Factors affecting wound healing

Hyperosmotic Agents and Antibiotics Affect Dissolved Oxygen and pH Concentration Gradients in Staphylococcus aureus Biofilms

Biofilms on wound surfaces are treated topically with hyperosmotic agents, such as medical-grade honey and cadexomer iodine; in some cases, these treatments are combined with antibiotics. Tissue repair requires oxygen, and a low pH is conducive to oxygen release from red blood cells and epithelialization. We investigated the variation of dissolved oxygen concentration and pH with biofilm depth and the variation in oxygen consumption rates when biofilms are challenged with medical-grade honey or cadexomer iodine combined with vancomycin or ciprofloxacin. Dissolved oxygen and pH depth profiles in Staphylococcus aureus biofilms were measured using microelectrodes. The presence of cadexomer iodine with vancomycin or ciprofloxacin on the surface of the biofilm permitted a measurable concentration of oxygen at greater biofilm depths (101.6 ± 27.3 μm, P = 0.02; and 155.5 ± 27.9 μm, P = 0.016, respectively) than in untreated controls (30.1 μm). Decreases in pH of ∼0.6 and ∼0.4 units were observed in biofilms challenged with medical-grade honey alone and combined with ciprofloxacin, respectively (P < 0.001 and 0.01, respectively); the number of bacteria recovered from biofilms was significantly reduced (1.26 log) by treatment with cadexomer iodine and ciprofloxacin (P = 0.002) compared to the untreated control. Combining cadexomer iodine and ciprofloxacin improved dissolved oxygen concentration and penetration depth into the biofilm, while medical-grade honey was associated with a lower pH; not all treatments established a bactericidal effect in the time frame used in the experiments.IMPORTANCE Reports about using hyperosmotic agents and antibiotics against wound biofilms focus mostly on killing bacteria, but the results of these treatments should additionally be considered in the context of how they affect physiologically important parameters, such as oxygen concentration and pH. We confirmed that the combination of a hyperosmotic agent and an antibiotic results in greater dissolved oxygen and reduced pH within an S. aureus biofilm.

Relationship Between Obesity and Surgical Complications After Reduction Mammaplasty: A Systematic Literature Review and Meta-Analysis

Background

Although many patients who undergo reduction mammaplasty are obese, reports on whether obesity is a risk factor for postoperative complications have been conflicting.

Objectives

This systematic literature review and meta-analysis aimed to evaluate the relationship between obesity and surgical complications after reduction mammaplasty.

Methods

The PubMed, Medline, and Embase databases were searched between 1998 and 2016 using the MeSH terms and keywords “reduction mammoplasty (mammaplasty),” “breast reduction,” “obesity,” “body weight,” “body mass index,” and “risk factor.”

Results

Among 26 studies that reported surgical complication risk and patient body weight, 11 concluded that obesity is not a risk factor and 15 reported that high body mass index increases surgical risk. On comparing obese and non-obese patients, we found that obese patients had a higher relative risk of surgical complications (1.38, 95% confidence interval 1.13-1.69), particularly skin and fat necrosis (2.01, 95% confidence interval 1.54-2.63). The pooled risk further increased with an increase in body mass index, and it was 1.71 for body mass index >35 kg/m2 and 2.05 for body mass index >40 kg/m2.

Conclusions

Our meta-analysis indicated that the risk of surgical complications and tissue necrosis after reduction mammaplasty is higher in obese patients than in non-obese patients and that the risk gradually increases with an increase in the severity of obesity. The findings of this study could form a basis for preoperative patient education, surgical method selection, and determination of the extent of postoperative care.

Oxygen ultra-fine bubbles water administration prevents bone loss of glucocorticoid-induced osteoporosis in mice by suppressing osteoclast differentiation

Oxygen ultra-fine bubbles (OUB) saline injection prevents bone loss of glucocorti\coid-induced osteoporosis in mice, and OUB inhibit osteoclastogenesis via RANK-TRAF6-c-Fos-NFATc1 signaling and RANK-p38 MAPK signaling in vitro.

INTRODUCTION

Ultra-fine bubbles (<200 nm in diameter) have several unique properties, and they are tested in various medical fields. The purpose of this study was to investigate the effects of oxygen ultra-fine bubbles (OUB) on glucocorticoid-induced osteoporosis (GIO) model mice.

METHODS

Prednisolone (PSL, 5 mg) was subcutaneously inserted in 6-month-old male C57BL/6J mice, and 200 μl of saline, OUB-diluted saline, or nitrogen ultra-fine bubbles (NUB)-diluted saline was intraperitoneally injected three times per week for 8 weeks the day after operations. Mice were divided into four groups; (1) control, sham-operation + saline; (2) GIO, PSL + saline; (3) GIO + OUB, PSL + OUB saline; (4) GIO + NUB, PSL + NUB saline. The effects of OUB on osteoblasts and osteoclasts were examined by serially diluted OUB medium in vitro.

RESULTS

Bone mass was significantly decreased in GIO [bone volume/total volume (%): control vs. GIO 12.6 vs. 7.9; p < 0.01] while significantly preserved in GIO + OUB (GIO vs. GIO + OUB 7.9 vs. 12.9; p < 0.05). In addition, tartrate-resistant acid phosphatase (TRAP)-positive cells in the distal femur [mean osteoclasts number/bone surface (mm^-1)] was significantly increased in GIO (control vs. GIO 6.8 vs. 11.6; p < 0.01) while suppressed in GIO + OUB (GIO vs. GIO + OUB 11.6 vs. 7.5; p < 0.01). NUB did not affect these parameters. In vitro experiments revealed that OUB significantly inhibited osteoclastogenesis by inhibiting RANK-TRAF6-c-Fos-NFATc1 signaling, RANK-p38 MAPK signaling, and TRAP/Cathepsin K/DC-STAMP mRNA expression in a concentration-dependent manner. OUB did not affect osteoblastogenesis in vitro.

CONCLUSIONS

OUB prevent bone loss in GIO mice by inhibiting osteoclastogenesis.

Impaired wound healing: facts and hypotheses for multi-professional considerations in predictive, preventive and personalised medicine

Whereas the physiologic wound healing (WH) successfully proceeds through the clearly defined sequence of the individual phases of wound healing, chronic non-healing wounds/ulcers fail to complete the individual stages and the entire healing process. There are many risk factors both modifiable (such as stress, smoking, inappropriate alcohol consumption, malnutrition, obesity, diabetes, cardio-vascular disease, etc.) and non-modifiable (such as genetic diseases and ageing) strongly contributing to the impaired WH. Current statistics demonstrate that both categories are increasingly presented in the populations, which causes dramatic socio-economic burden to the healthcare sector and society at large. Consequently, innovative concepts by predictive, preventive and personalised medicine are crucial to be implemented in the area. Individual risk factors, causality, functional interrelationships, molecular signature, predictive diagnosis, and primary and secondary prevention are thoroughly analysed followed by the expert recommendations in this paper.

Netrin-1 acts as a non-canonical angiogenic factor produced by human Wharton's jelly mesenchymal stem cells (WJ-MSC)

BACKGROUND

Angiogenesis, the process in which new blood vessels are formed from preexisting ones, is highly dependent on the presence of classical angiogenic factors. Recent evidence suggests that axonal guidance proteins and their receptors can also act as angiogenic regulators. Netrin, a family of laminin-like proteins, specifically Netrin-1 and 4, act via DCC/Neogenin-1 and UNC5 class of receptors to promote or inhibit angiogenesis, depending on the physiological context.

METHODS

Mesenchymal stem cells secrete a broad set of classical angiogenic factors. However, little is known about the expression of non-canonical angiogenic factors such as Netrin-1. The aim was to characterize the possible secretion of Netrin ligands by Wharton's jelly-derived mesenchymal stem cells (WJ-MSC). We evaluated if Netrin-1 presence in the conditioned media from these cells was capable of inducing angiogenesis both in vitro and in vivo, using human umbilical vein endothelial cells (HUVEC) and chicken chorioallantoic membrane (CAM), respectively. In addition, we investigated if the RhoA/ROCK pathway is responsible for the integration of Netrin signaling to control vessel formation.

RESULTS

The paracrine angiogenic effect of the WJ-MSC-conditioned media is mediated at least in part by Netrin-1 given that pharmacological blockage of Netrin-1 in WJ-MSC resulted in diminished angiogenesis on HUVEC. When HUVEC were stimulated with exogenous Netrin-1 assayed at physiological concentrations (10-200 ng/mL), endothelial vascular migration occurred in a concentration-dependent manner. In line with our determination of Netrin-1 present in WJ-MSC-conditioned media we were able to obtain endothelial tubule formation even in the pg/mL range. Through CAM assays we validated that WJ-MSC-secreted Netrin-1 promotes an increased angiogenesis in vivo. Netrin-1, secreted by WJ-MSC, might mediate its angiogenic effect through specific cell surface receptors on the endothelium, such as UNC5b and/or integrin α6β1, expressed in HUVEC. However, the angiogenic response of Netrin-1 seems not to be mediated through the RhoA/ROCK pathway.

CONCLUSIONS

Thus, here we show that stromal production of Netrin-1 is a critical component of the vascular regulatory machinery. This signaling event may have deep implications in the modulation of several processes related to a number of diseases where angiogenesis plays a key role in vascular homeostasis.

Hyperbaric oxygen therapy for chronic ulcers in systemic sclerosis - case series

BACKGROUND

Digital and leg ulcers are extremely painful, hard to heal manifestations of systemic sclerosis (SSc). Many treatments have been tried for these challenging complications, but use of hyperbaric oxygen therapy (HBOT) is very limited. HBOT has been used as an adjunctive therapy for treating chronic wounds, and nonhealing SSc wounds, which have a hypoxic nature, may also benefit from it.

METHODS

This is a retrospective analysis of six SSc patients who underwent HBOT for their ulcers. Patient demographics, ulcer properties, and details of treatments were evaluated.

RESULTS

Three patients had digital ulcers, and the other three had leg ulcers. Three patients (two leg ulcers and one digital ulcer) had bilateral lesions. All patients had been treated for at least one and a half months with various modalities. After HBOT was applied, four patients' ulcers healed completely and two patients had near-complete healing. Amputation was not required for any.

CONCLUSION

This case series, which has the largest patient population up to present, shows adjunctive HBOT may be helpful in the treatment of SSc ulcers.

Determination of the Wound Healing Potentials of Medicinal Plants Historically Used in Ghana

The present study was carried out to investigate the wound healing potentials of 17 medicinal plants historically used in Ghana for wound healing. Warm and cold water extracts were prepared from the 17 dried plant species and tested in vitro in the scratch assay with NIH 3T3 fibroblasts from mice. The wound healing scratch assay was used to evaluate the effect of the plants on cell proliferation and/or migration in vitro, as a test for potential wound healing properties. After 21 hours of incubation increased proliferation and/or migration of fibroblasts in the scratch assay was obtained for 5 out of the 17 plant species. HPLC separation of the most active plant extract, which was a warm water extract of Philenoptera cyanescens, revealed the wound healing activity to be attributed to rutin and a triglycoside of quercetin. The present study suggests that Allophylus spicatus, Philenoptera cyanescens, Melanthera scandens, Ocimum gratissimum, and Jasminum dichotomum have wound healing activity in vitro.

Wound Healing Effect of Arnebia euchroma gel on Excisional Wounds in Rats

BACKGROUND

Wound healing is a complex process leading to regeneration of damaged skin tissue. Arnebia euchroma (AE) have many effective activities such as anti-inflammatory, antimicrobial, antioxidative, and anti-tumoral effects. The extract of AE has positive effects on burn wounds. This study is designed to investigate the healing effects of AE on excisional wounds in rats.

MATERIALS AND METHODS

Thirty six rats with the age of 8 weeks divided into three groups. One group (E1) was treated with AE gel at a concentration of 10%. Control group (C1) received normal saline and the vehicle group (C2) was treated with carboxymethyl cellulose gel as the vehicle for 14 days. Stereological analysis was done to investigate the collagen bundle and hair follicale synthesis, vascularization, fibroblast proliferation. Pathological evaluation was also conducted.

RESULTS

In this study, pathological evaluation showed severe acute inflammation in C2 group, chronic and acute inflammation in C1 and also more wound contraction in E1 in comparison with other groups. There was a meaningful difference between E1 and C1 regarding fibroblast proliferation (P < 0.05).

CONCLUSION

Results of this study revealed the healing effect of AE on excisional wounds and recommend its administration after further clinical investigations.

Association between psychological health and wound complications after surgery

Background

Surgical wound complications remain a major cause of morbidity, leading to higher costs and reduced quality of life. Although psychological health is widely considered to affect wound healing, the evidence on wound outcomes after surgery is mixed. Studies generally focus on small samples of patients undergoing a specific procedure and have limited statistical power.

Methods

This study investigated the relationship between three different measures of anxiety and/or depression and seven adverse surgical outcomes using observational data collected before and after surgery between 2009 and 2011. A wide range of confounding factors was adjusted for, including patient demographics, physical co-morbidities, health-related behaviours, month of operation, procedure complexity and treating hospital.

Results

The estimation sample included 176 827 patients undergoing 59 410 hip replacements, 64 145 knee replacements, 38 328 hernia repairs and 14 944 varicose vein operations. Patients with moderate anxiety or depression had an increased probability of wound complications after a hip replacement (odds ratio (OR) 1·17, 95 per cent c.i. 1·11 to 1·24). They were more likely to be readmitted for a wound complication (OR 1·20, 1·02 to 1·41) and had an increased duration of hospital stay by 0·19 (95 per cent c.i. 0·15 to 0·24) days. Estimated associations were consistent across all four types of operation and for each measure of anxiety and/or depression.

Conclusion

Preoperative psychological health is a significant risk factor for adverse wound outcomes after surgery for four of the procedures most commonly performed in England.

Diagnostic and Prognostic Utility of Non-Invasive Multimodal Imaging in Chronic Wound Monitoring: a Systematic Review

Monitoring chronic wound [CW] healing is a challenging issue for clinicians across the world. Moreover, the health and cost burden of CW are escalating at a disturbing rate due to a global rise in population of elderly and diabetic cases. The conventional approach includes visual contour, sketches, or more rarely tracings. However, such conventional techniques bring forth infection, pain, allergies. Furthermore, these methods are subjective as well as time-consuming. As such, nowadays, non-touching and non-invasive CW monitoring system based on imaging techniques are gaining importance. They not only reduce patients' discomfort but also provide rapid wound diagnosis and prognosis. This review provides a survey of different types of CW characteristics, their healing mechanism and the multimodal non-invasive imaging methods that have been used for their diagnosis and prognosis. Current clinical practices as well as personal health systems [m-health and e-health] for CW monitoring have been discussed.

Immune regulation by glucocorticoids

Endogenous glucocorticoids are crucial to various physiological processes, including metabolism, development and inflammation. Since 1948, synthetic glucocorticoids have been used to treat various immune-related disorders. The mechanisms that underlie the immunosuppressive properties of these hormones have been intensely scrutinized, and it is widely appreciated that glucocorticoids have pleiotropic effects on the immune system. However, a clear picture of the cellular and molecular basis of glucocorticoid action has remained elusive. In this Review, we distil several decades of intense (and often conflicting) research that defines the interface between the endocrine stress response and the immune system.

The effect of midkine on growth factors and oxidative status in an experimental wound model in diabetic and healthy rats

Wound healing is important for longevity. Midkine is a cytokine involved in controlling tissue repair and new tissue development, and in regulating inflammation. We investigated the effect of midkine on wound healing in rats. In total, 108 Wistar albino rats were used: 12 as healthy and diabetic controls; 96 were split into 4 groups: healthy, saline treated; healthy, midkine (10 ng/kg, 48 h intervals) treated; diabetic, saline treated; and diabetic, midkine treated. Following wound creation, 6 rats per group were euthanized on days 3, 7, 14, and 28; the wounded skin was removed. Levels of epidermal growth factor (EGF), matrix metalloproteinase-8 (MMP-8), transforming growth factor beta (TGF-β), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and thiobarbituric acid reactive substances (TBARS) were measured. MMP-8 and PDGF levels fluctuated in all groups; TGF-β fluctuated in the diabetic groups and was significantly higher in the HM group than other groups after 14 days. EGF and VEGF levels were increased in the HM group after 3 days. TBARS levels were highest in the diabetic groups. Macroscopically, the midkine-treated groups healed better. Midkine can accelerate wound healing by influencing growth factors and oxidative status in wound tissues.

Impact of matrix stiffness on fibroblast function

Chronic non-healing wounds, caused by impaired production of growth factors and reduced vascularization, represent a significant burden to patients, health care professionals, and health care system. While several wound dressing biomaterials have been developed, the impact of the mechanical properties of the dressings on the residing cells and consequently on the healing of the wounds is largely overlooked. The primary focus of this study is to explore whether manipulation of the substrate mechanics can regulate the function of fibroblasts, particularly in the context of their angiogenic activity. A photocrosslinkable hydrogel platform with orthogonal control over gel modulus and cell adhesive sites was developed to explore the quantitative relationship between ECM compliance and fibroblast function. Increase in matrix stiffness resulted in enhanced fibroblast proliferation and stress fiber formation. However, the angiogenic activity of fibroblasts was found to be optimum when the cells were seeded on compliant matrices. Thus, the observations suggest that the stiffness of the wound dressing material may play an important role in the progression of wound healing.

* Collagen Cross-Linking: Biophysical, Biochemical, and Biological Response Analysis

Extracted forms of collagen are subjected to chemical cross-linking to enhance their stability. However, traditional cross-linking approaches are associated with toxicity and inflammation. This work investigates the stabilization capacity, cytotoxicity and inflammatory response of collagen scaffolds cross-linked with glutaraldehyde (GTA), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide, 4-arm polyethylene glycol (PEG) succinimidyl glutarate (4SP), genipin (GEN), and oleuropein. Although all cross-linking methods reduced free amine groups, variable data were obtained with respect to denaturation temperature, resistance to collagenase digestion, and mechanical properties. With respect to biological analysis, fibroblast cultures showed no significant difference between the treatments. Although direct cultures with human-derived leukemic monocyte cells (THP-1) clearly demonstrated the cytotoxic effect of GTA, THP-1 cultures supplemented with conditioned medium from the various groups showed no significant difference between the treatments. With respect to cytokine profile, no significant difference in secretion of proinflammatory (e.g., interleukin [IL]-1β, IL-8, tumor necrosis factor-α) and anti-inflammatory (e.g., vascular endothelial growth factor) cytokines was observed between the noncross-linked and the 4SP and GEN cross-linked groups, suggesting the suitability of these agents as collagen cross-linkers.

The impact of lifestyle risk factors on the rate of infection after surgery for a fracture of the ankle

Aims

Lifestyle risk factors are thought to increase the risk of infection after acute orthopaedic surgery but the evidence is scarce. We aimed to investigate whether smoking, obesity and alcohol overuse are risk factors for the development of infections after surgery for a fracture of the ankle.

Patients and Methods

We retrospectively reviewed all patients who underwent internal fixation of a fracture of the ankle between 2008 and 2013. The primary outcome was the rate of deep infection and the secondary outcome was any surgical site infection (SSI). Associations with the risk factors and possible confounding variables were analysed univariably and multivariably with backwards elimination.

Results

A total of 1043 patients were included; 64 (6.1%) had a deep infection and 146 (14.0%) had SSI. Obesity was strongly associated with both outcomes (odds ratio (OR) 2.21, p = 0.017 and OR 1.68, p = 0.032) in all analyses. Alcohol overuse was similarly associated, though significant only in unadjusted analyses. Surprisingly, smoking did not yield statistically significant associations with infections.

Conclusion

These findings suggest that obesity and possibly alcohol overuse are independent risk factors for the development of infection following surgery for a fracture of the ankle. This large study brings new evidence concerning these common risk factors; although prospective studies are needed to confirm causality. Cite this article: Bone Joint J 2017;99-B:225–30.

Reactive oxygen species (ROS) and wound healing: the functional role of ROS and emerging ROS-modulating technologies for augmentation of the healing process

Reactive oxygen species (ROS) play a pivotal role in the orchestration of the normal wound-healing response. They act as secondary messengers to many immunocytes and non-lymphoid cells, which are involved in the repair process, and appear to be important in coordinating the recruitment of lymphoid cells to the wound site and effective tissue repair. ROS also possess the ability to regulate the formation of blood vessels (angiogenesis) at the wound site and the optimal perfusion of blood into the wound-healing area. ROS act in the host's defence through phagocytes that induce an ROS burst onto the pathogens present in wounds, leading to their destruction, and during this period, excess ROS leakage into the surrounding environment has further bacteriostatic effects. In light of these important roles of ROS in wound healing and the continued quest for therapeutic strategies to treat wounds in general and chronic wounds, such as diabetic foot ulcers, venous and arterial leg ulcers and pressure ulcers in particular, the manipulation of ROS represents a promising avenue for improving wound-healing responses when they are stalled. This article presents a review of the evidence supporting the critical role of ROS in wound healing and infection control at the wound site, and some of the new emerging concepts associated with ROS modulation and its potential in improving wound healing are discussed.

Current Perspectives on the Use of Anti-VEGF Drugs as Adjuvant Therapy in Glaucoma

The approval of one of the first anti-vascular endothelial growth factor (VEGF) agents for the treatment of neovascular age-related macular degeneration one decade ago marked the beginning of a new era in the management of several sight-threatening retinal diseases. Since then, emerging evidence has demonstrated the utility of these therapies for the treatment of other ocular conditions characterized by elevated VEGF levels. In this article we review current perspectives on the use of anti-VEGF drugs as adjuvant therapy in the management of neovascular glaucoma (NVG). The use of anti-VEGFs for modifying wound healing in glaucoma filtration surgery (GFS) is also reviewed. Selected studies investigating the use of anti-VEGF agents or antimetabolites in GFS or the management of NVG have demonstrated that these agents can improve surgical outcomes. However, anti-VEGF agents have yet to demonstrate specific advantages over the more established agents commonly used today. Further studies are needed to evaluate the duration of action, dosing intervals, and toxicity profile of these treatments.

Comparative transcriptomics of elasmobranchs and teleosts highlight important processes in adaptive immunity and regional endothermy

BACKGROUND

Comparative genomic and/or transcriptomic analyses involving elasmobranchs remain limited, with genome level comparisons of the elasmobranch immune system to that of higher vertebrates, non-existent. This paper reports a comparative RNA-seq analysis of heart tissue from seven species, including four elasmobranchs and three teleosts, focusing on immunity, but concomitantly seeking to identify genetic similarities shared by the two lamnid sharks and the single billfish in our study, which could be linked to convergent evolution of regional endothermy.

RESULTS

Across seven species, we identified an average of 10,877 Swiss-Prot annotated genes from an average of 32,474 open reading frames within each species' heart transcriptome. About half of these genes were shared between all species while the remainder included functional differences between our groups of interest (elasmobranch vs. teleost and endotherms vs. ectotherms) as revealed by Gene Ontology (GO) and selection analyses. A repeatedly represented functional category, in both the uniquely expressed elasmobranch genes (total of 259) and the elasmobranch GO enrichment results, involved antibody-mediated immunity, either in the recruitment of immune cells (Fc receptors) or in antigen presentation, including such terms as "antigen processing and presentation of exogenous peptide antigen via MHC class II", and such genes as MHC class II, HLA-DPB1. Molecular adaptation analyses identified three genes in elasmobranchs with a history of positive selection, including legumain (LGMN), a gene with roles in both innate and adaptive immunity including producing antigens for presentation by MHC class II. Comparisons between the endothermic and ectothermic species revealed an enrichment of GO terms associated with cardiac muscle contraction in endotherms, with 19 genes expressed solely in endotherms, several of which have significant roles in lipid and fat metabolism.

CONCLUSIONS

This collective comparative evidence provides the first multi-taxa transcriptomic-based perspective on differences between elasmobranchs and teleosts, and suggests various unique features associated with the adaptive immune system of elasmobranchs, pointing in particular to the potential importance of MHC Class II. This in turn suggests that expanded comparative work involving additional tissues, as well as genome sequencing of multiple elasmobranch species would be productive in elucidating the regulatory and genome architectural hallmarks of elasmobranchs.

Broad-Spectrum Inhibition of the CC-Chemokine Class Improves Wound Healing and Wound Angiogenesis

Angiogenesis is involved in the inflammation and proliferation stages of wound healing, to bring inflammatory cells to the wound and provide a microvascular network to maintain new tissue formation. An excess of inflammation, however, leads to prolonged wound healing and scar formation, often resulting in unfavourable outcomes such as amputation. CC-chemokines play key roles in the promotion of inflammation and inflammatory-driven angiogenesis. Therefore, inhibition of the CC-chemokine class may improve wound healing. We aimed to determine if the broad-spectrum CC-chemokine inhibitor “35K” could accelerate wound healing in vivo in mice. In a murine wound healing model, 35K protein or phosphate buffered saline (PBS, control) were added topically daily to wounds. Cohorts of mice were assessed in the early stages (four days post-wounding) and in the later stages of wound repair (10 and 21 days post-wounding). Topical application of the 35K protein inhibited CC-chemokine expression (CCL5, CCL2) in wounds and caused enhanced blood flow recovery and wound closure in early-mid stage wounds. In addition, 35K promoted neovascularisation in the early stages of wound repair. Furthermore, 35K treated wounds had significantly lower expression of the p65 subunit of NF-κB, a key inflammatory transcription factor, and augmented wound expression of the pro-angiogenic and pro-repair cytokine TGF-β. These findings show that broad-spectrum CC-chemokine inhibition may be beneficial for the promotion of wound healing.

Blood vessel formation during tail regeneration in the leopard gecko (Eublepharis macularius): The blastema is not avascular

Unique among amniotes, many lizards are able to self-detach (autotomize) their tail and then regenerate a replacement. Tail regeneration involves the formation of a blastema, an accumulation of proliferating cells at the site of autotomy. Over time, cells of the blastema give rise to most of the tissues in the replacement tail. In non-amniotes capable of regenerating (such as urodeles and some teleost fish), the blastema is reported to be essentially avascular until tissue differentiation takes place. For tail regenerating lizards less is known. Here, we investigate neovascularization during tail regeneration in the leopard gecko (Eublepharis macularius). We demonstrate that the gecko tail blastema is not an avascular structure. Beginning with the onset of regenerative outgrowth, structurally mature (mural cell supported) blood vessels are found within the blastema. Although the pattern of blood vessel distribution in the regenerate tail differs from that of the original, a hierarchical network is established, with vessels of varying luminal diameters and wall thicknesses. Using immunostaining, we determine that blastema outgrowth and tissue differentiation is characterized by a dynamic interplay between the pro-angiogenic protein vascular endothelial growth factor (VEGF) and the anti-angiogenic protein thrombospondin-1 (TSP-1). VEGF-expression is initially widespread, but diminishes as tissues differentiate. In contrast, TSP-1 expression is initially restricted but becomes more abundant as VEGF-expression wanes. We predict that variation in the neovascular response observed between different regeneration-competent species likely relates to the volume of the blastema. J. Morphol. 278:380-389, 2017. © 2017 Wiley Periodicals, Inc.

Antimicrobials tethering on suture surface through a hydrogel: a novel strategy to combat postoperative wound infections

The present study aimed to develop a novel biocompatible suture biomaterial from Eri silk waste to avoid surgical site infections.

Mono-epoxy-tocotrienol-α enhances wound healing in diabetic mice and stimulates in vitro angiogenesis and cell migration

Diabetes mellitus is characterized by hyperglycemia and capillary hypoxia that causes excessive production of free radicals and impaired antioxidant defense, resulting in oxidative stress and diabetes complications such as impaired wound healing. We have previously shown that modified forms of tocotrienols possess beneficial effects on the biosynthesis of the mevalonate pathway lipids including increase in mitochondrial CoQ. The aim of this study is to investigate the effects of mono-epoxy-tocotrienol-α on in vitro and in vivo wound healing models as well as its effects on mitochondrial function. Gene profiling analysis and gene expression studies on HepG2 cells and human dermal fibroblasts were performed by microarray and qPCR, respectively. In vitro wound healing using human fibroblasts was studied by scratch assay and in vitro angiogenesis using human dermal microvascular endothelial cells was studied by the tube formation assay. In vivo wound healing was performed in the diabetic db/db mouse model. For the study of mitochondrial functions and oxygen consumption rate Seahorse XF-24 was employed. In vitro, significant increase in wound closure and cell migration (p<0.05) both in normal and high glucose and in endothelial tube formation (angiogenesis) (p<0.005) were observed. Microarray profiling analysis showed a 20-fold increase of KIF26A gene expression and 11-fold decrease of lanosterol synthase expression. Expression analysis by qPCR showed significant increase of the growth factors VEGFA and PDGFB. The epoxidated compound induced a significantly higher basal and reserve mitochondrial capacity in both HDF and HepG2 cells. Additionally, in vivo wound healing in db/db mice, demonstrated a small but significant enhancement on wound healing upon local application of the compound compared to treatment with vehicle alone. Mono-epoxy-tocotrienol-α seems to possess beneficial effects on wound healing by increasing the expression of genes involved in cell growth, motility and angiogenes as well as on mitochondrial function.

Bacterial cellulose–TiO2 nanocomposites promote healing and tissue regeneration in burn mice model

The development of novel cutaneous wound treatments particularly for burns is of paramount importance due to complex pathophysiology, prevalent infection and clinical complexities associated with burn care.

AgNP and rhEGF-incorporating synergistic polyurethane foam as a dressing material for scar-free healing of diabetic wounds

Synergistic polyurethane foams comprised of AgNPs and rhEGF (AgNP/rhEGF-PUFs) were developed to treat diabetic wounds, which exhibited complete wound closure.

A Randomized, Clinical Trial to Evaluate Efficacy and Tolerability of Trypsin:Chymotrypsin as Compared to Serratiopeptidase and Trypsin:Bromelain:Rutoside in Wound Management

INTRODUCTION

Systemic enzyme therapy can play an important role in maintaining normal inflammatory processes within the body and thereby helps support and speed up healing. In the course of the anti-inflammatory action, enzymes degrade damaged cells and necrotic material and, through the inactivation of mediators and toxic products, they restrict the edema and pain.

METHOD

The study conducted at Grant Medical College, Mumbai, India was a clinical trial comparing the efficacy and tolerability of three oral enzyme treatment groups-oral tablets containing trypsin:chymotrypsin (TC) (Chymoral Forte^®), serratiopeptidase (S) 5 mg oral tablets, and oral enzyme tablets containing trypsin 48 mg, bromelain 90 mg, and rutoside 100 mg (TBR)-to evaluate their healing potential in surgical wounds after orthopedic surgery.

RESULTS

A total of 75 patients were screened, randomized, and divided into three groups in 1:1:1 ratio receiving either of the three treatments. In the TC group, erythema was significantly reduced from 3.44 on day 3 to 1.16 on day 10 (p < 0.01). There was significantly better reduction in erythema scores in the TC group as compared to S and TBR groups (p < 0.05) at each follow-up visit. Similarly reduction in the local irritation, wound discharge, edema, induration, and tenderness score with TC treatment at the end of the study was significantly higher than that observed in the other two groups. In addition TC showed significant reduction in pain on the VAS scale (p < 0.01). Global assessment of response to therapy for efficacy and tolerability was reported to be good to excellent in 88% and 92% of the patients on TC as compared to 12% and 8% with S and 12% and 8% with TBR.

CONCLUSION

TC provides a better resolution of symptoms of inflammation after orthopedic surgery as compared to S and TBR, thus facilitating better wound healing. Further studies are warranted to confirm the findings.

TRIAL REGISTRATION

Clinical Trial Registry of India (Reg. No. CTRI/2011/07/001920).

Wound dressing application of pH-sensitive carbon dots/chitosan hydrogel

Monitoring the pH of wounds as an essential diagnosis factor during the healing process.

Diabetic wound regeneration using heparin-mimetic peptide amphiphile gel in db/db mice

There is an urgent need for more efficient treatment of chronic wounds in diabetic patients especially with a high risk of leg amputation.

Stingless Bee Honey, the Natural Wound Healer: A Review

<b><i>Background:</i></b> The stingless bee is a natural type of bee that exists in almost every continent. The honey produced by this bee has been widely used across time and space. The distinctive feature of this honey is that it is stored naturally in the pot (cerumen), thus contributing to its beneficial properties, especially in the wound healing process. <b><i>Methods:</i></b> In this article, several studies on stingless bee honey that pointed out the numerous therapeutic profiles of this honey in terms of its antioxidant, antimicrobial, anti-inflammatory, as well as moisturizing properties are reviewed. All of these therapeutic properties are related to wound healing properties. <b><i>Results:</i></b> Antioxidant in stingless bee honey could break the chain of free radicals that cause a detrimental effect to the wounded area. Furthermore, the antimicrobial properties of stingless bee honey could overcome the bacterial contamination and thus improve the healing rate. Moreover, the anti-inflammatory attribute in this honey could protect the tissue from highly toxic inflammatory mediators. The moisturizing properties of the honey could improve wound healing by promoting angiogenesis and oxygen circulation. <b><i>Conclusion:</i></b> The application of honey to the wound has been widely used since ancient times. As a result, it is essential to understand the pharmacological mechanism of the honey towards the physiology of the wounded skin in order to optimize the healing rate in the future.

A highly bioactive bone extracellular matrix-biomimetic nanofibrous system with rapid angiogenesis promotes diabetic wound healing

BGN-containing CPB nanofibrous scaffolds with rapid angiogenesis promotes diabetic wound healing.

Can tert-butylhydroquinone improve the healing of extracted tooth socket in rats?

BACKGROUND

Tooth extraction causes an open wound in the soft and hard tissues. During the inflammatory phase of the healing process, a large amount of free radicals are produced and cause oxidative stress, which leads to tissue damage and delayed wound healing. Thus, in this study, we evaluated the effect of tert-butylhydroquinone (TBHQ), as an antioxidant, on the healing process of tooth sockets in rats.

MATERIALS AND METHODS

To conduct this experimental study, male Wistar rats (n = 42) were divided into two groups. In each case, one upper second molar was extracted under general anesthesia. After the extraction, the tooth sockets of the experimental group were treated with a 0.02% TBHQ solution (0.1 ml) while the same volume of distilled water placed in the sockets of the control group. On days 3, 7, and 21 postoperatively, 7 rats from each group were euthanized, and histological slides were prepared from their tooth sockets. The prepared slides were examined histopathologically using a light microscope and compared using an independent two-sample t-test. The significance level was set at 0.05.

RESULTS

In the experimental group, a statistically significant (P = 0.003) increase in granulation tissue was observed on day 3, in comparison to the control group. The extent of bony trabeculation was also significantly higher in the TBHQ-treated group than in the control group on day 21 (P < 0.001).

CONCLUSION

Considering the limitations of an experimental study, it can be concluded that TBHQ may enhance the healing of the hard tissue in the tooth sockets.

Matrix regenerative therapy

The extracellular matrix (ECM) is responsible for many of the cell behavior processes, including cell proliferation and growth, survival, change in cell shape, migration, and differentiation. The most important component of the ECM is heparan sulfate (HS), because it insures the storage of many cell communication proteins, necessary for the continuous and identical renewal of cells and thus for tissue regeneration. Regenerating agents (RGTA®) are bioengineered structural analogues of heparan sulfate glycosaminoglycans that replace the degraded endogenous HS of the ECM. In the ophthalmological field, RGTA® represents an innovative approach for the improvement of the ocular surface wound healing and matrix remodeling and plays a role in controlling and regulating the wound healing process in various ocular diseases.

Electrospinning of Bioactive Wound-Healing Nets

The availability of appropriate dressings for treatment of wounds, in particular chronic wounds, is a task that still awaits better solutions than provided by currently applied materials. The method of electrospinning enables the fabrication of novel materials for wound dressings due to the high surface area and porosity of the electrospun meshes and the possibility to include bioactive ingredients. Recent results show that the incorporation of biologically active inorganic polyphosphate microparticles and microspheres and synergistically acting retinoids into electrospun polymer fibers yields biocompatible and antibacterial mats for potential dressings with improved wound-healing properties. The underlying principles and the mechanism of these new approaches in the therapy wounds, in particular wounds showing impaired healing, as well as for further applications in skin regeneration/repair, are summarized.

Potentiation effect of HB-EGF on facilitating wound healing via 2-N,6-O-sulfated chitosan nanoparticles modified PLGA scaffold

26SCS-nanoparticles modified PLGA have synergistic effect with HB-EGF on promoting the migration of keratinocyte, realizing the skin regeneration.

Inhibitory Activities of Platelet-Rich and Platelet-Poor Plasma on the Growth of Pathogenic Bacteria

BACKGROUND

The utility and efficacy of novel materials in tissue regeneration and antimicrobial therapy are contingent upon the employment of either blood derivatives rich in platelets or platelet-poor-plasma (PPP). This effect is largely mediated by the increased or decreased concentration of platelets in the plasma. The current study aimed to analyze and evaluate the impact of platelet-rich (PRP) or PPP on inhibiting the growth of human pathogenic bacteria and compare their effects with those of chloramphenicol and penicillin.

METHODS

In the current comparative study, PRP-1 was generated using 1-step blood centrifugation method; whereas, for PRP-2 and PPP the 2-step centrifugation protocol was used. The antimicrobial activity of PRP-1, 2, and PPP were tested on Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Streptococcus agalactiae, Staphylococcus epidermidis, Shigella sp. and Serratia sp. Well diffusion and serial micro-dilution methods were used for this purpose. Chloramphenicol and penicillin susceptibility were tested using the disk diffusion method.

RESULTS

While whole blood (WB) and PPP had no discernible impact on the growth parameters of any of the bacteria tested in the current study, PRP-1 reduced the growth rate of a few selected strains. In addition, while PRP-2 clearly inhibited the growth of Shigella sp., E. coli, S. aureus, S. agalactiae, and S. epidermidis, it had no impact on the growth of K. pneumoniae, P. aeruginosa, and Serratia sp.

CONCLUSION

It can be claimed that there is a strong correlation between the concentration of platelets and the antibacterial activity of PRP.

Effects of a novel NADPH oxidase inhibitor (S42909) on wound healing in an experimental ischemic excisional skin model

Chronic wounds are a serious healthcare problem. As non-healing wounds involve continuous pathologic inflammatory stage, research is focused on anti-inflammatory treatments. Our objective was to analyze the effect of S42909, a potent NADPH oxidase inhibitor activity, with vascular anti-inflammatory properties. An ischemic rabbit ear ulcer model (24 New Zealand white rabbits) was used to evaluate the reepithelialization/contraction areas, anti-/pro-inflammatory cytokines mRNA (TGF-β1/IL-10/IFN-γ/VEGF) by qRT-PCR, collagen I/III deposition, and neovascularization (TGF-β1/VEGF) by morphological and immunohistochemical analyses. Three different doses were administered by gavage for 2 weeks: 10 and 30 mg/kg/d in self-microemulsion drug delivery system (SMEDDS) and 100 mg/kg/d in arabic gum. Each vehicle was used as control. No signs of infection or necrosis were found. Reepithelialization was almost complete whatever the groups reaching 95% at the dose of 100 mg/kg. Wound contraction was significantly reduced in all S42909-treated groups. A significant increase in anti-inflammatory cytokines TGF-β1 mRNA and IL-10 mRNA was observed at the dose of 100 and 30 mg/kg/d, respectively. No changes were observed in pro-inflammatory factors INF-γ and VEGF mRNA. Ischemic skin wound areas had scarce expression of collagen I/III and showed rich glycosaminoglycans content. Treatment increased the collagen deposition and TGF-β1 protein expression and decreased glycosaminoglycan content dose dependently; however, no effect in VEGF was appreciated. Therefore, our results indicate that S42909 improved healing process by dampening excessive inflammation and facilitating collagen deposition without wound contraction phenomena. S42909 might be a promising therapy to treat chronic wounds as venous leg ulcers.

A Systematic Review of the Role of Dysfunctional Wound Healing in the Pathogenesis and Treatment of Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disorder showcasing an interaction between genetic predisposition and environmental risks. This usually involves the coaction of a mixture of cell types associated with abnormal wound healing, leading to structural distortion and loss of gas exchange function. IPF bears fatal prognosis due to respiratory failure, revealing a median survival of approximately 2 to 3 years. This review showcases the ongoing progress in understanding the complex pathophysiology of IPF and it highlights the latest potential clinical treatments. In IPF, various components of the immune system, particularly clotting cascade and shortened telomeres, are highly involved in disease pathobiology and progression. This review also illustrates two US Food and Drug Administration (FDA)-approved drugs, nintedanib (OFEV, Boehringer Ingelheim, Ingelheim am Rhein, Germany) and pirfenidone (Esbriet, Roche, Basel, Switzerland), that slow IPF progression, but unfortunately neither drug can reverse the course of the disease. Although the mechanisms underlying IPF remain poorly understood, this review unveils the past and current advances that encourage the detection of new IPF pathogenic pathways and the development of effective treatment methods for the near future.

Exploring the in vivo wound healing effects of a recombinant hemolin from the caterpillar Lonomia obliqua

Background

Hemolin proteins are cell adhesion molecules from lepidopterans involved in a wide range of cell interactions concerning their adhesion properties. However, hemolin’s roles in cell proliferation and wound healing are not fully elucidated. It has been recently reported that rLosac, a recombinant hemolin from the caterpillar Lonomia obliqua, presents antiapoptotic activity and is capable of improving in vitro wound healing. Therefore, this study aimed to explore rLosac’s in vivo effects using a skin wound healing model in rats.

Methods

Circular full-thickness wounds in the rat dorsum skin were treated either with rLosac, or with saline (control), allowing healing by keeping the wounds occluded and moist. During the wound healing, the following tissue regeneration parameters were evaluated: wound closure and collagen content. Furthermore, tissue sections were subjected to histological and immunohistochemical analyses.

Results

The rLosac treatment has demonstrated its capacity to improve wound healing, as reflected in findings of a larger number of activated fibroblasts, proliferation of epithelial cells, increase of collagen type 1, and decrease of inflammatory infiltrate.

Conclusion

The findings have indicated the rLosac protein as a very promising molecule for the development of new wound-healing formulations.

Pharmacological Evaluation of Chrozophora tinctoria as Wound Healing Potential in Diabetic Rat's Model

Objective. The study was designed to evaluate pharmacological potential of hydroalcoholic leaves extract of Chrozophora tinctoria intended for wound healing in diabetic rats' model. Methods. The method used to evaluate the pharmacological potential of hydroalcoholic leave extract was physical incision rat model. In this model, cutting of the skin and/or other tissues with a sharp blade has been made and the rapid disruption of tissue integrity with minimal collateral damage was observed shortly. Animals used in the study were divided into four groups that consist of six animals in each group. Group I serves as normal control, Group II serves as disease control, Group III was used as standard treatment (Povidone iodine 50 mg/kg b.w.), and Group IV was used for test drug (C. tinctoria 50 mg/kg b.w.). Result. The hydroalcoholic leave extract of Chrozophora tinctoria has been significantly observed to heal the wound (98%) in diabetic rats within 21 days, while standard drug (Povidone iodine) healed the wound about 95% in the same condition. The oral dose (50 mg/kg b.w.) of Chrozophora tinctoria was also found to improve the elevated blood glucose level in comparison to disease control group, which increased after the oral administration of Streptozotocin. Conclusion. The Chrozophora tinctoria has significant wound healing potential in the animal having physically damaged tissue in diabetic condition.

Preparation and in vitro evaluation of melatonin-loaded HA/PVA gel formulations

Melatonin-loaded hyaluronic acid (HA) and poly(vinyl alcohol) (PVA) gels were prepared by using freeze-thaw technique and an emulsion method followed by freeze-thaw technique to produce a new synergistic system for topical application. Freeze-thaw hydrogels and emulgels were characterized by means of Fourier transform infrared spectroscopy, rheology and swelling tests. The porous structure of the hydrogels was shown by scanning electron microscopy observations and thermal properties were tested by differential scanning calorimetry measurements. Bioadhesion and in vitro release characterization of formulations were performed by texture profile analysis and dialysis bag method, respectively. The pore size of both formulations was ranging from 900 nm to 30 μm. Melatonin showed a good compatibility with the polymeric matrices as the pores were smaller for the drug-loaded systems. In vitro release studies showed that the release was improved by emulgel formulations. After 24 h, the release percentage was found to be 13.240% ± 1.094 and 15.192% ± 2.270 for hydrogel and emulgel, respectively. Emulgels had better bioadhesion properties than simple freeze-thaw samples. As a conclusion, regarding the in vitro characterization studies HA and PVA hydrogel and emulgel formulations and their lyophilized forms could be promising systems for topical application of melatonin.

Circadian rhythms accelerate wound healing in female Siberian hamsters

Circadian rhythms (CRs) provide temporal regulation and coordination of numerous physiological traits, including immune function. CRs in multiple aspects of immune function are impaired in rodents that have been rendered circadian-arrhythmic through various methods. In Siberian hamsters, circadian arrhythmia can be induced by disruptive light treatments (DPS). Here we examined CRs in wound healing, and the effects of circadian disruption on wound healing in DPS-arrhythmic hamsters. Circadian entrained/rhythmic (RHYTH) and behaviorally-arrhythmic (ARR) female hamsters were administered a cutaneous wound either 3h after light onset (ZT03) or 2h after dark onset (ZT18); wound size was quantified daily using image analyses. Among RHYTH hamsters, ZT03 wounds healed faster than ZT18 wounds, whereas in ARR hamsters, circadian phase did not affect wound healing. In addition, wounds healed slower in ARR hamsters. The results document a clear CR in wound healing, and indicate that the mere presence of organismal circadian organization enhances this aspect of immune function. Faster wound healing in CR-competent hamsters may be mediated by CR-driven coordination of the temporal order of mechanisms (inflammation, leukocyte trafficking, tissue remodeling) underlying cutaneous wound healing.