ABSTRACT: This study aims to quantify by intravital microscopy and histological wound scoring the effect of radial pressure wave treatment (RPWT) on murine incisional wound healing. The dorsal skinfold chamber in mice was used for intravital microscopy, whereby an incisional wound was created within the chamber. RPWT to the wound was carried out using a ballistic pressure wave source (EMS Swiss DolorClast). Animals received a dose of 500 pulses at an energy flux rate of 0.1mJ/mm(2) and a frequency of 3Hz at day 1, 3, 5, 7, 9, and 11 post wounding. RPW treated and untreated ApoE depleted mice (ApoE(-/-)) were compared to normal healing wild type animals (WT). The microcirculation of the wound was analyzed quantitatively in vivo using epi-illumination intravital fluorescence microscopy. Tissue samples were examined ex vivo for wound scoring and immunohistochemistry. Upon RPWT total wound score in ApoE(-/-) mice was increased by 13% (not significant) on day 3, by 37% on day 7 (P<0.05), and by 39% on day 13 (P<0.05) when compared to untreated ApoE(-/-) mice. Improved wound healing was associated with an increase of functional angiogenetic density by 23% (not significant) on day 5, by 36% on day 7 (P<0.05), and by 41% on day 9 (P<0.05). Following RPWT, on day three we observed enhanced expression of capase-3 (2-fold), proliferating cell nuclear antibody (PCNA, 1,6-fold), and endothelial nitric oxide synthase (eNOS, 2.6-fold), all P<0.05. In conclusion repetitive RPWT accelerated wound healing in ApoE(-/-) mice by increasing functional neovascular density. In addition our findings strongly suggest that RPW may facilitate the linear progression of wound healing phases by fostering apoptosis.
Microvascular Research 03/2012; 84(1):24-33. · 2.83 Impact Factor
ABSTRACT: In the era of tissue engineering, the physiologic process of skin graft revascularization remains unclear, preventing the successful development of skin substitutes. Therefore, the authors developed a new in vivo model with which to visualize the process of engraftment and its microvascular architecture. The aim of this study was to specifically investigate the vascular transformations within the skin graft to gain applicable knowledge on how vascular processes during engraftment occur.
Microsurgical preparation of the modified dorsal skinfold chamber including autologous skin grafting was performed in male C57BL/6J mice (n = 10). In addition, immunohistochemistry of angiogenic factors, endothelial cells, and pericytes, and corrosion casting were performed to further characterize the specific mechanisms.
The graft exhibited capillary widening starting at day 3, resulting in the temporary formation of spherical protrusions at the graft capillary divisions starting in the center of the graft 24 to 48 hours after revascularization. Confocal microscopy showed the simultaneous expression of CD31 and desmin. Corrosion casting and evaluation by light microscopy and scanning electron microscopy showed the three-dimensional formation of capillaries in the wound bed that connected to the preexisting capillary loops of the skin graft.
The authors were able to show for the first time a temporary angiogenic response within the capillaries of the skin graft. This most likely represents a reaction to reperfusion allowing the supply of proangiogenic factors to the hypoxic skin graft. The detection of an angiogenic response within the graft capillaries is for the first time made possible in the newly developed model and is therefore completely novel.
Plastic and reconstructive surgery 07/2010; 126(1):61-70. · 2.74 Impact Factor
ABSTRACT: Cigarette smoking is linked to thromboembolic events; however, a relationship between nicotine exposition and thrombosis has not been established. Thus, we intended to study the effect of acute and chronic nicotine application in an in vivo mouse model.
In microvessels of the dorsal skin fold chamber, light-dye-induced thrombus formation was analyzed using intravital fluorescence microscopy. Male and female C57BL/6J mice received nicotine chronically via the drinking water (100 microg/ml) for 8 weeks. An additional series of experiments was performed with acute iv nicotine treatment (3 mg/kg body weight).
No significant differences in microvascular thrombus formation were detected after chronic nicotine application in male and female animals when compared with controls. Accordingly, flow cytometric analysis did not show significant effects on platelet activity. Chronic nicotine treatment resulted in a significantly reduced endothelial activation in male, but not in female mice. In contrast, acute iv application of nicotine revealed significantly shorter thrombosis times in arterioles of female mice and a significantly increased endothelial P-selectin expression in mice of both genders.
Chronic nicotine application does not promote microvascular thrombus formation in mice of either gender, whereas acute high-dose iv administration caused a significant increase of arteriolar thrombosis in female animals probably via a synergistic effect of increased endothelial P-selectin expression and female hormone levels. A gender-dependency of acute nicotine action can be presumed.
Langenbeck s Archives of Surgery 06/2007; 392(3):285-95. · 1.81 Impact Factor