR]