Search

BACKGROUND: The treatment of skin scars is a long-term focus and difficulty for plastic surgery and burn. Ultrasound has become a hot spot and trend in its scientific research due to its advantages of small trauma, fast recovery and low risk of scar treatment. OBJECTIVE: To explore the therapeutic effect of different intensities of ultrasound on abdominal skin scar in rabbits and its mechanism of action. METHODS: Sixteen 3-month-old New Zealand rabbits were selected and divided into four groups with four rabbits in each group, male and female, according to stratified random sampling method. After 21 days, sham ultrasound intervention was performed on abdominal scars in the sham ultrasound group, and 0.3, 0.5, and 0.8 W/cm2 ultrasound interventions were given to abdominal scars in the low-, medium- and high-intensity ultrasound groups, respectively, for 7 day each, for a total of two sessions with an interval of 2 days. The length and thickness of scars were measured before and after treatment. The area density of type I and III collagen in scar tissue after intervention was observed by Sirius red staining. The expression of serum N-terminal peptide of type III procollagen (PIIINP) was detected by ELISA before and after the intervention. RESULTS AND CONCLUSION: A total of 70 skin scars formed in 96 wound incisions, and the success rate of modeling was about 72.9%. After the intervention, the scar length in the low- and medium-intensity groups was significantly lower than that in the sham ultrasound group and the high-intensity group (P < 0.05). After the intervention, the scar thickness in the low-, medium- and high-intensity groups was significantly lower than that in the sham ultrasound group (P < 0.05). The scar thickness in the low-intensity group was significantly lower than that in the medium- and high-intensity groups (P < 0.05). After the intervention, the percentage of type I and III collagen in the low-intensity group was significantly higher than that in the high-intensity group (P < 0.05); the percentage of type I and III collagen in the high-intensity group was significantly lower than that in the sham ultrasound group (P < 0.05). After the intervention, the density ratio of type I/III collagen in the low-intensity group was significantly lower than that in the high-intensity group (P < 0.05). The difference of serum PIIINP expression before the intervention and after the first session was significantly lower in the low-, medium-, and high-intensity groups than the sham ultrasound group (P < 0.05), while the difference in the low-intensity group was lower than that in the medium- and high-intensity groups but with no statistical significance (P > 0.05). There was no significant difference between the two groups in the expression of serum PIIINP at the end of the first session and the end of the second session (P > 0.05). To conclude, low-intensity ultrasonic intervention has a better comprehensive effect on the treatment of hypertrophic scar. The mechanism of ultrasonic treatment may be to optimize the compliance of hypertrophic scar tissue through the mechanical, and physicochemica action on the arrangement of type I and III collagen fiber bundles in hypertrophic scar tissue, which still needs further research and confirmation. [ABSTRACT FROM AUTHOR]

Background: Hypertrophic scar (HS) is a common disease in plastic and cosmetic surgery, with limited treatment options, and is a challenge for clinicians. Objectives: This study aimed to evaluate the efficacy of fractional carbon dioxide (CO2) laser combined with botulinum toxin type A (BTXA) in treating HSs in rabbit ears and to provide new strategies for treating HS. Methods: Twenty‐four New Zealand white rabbits with induced HSs were randomly divided into one control and three treatment groups. After 4 weeks of modeling, BTXA (2.0 U) was injected into the HS of the BTXA and combination groups, whereas a fractional CO2 laser (combo mode, deep energy: 12.5 mJ; super energy: 90 mJ) was used in the fractional CO2 laser and combination groups. The laser treatments were repeated after 2 weeks. The HSs in the rabbit ears were observed and photographed 5 weeks after the first treatment. The scar thickness in each group was measured and compared, and the scar elevation index (SEI) was determined using hematoxylin and eosin staining. Collagen content and alignment were observed using Masson's trichrome staining. Western blotting and immunohistochemistry were performed to analyze scar‐related protein levels. Results: Hypertrophic scars were reduced in all treatment groups compared with the control group. The combination group had lower scar thickness, SEI, and expression of scar‐related proteins in HSs, with an appearance similar to that of normal rabbit ear skin. Furthermore, the fibroblast content and collagen deposition decreased significantly in the combination group (p < 0.001). Conclusions: Fractional CO2 laser combined with BTXA more effectively reduced HSs by inhibiting fibroblast proliferation, decreasing transforming growth factor‐β1 and α‐ smooth muscle actin expression, and causing collagen remodeling. [ABSTRACT FROM AUTHOR]

Objective To observe and investigate the therapeutic effect of scorpion ointment on early hypertrophic scar in rabbit ear model. Methods From October 2019 to October 2020, 8 New Zealand white rabbits were randomly divided into control group and treatment group, 4 rabbits in each group. The rabbit ear hypertrophic scar model was established. The scorpion ointment was used in the treatment group and the PBS was used in the control group. At 7 and 28 days after treatment, the tissues of each group were taken for HE staining, Masson's trichrome staining and immunohistochemistry. Results At 28 days after rabbit ear model established, the wounds of rabbit ears in each group were completely healed and hypertrophic scar was formed. Significant hyperplasia of scars was found in the control group. In the treatment group, the scar volume was gradually decreased, and the texture and color were improved. The results of HE staining and Masson's trichrome staining showed that the degree of tissue fibrosis was significantly reduced after treatment with scorpion ointment (P<0.05). Compared with the control group, the immunohistochemistry results showed that the expression of CD31 and vascular endothelial growth factor (VEGF) in the treatment group at 7 and 28 days were significantly decreased (P<0.05). Conclusion Scorpion ointment can treat hypertrophic scar by reducing the degree of fibrosis and down regulating the expression of CD31 and VEGF. [ABSTRACT FROM AUTHOR]

Objective To explore whether miR-9 can inhibit the growth of hypertrophic scar fibroblasts by targeting PI3K. Methods From September 2020 to September 2021, 12 healthy adult New Zealand long-eared rabbits were randomly divided into control group (6 rabbits) and scar group (6 rabbits). The histological morphology of both groups was detected by HE staining. The mRNA expression of miR-9 and PI3K in tissues was detected by real-time fluorescent quantitative PCR, and the expression of miR-9 and PI3K was analyzed by Pearson's correlation coefficient. The human hypertrophic scar fibroblasts (HSFb) were divided into psiCHECK-WT-PI3K+miR-9 control group, psiCHECK-WT-PI3K+miR-9 mimic group, psiCHECK-MUT-PI3K+miR-9 control group and psiCHECK-MUT-PI3K+ miR-9 mimic group. The corresponding sequences were transfected respectively. The expression of luciferase and renilla luciferase were detected by luciferase reporter gene assay at 48 h after transfection. The HSFb was divided into miR-9 control group and miR-9 mimic group. At 0, 12, 24, 36 and 48 h after transfection, the cell proliferation was detected by MTT. At 24 h after treatment, the cell apoptosis was detected by Annexin V-FITC/PI kit, and the expression of PI3K, caspase 3 and Bcl-2 protein was detected by protein immunoblotting. The number of samples in cell experiment was 3. The data were analyzed by t-test and Pearson's correlation coefficient. Results In HE staining, the excessive proliferation of fibroblasts and inflammatory cell infiltration were found in scar tissue. The model was successfully constructed. Compared with the control group, the miR-9 expression was significantly down-regulated (t=11.020, P<0.05) and PI3K expression was significantly up-regulated in the scar group (t=10.840, P<0.05). Pearson's correlation analysis showed that the expression of miR-9 and PI3K was negatively correlated in all tissues. At 48 h after transfection, the PI3K activity in the psiCHECK-WT-PI3K + miR-9 mimic group was significantly lower than that in the psiCHECK-WT-PI3K+miR-9 control group (t=8.648, P=0.001). The PI3K activity in the psiCHECK-MUT-PI3K+miR-9 control group was similar to that in the psiCHECKMUT-PI3K+miR-9 mimic group (t=2.053, P=0.109). At 12, 24, 36 and 48 h after transfection, the proliferation ability of miR-9 mimic group was significantly lower than that of the miR-9 control group (P<0.05). At 24 h after transfection, the early apoptotic rate of HSFb in the miR-9 mimic group was higher than that in the miR-9 control group (t=11.210, P=0.001). MiR-9 can down regulate the expression of PI3K, inhibit the expression of Bcl-2 and up regulate the content of caspase 3. Conclusion MiR-9 is down-regulated in the hypertrophic scar tissue, which can inhibit the growth of HSFb by targeting PI3K. [ABSTRACT FROM AUTHOR]

Hypertrophic scar is a disease with complicated treatment methods. Although there are numerous studies in the literature definitive therapy has not been reported yet. In this study, we aimed to evaluate the short and long‐term effects of HBOT on hypertrophic scar formation in a rabbit ear model. A total of 20 male New Zealand rabbits weighing 2.1 to 2.4 kg were used in this study. The rabbits in group 2 were exposed to hyperbaric oxygen treatment for 7 days starting from the first day following biopsy punch, while no extra treatment was applied to the rabbits in group 1. Macroscopic scar thickness, histopathological parameters and HI were assessed in both of the 30th day and 60th day scars. Scar thickness was found significantly less in the scars of the rabbits exposed to HBOT (P <.05). And less dermal hypertrophy was also found in HI results of group 2.(P ≈.022) There were differences between groups in terms of inflammation, vascularization and density of collagen fibrils. HBOT applied for 7 days from the first day of wound formation has both short and long‐term effects on the triggering factors of hypertrophic scar, especially on inflammation. [ABSTRACT FROM AUTHOR]

Purpose This study aims to explore the effects of BTXA on the proteins that affect the contraction of fibroblasts. Moreover, the optimal dose of BTXA on hypertrophic scars has not yet been determined. The current study investigated the effect of different doses of BTXA on scar formation. Materials and Methods 18 rabbits' ears of New Zealand rabbits were used to establish hypertrophic scar model. These wounds were divided into four groups as group B (treated with deferent dosage of BTXA), group T (treated with TAC), group S (not treated), and group C (normal skin). Fibroblast apoptosis was detected by the method of TUNEL. Collagen I, III, and TGF-β1 expression were examined by western blotting method. The immunohistochemical staining and computerized image analysis were used to measure the optical density (OD value) of positive staining of α-SMA and myosin II. Results With increasing BTXA dose, the apoptotic rates increased. Western blot showed that Collagen fibrils and TGF-β1 proteins were expressed lower with the increasing of dose of BTXA (P < 0.05). α-SMA and myosin II in Group B were significantly decreased than those in Group T (P < 0.05), moreover, more myosin II can be reduced with high concentrations of BTXA (2.0 IU). Conclusions It was shown that BTXA could induce fibroblast apoptosis and inhibit the expression of α-SMA and myosin II, which can inhibit FB contraction. It plays a positive role in the treatment of scar. [ABSTRACT FROM AUTHOR]

Tinospora cordifolia extract contains antioxidants such as polyphenols, and thus, it has been used as a natural phytochemical antioxidant therapeutic agent. Many of these compounds are insoluble or only partially soluble in water. In this study, we produced a novel aqueous nanoparticle formulation, with an average particle size of 182.9 ± 3.8 nm, to improve the dispersion of the bioactive compounds in water and to increment its bioavailability. The nanoparticles are composed of polyphenols, alkaloids, and glycosides. We studied the effect of this nanoparticle formulation on mouse 3T3 fibroblast cell viability and New Zealand rabbit dermal irritability tests. Concentrations of 2.5, 25, and 250 µg/mL resulted in similar cell viability to cells in culture media. An intermediate concentration of 12.45 mg/ml was used for the acute dermal irritability test. There were no severe alterations that compromised animal health. These results represent a precedent for application of such nanoparticles derived from plant stems, such as Tinospora cordifolia, in biomedicine and in antiaging cosmetic treatments. [ABSTRACT FROM AUTHOR]

Background. Although Botulinum Toxin Type A (BTXA) has been applied to scar prevention and treatment, the mechanisms still require further exploration. Objective. To investigate the effects of BTXA on microvessels in the hypertrophic scar models on rabbit ears. Methods. Eight big-eared New Zealand rabbits (males or females) were selected to establish scar models. One ear of each rabbit (4 models in each ear) was selected randomly to be injected with BTXA immediately after modeling and included in the treated group, while the opposite ear was untreated and included in the control group. The growth of scars in each group was observed and recorded, and 4 rabbits were sacrificed on days 30 and 45 after modeling. Then, scar height was measured by hematoxylin-eosin (HE) staining, vascular endothelial growth factor (VEGF) expression was detected by immunohistochemical (IHC) testing, and microvessel density (MVD) was calculated based on CD34 (human hematopoietic progenitor cell antigen). Results. The wounds in each group were well healed and free from infection or necrosis. On days 30 and 45, the scar height, MVD value, and VEGF expression in the treated group were lower than those in the control group (P < 0.05). For the treated group, the above indicators on day 45 were lower than on day 30 (P > 0.05). Besides, there was a positive correlation between the MVD value and the VEGF expression in the treated group (P < 0.05). Conclusion. The injection of BTXA immediately after modeling inhibits VEGF expression and reduces angiogenesis, thereby inhibiting hypertrophic scar formation. [ABSTRACT FROM AUTHOR]

Artesunate (ART) is the derivative of artemisinin isolated from the traditional Chinese medicine qinghao. Although several studies reported the efficiency of artesunate in the treatment of malaria, inhibiting fibroblasts and collagen synthesis, the association between artesunate and scar formation is unclear. The research was designed to study the significance of artesunate (ART) on the expression of transforming growth factor (TGF-β1) and small mother against decapentaplegic (SMAD3) in rabbit's ear hypertrophic scar model. Twenty-four New Zealand white rabbits were randomly divided into six groups: control group, matrix group, low-concentration artesunate group (0.48%), medium-concentration artesunate group (0.96%), high-concentration artesunate group (1.92%) and silicone gel group. Punched defects were established on each rabbit's ear which resulted in a hypertrophic scar. On the 28th day, topical artesunate creams were applied twice a day except on the control group. On the 56th day, scar samples were collected for histopathology and immunoassay. Hematoxylin and eosin staining, Van Gieson staining, immunohistochemistry and Western blot analysis were done. Amongst the six groups, findings showed that the medium-concentration artesunate group (0.92%) efficiently decreased hypertrophic scar formation and significantly reduced fibroblasts and collagen synthesis. The results had also shown a decrease in the expression of transforming growth factor (TGF-β1) and declined small signal mother against decapentaplegic (Smad3). The overall study shows efficacy and mechanism of artesunate. It concluded that the medium concentration of artesunate (0.92%) could be an effective therapeutic agent for hypertrophic scars. [ABSTRACT FROM AUTHOR]

Objective: To observe the early effect of scorpion ointment combined with asiaticoside ointment on hypertrophic scar and the effect of TGF-β signaling pathway in tissues was further explored. Methods: The New Zealand white rabbits were randomly divided into control group, model group, scorpion ointment group, asiaticoside ointment group and combined drug group. Scorpion ointment and/or asiaticoside ointment were applied immediately after operation in the treatment group for 35 consecutive days, and the treatment of scars in each group was recorded by photography. Pathological examination, real-time PCR and Western blot were performed on rabbit ear tissue samples of each group 35 days after operation. Results: Typical hypertrophic scars were observed in model group 35 days after operation and the inhibitory effect of combined drug treatment group was more significant than that of single drug treatment group. The results of H. E staining showed that compared with the model group, the degree of tissue fibrosis and the amount of collagen in each treatment group were reduced to some extent after treatment, but the combined use of drugs could significantly improve the degree of tissue fibrosis. The results of real-time PCR and western blot showed that the MMP level in the treated group was higher than that in the model group, and the levels of type Ⅰ collagen (Col I), type Ⅲ collagen (Col Ⅲ) and Samd 4 protein. The differences were all different, and the difference in the combination group was the most significant, and the treatment effect was better than that in the single drug group. Conclusion: The combination of scorpion ointment and asiaticoside ointment can effectively improve the level of cell fibrosis and reduce the deposition of collagen. The expression of Smad 4 protein can regulate the TGF-β signaling pathway and inhibit the formation of hypertrophic scar. [ABSTRACT FROM AUTHOR]

A hypertrophic scar (HS) is a cutaneous condition characterized by deposits of excessive amounts of collagen that produces a raised scar, causing physical, psychological, and cosmetic problems for the patient. The therapeutic efficacy of conventional transdermal drug delivery systems is often limited because the HS tissue is more compact than normal skin. At present, intralesional multi-injection of triamcinolone acetonide (TA) using a syringe is one of the most commonly used treatments for HS. However, the efficacy of this treatment is highly dependent on the skill of the medical professionals administering the injection. Even with co-administration of local anesthetics, traditional injection still causes pain to the patients, resulting in poor compliance. The purpose of this study was to provide an alternative treatment for HS by establishing a novel intradermal delivery system with a dissolving microneedle array (DMNA). To produce needles of higher mechanical strength for successful insertion into the compact and hard HS tissue, hydroxypropyl-β-cyclodextrin (HP-β-CD) was added into sodium hyaluronic acid (HA), the needle material. The hydrogen interaction between HP-β-CD and HA restricted the mobility of the molecular chains, and subsequently increased the elastic modulus of the complex materials. The HP-β-CD also contributed to improved loading of the hydrophobic drug molecules into the DMNA needle tips. To assess the delivery of TA to the HS site via DMNA, an HS model was established in the ventral skin of New Zealand rabbits' ears. It was found that the value of the scar elevation index was decreased to normal, together with the down regulation of mRNA expressions of Collagen I and transforming growth factor-β1 (TGF-β1) following the administration of DMNA containing TA (TA-DMNA). Western blotting results also revealed decreased protein expressions of both Collagen I and TGF-β1. Hence, TA-DMNA appears to be a promising alternative to multi-injection of TA injection, providing a convenient and low-pain therapeutic strategy for HS treatment. Unlabelled Image [ABSTRACT FROM AUTHOR]

• Dorsal laminectomy is indicated for treatment of patients with cauda equina syndrome. • Post-laminectomy fibrosis is common and gradually causes clinical signs to return. • Polypropylene mesh is resistant, have low immunological reaction and have low cost. • Polypropylene mesh, when placed in the laminectomy, is encapsulated by the organism. • Polypropylene mesh to prevent fibrosis was macro and microscopically effective. We evaluated the effect of polypropylene mesh placement on post-laminectomy compressive scar formation in rabbits. Twenty-two white male New Zealand rabbits were distributed into two groups (n = 11). In the control group, the animals underwent lumbosacral laminectomy, whereas in the mesh group, the rabbits were submitted to lumbosacral laminectomy followed by the attachment of a polypropylene mesh to the vertebrae by the application of N-butyl cyanoacrylate. After eight weeks, the rabbits were euthanized, and the laminectomy area was collected for macro- and microscopic analyses. Macroscopically, we evaluated the (1) vertebral canal height; (2) laminectomy width and (3) length; and (4) fibrosis width, (5) height, and (6) length. Microscopically, we evaluated (7) fibroblasts; (8) the thickness of the dura-mater; and (9) the distance between the dura-mater and the laminectomy area. Macroscopically, there were no differences between the groups regarding vertebral canal height; width and length of the laminectomy; and fibrosis width. However, the height, and length of fibrosis were smaller in the mesh group. Microscopically, there were no differences in dura mater thickness and the distance between the dura mater and laminectomy area, but fewer fibroblasts were observed in the mesh group. This indicated that the polypropylene mesh improved tissue repair, with greater tissue organization. The results demonstrate that the use of a polypropylene mesh in the treatment of post-laminectomy wounds in rabbits reduces the severity of compressive fibrous scar formation. Polypropylene mesh is presented as a good alternative to reduce complications associated with laminectomy surgeries. [ABSTRACT FROM AUTHOR]