Effect of asiaticoside on the healing of skin wounds in the carp Cirrhinus mrigala: An immunohistochemical investigation

In the present study effect of asiaticoside, on healing of skin wounds in Cirrhinus mrigala is reported. Skin wound, approx. 2 mm in diameter was excised using sterile disposable biopsy punch. Immediately after infliction of the wound, epidermis from wound edge starts migrating as thin sheet toward wound gap. Fronts of migrating epidermis gradually advance, and results in complete epithelialization of wound. Experiments were conducted for 30 days and fishes were divided into control, sham, vehicle control and asiaticoside treated groups. Immunohistochemical localization of proliferating cell nuclear antigen positive cells indicating cellular proliferation and caspase 3 positive cells reflecting apoptosis was carried out and their density at different post wound intervals in each fish group was analyzed. Significant increase in cellular proliferation as well as decrease in apoptosis in both epidermis and dermis in fish treated with asiaticoside compared to sham and vehicle control fish is observed at different intervals of wound repair. This suggests that in treated group healing of skin wounds in fish is enhanced than in sham and vehicle control groups. Asiaticoside treatment in healing of skin wounds would greatly be beneficial to fish farmers as it could protect fish from invasion of pathogens and check fish mortality.     

HUMAN WOUND REPAIR : I. Epidermal Regeneration

A series of linearly incised superficial skin wounds was made on the forearms of young adult male volunteers. Wounds were sampled at several intervals between 3 hr and 21 days after wounding, for study by light and electron microscopy. The light microscopic observations show that regeneration of epidermis in human wounds conforms chronologically to that reported for the epidermis in superficial wound repair in laboratory animals. It is further shown that "ruffling" of cell membranes characterizes the cells of the migrating epidermis in early wound healing. This study reveals that the basement lamina and hemidesmosomes are established by epidermis in contact with the fibrin net at the base of early wounds. Epidermal cells in the wound environment are shown to be phagocytic. Analysis of the submicroscopic cytology of differentiating and maturing regenerated epidermis reveals that, in the sequence of events, the formation of filaments, basal lamina, and desmosomes is followed chronologically by evolution of keratohyalin granules and, subsequently, by keratinization of the surface epidermal elements. The entire sequence of migration, differentiation, and ultimate keratinization in the superficial wounds studied requires 3–5 days for completion.     

A Randomized and Controlled Multicenter Prospective Study of the Chinese Medicinal Compound Fufang Xuelian Burn Ointment for the Treatment of Superficial and Deep Second-Degree Burn Wounds

The objective of this study was to evaluate the efficacy and safety of a traditional Chinese medicine, Fufang Xuelian Burn Ointment (FXBO), to treat superficial and deep second-degree burn wounds. A four-center, randomized, controlled, and prospective study was conducted. Overall, 240 patients with either superficial or deep second-degree burn wounds were enrolled consecutively in this study. Patients who were randomly assigned to the control group (superficial: 72, deep: 48) underwent common burn wound therapy, whereas those randomized to the treatment group (superficial: 72, deep: 48) received common burn wound therapy plus topical FXBO. The healing rate, healing time, effective rate, and safety data were compared between the two groups. The baseline characteristics were comparable for the two groups. The healing rate was 94.79(±7.50) in the control group and 98.60(±5.69) in the FXBO group after 14 days for patients with superficial second-degree burn wounds (P = 0.000), and 95.17(±9.68) versus 97.44(±9.81) at 28 for deep second-degree burn wounds (P = 0.025). The median healing time in the FXBO group were 9 and 21 days for superficial and deep second-degree burns, respectively, compared to 10.5 and 22.5 days, respectively, in control group (P _superficial = 0.000 and P _deep = 0.009). The results of the effective rate showed that comprehensive efficacy of the FXBO group was improved compared to the control group for either superficial or deep second-degree burns (P _superficial = 0.035 and P _deep = 0.003). There were no reported drug-related adverse events in both groups. Therefore, FXBO was well tolerated and more effective than control group for treating superficial and deep second-degree burn wounds.     

Accelerated healing of full-thickness skin wounds in a wet environment

Full-thickness skin wounds are preferably allowed to heal under controlled hydration dressings such as hydrocolloids. It was hypothesized that a wet (liquid) environment rather than a dry or moist one would accelerate the wound healing process. We compared skin repair by secondary intention in full-thickness skin wounds in wet (saline), moist (hydrocolloid), and dry (gauze) conditions in an established porcine wound healing model. The study included three animals with a total of 70 wounds layered in a standardized fashion on the back of young Yorkshire pigs. Twelve days after wounding, 0 percent of dry, 20 percent of moist, and 86 percent of saline-treated wounds were completely reepithelialized (p values = 0.0046 and 0.027 for saline wounds compared with dry and moist wounds, respectively). The accelerated healing was caused at least in part by faster contraction in wet wounds (p value < 0.005 compared with that of other groups 9 and 12 days after wounding). Development of granulation tissue was faster in moist conditions than it was for dry and wet wounds. The thickness and number of cell layers of the newly formed epidermis were greater in dry and wet wounds than in moist ones. It was concluded that these full-thickness porcine skin wounds healed faster in a wet environment than in a moist one. Dry wounds healed more slowly than moist wounds. The basic mechanisms of skin wound repair were influenced by the treatment modality as demonstrated by the observed differences in granulation tissue formation, reepithelialization, and rate of wound contraction.     

A study of the effect of low-intensity laser radiation of the blue, green, and red spectral regions on the healing of experimental skin wounds in rats

The effect of low-intensity laser radiation of the blue (441.2 nm), green (532 nm), and red (632.8 nm) spectral regions on the healing of experimental skin wounds in rats has been studied. The effect of the traditionally applied laser radiation in the red region has been compared with the effect of laser radiation in the other spectral regions, assuming that, upon irradiation of wounds by lasers emitting in the blue and green regions, a similar effect can be achieved at lower doses. The following parameters characterizing the healing of experimental wounds were used: the functional activity of phagocytes of wound exudates, which was determined by luminol-dependent chemiluminescence, and their number; the antioxidant activity of wound exudates; and the rate of healing, which was determined as a change in the wound area. It was shown that irradiation with laser accelerated the healing of wounds in all cases. The exposure to laser radiations in the red (1.5 J/cm), blue, and green (0.75 J/cm2) spectral regions shortened the time of wound healing from 22 to 17 and 19 days, respectively. The functional activity of leukocytes after the exposure increased on day 5 after the infliction of the wound, whereas in the control it decreased. The superoxide dismutase activity increased in all experimental groups by day 5 after the operation. A maximum increase in the superoxide dismutase activity occurred after the exposure to laser radiation in the red region at a dose of 1.5 J/cm and in the blue and green spectral regions at a dose of 0.75 J/cm2.     

Urothelial injuries and the early wound healing response: tight junctions and urothelial cytodifferentiation

Using primary explant cultures of mouse bladder, the early response of the urothelium after superficial and full-thickness injuries was investigated. In such an in vitro wound healing model, explant surfaces with a mostly desquamated urothelial superficial layer represented superficial wounds, and the exposed lamina propria at the cut edges of the explants represented full-thickness wounds. The urothelial cell ultrastructure, the expression and subcellular distribution of the tight junctional protein occludin, and differentiation-related proteins CK 20, uroplakins, and actin were followed. Since singular terminally differentiated superficial cells remained on the urothelium after superficial injury (i.e., original superficial cells), we sought to determine their role during the urothelial wound-healing process. Ultrastructural and immunocytochemical studies have revealed that restored tight junctions are the earliest cellular event during the urothelial superficial and full-thickness wound-healing process. Occludin-containing tight junctions are developed before the new superficial cells are terminally differentiated. New insights into the urothelium wound-healing process were provided by demonstrating that the original superficial cells contribute to the urothelium wound healing by developing tight junctions with de novo differentiated superficial cells and by stretching, thus providing a large urothelial surface with asymmetric unit membrane plaques.     

Connexins in wound healing; perspectives in diabetic patients

Skin lesions are common events and we have evolved to rapidly heal them in order to maintain homeostasis and prevent infection and sepsis. Most acute wounds heal without issue, but as we get older our bodies become compromised by poor blood circulation and conditions such as diabetes, leading to slower healing. This can result in stalled or hard-to-heal chronic wounds. Currently about 2% of the Western population develop a chronic wound and this figure will rise as the population ages and diabetes becomes more prevalent [1]. Patient morbidity and quality of life are profoundly altered by chronic wounds [2]. Unfortunately a significant proportion of these chronic wounds fail to respond to conventional treatment and can result in amputation of the lower limb. Life quality and expectancy following amputation is severely reduced. These hard to heal wounds also represent a growing economic burden on Western society with published estimates of costs to healthcare services in the region of $25B annually [3]. There exists a growing need for specific and effective therapeutic agents to improve healing in these wounds. In recent years the gap junction protein Cx43 has been shown to play a pivotal role early on in the acute wound healing process at a number of different levels [4-7]. Conversely, abnormal expression of Cx43 in wound edge keratinocytes was shown to underlie the poor rate of healing in diabetic rats, and targeting its expression with an antisense gel restored normal healing rates [8]. The presence of Cx43 in the wound edge keratinocytes of human chronic wounds has also been reported [9]. Abnormal Cx43 biology may underlie the poor healing of human chronic wounds and be amenable therapeutic intervention [7]. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics.     

Healing of burns after treatment with 670-nanometer low-power laser light

Recent investigations have reported contradictory results on the influence of low-power laser light on wound healing. Low-power laser with a power output of 250 mW and an emitted laser light of 670 nm have been insufficiently investigated to date. The effect of a 250-mW/670-nm laser light on the healing of burning wounds in rats was investigated. Thirty rats were burned on both flanks. One wound was irradiated with 670-nm laser light (2 J/cm2), whereas the other side remained untreated. Macroscopic evaluation of the wounds was performed daily; 10, 20, and 30 days after burning, 10 rats were killed and the wounds histologically evaluated. Neither macroscopic nor histologic examination of the irradiated wound showed accelerated wound healing when compared with control wounds. In the present study, irradiation of burns with a 250-mW/670-nm laser light produced no beneficial effects on wound-healing processes.     

Galectins-3 and -7, but not galectin-1, play a role in re-epithelialization of wounds

Disorders of wound healing characterized by impaired or delayed re-epithelialization are a serious medical problem. These conditions affect many tissues, are painful, and are difficult to treat. In this study, using cornea as a model, we demonstrate for the first time the importance of carbohydrate-binding proteins galectins-3 and -7 in re-epithelialization of wounds. In two different models of corneal wound healing, re-epithelialization of wounds was significantly slower in galectin-3-deficient (gal3(-/-)) mice compared with wild-type (gal3(+/+)) mice. In contrast, there was no difference in corneal epithelial wound closure rates between galectin-1-deficient and wild-type mice. Quantitation of the bromodeoxyuridine-labeled cells in gal3(+/+) and gal3(-/-) corneas revealed that corneal epithelial cell proliferation rate is not perturbed in gal3(-/-) corneas. Exogenous galectin-3 accelerated re-epithelialization of wounds in gal3(+/+) mice but, surprisingly, not in the gal3(-/-) mice. Gene expression analysis using cDNA microarrays revealed that healing corneas of gal3(-/-) mice contain markedly reduced levels of galectin-7 compared with those of gal3(+/+) mice. More importantly, unlike galectin-3, galectin-7 accelerated re-epithelialization of wounds in both gal3(-/-) and gal3(+/+) mice. In corresponding experiments, recombinant galectin-1 did not stimulate the corneal epithelial wound closure rate. The extent of acceleration of re-epithelialization of wounds with both galectin-3 and galectin-7 was greater than that observed in most of the published studies using growth factors. These findings have broad implications for developing novel therapeutic strategies for treating nonhealing wounds.     

Carnosine enhances diabetic wound healing in the db/db mouse model of type 2 diabetes

Diabetes mellitus (DM) is a progressive disorder with severe late complications. Normal wound healing involves a series of complex and well-orchestrated molecular events dictated by multiple factors. In diabetes, wound healing is grossly impaired due to defective, and dysregulated cellular and molecular events at all phases of wound healing resulting in chronic wounds that fail to heal. Carnosine, a dipeptide of alanine and histidine and an endogenous antioxidant is documented to accelerate healing of wounds and ulcers. However, not much is known about its role in wound healing in diabetes. Therefore, we studied the effect of carnosine in wound healing in db/db mice, a mice model of Type 2 DM. Six millimeter circular wounds were made in db/db mice and analyzed for wound healing every other day. Carnosine (100?mg/kg) was injected (I.P.) every day and also applied locally. Treatment with carnosine enhanced wound healing significantly, and wound tissue analysis showed increased expression of growth factors and cytokines genes involved in wound healing. In vitro studies with human dermal fibroblasts and microvascular-endothelial cells showed that carnosine increases cell viability in presence of high glucose. These effects, in addition to its known role as an antioxidant and a precursor for histamine synthesis, provide evidence for a possible therapeutic use of carnosine in diabetic wound healing.     

Matrigel increases the rate of split wound healing and promotes keratinocyte `take' in deep wounds in rats

The influence of matrigel, a mixture of the components of thebasement membrane, on the wound healing was studied in a modelof experimental wounds in rats. Matrigel was found to increasethe rate of epithelization of split-thickness wounds. The modelof deep wound was developed in which the host animal could notprovide enough migrating and proliferating keratinocytes tocover the wound area. The model is relevant to severe burns andinjuries in humans. When rat keratinocyte suspension wastransplanted into deep wounds, cell retention in the wound bedwas only observed if matrigel was added together with the cells.Increasing matrigel concentration in the wound was seen toenhance the rate of wound area coverage by the cells. Althoughthe process of healing seemed macroscopically normal, afterhistological screening of the biopsies cell in the wouldappeared as amorphous aggregates and tubules rather thenstratified epidermis.     

Oral nutritional supplementation accelerates skin wound healing: a randomized, placebo-controlled, double-arm, crossover study

Nutritional therapy is critical for wound healing in people with severe malnutrition or specific metabolic deficiencies. Medical claims from manufacturers of many oral supplements are marketed to surgical patients for decreasing edema, bruising, and discomfort. The effect of supplementing nutrients on soft-tissue wound healing in otherwise normal, healthy adults is an area of clinical importance, but little information is available. Proteolytic enzymes have been reported to moderate the inflammatory cycle and may up-regulate the healing process. The goal of this study was to perform a clinical trial in normal, healthy adults that examined the effects of an oral nutritional supplement (InflammEnz, Enzymes, Inc., Parkville, Mo.) on soft-tissue healing times. Twenty-six normal, healthy volunteers were recruited into a randomized, crossover, placebo-controlled, clinical trial consisting of two phases, each lasting 21 days. In phase I, subjects were subjected to a 3-mm forearm skin biopsy and randomly received a placebo or oral supplement (four capsules per day for 7 days). After a 2-week washout period, a second biopsy was performed to start phase II, with each subject receiving the respective placebo or supplement capsules. Digital photographs were taken during wound healing in both phases and analyzed for wound areas (in square millimeters) and perimeters (in millimeters). Twenty-two subjects completed the clinical trial. On the basis of wound surface areas, 17 subjects had improved wound healing and five subjects did not respond or responded only slightly to the supplement treatment. The mean +/- SD healing time of the subjects responding to supplement-treated wounds was 15 +/- 2.2 days, compared with 18 +/- 2.5 days for the placebo group. The 17 percent acceleration of wound-healing time was significant (p < 0.005). In subjects responding to oral supplements, less redness in the wounds was observed that may have been associated with less inflammation. The authors' results demonstrate that InflammEnz oral supplementation accelerated soft-tissue wound healing in 77 percent of normal, healthy subjects studied. The authors' study validates observations made that this supplement modulates the wound-healing process and suggests that many patients with minor soft-tissue wounds may benefit from treatment.     

The extracellular matrix of lip wounds in fetal, neonatal and adult mice.

Wound healing in the fetus occurs rapidly, by a regenerative process and without an inflammatory response, resulting in complete restitution of normal tissue function. By contrast, in the adult, wounds heal with scar formation, which may impair function and inhibit further growth. The cellular mechanisms underlying these differing forms of wound healing are unknown but the extracellular matrix (ECM), through its effects on cell function, may play a key role. We have studied the ECM in upper lip wounds of adult, neonatal and fetal mice at days 14, 16 and 18 of gestation. The spatial and temporal distribution of collagen types I, III, IV, V and VI, fibronectin, tenascin, laminin, chondroitin and heparan sulphates were examined immunohistochemically. Results from the fetal groups were essentially similar whilst there were distinct differences between fetus, neonate and adult. Fibronectin was present at the surface of the wound in all groups at 1 h post-wounding. Tenascin was also present at the wound surface but the time at which it was first present differed between fetus (1 h), neonate (12 h) and adult (24 h). The time of first appearance paralleled the rate of wound healing which was most rapid in the fetus and slowest in the adult. Tenascin inhibits the cell adhesion effect of fibronectin and during development the appearance of tenascin correlates with the initiation of cell migration. During wound healing the appearance of tenascin preceded cell migration and the rapid closure of fetal wounds may be due to the early appearance of tenascin in the wound. Collagen types I, III, IV, V and VI were present in all three wound groups but the timing and pattern of collagen deposition differed, with restoration of the normal collagen pattern in the fetus and a scar pattern in the adult. This confirms that lack of scarring in fetal wounds is due to the organisation of collagen within the wound and not simply lack of collagen formation. The distribution of chondroitin sulphate differed between normal fetal and adult tissues and between fetal and adult wounds. Its presence in the fetal wound may alter collagen fibril formation. No inflammatory response was seen in the fetal wounds. The differences in the ECM of fetal and adult wounds suggests that it may be possible to alter the adult wound so that it heals by a fetal-like process without scar formation, loss of tissue function or restriction of growth.     

Stimulated healing of recalcitrant wounds by topical application of enriched cell culture medium: a clinical report.

This study was designed to test the efficacy of enriched cell culture medium as a wound dressing. The rationale was to create within the wound space an optimal microenvironment, conducive to cellular proliferation, vascular granulation tissue formation, and epithelialization. This study was performed on various wounds that failed to respond to previous conventional treatments.A total of 288 wounds were within the inclusion criteria, with only contaminated and neoplastic wounds excluded. Most of the patients (80 percent) were ambulatory, and the wounds were examined by the attending physician once every 7 to 14 days at an outpatient clinic. The remaining 20 percent of patients were admitted to the study while hospitalized.Cell culture medium MCDB, supplemented with insulin, thyroxin, and growth hormone, was gelled. The gel was self-applied once a day to freshly washed wounds, covered with a gauze pad, and anchored with netting.Healing started 7 to 14 days after the initiation of treatment with enriched cell culture medium. However, the criterion for success of the treatment was determined on complete wound closure, which was achieved in 189 of 288 wounds (65.6 percent). Wound closure was correlated with the initial wound volume, stage, and origin. The average time required for closure of wounds caused by systemic pathologies (n = 181) and those based on regional status (n = 107) were 12.0 and 4.4 weeks, respectively, compared with 290 and 10.3 weeks of the previous conventional treatment. In 19 extensive wounds, when vascularized granulation tissue was established, a successful surgical closure was attained.Most wounds of patients who did not continue the enriched cell culture medium treatment (34.4 percent) manifested reduced wound volume, ranging from 11 to 98 percent of initial volume. Discontinuation of treatment was associated with difficulties in reaching the clinic for the weekly examination, rather than for reasons directly related to the treatment itself, and occurred significantly earlier during the treatment period.Thus, enriched cell culture medium was effective in stimulating wound healing in recalcitrant wounds. The healing was rapid with minimum scarring and pain. No side effects or allergic reactions were reported or observed.     

Effect of parotid submandibular and sublingual saliva on wound healing in rats.

1. The effectiveness of wound licking with parotid, submandibular or sublingual saliva on wound healing was evaluated in selectively sialadenectomized rats. 2. The rate of healing of experimentally induced cutaneous wounds was evaluated macroscopically by photography at 0, 2, 4 and 6 days after surgery. 3. Sialadenectomy of all major glands significantly slowed down wound healing compared to sham-operated controls. 4. Parotid licking had no effect compared to controls; submandibular licking and sublingual licking appeared to be very effective. 5. The results suggest that saliva promotes wound healing in experimentally induced cutaneous wounds by communal licking; this is a result of the submandibular and sublingual saliva and not the parotid saliva.     

Cellular mechanisms of skin repair in humans and other mammals

The increased incidence of non-healing skin wounds in developed societies has prompted tremendous research efforts on the complex process known as “wound healing”. Unfortunately, the weak relevance of modern wound healing research to human health continues to be a matter of concern. This review summarizes the current knowledge of the cellular mechanisms that mediate wound closure in the skin of humans and laboratory animals. The author highlights the anatomical singularities of human skin vs. the skin of other mammals commonly used for wound healing research (i.e. as mice, rats, rabbits, and pigs), and discusses the roles of stem cells, myofibroblasts, and the matrix environment in the repair process. The majority of this review focuses on reepithelialization and wound closure. Other aspects of wound healing (e.g. inflammation, fibrous healing) are referred to when relevant to the main topic. This review aims at providing the reader with a clear understanding of the similarities and differences that have been reported over the past 100 years between the healing of human wounds and that of other mammals.     

The wound healing and haemocyte response in the skin of the lesser octopus Eledone cirrhosa (Mollusca: Cephalopoda) in the presence of Vibrio tubiashii

The sequential response of wound closure in the skin of the lesser octopus Eledone cirrhosa is described following experimentally induced infections by the Gram-negative bacterium, Vibrio tubiashii. Results show that the post-infection healing response varied considerably from the response observed in non-infected wounds reported previously. Prominent among the findings was the much more extensive haemocyte response noted throughout healing when compared with non-infected wounds. In addition, there was a generalized inhibition of epidermal migration so that wound closure was never completed during the experiment. The presence of a 'double tier' amorphous zone was evident at certain stages of the healing response and the implications of this finding in relation to post-infection wound closure is discussed.     

The effect of low-intensity laser irradiation in the blue, green, and red spectral ranges on healing of experimental skin wounds in rats

The effects of low-intensity laser irradiation in the red (632.8 nm), green (532 nm), and blue (441.2 nm) spectral ranges on wound healing has been studied in rats. The effect of the traditionally used red laser irradiation has been compared with the effect caused by laser irradiation in other spectral ranges, aiming to support the provisional hypothesis that a similar healing effect could be achieved at lower doses of wound irradiation by lasers emitting in the blue and green spectral ranges. The following parameters have been used to characterize healing of the experimental wounds: the functional activity of phagocytes in the wound exudate, which was determined from luminol-dependent chemiluminescence, the phagocyte number; the wound exudates’ antioxidant activity; and the rate of healing, which was determined as the change of the wound surface area. It was found that in all cases the laser irradiation accelerated the healing of wounds. Exposure to red laser irradiation at the dose of 1.5 J/cm²), and to blue or green laser irradiation at a dose of 0.75 J/cm² shortened the time of the wound healing from 22 to 17 and 19 days, respectively. The functional activity of leukocytes in irradiated groups increased by day 5 after surgery, whereas in the control group it decreased. The superoxide dismutase activity increased in all experimental groups by day 5 after surgery. Laser irradiation in the red spectral range at a dose of 1.5 J/cm² resulted in a larger increase in superoxide dismutase activity, as compared to that found after exposure to laser irradiation in the blue and green spectral ranges at a dose of 0.75 J/cm².     

Frozen cultured sheets of human epidermal keratinocytes enhance healing of full-thickness wounds in mice

Sheets of cultured allogeneic human keratinocytes have been used for the treatment of burns and chronic leg ulcers but there has been no animal assay for the therapeutic action of these cultures. In order to analyze the effects of frozen cultures of human keratinocytes on wound healing, we have developed such an assay based on the rate of repair of full-thickness skin wounds in immunocompetent NMR1 mice. Reepithelialization of the control wounds, originating from the murine epithelium at the edge of the wound, occurred at a constant rate of advance of 150 microm/day. When frozen cultured human epidermal sheets were thawed at room temperature for 5-10 min and applied to the surface of the wound, the murine epithelium advanced at 267 microm/day. Most wounds treated with frozen cultures completely healed after 10 days, whereas most control wounds required 16 days. The accelerated reepithelialization did not depend on the presence of proliferative human keratinocytes in the frozen cultures. The cultures also promoted early formation of granulation tissue and laminin deposition over the surface of the wound bed. This simple assay should permit quantitative analysis of the effects on healing exerted not only by cultured cells, but also by proteins and small molecules.