Physiology of the Acute Wound

Improving Osteoblast Response In Vitro by a Nanostructured Thin Film with Titanium Carbide and Titanium Oxides Clustered around Graphitic Carbon

Introduction

Recently, we introduced a new deposition method, based on Ion Plating Plasma Assisted technology, to coat titanium implants with a thin but hard nanostructured layer composed of titanium carbide and titanium oxides, clustered around graphitic carbon. The nanostructured layer has a double effect: protects the bulk titanium against the harsh conditions of biological tissues and in the same time has a stimulating action on osteoblasts.

Results

The aim of this work is to describe the biological effects of this layer on osteoblasts cultured in vitro. We demonstrate that the nanostructured layer causes an overexpression of many early genes correlated to proteins involved in bone turnover and an increase in the number of surface receptors for α3β1 integrin, talin, paxillin. Analyses at single-cell level, by scanning electron microscopy, atomic force microscopy, and single cell force spectroscopy, show how the proliferation, adhesion and spreading of cells cultured on coated titanium samples are higher than on uncoated titanium ones. Finally, the chemistry of the layer induces a better formation of blood clots and a higher number of adhered platelets, compared to the uncoated cases, and these are useful features to improve the speed of implant osseointegration.

Conclusion

In summary, the nanostructured TiC film, due to its physical and chemical properties, can be used to protect the implants and to improve their acceptance by the bone.

Assessment of circular wound healing in rats after exposure to 808-nm laser pulses during specific healing phases

BACKGROUND AND OBJECTIVES

Low-level laser therapy (LLLT), is an important application modality for the advancement of wound healing processes. In this study, histological and morphometric analyses have been made to understand and compare effects of high-power 808-nm pulses on circular skin wounds among groups irradiated immediately after wounding and groups irradiated at specific stages of the healing period.

STUDY DESIGN

Experimental groups were as follows: Laser Therapy (LT) was received as three sessions of laser irradiation (6.38 J/cm2, 1.276 W/cm2, 808 nm) immediately after wounding (Inflammatory group, n = 12), 24 hours post-wounding (Proliferative group, n = 12), and 72 hours post-wounding (Remodeling group, n = 12); the Control group (n = 12) received no irradiation. Histological analyses were performed on the 3rd, 7th, and 14th days post-wounding.

RESULTS

Mean wound diameters were 5 mm for all groups. On Day 7, wound diameters were measured as 2.99 ± 0.17, 2.95 ± 0.3, 2.52 ± 0.11, and 2.41 ± 0.34 mm for the Control, Inflammatory, Proliferative, and Remodeling groups, respectively. At 2 weeks post-wounding, dermal tissue in the Inflammatory and Proliferative groups closed superficially, while 1.30 ± 0.1 mm and 1.30 ± 0.06 mm openings remained in the Control and Remodeling groups, respectively. Mean wound healing rates (WHR) for all treatment groups were found to differ significantly from the control group (P < 0.05). Upon comparing the Proliferative group with the other treatment groups, a significant difference was found. However, no significant difference was found between the Inflammatory and Remodeling groups, with the former having a slightly higher mean value.

CONCLUSION

Histological and morphometric results showed that high-power, low-energy application has the best effect when first applied 24 hours post-wounding (late inflammatory, early proliferative stage) as demonstrated by increases in granulation tissue, fibroblasts and collagen deposition, which lead to faster rates of wound contraction and thus accelerated healing.

Early versus delayed dressing removal after primary closure of clean and clean-contaminated surgical wounds

BACKGROUND

Most surgical procedures involve a cut in the skin that allows the surgeon to gain access to the deeper tissues or organs. Most surgical wounds are closed fully at the end of the procedure (primary closure). The surgeon covers the closed surgical wound with either a dressing or adhesive tape. The dressing can act as a physical barrier to protect the wound until the continuity of the skin is restored (within about 48 hours) and to absorb exudate from the wound, keeping it dry and clean, and preventing bacterial contamination from the external environment. Some studies have found that the moist environment created by some dressings accelerates wound healing, although others believe that the moist environment can be a disadvantage, as excessive exudate can cause maceration (softening and deterioration) of the wound and the surrounding healthy tissue. The utility of dressing surgical wounds beyond 48 hours of surgery is, therefore, controversial.

OBJECTIVES

To evaluate the benefits and risks of removing a dressing covering a closed surgical incision site within 48 hours permanently (early dressing removal) or beyond 48 hours of surgery permanently with interim dressing changes allowed (delayed dressing removal), on surgical site infection.

SEARCH METHODS

In March 2015 we searched the following electronic databases: The Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Database of Abstracts of Reviews of Effects (DARE) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; and EBSCO CINAHL. We also searched the references of included trials to identify further potentially-relevant trials.

SELECTION CRITERIA

Two review authors independently identified studies for inclusion. We included all randomised clinical trials (RCTs) conducted with people of any age and sex, undergoing a surgical procedure, who had their wound closed and a dressing applied. We included only trials that compared early versus delayed dressing removal. We excluded trials that included people with contaminated or dirty wounds. We also excluded quasi-randomised studies, and other study designs.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data on the characteristics of the trial participants, risk of bias in the trials and outcomes for each trial. We calculated risk ratios (RR) with 95% confidence intervals (CI) for binary outcomes and mean difference (MD) with 95% CI for continuous outcomes. We used RevMan 5 software to perform these calculations.

MAIN RESULTS

Four trials were identified for inclusion in this review. All the trials were at high risk of bias. Three trials provided information for this review. Overall, this review included 280 people undergoing planned surgery. Participants were randomised to early dressing removal (removal of the wound dressing within the 48 hours following surgery) (n = 140) or delayed dressing removal (continued dressing of the wound beyond 48 hours) (n = 140) in the three trials. There were no statistically significant differences between the early dressing removal group and delayed dressing removal group in the proportion of people who developed superficial surgical site infection within 30 days (RR 0.64; 95% CI 0.32 to 1.28), superficial wound dehiscence within 30 days (RR 2.00; 95% CI 0.19 to 21.16) or serious adverse events within 30 days (RR 0.83; 95% CI 0.28 to 2.51). No deep wound infection or deep wound dehiscence occurred in any of the participants in the trials that reported this outcome. None of the trials reported quality of life. The hospital stay was significantly shorter (MD -2.00 days; 95% CI -2.82 to -1.18) and the total cost of treatment significantly less (MD EUR -36.00; 95% CI -59.81 to -12.19) in the early dressing removal group than in the delayed dressing removal group in the only trial that reported these outcomes.

AUTHORS' CONCLUSIONS

The early removal of dressings from clean or clean contaminated surgical wounds appears to have no detrimental effect on outcomes. However, it should be noted that the point estimate supporting this statement is based on very low quality evidence from three small randomised controlled trials, and the confidence intervals around this estimate were wide. Early dressing removal may result in a significantly shorter hospital stay, and significantly reduced costs, than covering the surgical wound with wound dressings beyond the first 48 hours after surgery, according to very low quality evidence from one small randomised controlled trial. Further randomised controlled trials of low risk of bias are necessary to investigate whether dressings are necessary after 48 hours in different types of surgery and levels of contamination and investigate whether antibiotic therapy influences the outcome.

Early versus delayed post-operative bathing or showering to prevent wound complications

BACKGROUND

Many people undergo surgical operations during their life-time, which result in surgical wounds. After an operation the incision is closed using stiches, staples, steri-strips or an adhesive glue. Usually, towards the end of the surgical procedure and before the patient leaves the operating theatre, the surgeon covers the closed surgical wound using gauze and adhesive tape or an adhesive tape containing a pad (a wound dressing) that covers the surgical wound. There is currently no guidance about when the wound can be made wet by post-operative bathing or showering. Early bathing may encourage early mobilisation of the patient, which is good after most types of operation. Avoiding post-operative bathing or showering for two to three days may result in accumulation of sweat and dirt on the body. Conversely, early washing of the surgical wound may have an adverse effect on healing, for example by irritating or macerating the wound, and disturbing the healing environment.

OBJECTIVES

To compare the benefits (such as potential improvements to quality of life) and harms (potentially increased wound-related morbidity) of early post-operative bathing or showering (i.e. within 48 hours after surgery, the period during which epithelialisation of the wound occurs) compared with delayed post-operative bathing or showering (i.e. no bathing or showering for over 48 hours after surgery) in patients with closed surgical wounds.

SEARCH METHODS

We searched The Cochrane Wounds Group Specialised Register (30th June 2015); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); The Database of Abstracts of Reviews of Effects (DARE) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; EBSCO CINAHL; the metaRegister of Controlled Trials (mRCT) and the International Clinical Trials Registry Platform (ICTRP).

SELECTION CRITERIA

We considered all randomised trials conducted in patients who had undergone any surgical procedure and had surgical closure of their wounds, irrespective of the location of the wound and whether or not the wound was dressed. We excluded trials if they included patients with contaminated, dirty or infected wounds and those that included open wounds. We also excluded quasi-randomised trials, cohort studies and case-control studies.

DATA COLLECTION AND ANALYSIS

We extracted data on the characteristics of the patients included in the trials, risk of bias in the trials and outcomes from each trial. For binary outcomes, we calculated the risk ratio (RR) with 95% confidence interval (CI). For continuous variables we planned to calculate the mean difference (MD), or standardised mean difference (SMD) with 95% CI. For count data outcomes, we planned to calculate the rate ratio (RaR) with 95% CI. We used RevMan 5 software for performing these calculations.

MAIN RESULTS

Only one trial was identified for inclusion in this review. This trial was at a high risk of bias. This trial included 857 patients undergoing minor skin excision surgery in the primary care setting. The wounds were sutured after the excision. Patients were randomised to early post-operative bathing (dressing to be removed after 12 hours and normal bathing resumed) (n = 415) or delayed post-operative bathing (dressing to be retained for at least 48 hours before removal and resumption of normal bathing) (n = 442). The only outcome of interest reported in this trial was surgical site infection (SSI). There was no statistically significant difference in the proportion of patients who developed SSIs between the two groups (857 patients; RR 0.96; 95% CI 0.62 to 1.48). The proportions of patients who developed SSIs were 8.5% in the early bathing group and 8.8% in the delayed bathing group.

AUTHORS' CONCLUSIONS

There is currently no conclusive evidence available from randomised trials regarding the benefits or harms of early versus delayed post-operative showering or bathing for the prevention of wound complications, as the confidence intervals around the point estimate are wide, and, therefore, a clinically significant increase or decrease in SSI by early post-operative bathing cannot be ruled out. We recommend running further randomised controlled trials to compare early versus delayed post-operative showering or bathing.

A pilot study evaluating protein abundance in pressure ulcer fluid from people with and without spinal cord injury

OBJECTIVE

To determine whether the biochemistry of chronic pressure ulcers differs between patients with and without chronic spinal cord injury (SCI) through measurement and comparison of the concentration of wound fluid inflammatory mediators, growth factors, cytokines, acute phase proteins, and proteases.

DESIGN

Survey.

SETTING

Tertiary spinal cord rehabilitation center and skilled nursing facilities.

PARTICIPANTS

Twenty-nine subjects with SCI and nine subjects without SCI (>18 years) with at least one chronic pressure ulcer Stage II, III, or IV were enrolled.

OUTCOME MEASURES

Total protein and 22 target analyte concentrations including inflammatory mediators, growth factors, cytokines, acute phase proteins, and proteases were quantified in the wound fluid and blood serum samples. Blood samples were tested for complete blood count, albumin, hemoglobin A1c, total iron binding capacity, iron, percent (%) saturation, C-reactive protein, and erythrocyte sedimentation rate.

RESULTS

Wound fluid concentrations were significantly different between subjects with SCI and subjects without SCI for total protein concentration and nine analytes, MMP-9, S100A12, S100A8, S100A9, FGF2, IL-1b, TIMP-1, TIMP-2, and TGF-b1. Subjects without SCI had higher values for all significantly different analytes measured in wound fluid except FGF2, TGF-b1, and wound fluid total protein. Subject-matched circulating levels of analytes and the standardized local concentration of the same proteins in the wound fluid were weakly or not correlated.

CONCLUSIONS

The biochemical profile of chronic pressure ulcers is different between SCI and non-SCI populations. These differences should be considered when selecting treatment options. Systemic blood serum properties may not represent the local wound environment.

Promising role of ANGPTL4 gene in diabetic wound healing

Diabetes mellitus (DM) is one of the severe metabolic disorders of carbohydrate metabolism worldwide. Developing countries are at higher risk of DM, and there is significant evidence that it is epidemic in many economically developing and newly industrialized countries. Among all other complications associated with DM, delayed wound healing is a major concern in diabetic patients. Wound healing is a natural healing process that starts immediately after injury. This involves interaction of a complex cascade of cellular events that generates resurfacing, reconstitution, and restoration of the tensile strength of injured skin. There are multiple factors responsible for delayed wound healing among which the contribution of DM has been well documented. The wound healing process is also delayed by the metabolic, vascular, neurological, and inflammatory alterations, which are well known in both type 1 and type 2 diabetes. Keratinocytes are crucial for wound re-epithelialization, and defects in directed migration of keratinocytes due to DM are associated with the delayed wound healing process. Many factors responsible for re-epithelialization have been identified, characterized, and well described; however, the genes responsible for the healing process have only partially been illustrated. This article will therefore focus on the efficacy of ANGPTL4 (angiopoietin-like 4) gene, which plays a novel role in keratinocyte migration during wound healing.

Therapeutic potential of electromagnetic fields for tissue engineering and wound healing

Ability of electromagnetic fields (EMF) to stimulate cell proliferation and differentiation has attracted the attention of many laboratories specialized in regenerative medicine over the past number of decades. Recent studies have shed light on bio-effects induced by the EMF and how they might be harnessed to help control tissue regeneration and wound healing. Number of recent reports suggests that EMF has a positive impact at different stages of healing. Processes impacted by EMF include, but are not limited to, cell migration and proliferation, expression of growth factors, nitric oxide signalling, cytokine modulation, and more. These effects have been detected even during application of low frequencies (range: 30-300 kHz) and extremely low frequencies (range: 3-30 Hz). In this regard, special emphasis of this review is the applications of extremely low-frequency EMFs due to their bio-safety and therapeutic efficacy. The article also discusses combinatorial effect of EMF and mesenchymal stem cells for treatment of neurodegenerative diseases and bone tissue engineering. In addition, we discuss future perspectives of application of EMF for tissue engineering and use of metal nanoparticles activated by EMF for drug delivery and wound dressing.

Healing efficiency of oligosaccharides generated from almond gum (Prunus amygdalus) on dermal wounds of adult rats

Almond gum is a naturally occurring polymer produced by almond trees and shrubs. Its abundance, as well as its low cost production makes it a potential feedstock for use in food and pharmaceuticals. In this regard, almond gum oligosaccharides were enzymatically generated, purified and their monosaccharide composition assessed using gas chromatography-flame ionization detector. Oligosaccharide analyses show that the most prominent residues were galactose and arabinose with traces of xylose, rhamnose, glucose and mannose. The glycosyl linkage positions were analyzed using gas chromatography - mass spectrometry showing a main chain composed of galactose units [→3)-Gal-(1→] branched mainly with arabinose residues [Ara-(1→]. The potent role of the generated oligosaccharides on rats wound healing was investigated. They have been applied either alone or supplemented, as active substance, with cream formulation, on full-thickness wound created on the dorsum of the rats. The effect of oligosaccharides was assessed by measuring the wound closure percentage, reaching an average of around 100% when applied alone or supplemented to cream formulation. The healing percentage for the control group was only 74.3% at the same day. The histological evaluation of skin sections visualized by light microscopy revealed an improved collagen deposition and an increased fibroblast and vascular densities.

Nanovesicles engineered from ES cells for enhanced cell proliferation

Extracellular vesicles (Exosomes and microvesicles) have drawn wide attentions in both diagnostic and therapeutic applications, since they are considered to shuttle biological signals intercellularly. However, further research on exosomes is limited by their rarity and heterogeneity even after lengthy isolation processes. In particular, these limitations are challenging in therapeutic applications. To meet these demands, cell-derived nanovesicles that mimic exosomes were generated by extruding living embryonic stem cells through micro-filters. These nanovesicles have an enclosed lipid bilayer and contain cellular contents. The present study investigated the ability of these nanovesicles to improve proliferation by treating primary murine skin fibroblasts with the nanovesicles. The treated skin fibroblasts showed higher expression levels of mRNA, VEGF-α, protein levels of TGF-β collagen I, PCNA, and Ki-67, as well as enhanced cell proliferation rate and number, compared to non-treated cells. The results indicate that treatment with the nanovesicles could potentially contribute to recovery or wound healing process of tissues.

Role of polymeric biomaterials as wound healing agents

In uncontrolled hemorrhage, the main cause of death on the battlefield and in accidents, half of the deaths are caused by severe blood loss. Polymeric biomaterials have great potential in the control of severe hemorrhage from trauma, which is the second leading cause of death in the civilian community following central nervous system injuries. The intent of this article is to provide a review on currently available biopolymers used as wound dressing agents and to describe their best use as it relates to the condition and type of the wound (acute, chronic, superficial, and full thickness) and the phases of the wound healing process. These biopolymers are beneficial in tissue engineering as scaffolds, hydrogels, and films. Different types of wound dressings based on biopolymers are available in the market, with various physical, chemical, and biological properties. The use of biopolymers as a hemostatic agent depends on its biocompatibility, biodegradability, nonimmunogenicity, and optimal mechanical property. This review summarizes different biopolymers, their physiological characters, and their use as wound healing agents along with biomedical applications.

Growth factor therapy in patients with partial-thickness burns: a systematic review and meta-analysis

Growth factor (GF) therapy has shown promise in treating a variety of refractory wounds. However, evidence supporting its routine use in burn injury remains uncertain. We performed this systematic review and meta-analysis assessing randomised controlled trials (RCTs) to investigate efficacy and safety of GFs in the management of partial-thickness burns. Electronic searches were conducted in PubMed and the Cochrane databases. Endpoint results analysed included wound healing and scar formation. Thirteen studies comprising a total of 1924 participants with 2130 wounds (1131 GF receiving patients versus 999 controls) were identified and included, evaluating the effect of fibroblast growth factor (FGF), epidermal growth factor (EGF) and granulocyte macrophage-colony stimulating factor (GM-CSF) on partial-thickness burns. Topical application of these agents significantly reduced healing time by 5·02 (95% confidence interval, 2·62 to 7·42), 3·12 (95% CI, 1·11 to 5·13) and 5·1 (95% CI, 4·02 to 6·18) days, respectively, compared with standard wound care alone. In addition, scar improvement following therapy with FGF and EGF was evident in terms of pigmentation, pliability, height and vascularity. No significant increase in adverse events was observed in patients receiving GFs. These results suggested that GF therapy could be an effective and safe add-on to standard wound care for partial-thickness burns. High-quality, adequately powered trials are needed to further confirm the conclusion.

Ethanolic extract of sharah, Plectranthus aegyptiacus, enhances healing of skin wound in rats

Sharah, Plectranthus aegyptiacus (Forssk.) C. Chr. is a common native plant in the Taif region of Saudi Arabia. An ethanolic extract of freeze dried sharah leaves was added as 10% (w/w) to an ointment base of beeswax and sesame oil. The resultant ointment was examined as a potential enhancer of wound healing. Excision wounds in the nape region of the skin were induced in sixty albino Wistar rats. Animals were allocated in 4 groups (n=15) and kept individually in clean cages. The first group served as negative untreated controls without medication; the second group was treated with ointment base (vehicle); the third group represented the positive control and was treated with a reference ointment and the fourth one served as the experimental group and received the test plant extract (as ointment). Animal groups received the respective medications for 14 successive days. Wounds were measured and photographed every 3 days till the end of the experiment (day 21) in order to determine the wound closure rate (WCR). Specimens from wounds and surrounding skin were collected from sacrificed animals for histological and molecular studies. Both morphometric (based on WCR) and histological findings showed that the healing in animals treated with the sharah plant extract was better than those in control group or vehicle-treated group and was similar to that in the group that received the reference ointment. Moreover, the molecular findings concerning the expression levels of hepatocyte growth factor (HGF) and its receptor (c-Met) displayed a reasonable healing enhancing effect of the plant extract with the expression levels of both being higher in the extract-treated group than in the control group.

From basics to clinical: a comprehensive review on spinal cord injury

Spinal cord injury (SCI) is a devastating neurological disorder that affects thousands of individuals each year. Over the past decades an enormous progress has been made in our understanding of the molecular and cellular events generated by SCI, providing insights into crucial mechanisms that contribute to tissue damage and regenerative failure of injured neurons. Current treatment options for SCI include the use of high dose methylprednisolone, surgical interventions to stabilize and decompress the spinal cord, and rehabilitative care. Nonetheless, SCI is still a harmful condition for which there is yet no cure. Cellular, molecular, rehabilitative training and combinatorial therapies have shown promising results in animal models. Nevertheless, work remains to be done to ascertain whether any of these therapies can safely improve patient's condition after human SCI. This review provides an extensive overview of SCI research, as well as its clinical component. It starts covering areas from physiology and anatomy of the spinal cord, neuropathology of the SCI, current clinical options, neuronal plasticity after SCI, animal models and techniques to assess recovery, focusing the subsequent discussion on a variety of promising neuroprotective, cell-based and combinatorial therapeutic approaches that have recently moved, or are close, to clinical testing.

Early versus delayed post-operative bathing or showering to prevent wound complications

BACKGROUND

Many people undergo surgical operations during their life-time, which result in surgical wounds. After an operation the incision is closed using stiches, staples, steri-strips or an adhesive glue. Usually, towards the end of the surgical procedure and before the patient leaves the operating theatre, the surgeon covers the closed surgical wound using gauze and adhesive tape or an adhesive tape containing a pad (a wound dressing) that covers the surgical wound. There is currently no guidance about when the wound can be made wet by post-operative bathing or showering. Early bathing may encourage early mobilisation of the patient, which is good after most types of operation. Avoiding post-operative bathing or showering for two to three days may result in accumulation of sweat and dirt on the body. Conversely, early washing of the surgical wound may have an adverse effect on healing, for example by irritating or macerating the wound, and disturbing the healing environment.

OBJECTIVES

To compare the benefits (such as potential improvements to quality of life) and harms (potentially increased wound-related morbidity) of early post-operative bathing or showering (i.e. within 48 hours after surgery, the period during which epithelialisation of the wound occurs) compared with delayed post-operative bathing or showering (i.e. no bathing or showering for over 48 hours after surgery) in patients with closed surgical wounds.

SEARCH METHODS

We searched The Cochrane Wounds Group Specialised Register;The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); The Database of Abstracts of Reviews of Effects (DARE) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; EBSCO CINAHL; the metaRegister of Controlled Trials (mRCT) and the International Clinical Trials Registry Platform (ICTRP).

SELECTION CRITERIA

We considered all randomised trials conducted in patients who had undergone any surgical procedure and had surgical closure of their wounds, irrespective of the location of the wound and whether or not the wound was dressed. We excluded trials if they included patients with contaminated, dirty or infected wounds and those that included open wounds. We also excluded quasi-randomised trials, cohort studies and case-control studies.

DATA COLLECTION AND ANALYSIS

We extracted data on the characteristics of the patients included in the trials, risk of bias in the trials and outcomes from each trial. For binary outcomes, we calculated the risk ratio (RR) with 95% confidence interval (CI). For continuous variables we planned to calculate the mean difference (MD), or standardised mean difference (SMD) with 95% CI. For count data outcomes, we planned to calculate the rate ratio (RaR) with 95% CI. We used RevMan 5 software for performing these calculations.

MAIN RESULTS

Only one trial was identified for inclusion in this review. This trial was at a high risk of bias. This trial included 857 patients undergoing minor skin excision surgery in the primary care setting. The wounds were sutured after the excision. Patients were randomised to early post-operative bathing (dressing to be removed after 12 hours and normal bathing resumed) (n = 415) or delayed post-operative bathing (dressing to be retained for at least 48 hours before removal and resumption of normal bathing) (n = 442). The only outcome of interest reported in this trial was surgical site infection (SSI). There was no statistically significant difference in the proportion of patients who developed SSIs between the two groups (857 patients; RR 0.96; 95% CI 0.62 to 1.48). The proportions of patients who developed SSIs were 8.5% in the early bathing group and 8.8% in the delayed bathing group.

AUTHORS' CONCLUSIONS

There is currently no conclusive evidence available from randomised trials regarding the benefits or harms of early versus delayed post-operative showering or bathing for the prevention of wound complications, as the confidence intervals around the point estimate are wide, and, therefore, a clinically significant increase or decrease in SSI by early post-operative bathing cannot be ruled out. We recommend running further randomised controlled trials to compare early versus delayed post-operative showering or bathing.

Early versus delayed dressing removal after primary closure of clean and clean-contaminated surgical wounds

BACKGROUND

Most surgical procedures involve a cut in the skin that allows the surgeon to gain access to the deeper tissues or organs. Most surgical wounds are closed fully at the end of the procedure (primary closure). The surgeon covers the closed surgical wound with either a dressing or adhesive tape. The dressing can act as a physical barrier to protect the wound until the continuity of the skin is restored (within about 48 hours) and to absorb exudate from the wound, keeping it dry and clean, and preventing bacterial contamination from the external environment. Some studies have found that the moist environment created by some dressings accelerates wound healing, although others believe that the moist environment can be a disadvantage, as excessive exudate can cause maceration (softening and deterioration) of the wound and the surrounding healthy tissue. The utility of dressing surgical wounds beyond 48 hours of surgery is, therefore, controversial.

OBJECTIVES

To evaluate the benefits and risks of removing a dressing covering a closed surgical incision site within 48 hours permanently (early dressing removal) or beyond 48 hours of surgery permanently with interim dressing changes allowed (delayed dressing removal), on surgical site infection.

SEARCH METHODS

In July 2013 we searched the following electronic databases: The Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Database of Abstracts of Reviews of Effects (DARE) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; and EBSCO CINAHL. We also searched the references of included trials to identify further potentially-relevant trials.

SELECTION CRITERIA

Two review authors independently identified studies for inclusion. We included all randomised clinical trials (RCTs) conducted with people of any age and sex, undergoing a surgical procedure, who had their wound closed and a dressing applied. We included only trials that compared early versus delayed dressing removal. We excluded trials that included people with contaminated or dirty wounds. We also excluded quasi-randomised studies, and other study designs.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data on the characteristics of the trial participants, risk of bias in the trials and outcomes for each trial. We calculated risk ratios (RR) with 95% confidence intervals (CI) for binary outcomes and mean difference (MD) with 95% CI for continuous outcomes. We used RevMan 5 software to perform these calculations.

MAIN RESULTS

Four trials were identified for inclusion in this review. All the trials were at high risk of bias. Three trials provided information for this review. Overall, this review included 280 people undergoing planned surgery. Participants were randomised to early dressing removal (removal of the wound dressing within the 48 hours following surgery) (n = 140) or delayed dressing removal (continued dressing of the wound beyond 48 hours) (n = 140) in the three trials. There were no statistically significant differences between the early dressing removal group and delayed dressing removal group in the proportion of people who developed superficial surgical site infection within 30 days (RR 0.64; 95% CI 0.32 to 1.28), superficial wound dehiscence within 30 days (RR 2.00; 95% CI 0.19 to 21.16) or serious adverse events within 30 days (RR 0.83; 95% CI 0.28 to 2.51). No deep wound infection or deep wound dehiscence occurred in any of the participants in the trials that reported this outcome. None of the trials reported quality of life. The hospital stay was significantly shorter (MD -2.00 days; 95% CI -2.82 to -1.18) and the total cost of treatment significantly less (MD EUR -36.00; 95% CI -59.81 to -12.19) in the early dressing removal group than in the delayed dressing removal group in the only trial that reported these outcomes.

AUTHORS' CONCLUSIONS

The early removal of dressings from clean or clean contaminated surgical wounds appears to have no detrimental effect on outcomes. However, it should be noted that the point estimate supporting this statement is based on very low quality evidence from three small randomised controlled trials, and the confidence intervals around this estimate were wide. Early dressing removal may result in a significantly shorter hospital stay, and significantly reduced costs, than covering the surgical wound with wound dressings beyond the first 48 hours after surgery, according to very low quality evidence from one small randomised controlled trial. Further randomised controlled trials of low risk of bias are necessary to investigate whether dressings are necessary after 48 hours in different types of surgery and levels of contamination and investigate whether antibiotic therapy influences the outcome.

Topical effects of frog "Rana ridibunda" skin secretions on wound healing and reduction of wound microbial load

ETHNOPHARMACOLOGICAL RELEVANCE

Study of the interrelationships between human and the animals in their environment has always been a subject of interest and caused discoveries of the animal applications in medicine. From the latest century, these remedies called back in traditional medicine of Vietnam and South America and frog skin was used as a biological dressing and had good effects in healing wounds. Also, frog skin secretions have wound healing properties and reduce inflammation. In this study we applied these secretions in the form of ointment to investigate their healing activities.

MATERIALS AND METHODS

Skin secretions were extracted from Rana ridibunda to evaluate their effects on wound healing in mice. Secretion used as raw extract (RE) and ultrafiltrated extract, using a membrane with cutoff 10kDa as under 10kDa (U10E), was administrated as ointment every 48h on wound site. Control group was left without any treatment and also there was other group treated with ointment (O group) alone. On 2, 4 and 6 days post injury, animals were euthanized and images were taken for wound closure evaluation. Then wound locations were removed for histological assays. Also wound microbial load was examined. Observational parameters including wound closure and wound microbiology in experimental groups compared with the control and O groups have been studied.

RESULTS

The results showed U10E group has better effects than RE, O and control groups. Histological parameters, including numbers of inflammatory and fibroblast cells and amount of collagen fibers, neovascularization, as well, represented greater degree of wound healing in U10E group compared with RE, O, and control groups.

CONCLUSIONS

Our results showed that frog skin secretions were significantly effective in promoting wound healing process. The U10E extract from the frog R. ridibunda possesses a potent accelerating wound healing effect that promises good potential for clinical application in wound care. Further studies will be required to characterize special molecules encompassing healing properties.

Innovative approaches in wound healing: trajectory and advances

Wound is one of the oldest suffering associated with the mankind and its history is as old as humanity. Advances in the field of medical sciences created a pile of knowledge and paved the path for the development of a separate branch specifically devoted for wound healing. The understanding and treatment strategies for wound healing have gone through a great revolution. This article reviews all the aspects of wound healing including the pathway, types and recent advances made in the wound care management in particular moist wound dressings using natural polymers, skin grafts, debridement, growth factor and drug delivery.

Is tissue augmentation a reality in biosurgery? An experimental study of endothelial cell invasion into tissue filler

New therapeutic approaches for wound treatment are evolving. Non healing wounds in oncology and after trauma may be cured by a novel technique of tissue augmentation with soft tissue fillers. The principle resides in filling the wound with collagen filler in order to seal the defect and promote healing. Successful angiogenesis forms the basis of tissue filler survival and determines the outcome of the healing process. During this study, basic data about endothelial cell invasion into collagen-made substratum was collected that could be used for neoangiogenesis studies in tissue augmentation techniques for large wound defect treatment. In the in vitro assay, the human umbilical vein endothelial cells (HUVEC) grow into a three-dimensional framework of collagenous tissue fillers, forming the basic step for angiogenesis. After heparins were used as chemotactic agents, a typical bell-shaped relationship between chemotaxis and agent concentrations was found. Significant cell infiltration was present in the assays with chemotactic agents. These observations support the potential for tissue augmentation with soft tissue fillers that could be used in acute and chronic non healing traumatic and oncology wounds after extensive surgical resections and radiotherapy.

Anatomy, physiology, and general concepts in nasal reconstruction

Nasal reconstruction provides a challenging task for any facial plastic surgeon. In performing reconstructive surgery on the nose, one must balance both the functional aspects of the nasal airway with the aesthetic responsibilities of being the central fixture of the face. Before performing surgery, the surgeon must grasp the importance of the anatomic nasal relationships and subunits, the physiology of the skin, the flaps or grafts used to reconstruct these areas, and the basic steps in wound healing. Accurate preoperative planning and analysis of the nasal defect are also vital to producing both an aesthetic and functional nose.

VEGF-A and FGF gene therapy accelerate healing of ischemic colonic anastomoses (experimental study)

BACKGROUND

Reducing ischemic damage is one of the goals of surgery. The aim of this study was to apply human VEGF-A and FGF-2 DNA-mediated gene therapy in order to identify their effects in the healing of ischemic colon anastomoses and eliminating the negative effects of ischemia.

METHODS

Forty male Wistar albino rats weighing 250-280 g were divided into five equal groups (n = 8) as follows: group 1: control, ischemic left colonic anastomosis; group; 2: ischemic left colonic anastomosis with control plasmid delivery; group 3: ischemic left colonic anastomosis with VEGF plasmid delivery; group 4: ischemic left colonic anastomosis with FGF plasmid delivery; group 5: ischemic left colonic anastomosis with VEGF and FGF plasmid delivery. All rats were sacrificed on the 4th postoperative day. Anastomosis burst pressures were measured for mechanical examination of anastomosis. Tissue hydroxyprolin, VEGF and FGF levels were determined as biochemical parameters. Necrosis, epithelisation, inflammatory processes, fibroblastic activity, collagen deposition and neovascularisation at the anastomic site were studied.

RESULTS

VEGF, FGF and combined therapy significantly accelerated many of the histological parameters of healing, including fibroblast activation, collagen deposition, and angiogenesis, and augmented the levels of hydroxyproline and bursting pressure.

CONCLUSIONS

This is the first study to use gene therapy with growth factors for the healing of ischemic colonic anastomosis. This therapy can be effectively used in increasing ischemic anastomosis wound healing.

Temporal spatial expression and function of non-muscle myosin II isoforms IIA and IIB in scar remodeling

Scar contracture is believed to be caused by the cell contractility during the remodeling phase of wound healing. Cell contractility is mediated by non-muscle myosin II (NMMII) and actin, but the temporal-spatial expression profile of NMMII isoforms A and B (IIA and IIB) during the remodeling phase and the role of NMMII in scar fibroblast tissue remodeling are unknown. Human scar tissue immunostained for IIA and IIB showed that both isoforms were highly expressed in scar tissue throughout the remodeling phase of repair and expression levels returned to normal after the remodeling phase. Human scar tissue immunostained for β-, γ- and α-smooth muscle actin showed that all isoforms were consistently expressed throughout the remodeling phase of repair. The β- and γ-smooth muscle actin were widely expressed throughout the dermis, but α-smooth muscle actin was only locally expressed within the dermis. In vitro, fibroblasts explanted from scar tissue were shown to express more IIA than fibroblasts explanted from normal tissue and scar fibroblasts contracted collagen lattices to a greater extent than normal fibroblasts. Blebbistatin was used to demonstrate the function of NMMII in collagen lattice contraction. In normal tissue, fibroblasts are stress-shielded from external tensile stress by the extracellular matrix. After dermal injury and during remodeling, fibroblasts are exposed to a matrix of increased stiffness. The effect of matrix stiffness on IIA and IIB expression was examined. IIA expression was greater in fibroblasts cultured in collagen lattices with increasing stiffness, and in fibroblasts cultured on glass slides compared with polyacrylamide gels with stiffness of 1 kPa. In conclusion, NMMII and actin isoform expression changes coordinately with the remodeling phase of repair, and NMMII is increased as matrix stiffness increases. As NMMII expression increases, so does the fibroblast contractility.

Wound healing and regenerative strategies

Wound healing is a complex biological process that affects multiple tissue types. Wounds in the oral cavity are particularly challenging given the variety of tissue types that exist in close proximity to one another. The goal of regenerative medicine is to facilitate the rapid replacement of lost or damaged tissue with tissue that is functional, and physiologically similar to what previously existed. This review provides a general overview of wound healing and regenerative medicine, focusing specifically on how recent advances in the fields of stem cell biology, tissue engineering, and oral disease could translate into improved clinical outcomes.

Modulated and continuous-wave operations of low-power thulium (Tm:YAP) laser in tissue welding

Our aim is to explore the welding capabilities of a thulium (Tm:YAP) laser in modulated and continuous-wave (CW) modes of operation. The Tm:YAP laser system developed for this study includes a Tm:YAP laser resonator, diode laser driver, water chiller, modulation controller unit, and acquisition/control software. Full-thickness incisions on Wistar rat skin were welded by the Tm:YAP laser system at 100 mW and 5 s in both modulated and CW modes of operation (34.66 Wcm(2)). The skin samples were examined during a 21-day healing period by histology and tensile tests. The results were compared with the samples closed by conventional suture technique. For the laser groups, immediate closure at the surface layers of the incisions was observed. Full closures were observed for both modulated and CW modes of operation at day 4. The tensile forces for both modulated and CW modes of operation were found to be significantly higher than the values found by conventional suture technique. The 1980-nm Tm:YAP laser system operating in both modulated and CW modes maximizes the therapeutic effect while minimizing undesired side effects of laser tissue welding. Hence, it is a potentially important alternative tool to the conventional suturing technique.

Effectiveness of topical zinc oxide application on hypertrophic scar development in rabbits

BACKGROUND

The etiology, biology, prevention and effective treatment of hypertrophic scars have not exactly been defined. Topical zinc oxide application was shown to be effective in the treatment of proliferative scars. We studied the effectiveness of topical zinc oxide ointment in the prevention of hypertrophic scar development by using the rabbit ear hypertrophic scar model.

METHODS

Circular full-thickness skin excisions were performed on both ears of 10 rabbits. The rabbits were divided into two groups and topical 40% zinc oxide ointment was applied daily to one ear and the ointment base was applied as placebo to the other ear. Scar samples were taken in the 3rd week in group 1 and in the 6th week in group 2. All of the specimens were divided into two halves: one half for histopathologic/histomorphometric examinations and the other half for biochemical studies.

RESULTS

Application of topical zinc oxide ointment decreased clinical scar hypertrophy scores significantly (p=0.017) at 6th week in comparison with placebo. Topical zinc oxide also reduced nodule formation histopathologically at 6th week in comparison with placebo but this was not significant statistically (p>0.05).

CONCLUSION

The findings of this study may have clinical implications on the management of human hypertrophic scars.

The wound healing process: an overview of the cellular and molecular mechanisms

Wound healing remains a challenging clinical problem and correct, efficient wound management is essential. Much effort has been focused on wound care with an emphasis on new therapeutic approaches and the development of technologies for acute and chronic wound management. Wound healing involves multiple cell populations, the extracellular matrix and the action of soluble mediators such as growth factors and cytokines. Although the process of healing is continuous, it may be arbitrarily divided into four phases: (i) coagulation and haemostasis; (ii) inflammation; (iii) proliferation; and (iv) wound remodelling with scar tissue formation. The correct approach to wound management may effectively influence the clinical outcome. This review discusses wound classification, the physiology of the wound healing process and the methods used in wound management.

Promotion of incisional wound repair by human mesenchymal stem cell transplantation

The purpose of this study was to determine the effect of transplanted human mesenchymal stem cells (hMSCs) on wound healing. In this model, full-thickness cutaneous wounds were created by incision in the skin of adult New Zealand white rabbits and treated by transplanted hMSCs into the wounds. Wound healing was evaluated by histological analysis and tensiometry over time. A total of 15 New Zealand white rabbits with 10 wounds per animal were examined in this study. Animals were treated with hMSCs and euthanised at 3, 7, 14, 21 and 80 days after manipulation. The hMSCs were labelled with a fluorescent dye (CM-DiI), suspended in phosphate-buffered saline and used to treat full-thickness incisional wounds in rabbit skin. Tensiometry and histology were used to characterise the wound-healing rate of the incisional wounds. These results showed that transplanted hMSCs significantly inhibited scar formation and increased the tensile strength of the wounds. Importantly, MSCs from genetically unrelated donors did not appear to induce an immunologic response. In conclusion, human mesenchymal stem cell therapy is a viable approach to significantly affect the course of normal cutaneous wound healing and significantly increase the tensile strength.

Inflammatory cytokine responses to synthetic extracellular matrix injection to the vocal fold lamina propria

OBJECTIVES

We determined cytokine profiles for tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-6, IL-1alpha, and IL-1beta after injection of a synthetic extracellular matrix into the vocal fold lamina propria.

METHODS

Transcript expression of inflammatory cytokines was measured with real-time polymerase chain reaction on postoperative days 1, 3, 5, 10, and 21 in 25 rabbits that underwent bilateral vocal fold biopsy with Extracel-LG (Carbylan-GSX 5%) immediately injected into the wound in the left vocal fold and saline solution injected into the wound in the right vocal fold. Two unwounded normal rabbit larynges were also harvested for controls.

RESULTS

Significantly elevated levels of TNF-alpha, IL-1beta, and IL-6 were measured on day 3 in a comparison between Extracel-LG-injected vocal folds and saline solution-injected control vocal folds and between Extracel-LG-injected vocal folds and normal vocal folds. All cytokine levels returned to baseline by day 21.

CONCLUSIONS

A mild short-term inflammatory response was measured early after injection of a synthetic extracellular matrix into the vocal fold lamina propria.

In vitro binding of matrix metalloproteinase-2 (MMP-2), MMP-9, and bacterial collagenase on collagenous wound dressings

Chronic wounds are characterized by failure in wound-healing response and a delay in healing or nonclosure of the wounds. This results in a high effort in clinical treatment and/or home care. A major difference between acute wounds and chronic wounds is the imbalance of proteinase inhibitors and proteinase activity that regulates the degradation and regeneration of the extracellular matrix proteins. Collagen and collagen/oxidized regenerated cellulose dressings act as a competitive substrate for matrix metalloproteinase-2, matrix metalloproteinase-9, and bacterial collagenase and influence this imbalance positively. Both wound dressings, approved for chronic wound treatment, the bovine collagen type I sponge and the oxidized regenerated cellulose collagen sponge, did not differ significantly in their sorption profiles for all enzymes. In general, binding was enhanced with a longer incubation time. The density of the device and the accessible surface, which can be controlled by the manufacturing process, are the crucial factors for the efficiency of the wound dressing.

Effect of adenoviral mediated overexpression of fibromodulin on human dermal fibroblasts and scar formation in full-thickness incisional wounds

Fibromodulin, a member of the small leucine-rich proteoglycan family, has been recently suggested as a biologically significant mediator of fetal scarless repair. To assess the role of fibromodulin in the tissue remodeling, we constructed an adenoviral vector expressing human fibromodulin cDNA. We evaluated the effect of adenovirus-mediated overexpression of fibromodulin in vitro on transforming growth factors and metalloproteinases in fibroblasts and in vivo on full-thickness incisional wounds in a rabbit model. In vitro, we found that Ad-Fibromodulin induced a decrease of expression of TGF-beta(1) and TGF-beta(2) precursor proteins, but an increase in expression of TGF-beta(3) precursor protein and TGF-beta type II receptor. In addition, fibromodulin overexpression resulted in decreased MMP-1 and MMP-3 protein secretion but increased MMP-2, TIMP-1, and TIMP-2 secretion, whereas MMP-9 and MMP-13 were not influenced by fibromodulin overexpression. In vivo evaluation by histopathology and tensile strength demonstrated that Ad-Fibromodulin administration could ameliorate wound healing in incisional wounds. In conclusion, although the mechanism of scar formation in adult wounds remains incompletely understood, we found that fibromodulin overexpression improves wound healing in vivo, suggesting that fibromodulin may be a key mediator in reduced scarring.

Photoepilation: a potential threat to wound healing in a mouse

BACKGROUND

Theoretically, the bulge area which is known to be a reservoir of epidermal stem cells should be destroyed to achieve permanent photoepilation. We wished to determine whether wound healing capability is perturbed after photoepilation.

METHODS

Twenty C57/BL6 mice were used. After wax epilation to synchronize the hair cycle, one-half of the backs of mice were photoepilated in the early anagen stage. After the two hair cycles of the mice to confirm the hair removal effect, 30% trichloroacetic acid was applied to the both halves of the backs of the mice. A skin biopsy was performed on both sides before and just after the injury, and 2, 6, 9, and 14 days thereafter. The specimens were evaluated histologically after staining with hematoxylin and eosin, Masson trichrome, and Verhoeff-van Gieson.

RESULTS

No differences in wound healing times were evident upon gross observation by the naked eye. However, the photoepilated hairless skin was observed to have a thicker epidermis and dermis than normal hairy skin by histological evaluation. The cellularity of the healed wound was much denser in the photoepilated. Collagen production of the neodermis in the normal hairy skin was first observed around the lower part of hair follicle, while it started from the upper papillary dermis in photoepilated skin.

CONCLUSION

Photoepilation may disturb the normal wound healing process, especially dermal wound healing, and increases the risk of producing hypertropic scar or keloid.

Intra-lesional injections of collagenase are ineffective in the treatment of keloid and hypertrophic scars

The treatment of keloid and hypertrophic scars remains difficult. Enzymatic digestion of keloid scars has been previously proposed as an effective treatment strategy for reducing the volume of keloid scars. To test this, we administered intra-lesional injections of pure collagenase (between 600 and 4500 units for each scar) into the keloid and hypertrophic scars of seven human volunteers (five keloid and two hypertrophic scars). Five patients (three keloid and two hypertrophic) received more than one injection of collagenase. The treatment resulted in a temporary reduction in scar volume for three of the patients with keloid scars. However, scar volumes for these three patients returned to the same (or greater) levels after 6 months of follow-up. Treatment with collagenase produced no change in scar volume for the two patients with hypertrophic scar. Side effects were numerous and severe including; pain, swelling, blistering, ulceration and ecchymosis at the site of injection. One patient required admission to hospital for 48 h after the first injection. Maximum length of follow-up was 6 months. None of the seven patients completed the study and returned for final follow-up at 2 years. This pilot study suggests that treatment of keloid and hypertrophic scars with intra-lesional injections of collagenase is ineffective.

Lactoferrin promotes collagen gel contractile activity of fibroblasts mediated by lipoprotein receptorsThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process

Lactoferrin is an iron-binding glycoprotein that belongs to the transferrin family. Recent studies in vitro and in vivo suggest that lactoferrin is a potential therapeutic agent for wound healing. We have shown that both bovine and human lactoferrin enhance the collagen gel contractile activity of WI-38 human fibroblasts. The collagen gel contraction is considered as an in vitro model for reorganization of the collagen matrix during the wound healing process. The elevation of collagen gel contractile activity induced by lactoferrin was accompanied by activation of extracellular-regulated kinase (ERK) 1/2 and myosin light chain kinase (MLCK), and subsequent elevation of myosin light chain (MLC) phosphorylation. The effects of lactoferrin on collagen gel contraction and the activation of the signaling pathway were dependent on the expression of low-density lipoprotein receptor - related protein (LRP) - 1 in the fibroblasts. LRP-1 is known as an endocytosis receptor and is involved in the cellular uptake of diverse ligands, including lactoferrin. In addition, LRP-1 acts as a signaling lactoferrin receptor in mammalian cells by converting the lactoferrin-binding signal into the activation of the intracellular signaling pathway. This property was found to be independent of the endocytic function of LRP-1, as seen in osteoblast-like cells.

Immune-Based Therapy for Spinal Cord Repair: Autologous Macrophages and Beyond

Spinal cord injury is a devastating condition of the central nervous system (CNS), often resulting in severe loss of tissue, functional impairment, and only limited repair. Studies over the last few years have shown that response to the insult and spontaneous attempts at repair are multiphasic processes, with varying and sometimes conflicting requirements. This knowledge has led to novel strategies of therapeutic intervention. Our view is that a pivotal role in repair, maintenance, healing, and cell renewal in the CNS, as in other tissues, is played by the immune system. The mode and timing of intervention must be carefully selected, however, as the capacity of the CNS to tolerate local repair mechanisms is limited. Studies have shown that the spontaneously evoked early innate response to CNS injury is characterized by invasion of neutrophils and is unfavorable for cell survival. This is followed by a response of the resident innate immune cells (microglia), which however cannot supply all the needs of the damaged tissue; moreover, once evoked, and for as long as the damage persists, the microglial response remains beyond the capacity of the CNS to tolerate it. Immune-based clinical intervention is most effective in improving functional and morphological recovery when delayed for a certain period. Effective intervention might be in the form of (1) local injection of "alternatively activated" macrophages, (2) systemic injection of dendritic cells specific to CNS antigens, or (3) T-cell-based vaccination. The treatment of choice depends on the severity of the insult, the site of injury, the therapeutic window, and safety considerations.

Wound Healing in the Veterinary Rehabilitation Patient

Wound healing is a biologically complex cascade of predictable overlap-ping events and is a natural restorative response to tissue injury. The biologic process for wound healing is the same for all wounds, although the specific mechanisms may vary. This article reviews the wound heal-ing process, discussing factors that may delay normal healing progression and potential modalities and treatments to aid healing.

Biochemical markers associated with acute vocal fold wound healing: a rabbit model

This study seeks to determine the ability of enzyme-linked immunosorbent assays (ELISAs) of vocal fold secretions to detect and describe the acute tissue response to injury in a rabbit vocal fold model. Vocal fold secretions were collected before the induction of a unilateral surgical injury to the vocal fold and at 6 timepoints after injury (1, 5, 7, 10, 14, and 21 days). Secretions were then subjected to ELISAs to assess concentrations of interleukin-1 beta (IL-1beta) and prostaglandin-E2 (PGE-2). The results indicate that ELISAs may be useful in documenting fluctuations in these markers associated with the wound healing process in the rabbit model. The temporal expression of both IL-1beta and PGE-2 was consistent with their proposed roles in the wound healing cascade in other systems, pointing to the potential that surface secretions may be at least partial indicators of wound healing events within the tissue.

Normal cutaneous wound healing: clinical correlation with cellular and molecular events

BACKGROUND

Cutaneous wound healing is a normal physiologic function, observed and described for centuries by those afflicted with wounds and by those caring for them. Recently, tremendous progress has been made in discovering the cellular and molecular mechanisms responsible for wound healing. Counseling patients appropriately and planning future therapeutic interventions in delayed or abnormal wound healing may be improved by a thorough understanding of the relationship between clinical, cellular, and subcellular events occurring during the normal healing process.

MATERIALS AND METHODS

A review of the wound healing literature from the past several decades, with a focus on the past 5 to 10 years in particular, along with illustrative case examples from our clinical practice over the past decade.

RESULTS

Traditional clinical stages of wounding healing are still relevant, but more overlap between stages is likely a more accurate depiction of events. The role of cells such as platelets, macrophages, leukocytes, fibroblasts, endothelial cells, and keratinocytes is much better known, particularly during the inflammatory and proliferation stages of healing. Molecules such as interferon, integrins, proteoglycans and glycosaminoglycans, matrix metalloproteinases, and other regulatory cytokines play a critical role in the regulation of healing mechanisms.

CONCLUSION

Cutaneous wound healing in normal hosts follows an orderly clinical process. The scientific underpinnings for healing are better understood than ever, although much remains to be discovered. Eventually, such improved understanding of cellular and subcellular physiology may lead to new or better forms of therapy for patients with acute, chronic, and surgical skin wounds.

Mechanics of wound healing and importance of Vacuum Assisted Closure in urology

PURPOSE

We discuss the mechanisms of wound healing and our experience with the Vacuum Assisted Closure device (Kinetic Concepts, Inc., San Antonio, Texas) for complex urogenital wounds.

MATERIALS AND METHODS

The literature obtained from a Medline search on wound healing, wound failure and vacuum assisted closure was reviewed. In addition, we reviewed our experience with negative pressure wound therapy.

RESULTS

Wound healing is a complex interaction between the reticuloendothelial and immune systems, in addition to correctable internal and external factors. Understanding the healing process improves outcomes and decreases patient morbidity. Negative pressure wound therapy has hastened wound healing and it adds significant improvement in the arsenal of choices available.

CONCLUSIONS

Vacuum Assisted Closure is a therapeutic alternative that complements surgical and medical intervention in patients with complex wounds.