Rat Skin Flap Model Research Articles

Microvascular Fragment Transplantation Improves Rat Dorsal Skin Flap Survival.

Background:The development of flap necrosis distally remains a concern during microsurgical flap transfers because, at least in part, of decreased perfusion. Microvascular fragments (MVFs) are microvessels isolated from adipose tissue that are capable of improving tissue perfusion in a variety of tissue defects. The aim of this study was to determine whether the transplantation of MVFs in a dorsal rat skin flap model can improve flap survival.Methods:A 10 × 3 cm flap was raised in a cranial to caudal fashion on the dorsal side of 16 Lewis rats, with the caudal side remaining intact. The rats were equally divided into a treatment group (MVFs) and a control group (sterile saline). At the time of surgery, sterile saline with or without MVFs was injected directly into the flap. Microvessel density was determined after harvesting flap tissue by counting vessels that positively stained for Griffonia simplicifolia lectin I-isolectin B4. Laser Doppler was used to measure blood flow before and after surgery and 7 and 14 days later. Flap survival was evaluated 7 and 14 days after surgery by evaluating the percentage of viable tissue of the flap with photodigital planimetry.Results:Despite the lack of a significant difference in microvessel density and tissue perfusion, flap survival increased 6.4% (P < 0.05) in MVF-treated animals compared with controls.Conclusions:The use of MVFs may be a means to improve flap survival. Future studies are required to delineate mechanisms whereby this occurs and to further optimize their application.

Spectral diffuse reflectance and autofluorescence imaging can perform early prediction of blood vessel occlusion in skin flaps

Flap transfer has become a common technique in reconstructive surgery. However, a significant number of compromised skin flaps are not successfully salvaged because the current clinical method for flap assessment relies heavily on the clinician's experience. Vascular occlusion is the major reason for flap failure, thus the accurate and objective early prediction of blood vessel occlusion is vitally important. Our parallel point measurement study has demonstrated the great potential of joint diffuse reflectance and autofluorescence spectroscopy in the early detection and differentiation of venous and arterial occlusion in skin flaps. Unfortunately, the technique of point measurements is not suitable to examine a large skin flap when a high spatial resolution is required. In this study, we attempted to overcome this problem by performing spectral diffuse reflectance and autofluorescence imaging on a rat skin flap model. Both imaging data and reconstructed spectra were used to statistically differentiate control flaps, arterially occluded flaps and venously occluded flaps. Our preliminary results suggest that the technique of joint diffuse reflectance and autofluorescence spectroscopic imaging can achieve high classification accuracy thus could be used to detect and differentiate flaps with venous and arterial occlusion accurately at an early time point in a large skin flap. Typical reconstructed spectra of (a) diffuse reflectance and (b) autofluorescence after normalization.

Protective effect of telomerase-based 16-mer peptide vaccine (GV1001) on inferior epigastric island skin flap survivability in ischaemia-reperfusion injury rat model

Background: Ischaemia-reperfusion injury (IRI) results in oxidative damage and a profound inflammatory reaction, leading to cell death. GV 1001 is a telomerase-based 16-mer peptide vaccine developed against cancer. However, it has also been reported to possess antioxidant and anti-inflammatory properties. The aim of this study was to determine if GV 1001 can reduce the negative effects caused by IRI in a rat skin flap model owing to its anti-oxidant and anti-inflammatory properties.Materials and methods: In order to evaluate the effect of GV 1001, 5 × 5 cm2 inferior epigastric artery based island skin flaps were dissected in 39 8-week-old Sprague-Dawley rats weighing 220–270 g. The rats were divided into three groups: (I) non-ischaemic group; (II) IRI with saline; and (III) IRI with 10 mg GV 1001 treatment. Drugs were administered intra-muscularly directly before and after ischaemia. Flap survival area, neutrophil infiltration, cytokine levels (interleukin [IL]-1, IL-6, and tumour necrosis factor-α), malondialdehyde (MDA) level, and superoxide dismutase (SOD) activity were measured. Flap survivability was analysed at 7 days after surgery.Results: Flap survival area was significantly larger in group III than in group II. Cytokine release level was also significantly lower in group III. Neutrophil infiltration grade, MDA level, and SOD activity slightly decreased in Group III; however, the changes were not statistically significant.Conclusion: These results imply that GV 1001 exerts a protective effect against IRI through antioxidant effects, reducing reactive oxygen species, and suppressing the inflammatory cascade.

Chlorogenic Acid Enhances Abdominal Skin Flap Survival Based on Epigastric Artery in Nondiabetic and Diabetic Rats.

Previous studies showed that chlorogenic acid (CGA) accelerates wound healing via its antioxidant activity. We aimed to investigate the effect of CGA in an experimental epigastric abdominal skin flap model in nondiabetic and diabetic rats. Rats were firstly divided into 2 groups: nondiabetic and diabetic. Diabetes was induced by streptozotocin. Then, 4 subgroups were created for each group: vehicle as well as 0.2 mg/0.5 mL, 1 mg/0.5 mL, and 5 mg/0.5 mL CGA treatments. Right epigastric artery-based abdominal skin flaps were elevated and sutured back into their original position. Chlorogenic acid or vehicle was injected once into the femoral arteries by leaving the epigastric artery as the single artery feeding the flaps during the injection. On postoperative day 7, flap survivals were evaluated, and the rats were killed. Distal flap tissues were collected for histopathological and biochemical assays. Chlorogenic acid showed greater flap survival in both nondiabetic and diabetic rats. Capillary density was increased, and necrosis was reduced in the CGA-treated rats. Chlorogenic acid decreased malondialdehyde levels as well as increased reduced glutathione and superoxide dismutase levels in the flap tissues. This study showed that CGA significantly improved flap survival by its antioxidant activities with intra-arterial local injections.

Calculation of contraction patterns in rat skin flap model

abstractIntroduction: In this study rat abdominal skin flaps were observed daily to explain their contraction behavior and a mathematical formula has been developed.Methods: 24 male rats were used for the study. Abdominal skin flaps based on the inferior epigastric neurovascular bundles were raised. In the first group all flaps were sutured to their donor area without any extra physical or chemical interference. In the second groups steroid was applied under the flaps to change the contraction rate.Results: Contraction rate was significantly higher in necrotic tissues in both groups. A formula was used to correct for the contraction. The corrected results for the seventh day necrotic area percentage measurements were significantly higher than actual measurements. (p = 0.0001).Conclusions: By using the mathematical formula developed in this study, pre-contraction value of the experimental skin flaps can be achieved and the results can be interpreted more accurately.

Effects of calcitriol on random skin flap survival in rats.

Calcitriol, a metabolite of vitamin D, is often used in osteoporosis clinics. However, the material has other bioactivities; for example, it accelerates angiogenesis, has anti-inflammatory properties, and inhibits oxidative stress. We investigated the effects of calcitriol in a random skin flap rat model. “McFarlane flap” models were established in 84 male Sprague Dawley rats, divided into two groups. One group received intraperitoneal injections of calcitriol (2 μg/kg/day) whereas control rats received intraperitoneal injections of saline. The percentage flap survival area and tissue water content were measured 7 days later, which showed that calcitriol improved flap survival area and reduced tissue edema. It also increased the mean vessel density and upregulated levels of VEGF mRNA/protein, both of which promote flap angiogenesis. Moreover, it decreased leukocyte and macrophage infiltration, reduced the inflammatory proteins IL1β and IL6, increased SOD activity, decreased MDA content, and upregulated the level of autophagy. Overall, our results suggest that calcitriol promotes skin flap survival by accelerating angiogenesis, having anti-inflammatory effects, reducing oxidative stress, and promoting autophagy.

Comparison of Bone Marrow-derived Mononuclear Cells vs. Mesenchymal Stem Cells in Protecting Random-pattern Skin Flap Survival in Rats

Both cultured Bone Marrow Mesenchymal Stem Cells (BMSCs) and non-cultured Bone Marrow Mononuclear Cells (BM-MNCs) can improve random-pattern skin flap survival. However, whether prior culture expansion of bone marrow cells is beneficial for this therapy remains unclear. In the current study, the protective effects of BM-MNCs and BMSCs derived from identical bone marrow aspirates were compared in a random-pattern skin flap rat model. The mean skin flap survival rates were 71.6 ± 8.4% in the BM-MNC-treated group and 66.2 ± 3.1% in the BMSCtreated group, both of which were significantly higher than the control group (55.9 ± 3.4%). The protective effects were confirmed by blood perfusion analysis and vessel density assay. However, no significant difference was observed between the cell transplanted groups. These results indicate that the current method for pre-culture of BMSCs does not bring therapeutic benefits in skin flap protection. Therefore, BM-MNCs without pre-culture might be more practicable in the clinical setting.

The Effect of Platelete Rich Plasma Combined with Microneedling on Full Venous Outflow Compromise in a Rat Skin Flap Model

The Effect of Platelete Rich Plasma Combined with Microneedling on Full Venous Outflow Compromise in a Rat Skin Flap Model

Effects of Kaurenoic Acid and Arginine on Random Skin Flap Oxidative Stress, Inflammation, and Cytokines in Rats.

Kaurenoic acid (KA), a diterpene extracted from copaíba oil-resin, is known to have potent antioxidant and anti-inflammatory properties. L-Arginine (LA) is an amino acid and a nitrogenous precursor for the synthesis of nitric oxide (NO). NO paper in wound healing has already been well documented. The aim of this study was to investigate the protective effects of LA and KA against ischemia reperfusion injury in a randomized skin flap model in rats. A modified McFarlane flap model measuring 2.5 wide × 8 cm long was established in 36 anesthetized rats and evaluated within 3 groups: group control, group L-arginine, and group kaurenoic acid. Each group was subdivided into two subgroups (T1 and T2, n = 6 each). Samples were collected 24 h (T1)/48 h (T2) postoperatively for oxidative stress (glutathione), as non-protein thiols, malondialdehyde (MDA), NO2, inflammation [myeloperoxidase (MPO)], and cytokines TNF-α and IL-1β assays. KA promoted a significant decrease of TNF-α and IL-1 expression and MPO activity at T1/T2 time points. NSGH levels increased significantly in KA-treated rats, while MDA levels decreased significantly in the same rats. Arginine promoted a significant decrease in MDA levels at the T1 time point and a significant increase in non-protein thiols concentrations at T1/T2 time points. NO2 concentration also decreased at the T1 time point. KA may attenuate the oxidative stress and the inflammation, thereby reducing tissue damage induced by ischemia/reperfusion in rats subjected to dorsal skin flaps. This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266.

Prevention of distal flap necrosis in a rat random skin flap model by gene electro transfer delivering VEGF(165) plasmid.

Background Therapeutic delivery of angiogenic growth factors is a promising approach for treating ischemia observed in skin flaps and chronic wounds.Several studies have demonstrated that vascular endothelial growth factor(VEGF) helps mitigate skin flap necrosis by facilitating angiogenesis. The present study aimed to demonstrate an electrically-mediated nonviral gene delivery approach using a non-invasive multi-electrode array (MEA) for effective treatment of ischemic skin flaps.Methods We used a standard random dorsal skin flap model in rats. The study aimed to determine the optimal treatment sites on the skin flap, optimal plasmid dose and timing of the treatment for preventing distal flap necrosis.Results We determined that two treatment sites on the ischemic flap with a plasmid dose of 50-100 μg per treatment site proved adequate to prevent 95% flap necrosis, and that this was significantly better than the no treatment or injection only group. A 2-day window was critical to deliver the VEGF to achieve flap survival and prevent necrosis. Histological examination demonstrated minimal electro transfer associated tissue damage.Conclusions Our results demonstrate that MEA can be used as a non-invasive physical gene delivery method for plasmid VEGF, resulting in a significant reduction of necrosis in ischemic wounds. We propose that this method could be translated into a potential therapeutic approach to deliver growth factors to prevent ischemia in cases of chronic wounds, burns and skin flap necrosis.

Comparing Different Postconditioning Cycles After Ischemia Reperfusion Injury in the Rat Skin Flap

Ischemic postconditioning is a useful manipulation to reduce the undesirable effects of ischemia-reperfusion (I/R) injury. The beneficial results of this phenomenon against I/R injury have been seen in several flap models. However, there are no published works comparing different postconditioning (post-con) cycles in skin flaps. In this study, we investigated the effectiveness of different post-con cycles in a skin flap model. Epigastric island flap (6 × 3 cm) model which was based on the left superficial epigastric artery and vein was used, and complete 6 hours of ischemia was generated by occlusion of the pedicle. Forty male Wistar rats were allocated into 5 groups (n = 8 in each group). Group 1 (sham group): the elevated skin flap was repositioned without an episode of ischemia. Group 2 (control group): skin flap was elevated and 6 hours of complete ischemia was induced by clamping the pedicle. Group 3 (post-con 1): After ischemia, post-con was performed by 6 cycles of 15 seconds of repeated I/R periods. Group 4 (post-con 2): After ischemia, post-con was performed by 6 cycles of 30 second of repeated I/R periods. Group 5 (post-con 3): After ischemia, post-con was performed by 6 cycles of 60 second of repeated I/R periods. Flap viability was assessed 1 week after the surgical procedure, the necrotic area of the skin flap was measured using image analysis on the computer. The area of flap necrosis was statistically significant between the control and post-con group 4 and group 5, and no statistically significant difference was obtained between the control and post-con group 3. Groups 4 and 5 demonstrated lesser area of flap necrosis than the control group and group 4 was superior to group 5. The results revealed that the post-con applied by means of 6 cycles of 30 seconds yields the best protection against I/R injury in the rat skin flap model.

Effects of Systemic Chlorogenic Acid on Random-Pattern Dorsal Skin Flap Survival in Diabetic Rats

There has been considerable interest in understanding the effects of antioxidants in flap survival during diabetes. Previous studies showed that chlorogenic acid (CGA) exhibits potent antioxidant effects. We aimed to determine the effects of systemic CGA treatment on skin flap survival in an experimental random-pattern dorsal skin flap model in diabetic rats. Twenty-eight male Wistar rats were divided into four groups: phosphate buffered saline (PBS)-treated or CGA-treated nondiabetic rats, PBS-treated or CGA-treated diabetic rats. Diabetes was induced by streptozotocin (45 mg/kg). Caudally based bipedicled dorsal skin flaps were elevated. CGA (100 mg/kg) or PBS (mL/kg; as vehicle) was administered intraperitoneally once daily. On postoperative day 7, flap survival, regional blood perfusion and microangiography were evaluated. The malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) and nitric oxide (NO) levels were evaluated from the flap tissue. Capillary density and vascular endothelial growth factor (VEGF) expression were assessed. Harmful effects of diabetes on flap survival were observed. CGA attenuated these effects and allowed greater survival and blood perfusion. CGA decreased MDA and NO levels and increased GSH and SOD levels. CGA elevated capillary density and VEGF expression. This study showed that peripherally administered CGA significantly improved flap survival in diabetic and nondiabetic rats.

Topical application of recombinant platelet‐derived growth factor increases the rate of healing and the level of proteins that regulate this response

A bipedicle ischaemic rat skin flap model was used to study the effects of daily topical applications of platelet-derived growth factor (PDGF) on the healing of ischaemic wounds. Levels of tumour necrosis factor-alpha (TNFA), interleukin 1-beta (IL1B) and both the latent and active forms of matrix metalloproteinase 2 (MMP2) and 9 (MMP9) were measured. Full-thickness wounds were made on a total of 72 adult male Sprague-Dawley rats. Each group of 18 rats with normal and ischaemic wounds received either vehicle or 0·01% recombinant PDGF-BB. Additional applications were made on the wounds on a daily basis. Wound areas were measured at 0, 1, 3, 5, 7 9 and 13 days after wounding. Ischaemia caused a delay in wound healing as well as an increase in TNFA, IL1B and both the pro and active forms of MMP2 and MMP9. PDGF accelerated the rate of wound healing in both normal and ischaemic wounds and negated the effect of ischaemia. PDGF reduced the TNFA concentration in both normal and ischaemic wounds, and the rate of wound healing closely resembled the pattern of TNFA protein expression. PDGF also reduced both the magnitude and duration of the increases in IL1B and both the pro and active forms of MMP2 and MMP9 induced by ischaemia.

Preclinical Efficacy of Slow-Release bFGF in Ischemia-Reperfusion Injury in a Dorsal Island Skin Flap Model

The effect of slow-release basic fibroblast growth factor (bFGF) on ischemia-reperfusion injury was examined using an island skin flap model in rats. Paired rectangular island skin flaps were elevated on the dorsum of 30 Fischer rats. The flaps were subjected to 6 hours of ischemia. Before reperfusion the flaps were injected with acidic gelatin hydrogel microspheres + phosphate-buffered saline (PBS) (group I), 20 μg slow-release bFGF + PBS (group II), 50 μg slow-release bFGF + PBS (group III), and 150 μg slow-release bFGF + PBS (group IV). The mean percent flap survival area and the average number of vessels detected by microangiography were significantly higher in group IV (p < 0.05) than in groups I, II, and III. The immunohistochemical staining for vasculogenic growth factors was quantitatively higher in group IV (p < 0.01). In conclusion, slow-release bFGF prevents ischemia-reperfusion injury by upregulating the secretion of vasculogenic growth factors.

Tadalafil significantly reduces ischemia reperfusion injury in skin island flaps

Introduction:Numerous pharmacological agents have been used to enhance the viability of flaps. Ischemia reperfusion (I/R) injury is an unwanted, sometimes devastating complication in reconstructive microsurgery. Tadalafil, a specific inhibitor of phosphodiesterase type 5 is mainly used for erectile dysfunction, and acts on vascular smooth muscles, platelets and leukocytes. Herein, the protective and therapeutical effect of tadalafil in I/R injury in rat skin flap model is evaluated.Materials and Methods:Sixty epigastric island flaps were used to create I/R model in 60 Wistar rats (non-ischemic group, ischemic group, medication group). Biochemical markers including total nitrite, malondialdehyde (MDA) and myeloperoxidase (MPO) were analysed. Necrosis rates were calculated and histopathologic evaluation was carried out.Results:MDA, MPO and total nitrite values were found elevated in the ischemic group, however there was an evident drop in the medication group. Histological results revealed that early inflammatory findings (oedema, neutrophil infiltration, necrosis rate) were observed lower with tadalafil administration. Moreover, statistical significance (P < 0.05) was recorded.Conclusions:We conclude that tadalafil has beneficial effects on epigastric island flaps against I/R injury.

A Novel In Vivo Technique for Observations of Choke Vessels in a Rat Skin Flap Model

Choke vessels are reduced-caliber vessels that link adjacent vascular territories throughout the body. The behavior of choke vessels determines flap survival. Therefore, it is important to develop a reliable technique with which to study these vessels. The purpose of this report is to document a novel in vivo technique for the study of choke anastomotic vessels in a rat skin flap model. This study was divided into two parts. In part I, 30 adult Sprague-Dawley rats underwent whole-body lead oxide/gelatin injection and the skin was removed for radiography to analyze the skin vasculature. In part II, a dorsal skin flap was elevated in 12 rats, and a skinfold chamber was installed to observe the choke vessels between the iliolumbar artery perforator and the posterior intercostal artery perforator for 8 days. Evans blue dye was injected through the lateral tail vein. Blood flow velocity was calculated. In part I, three distinct patterns of dorsal cutaneous vasculature were found. A three-territory, 3.5×10-cm flap can be elevated on the dorsum of the rat. In part II, an increase in diameter of the choke arteries and the choke veins was observed, particularly in the fine venules. Blood flow velocity across the arterial segment of the choke zone was found to be 2.5 mm/second. The observation chamber technique for in vivo study of the choke anastomotic region of the rat dorsal skin flap model is a promising novel method for studying skin microcirculation. The time sequence of microvascular events in the choke anastomotic zone of this rat model was documented.

Effects of natural and recombinant hirudin on superoxide dismutase, malondialdehyde and endothelin levels in a random pattern skin flap model

We have assessed the anti-inflammatory, anti-oxidative and anti-coagulant effects of locally applied natural and recombinant hirudin in a random skin flap rat model. Thirty Wistar rats with venous congested skin flaps were randomly divided into two treatment groups and a control group to receive subcutaneous injections of natural hirudin (6 U), recombinant hirudin (6 U) or physiological saline, respectively. Superoxide dismutase, malondialdehyde and endothelin levels as well as flap survival rates of the skin flaps were measured after surgery. Compared to the control group, the treatment groups had significant higher superoxide dismutase levels and lower malondialdehyde and endothelin levels in the skin flaps. The surviving areas of the flaps were larger in the treatment groups than the control group. Our results demonstrated that hirudin could improve skin flap survival through its anti-inflammatory, anti-oxidative and anti-coagulant activities.

Quantitative regression analysis of the cutaneous vascular territories in a rat model

The rat skin flap model has been widely used in experimental flap survival studies; however, most of these have been qualitative studies. The purpose of this study was to investigate the quantitative relationship between the diameter of a cutaneous artery and the area of skin that it supplies, and also to explore the factors that influence this relationship. Thirty rats were injected with lead oxide and gelatin and then radiographed. Computer imaging of the diameter and the area of blood supply of the cutaneous artery were made to investigate the mathematical relationship between the arterial diameter and its perfusion area. Angiograms were assembled using Adobe Photoshop and analyzed with Scion Image and SPSS software. The blood vessels had an average diameter of 0.53 ± 0.12 mm, perimeter of 18.74 ± 4.84 cm, vascular density of 391.31 ± 76.58 gray value/pixel cm, vascular territory of 22.32 ± 10.04 cm(2) and supplying volume of 4.88 ± 3.02 cm(3). There was a positive correlation between the diameter and the perimeter of the vascular territory, and the area and volume of the vascular territory. The linear regression equation was y = 32.44x + 1.23 [y: nutrition region perimeter (cm), x: cutaneous artery diameter (mm)], y = 72.70x-15.93 [y: supplying area (cm(2)), x: cutaneous artery diameter (mm)] and y = 20.36x-5.83 [y: supplying volume (cm(3)), x: cutaneous artery diameter (mm)], respectively. Based on this data, it is postulated that the size of reliable skin flaps can be calculated by the diameter and the distribution patterns of the cutaneous artery. With the same diameter, the area of the flap supplied by branch-style artery is larger than the one supplied by the axial artery.

Preoperative shock wave treatment enhances ischemic tissue survival, blood flow and angiogenesis in a rat skin flap model

Introduction Extracorporeal shock wave treatment (ESWT) has recently been shown to enhance skin flap survival. However, the bio-mechanisms operating during preoperative ESWT remain unclear. The aim of our study was to investigate whether preoperative ESWT can improve blood flow in ischemic skin flaps and to elucidate its possible mechanisms. Methods 14 male-rats were randomized into two groups and an oversized ventral random-pattern flap was raised. Experimental group received extracorporeal shock-wave treatment (ESWT) with an energy of 500 mJ/mm 2 seven days prior to total flap elevation, while control group received no treatment prior to total flap elevation. Seven days postoperatively, surviving flap area, perfused flap area, microvessel density and VEGF concentration were measured. Results Surviving flap area (59.43 ± 14.72 % to 42.71 ± 10.75 %, p = 0.026), perfused flap area (62.00 ± 8.58 % to 45.14 ± 10.50 %, p = 0.007), microvessel density (18.13 ± 5.11 to 11.09 ± 1.12, p = 0.016) and VEGF to total protein ratio (0.2107 ± 0.0935 to 0.0123 ± 0.0069, p = 0.008) were significantly elevated in the ESWT group. Conclusion Preoperative ESWT can improve skin flap survival through enhanced topical blood perfusion and neovascularization via elevation of angio-active factors.

Light therapy by blue LED improves wound healing in an excision model in rats

Background Low level light therapy (LLLT) is an attractive alternative to enhance wound healing. So far most studies are performed with red or infrared irradiation. However, we recently showed that blue light (470 nm) can significantly influence biological systems, improving perfusion by release of nitric oxide from nitrosyl complexes with haemoglobin in a skin flap model in rats. Here, we compared the effects of blue and red low level light by light-emitting diodes (LEDs) on in vivo wound healing in an excision wound model in rats. Methods Circular excision wounds were surgically created on the dorsum of each rat. Excisions on either the left or right side were illuminated post-OP and on five consecutive days for 10 min by LED at 470 nm or 630 nm with an intensity of 50 mW/cm 2, while protecting the contralateral side from exposure. In the control group, neither side was illuminated. On day 7 post-OP, we analysed planimetric and histological parameters, as well as expression of keratin-1, keratin-10 and keratin-17 on mRNA level. Results Illumination substantially influenced wound healing. Blue light significantly decreased wound size on day 7, which correlated with enhanced epithelialisation. Light also affected mRNA expression. Both wavelengths decreased keratin-1 mRNA on day 7 post-OP, while keratin-10 mRNA level was elevated in both light treated group compared to control. Keratin-17 mRNA was also elevated in the red light group, but was unchanged in the blue light group. Conclusion In contrast to previous studies, we showed that also blue light significantly influences wound healing. Furthermore, our data suggest that light therapy can play an important role in normotrophic wound healing by affecting keratin expression. Illumination would provide an easily applicable, safe and cost-effective treatment of surface wounds.