Skin Wounds In Rats Research Articles

Bioactive polymeric formulations for wound healing

Ricinoleic acid (RA) has potential to promote wound healing because of its analgesic and anti-inflammatory properties. This study investigates the synthesis and characterization of RA liposomes infused in a hydrogel for topical application. Lecithin liposomes containing RA were prepared and incorporated into a chitosan solution and were subsequently cross-linked with dialdehyde β-cyclodextrin (Di-β-CD). Chitosan/Di-β-CD concentrations and reaction temperatures were varied to alter gelation time, water content, and mechanical properties of the hydrogel in an effort to obtain a wide range of RA release profiles. Hydrogel cross-linking was confirmed by spectroscopy, and liposome and carrier hydrogel morphology via microscopy. Chitosan, Di-β-CD, and liposome concentrations within the formulation affected the extent of matrix swelling, mechanical strength, and pore and overall morphology. Higher cross-linking density of the hydrogel led to lower water uptake and slower release rate of RA. Optimized formulations resulted in a burst release of RA followed by a steady release pattern accounting for 80% of the encapsulated RA over a period of 48 hours. However, RA concentrations above 0.1 mg/mL were found to be cytotoxic to fibroblast cultures in vitro because of the oily nature of RA. These formulations promoted wound healing when used to treat full thickness skin wounds (2 cm2) in Wister male rats. The wound contraction rates were significantly higher compared to a commercially available topical cream after a time period of 21 days. Histopathological analysis of the RA-liposomal chitosan hydrogel group showed that the epidermis, dermis, and subcutaneous skin layers displayed an accelerated yet normal healing compared to control group.

Effects of the application of the amniotic membrane in the healing process of skin wounds in rats.

To evaluate the efficacy of the application of the human amniotic membrane (HAM) on the inflammatory process, fibroblast proliferation, formation of collagenand reduction of skin wound areas in rats. Thirty six rats were submitted to a surgical injury induction and divided into two groups (n = 18): group C (control) and T (treated with the HAM). The macroscopic evolution in the wound area and the histological characteristics of the skin samples were evaluated. The regression of the wound area was greater in group T. The histological analysis revealed a significant reduction (p < 0.05) in the inflammatory infiltrate in group T at all experimental periods compared with that in the control group. Furthermore, the group T presented a significant increase in the proliferation of fibroblasts at 14 and 21 days compared with group C (p < 0.05). Regarding the deposition of mature collagen fibers, there was an increase in the replacement of type III collagen by type I collagen in group T (p < 0.05). Treatment with the HAM reduced the healing time as well as the inflammatory responses, increased the proliferation of fibroblasts, and induced a higher concentration of mature collagen fibers.

The effect of Korean Red Ginseng on full-thickness skin wound healing in rats

BackgroundPanax ginseng is regarded as one of the best compounds for promoting health, and it has been used traditionally as a medicinal herb. Recently, Korean Red Ginseng (RG) has been shown to protect skin from aging and wrinkling; it can also relieve atopic dermatitis and allergy symptoms. This study aimed to evaluate RG's effects on the regeneration of the full-thickness skin wounds in rat. MethodsFull-thickness skin wounds were generated in rats, and then RG was administered either orally or topically. The wound-healing effects of RG were investigated by assessing wound size, mRNA expression patterns of genes related to wound healing, histological staining, and measurements of lipid, moisture, and elasticity in skin tissues. ResultsThe wound size was smaller, and tissue regeneration rate was faster in the RG-treated group than that in the control group on days 15 and 20 after initiating treatment. On postoperative day 20, skin lipid and moisture content had increased significantly in the RG-treated group. Significant increases in the gene expression levels of transforming growth factor-β1 and vascular endothelial growth factor were found in the RG group during the early stages of wound healing. Matrix metalloproteinase-1 and matrix metalloproteinase-9 showed significant increases in gene expression levels on day 20. ConclusionThe results suggested that RG may promote healing of full-thickness skin wounds in rats. They also provided basic insights into the effects of RG on skin regeneration, supporting its use as a dressing material for wound treatment and its development as a functional food.

ГИДРОСКРЕПЛЕННЫЙ НЕТКАНЫЙ СЕРЕБРОСОДЕРЖАЩИЙ МАТЕРИАЛ В ЛЕЧЕНИИ АСЕПТИЧЕСКИХ РАН

Background. The urgent problem of surgery is the search for new and promising bandaging materials for the treatment of wounds. One of the variants may be a hydrobonded nonwoven material with silver nanoparticles, obtained by the laser ablation method. Aim of the research. To study the effect of a hydrobonded nonwoven material, containing silver nanoparticles of various sizes, on the healing of an experimental aseptic cutaneous wound and the parameters of complete and biochemical blood tests as well as to determine the possible toxicity of silver nanoparticles on the liver, kidneys and myocardium. Material and methods. Silver nanoparticles were obtained by the laser ablation method in a liquid. The wound healing effect was evaluated on a model of an aseptic skin wound in laboratory white rats. After the healing of the wound blood was taken for complete and biochemical tests. The toxic effect of a hydrobonded bandaging material on the liver, kidneys and myocardium was assessed pathomorphologically and by changes in the biochemical blood test. Results. The obtained data demonstrated acceleration of the healing of the experimental aseptic skin wound with the use of silver nanoparticles by 9.2-15.6 % and the absence of toxic effects of silver nanoparticles on the liver, kidneys and myocardium, as well as significant changes in the indices of complete and biochemical blood tests. Conclusions. Hydrobonded nonwoven material with silver nanoparticles accelerates the healing of an aseptic skin wound without causing toxic effects on the liver, kidneys and myocardium. It can be used in clinical practice after further studying.

Spatiotemporal alterations of autophagy marker LC3 in rat skin fibroblasts during wound healing process.

To investigate the possible implications of autophagy, one of the degradation pathways induced by metabolic stress, in the dynamic reconstructive process of wound healing, the appearance and changes of punctate structures for microtubule-associated protein 1 light chain 3 (LC3), an autophagosome marker, were examined in a rat skin wound healing model. Although the ratio of LC3-II/LC3-I in Western blotting was not evidently changed during the wound healing process, LC3-positive dots were clearly observed in fibroblasts and myofibroblasts, and occasionally in macrophages, by immunohistofluorescence microscopy. Some of the LC3-positive dots were colocalized with Atg16L signal, an isolation membrane marker, and electron microscopy revealed the presence of typical autophagosomes in fibroblasts near the margin of the wound. The number of LC3-positive dots per fibroblast increased during the later period of the proliferation phase, and interestingly, it was higher in the margin than the center of the wound. It was also high in the periwound skin area. These results suggest that drastic functional changes in fibroblasts during wound healing process are accompanied by the alteration of the autophagy-lysosomal degradation system.

흰쥐의 피부상처 동물모델에서 苦蔘이 신생혈관형성에 미치는 영향

Wound healing is the restoration in injured skin tissue and one of the most important therapeutic targets. The process consists of inflammation, proliferation, and remodeling. There have been reported multiple factors that accelerate and delay wound healing. In this study we tested the hypothesis that Sophorae Radix extract would improve the recovery of wound healing after full-thickness skin wound in rats. Twenty young male Sprague-Dawley rats were used for the studies. A full-thickness skin wound was made on the dorsal skin of the rats. Either Sophorae Radix water extract (SR) or saline (Control) was orally administrated every day. The wound area was measured and the percentages of wound contraction, wound healed and wound epithelization were evaluated. After 15 days, the skin tissues were excised and examined by histopathological and immunohistochemistrical method. In results, wound area in SR group was significantly decreased to compared with Control. SR group showed the significant enhancements in the percentages of wound contraction, wound healed and wound epithelization. Histopathological examination revealed that SR induces neo-vascularization potential in wound healing process. SR treatment in rats significantly accelerated cutaneous wound healing in the angiogenesis process by increasing VEGF and TGF-β1 synthesis. These results suggest that Sophorae Radix enhance skin wound repair by increasing the angiogenic agents such as VEGF and TGF-β1.

Upregulation of BAG3 with apoptotic and autophagic activities in maggot extract‑promoted rat skin wound healing.

Maggot extract (ME) accelerates rat skin wound healing, however its effect on cell maintenance in wound tissues remains unclear. B‑cell lymphoma (Bcl) 2‑associated athanogene (BAG)3 inhibits apoptosis and promotes autophagy by associating with Bcl‑2 or Beclin 1. Bcl‑2, the downstream effector of signal transducer and activator of transcription 3 signaling, is enhanced in ME‑treated wound tissues, which may reinforce the Bcl‑2 anti‑apoptotic activity and/or cooperate with Beclin 1 to regulate autophagy during wound healing. The present study investigated expression levels of BAG3, Bcl‑2, Beclin 1 and light chain (LC)3 levels in rat skin wound tissues in the presence and absence of ME treatment. The results revealed frequent TUNEL‑negative cell death in the wound tissues in the early three days following injury, irrespective to ME treatment. TUNEL‑positive cells appeared in the wound tissues following 4days of injury and 150µg/ml ME efficiently reduced apoptotic rate and enhanced BAG3 and Bcl‑2 expression. Elevated Beclin 1 and LC3 levels and an increased LC3 II ratio were revealed in the ME‑treated tissues during the wound healing. The results of the present study demonstrate the anti‑apoptotic effects of BAG3 and Bcl‑2 in ME‑promoted wound healing. Beclin 1/LC3 mediated autophagy may be favorable in maintaining cell survival in the damaged tissues and ME‑upregulated BAG3 may enhance its activity.

Effects and Mechanisms of Total Flavonoids from Blumea balsamifera (L.) DC. on Skin Wound in Rats.

Chinese herbal medicine (CHM) evolved through thousands of years of practice and was popular not only among the Chinese population, but also most countries in the world. Blumea balsamifera (L.) DC. as a traditional treatment for wound healing in Li Nationality Medicine has a long history of nearly 2000 years. This study was to evaluate the effects of total flavonoids from Blumea balsamifera (L.) DC. on skin excisional wound on the back of Sprague-Dawley rats, reveal its chemical constitution, and postulate its action mechanism. The rats were divided into five groups and the model groups were treated with 30% glycerol, the positive control groups with Jing Wan Hong (JWH) ointment, and three treatment groups with high dose (2.52 g·kg−1), medium dose (1.26 g·kg−1), and low dose (0.63 g·kg−1) of total flavonoids from B. balsamifera. During 10 consecutive days of treatment, the therapeutic effects of rates were evaluated. On day 1, day 3, day 5, day 7, and day 10 after treatment, skin samples were taken from all the rats for further study. Significant increases of granulation tissue, fibroblast, and capillary vessel proliferation were observed at day 7 in the high dose and positive control groups, compared with the model group, with the method of 4% paraformaldehyde for histopathological examination and immunofluorescence staining. To reveal the action mechanisms of total flavonoids on wound healing, the levels of CD68, vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1), and hydroxyproline were measured at different days. Results showed that total flavonoids had significant effects on rat skin excisional wound healing compared with controls, especially high dose ones (p < 0.05). Furthermore, the total flavonoid extract was investigated phytochemically, and twenty-seven compounds were identified from the total flavonoid sample by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry/diode array detector (UPLC-Q-TOF-MS/DAD), including 16 flavonoid aglucons, five flavonoid glycosides (main peaks in chromatogram), five chlorogenic acid analogs, and 1 coumarin. Reports show that flavonoid glycoside possesses therapeutic effects of curing wounds by inducing neovascularization, and chlorogenic acid also has anti-inflammatory and wound healing activities; we postulated that all the ingredients in total flavonoids sample maybe exert a synergetic effect on wound curing. Accompanied with detection of four growth factors, the upregulation of these key growth factors may be the mechanism of therapeutic activities of total flavonoids. The present study confirmed undoubtedly that flavonoids were the main active constituents that contribute to excisional wound healing, and suggested its action mechanism of improving expression levels of growth factors at different healing phases.

Effect of high- and low- frequency transcutaneous electrical nerve stimulation (TENS) on angiogenesis and wound contraction in acute excisional wounds in rat skin

Abstract Introduction: Transcutaneous electrical nerve stimulation (TENS) can alter the local temperature, increase skin blood flow and induce the release of vasodilator neuropeptides and growth factors. These changes may be related to the effects of TENS on the tissue repair process. Objective: To assess the effect of high- and low-frequency TENS on angiogenesis and the contraction of acute excisional wounds in rat skin. Methods: Fifty-four young adult male EPM1-Wistar rats were used in the study. An excisional wound was performed on the back of each animal using an 8mm punch. The animals were randomly assigned to three groups: the High-frequency Group (HG: 80 Hz), Low-frequency Group (LG: 5 Hz), and Sham Group (SG: TENS turned off). TENS was delivered on three days consecutives. Pulse duration and current intensity were 200 µs and 15 mA. The length of each TENS session was 60 minutes. Microscopic and macroscopic assessments were performed on 3, 7 and 14 postoperative (PO) days. Hematoxylin-eosin staining was utilized to quantify the neoformed blood vessels. Photographs were taken to determine the percentage of wound contraction. After assessment, the animals were painlessly sacrificed. Results: There were increases in angiogenesis in the HG on the 3 PO day, and in the LG on the 14 PO day. No significant differences in wound contraction were found between the groups on the different PO days. Conclusion: High frequency TENS improved angiogenesis, and neither frequency of TENS had any influence on the contraction of acute excisional wounds in rat skin.

Plasticity of oral mucosal cell sheets for accelerated and scarless skin wound healing

ObjectivesWound healing is generally faster and associated with less scarring in the oral mucosa than in the skin. Although rarely studied, oral mucosa equivalents may contribute to rapid, scarless cutaneous wound healing. Therefore, we examined the potential utility of our newly developed oral mucosal cell sheet in skin wound healing. Materials and methodsOral mucosa and skin samples were obtained from surgical patients and Sprague-Dawley rats. Keratinocytes and fibroblasts were primarily cultured for in vitro cell expansion. Mucosa and skin equivalents were produced with a mixture of cultured fibroblasts and autologous fibrin from plasma and seeding keratinocytes. Mucosal and skin cell sheets were transplanted in full-thickness excisional wounds of rat skin with control wounds. Gross, histological, and molecular characteristics of wound healing according to different postsurgical days were compared in control and cell sheet-covered wounds. ResultsKeratinocytes and fibroblasts derived from the oral mucosa were cultured faster than those derived from the skin. The in vitro-engineered oral mucosa and skin equivalents were successfully produced using complete autologous mucosa or skin and plasma fibrin, showing similarity to the histological characteristics of the skin or mucosa. In the in vivo rat model, the oral mucosal and skin cell sheet promoted wound healing with early wound closure and less scarring. The cell sheet-treated wounds showed lower TGF-β1, α-smooth muscle actin, and fibronectin mRNA expression than the control wounds. ConclusionsThe oral mucosal cell sheet demonstrated in vivo tissue plasticity through good adaptation to skin wounds, contributing to accelerated and scarless healing.

Spirulina extract-impregnated alginate-PCL nanofiber wound dressing for skin regeneration

In recent years, nanofibers have been developed and widely used in many products, such as cosmetics and medical supplies. They can be fabricated from various synthetic or natural polymers and attached to bioactive compounds. In previous research, polycaprolactone (PCL) nanofibers containing Spirulina extract were demonstrated to be effective on dermal wound healing in a rat model. In this study, we fabricated Spirulina extract-alginate PCL nanofibers using alginate, which has hydrophilic structures capable of holding large amounts of water, to support the backbone of the nanofibers. The morphological characteristics, hydrophilicity, water absorbance, skin adhesiveness, toxicity to human keratinocyte cells (HaCaT), and Spirulina extract emission over time were assessed. Alginate improved the efficacy of Spirulina PCL nanofibers in moisture maintenance and adhesion ability, which highly affected recovery in the rat skin wound model. In conclusion, Spirulina extract-alginate PCL nanofibers could be considered a promising candidate for wound care.

Critical‐sized full‐thickness skin defect regeneration using ovine small intestinal submucosa with or without mesenchymal stem cells in rat model

Decellularized extracellular matrices (ECM) based materials are routinely used for a variety of clinical applications. Hereof, in vivo application of decellularized ovine small intestinal submucosal (DOSIS) layer as, a scaffold is yet to be investigated. In this study, the effectiveness of the DOSIS scaffold, with or without rat bone marrow mesenchymal stem cells (BM-MSCs), in full-thickness wound healing of critical-sized defect was experimentally studied in a rat model. The experimental groups included; group I (control), group II (DOSIS), and group III (BM-MSCs-seeded DOSIS). Wound healing of all groups was examined and compared clinically and histopathologically on days 7, 14, and 21 postoperation. Our results represented BM-MSCs-seeded DOSIS accelerated wound contraction and healing compared to both the DOSIS alone and control groups. Epithelization was close to completion 21 days postoperation in DOSIS alone. In OSIS with BM-MSCs group, epithelization was faster and had fully taken place at the subsequent time points. DOSIS layer, as cell-free form with low substantially DNA content, accelerated healing of rat skin wound defects that was created at critical-size and full-thickness. In conclusion, decellularized OSIS alone and in combination with BM-MSCs has the potential to be used as a wound graft material in skin regenerative medicine. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2177-2190, 2018.

Study of the non-clinical healing activities of the extract and gel of Portulaca pilosa L. in skin wounds in wistar rats: A preliminary study

IntroductionPortulaca pilosa L., belonging to the family Portulacaceae, is a common herbaceous plant in the Americas and in the Amazon, is popularly known as love-grown and is traditionally used as an aid in the treatment of burns, buds, insect bites and wound healing. This study aims to evaluate the non-clinical topical healing activity of the P. pilosa gel (GPP) and the propyleneglycol extract of P. pilosa (EPP) in Wistar rats. MethodsFor the healing activity, wistar rats were divided into the following groups: negative control (GVE – vehicle, 150mg/kg), positive control (Fibrinase®- FIB, 100U/kg), Portulaca pilosa gel 10%, (GPP, 150mg/kg), and propylenglycollic extract of Portulaca pilosa (EPP, 150 mg/kg), which were submitted to a surgical procedure to obtain the wounds, and were treated topically for 7days. After treatment, the treated area was removed and a histopathological analysis was performed. ResultsThe EPP when analyzed in HPLC was able to identify the presence of gallic acid. EPP significantly modulated the tissue inflammatory response, presenting low number of inflammatory cells in the histopathological study. Treatment with EPP and GPP significantly stimulated angiogenesis and this response was superior to the fibrinase® group. Treatment with EPP and GPP significantly stimulated the proliferation of fibroblasts. The groups treated with EPP and GPP presented an organization pattern of the epidermis and dermis better than the control group, with a mild inflammatory process, with fibroblast proliferation and increased formation of collagen fibers. ConclusionThus, from the results obtained it can be suggested that the phytochemical marker of the P. pilosa species for healing activity is gallic acid and, together with the macroscopic and microscopic findings triggered by the topical applications of EPP and GPP, it can be concluded that this plant species has topical healing activity, with great potential for use, since this pharmacological action is associated with a possible topical anti-inflammatory activity.

Therapeutic potential of d-δ-tocotrienol rich fraction on excisional skin wounds in diabetic rats

Therapeutic potential of d-δ-tocotrienol rich fraction on excisional skin wounds in diabetic rats

Evaluation of apoptotic caspase levels in estimation of the wound age

Abstract Objectives We aimed to investigate the potential use of the expression of apoptotic signaling pathway genes of rat in skin wound age estimation. Material and methods For this purpose, we formed cutting tool injuries using a scalpel in an experimental model. Then, we assessed Caspase 3, 8 and 9 mRNA levels by using quantitative real-time PCR and protein levels by using immunohistochemistry in rat skin wounds. In addition, we used TUNEL assay to detect apoptotic cells. Results We observed that Caspase 3 mRNA level significantly increased (2.1±0.4 folds) on day 3 (p&lt;0.05) and Caspase 8 mRNA level significantly increased (1.8±0.2 folds) on day 5 (p&lt;0.05). Caspase 9 mRNA level increased (1.9±0.1 folds) on day 3 and (2.5±0.4 folds) on day 5 (p&lt;0.05). The percentage values of polymorphonuclear leukocytes (PMNLs) and inflammatory mononuclear cells (IMCs) were observed after immunohistochemical staining by Caspase 3, 8, 9 antibodies. Our immunohistochemistry results were found to be consistent with the mRNA results observed. We reported a statistically significant increase in Caspase 3, 8 and 9-positive cells on days 3 and 5 after immunohistochemical staining as well. Conclusion Our results suggest that time-dependent features of apoptotic factors might offer a potential tool in estimating wound age.

Vitamin E isoforms (d α-tocopherol and δ-tocotrienol) promote healing of secondary skin wounds in diabetic rats

l-theanine, the most abundant free amino acid in tea, has been documented to possess many different bioactive properties through oral or intragastrical delivery. However, little is known about the effect of topical delivery of l-theanine on acute inflammation. In the present study, by using 12-O-tetradecanoylphorbol-13-acetate (TPA, 2.5 μg/ear)-induced ear edema model in mice, we first found that single-dose local pretreatment of l-theanine 30 min before TPA time- and dose-dependently suppressed the increases in both skin thickness and weight. Subsequently l-theanine ameliorated TPA-induced erythema, vascular permeability increase, epidermal and dermal hyperplasia, neutrophil infiltration and activation via downregulating the expression of PECAM-1 (a platelet endothelial adhesion molecule-1) in blood vessels and the production of pro-inflammatory cytokines IL-1β, TNF-α, and mediator cyclooxygenase-2 (COX-2), which is mainly expressed in neutrophils. It highlighted the potential of l-theanine as a locally administrable therapeutic agent for acute cutaneous inflammation.

Bacteriostatic Characteristics of Bone Substituting Constructors Obtained from Composite Materials Based on Natural Polymers, Calcium Phosphates and Vancomycin

Introduction.The local delivery of therapeutic antibiotic concentrations to the zone of surgical intervention in bone pathology enables either to prevent or significantly decrease the rate of osteomyelitis development. It that study the efficacy of vancomycin inclusion and release from three dimensional constructors based on sodium alginate, gelatin and octacalcium phosphate and vancomycin intended for bone defect substitution was studied.Materials and methods. Prototyping of 3D constructors was performed by extrusion 3D printing. Various concentrations of vancomycin were added as an additional component at the stage of preparation of hydrogel (“ink”) for printing. Physical testing of the constructors included electron microscopic evaluation of their microstructure and porosity as well as the study of mechanical strength for compression and stretching. Functional activity of printed constructors with respect to the test strain S. aureus ATCC 6538-P was assessed by a disc-diffusion method in vitro and on the model of infected excision skin wound in rats -in vivo.Results. Analysis of the kinetic curves showed that the principal release of the drug in the model liquid took place within the first day. The total volume of the bound and released vancomycin made up approximately 20% of the calculated initial amount for all three concentrations. Formation of the marked growth inhibition zone of S. aureus strain in presence of vancomycin rich constructors was demonstrated in vitro. Insertion of constructors into the zone of infected skin defect resulted in a decrease of inflammatory processes severity and rate as well as accelerated the terms of complete wound healing.Conclusion. Study results showed the principle potentiality of bone substituting implants 3D-printing using multicomponent hydrogel compositions without change of separate components characteristics.

Effects of Lucilia sericata on wound healing in streptozotocin-induced diabetic rats and analysis of its secretome at the proteome level

The use of Lucilia sericata larvae on the healing of wounds in diabetics has been reported. However, the role of the excretion/secretion (ES) products of the larvae in treatment of diabetic wounds remains unknown. This study investigated whether application of the ES products of L. sericata on the wound surface could improve the impaired wound healing in streptozotocin-induced diabetic rats. Additional analysis was performed to understand proteome content of L. sericata secretome to understand ES contribution at the molecular level. For this purpose, full-thickness skin wounds were created on the backs of diabetic and control rats. A study was conducted to assess the levels of the ES-induced collagen I/III expression and to assay nuclear factor κB (NF-κB) (p65) activity in wound biopsies and ES-treated wounds of diabetic rat skin in comparison to the controls. The expression levels of collagen I/III and NF-κB (p65) activity were determined at days 3, 7, and 14 after wounding using immunohistological analyses and enzyme-linked immunosorbent assay technique. The results indicated that treatment with the ES extract increased collagen I expressions of the wound control and diabetic tissue. But the increase in collagen I expression in the controls was higher than the one in the diabetics. NF-κB (p65) activity was also increased in diabetic wounds compared to the controls, whereas it was decreased in third and seventh days upon ES treatment. The results indicated that ES products of L. sericata may enhance the process of wound healing by influencing phases such as inflammation, NF-κB (p65) activity, collagen synthesis, and wound contraction. These findings may provide new insights into understanding of therapeutic potential of ES in wound healing in diabetics.

Bacteriostatic Characteristics of Bone Substituting Constructors Obtained from Composite Materials Based on Natural Polymers, Calcium Phosphates and Vancomycin

Introduction. The local delivery of therapeutic antibiotic concentrations to the zone of surgical intervention in bone pathology enables either to prevent or significantly decrease the rate of osteomyelitis development. It that study the efficacy of vancomycin inclusion and release from three dimensional constructors based on sodium alginate, gelatin and octacalcium phosphate and vancomycin intended for bone defect substitution was studied. Materials and methods . Prototyping of 3D constructors was performed by extrusion 3D printing. Various concentrations of vancomycin were added as an additional component at the stage of preparation of hydrogel (“ink”) for printing. Physical testing of the constructors included electron microscopic evaluation of their microstructure and porosity as well as the study of mechanical strength for compression and stretching. Functional activity of printed constructors with respect to the test strain S. aureus ATCC 6538-P was assessed by a disc-diffusion method in vitro and on the model of infected excision skin wound in rats - in vivo. Results . Analysis of the kinetic curves showed that the principal release of the drug in the model liquid took place within the first day. The total volume of the bound and released vancomycin made up approximately 20% of the calculated initial amount for all three concentrations. Formation of the marked growth inhibition zone of S. aureus strain in presence of vancomycin rich constructors was demonstrated in vitro. Insertion of constructors into the zone of infected skin defect resulted in a decrease of inflammatory processes severity and rate as well as accelerated the terms of complete wound healing. Conclusion. Study results showed the principle potentiality of bone substituting implants 3D-printing using multicomponent hydrogel compositions without change of separate components characteristics.

Achillea asiatica extract and its active compounds induce cutaneous wound healing

Ethnopharmacological relevanceAchillea asiatica Serg. is a perennial herb belonging to the Asteraceae family that has long been traditionally used to treat acute intestinal and stomach inflammation, persistent fever, ulcers, wounds, and rheumatism. Aim of the studyWe investigated the effect of A. asiatica extract (AAE) on cutaneous wound healing. Materials and methodsTo assess the effect of AAE on wounds, an incisional Sprague-Dawley (SD) rat model was topically treated with AAE for 2 weeks. HaCaT keratinocytes, Hs68 dermal fibroblasts, and RAW 264.7 macrophages were used for in vitro experiments. After treatment with AAE, cell viability, cell migration, and production of nitric oxide (NO) and prostaglandin E2 (PGE2) were investigated. mRNA expression of collagen type I and III and inflammatory cytokines was measured by RT-PCR. The effect of AAE on activation of β-catenin and other markers was determined by Western blot analysis. ResultsAAE treatment significantly increased epithelialization and accelerated wound healing in SD rats. Meanwhile, AAE and its active compounds reduced NO and PGE2 release and mRNA expression of inflammatory cytokines in RAW 264.7 macrophages, reflecting anti-inflammatory activity. Furthermore, AAE and its constituents stimulated collagen expression in Hs68 fibroblasts by activating transforming growth factor-β and stimulated keratinocyte differentiation and motility by inducing β-catenin, Akt, and keratinocyte differentiation markers. ConclusionsAAE improves skin wounds in SD rats and supports keratinocyte development.