A hydrocellular foam dressing versus gauze: effects on the healing of rat excisional wounds

Study of hydrocellular functional material as microbicidal wound dressing for diabetic wound healing

A hydrocellular functional material as a wound dressing is developed and it is found to be superior in its efficacy as compared to some of the comparator controls in diabetic wound healing studies. A study on wound contraction and Histopathological analysis is done in rats. The efficacy of the dressing is comparable to the established wound dressings like Carboxymethyl cellulose alginate dressings and autolytic enzyme based hydrogel. It is found to be superior to Polyhexamethylene biguanide dressing used as reference controls in this study.The reason for good wound healing performance of the dressing can be attributed to a combined property of effective exudates management and broad spectrum antimicrobial effect. The concept of functional hydro cellular material has shown good results due to the excellent balance of exudates pickup and drying it out. This ensures moist wound healing conditions on the wound. Because of its porous nature it allows good air flow and gaseous exchange in the structure.The cationic sites created on the surface of the dressing ensure a good antimicrobial action on the exudates in the dressing. It reduces the infection load on the wound. The nonleaching property of the dressing also helps in preventing the generation of more resistant and mutant strains of the microbes.The developed dressing can be used as a relatively durable long lasting dressing for wound management in diabetic wounds. The need of repetitive wound dressing changes can be brought down with this concept of dressing. It is not only cost effective in terms of its material cost but also is a cost effective solution when entire wound management cost is considered. Such novel wound dressing material can change the quality of life of diabetic wound patients especially in developing world, where access to functional advanced wound care dressings is limited.

M-score and wound healing assessment of two nonantibiotic topical gel treatments of active digital dermatitis lesions in dairy cattle

This open-label, randomized clinical trial with positive control compared the treatment of active digital dermatitis (DD) lesions (stages M1, M2, and M4.1) on dairy cattle hind feet with an enzyme alginogel or a copper and zinc chelate gel (coppergel). Upon recruitment (d 0), active DD lesions were cleaned, photographed, treated, and bandaged. This procedure was repeated on d 3 and d 7, with treatment and bandaging discontinued for those lesions that had transitioned to the M0, M3, or M4 stage on d 7. Day 10 was considered the end of the treatment trial, and all recruited feet were cleaned and photographed. Treatment effect of the 2 products was assessed not only using the M-score but also using general wound healing progress criteria. Improvement of M-score was defined as transition to M0, M3, or M4 stages, or to lesions with a smaller ulcerative area (e.g., M2 stage to M1 stage). Lesions with improved wound healing had at least one of the following criteria when compared with the previous observation: decreased defect size, healthier granulation tissue color (pink-red instead of purple-grayish), more regular aspect of granulation tissue surface, wound contraction, or epithelization starting from the surrounding skin. Both primary outcomes were assessed using a multivariable logistic regression analysis. Lesions treated with the enzyme alginogel had a decreased adjusted odds ratio for M-score improvement (aOR: 0.04; 95% confidence interval: 0.01-0.11). Lesions treated with the coppergel mostly transitioned to chronic lesions, whereas lesions treated with the enzyme alginogel mostly remained active lesions. The wound healing progress of almost 70% of the lesions treated with coppergel could not be scored, for the greater part due to the presence of crust materials. With these unscorable lesions classified as "improved," there was no treatment effect on wound healing progress (aOR: 0.99; 95% confidence interval: 0.34-3.05), whereas with unscorable lesions classified as "not improved," the enzyme alginogel outperformed the coppergel with regard to wound healing progress (aOR: 2.48; 95% confidence interval: 1.07-5.79). None of the products used in our study achieved high cure rates (transition to the M0 stage) for active DD lesions. Low cure rates of topical treatment of DD, together with the important role of chronic lesions in the epidemiology of DD, indicate that future research should investigate how to achieve successful wound management of DD lesions, thereby mitigating pain associated with the lesions and reducing both transmission and prevalence of DD within herds.

Adipose-Derived Stem Cells Based on Electrospun Biomimetic Scaffold Mediated Endothelial Differentiation Facilitating Regeneration and Repair of Abdominal Wall Defects via HIF-1α/VEGF Pathway

Application of synthetic or biological meshes is the main therapy for the repair and reconstruction of abdominal wall defects, a common disease in surgery. Currently, no ideal materials are available, and there is an urgent need to find appropriate ones to satisfy clinical needs. Electrospun scaffolds have drawn attention in soft tissue reconstruction. In this study, we developed a novel method to fabricate a composite electrospun scaffold using a thermoresponsive hydrogel, poly (N-isopropylacrylamide)-block-poly (ethylene glycol), and a biodegradable polymer, polylactic acid (PLA). This scaffold provided not only a high surface area/volume ratio and a three-dimensional fibrous matrix but also high biocompatibility and sufficient mechanical strength, and could simulate the native extracellular matrix and accelerate cell adhesion and proliferation. Furthermore, rat adipose-derived stem cells (ADSCs) were seeded in the composite electrospun scaffold to enhance the defect repair and regeneration by directionally inducing ADSCs into endothelial cells. In addition, we found early vascularization in the process was regulated by the hypoxia inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) pathway. In our study, overexpression of HIF-1α/VEGF in ADSCs using a lentivirus system promoted early vascularization in the electrospun scaffolds. Overall, we expect our composite biomimetic scaffold method will be applicable and useful in abdominal wall defect regeneration and repair in the future.

Effects of insulin on wound healing: A review of animal and human evidences

AIMS

Several studies have indicated that insulin that is used in reducing blood glucose is also affective on wound healing by various mechanisms. To understand the outcomes of insulin therapy on wound healing, a meta-analysis and systematic review was performed.

MAIN METHODS

The Cochrane library, PubMed, and Science Direct were searched for the literature published from January the 1st 1990 to September the 30th 2016. Twelve animals and nine clinical studies were included. A quantitative and qualitative review was performed on the clinical trials and the animal studies were comprehensively overviewed. Statistical analysis for development of granulation tissue, microvessel density, and time of healing was conducted in this systematic review.

KEY FINDINGS

The animal studies revealed that treatment with topical insulin lead to faster wound contraction and re-epithelialization. Meta-analysis of wound studies revealed that insulin therapy is significantly favored for growth of granulation tissue. Based on these findings, insulin enhanced development of granulation tissue on day 7 after treatment. The meta-analysis studies indicated significant reduction in time of healing in the patients treated with insulin. These studies also disclosed that the new vessels were observable from five days after injection in the treated group, compared to the control animals that developed significantly at later stage.

SIGNIFICANCE

Insulin is a low cost growth factor and can be considered as a therapeutic agent in wound healing. However, further studies are necessary to gain a better understanding of the role of insulin in wound healing.

Effect of Topical Insulin on Second-Degree Burns in Diabetic Rats

The healing process is complex in diabetic wounds, and the healing mechanism of burn wounds is different from that of incisional or excisional wounds. Data from our previous study indicated that topical insulin cream reduced wound closure time in diabetic rats. Our aim was to investigate the effect of topical insulin cream on wound healing following second-degree burns in control and diabetic rats. Rats were divided into four groups: control (nondiabetic) rats treated with placebo (CP), control (nondiabetic) rats treated with topical insulin cream (CI), diabetic rats treated with placebo (DP), and diabetic rats treated with topical insulin cream (DI). The wounds were assessed at 4 time points (1, 7, 14, and 26 days) post-wounding for morphometric analysis of wound sections stained with hematoxylin/eosin, α-smooth muscle actin, and Picrosirius red to evaluate general aspects of the wound, inflammatory infiltrate, blood vessels, and Types I and III collagen fibers. Histological analysis showed that topical insulin cream increased the inflammatory cell infiltrate in the DI group (at 7 and 14 days postburn, p < .05) and blood vessels (at 14 days postburn, p < .05) to levels similar to those of groups CP and CI. Wounds treated with topical insulin cream (CI and DI groups) showed significantly stronger staining for fibrillar collagen than wounds of the DP group. The use of topical insulin may reduce the duration of the inflammatory phase; improve wound reepithelialization, tissue granulation, and wound contraction; and increase collagen deposition in second-degree burns in healthy and diabetic animals.

Hydrocellular foam dressings promote wound healing associated with decrease in inflammation in rat periwound skin and granulation tissue, compared with hydrocolloid dressings

The effects of modern dressings on inflammation, which represent the earliest phase of wound healing, are poorly understood. We investigated the effects of modern hydrocellular foam dressings (HCFs) on wound healing and on the gene expression levels of the inflammatory markers—interleukin (IL)-1β, IL-6, and IL-10—in rat periwound skin and granulation tissue by quantitative reverse transcription-polymerase chain reaction. HCF absorbed significantly higher volume of water than hydrocolloid dressing (HCD) and increased the contraction of wounds. Polymorphonuclear neutrophils were massively infiltrated to the wound edge and boarded between granulation and dermis in the HCD group. IL-1β, IL-6, and IL-10 mRNA levels were significantly decreased in the periwound skin around the wounds and granulation tissue covered with HCF. These findings suggest that HCF may promote wound healing along with decrease in inflammation by reducing gene expression levels of IL-1β, IL-6, and IL-10.

Hydrocellular foam dressing promotes wound healing along with increases in hyaluronan synthase 3 and PPARα gene expression in epidermis

BACKGROUND

Hydrocellular foam dressing, modern wound dressing, induces moist wound environment and promotes wound healing: however, the regulatory mechanisms responsible for these effects are poorly understood. This study was aimed to reveal the effect of hydrocellular foam dressing on hyaluronan, which has been shown to have positive effects on wound healing, and examined its regulatory mechanisms in rat skin.

METHODOLOGY/PRINCIPAL FINDINGS

We created two full-thickness wounds on the dorsolateral skin of rats. Each wound was covered with either a hydrocellular foam dressing or a film dressing and hyaluronan levels in the periwound skin was measured. We also investigated the mechanism by which the hydrocellular foam dressing regulates hyaluronan production by measuring the gene expression of hyaluronan synthase 3 (Has3), peroxisome proliferator-activated receptor α (PPARα), and CD44. Hydrocellular foam dressing promoted wound healing and upregulated hyaluronan synthesis, along with an increase in the mRNA levels of Has3, which plays a primary role in hyaluronan synthesis in epidermis. In addition, hydrocellular foam dressing enhanced the mRNA levels of PPARα, which upregulates Has3 gene expression, and the major hyaluronan receptor CD44.

CONCLUSIONS/SIGNIFICANCE

These findings suggests that hydrocellular foam dressing may be beneficial for wound healing along with increases in hyaluronan synthase 3 and PPARα gene expression in epidermis. We believe that the present study would contribute to the elucidation of the mechanisms underlying the effects of hydrocellular foam dressing-induced moist environment on wound healing and practice evidence-based wound care.

Which medical devices and/or local drug should be curatively used, as of 2012, for PU patients? How can granulation and epidermidalization be promoted? Developing French guidelines for clinical practice

INTRODUCTION

Management of a patient with pressure ulcer sore(s) must associate local and general treatment.

OBJECTIVES

To determine which medical devices other than supports and which treatments may be used for pressure sore healing (granulation tissue and epithelization/epidermidalization) as of 2012.

METHODS

Systematic review of the literature querying the databases: PASCAL Biomed, PubMed, and Cochrane library from 2000 through 2010.

RESULTS

Data in the literature on granulation tissue and epithelisation/epidermidalization in pressure sore healing are poor. The level of evidence regarding the relative effectiveness of one modern dressing compared to another has remained low. However, the study data on the interest of hydrocolloid dressing compared with impregnated gases are more significant.

DISCUSSION

Studies with heterogeneous results and populations have shown low power. Meta-analyses are difficult due to the wide range of therapeutic aims. Further clinical studies with adequate methodology are needed prior to elaboration of more specific recommendations.

CONCLUSION

The use of hydrocolloid dressing may be recommended to improve granulation tissue development and epithelization/epidermidalization in pressure sore (Level B).