Factors affecting wound healing

Integrated poly-d,l-lactide-co-glycolide/silver nanocomposite: synthesis, characterization and wound healing potential in Wistar Albino rats

PLGA polymer based biogenic synthesized silver nanocomposite for wound healing potential in Albino rats.

The Role of Matrix Metalloproteinases in Diabetic Wound Healing in relation to Photobiomodulation

The integration of several cellular responses initiates the process of wound healing. Matrix Metalloproteinases (MMPs) play an integral role in wound healing. Their main function is degradation, by removal of damaged extracellular matrix (ECM) during the inflammatory phase, breakdown of the capillary basement membrane for angiogenesis and cell migration during the proliferation phase, and contraction and remodelling of tissue in the remodelling phase. For effective healing to occur, all wounds require a certain amount of these enzymes, which on the contrary could be very damaging at high concentrations causing excessive degradation and impaired wound healing. The imbalance in MMPs may increase the chronicity of a wound, a familiar problem seen in diabetic patients. The association of diabetes with impaired wound healing and other vascular complications is a serious public health issue. These may eventually lead to chronic foot ulcers and amputation. Low intensity laser irradiation (LILI) or photobiomodulation (PBM) is known to stimulate several wound healing processes; however, its role in matrix proteins and diabetic wound healing has not been fully investigated. This review focuses on the role of MMPs in diabetic wound healing and their interaction in PBM.

Partial Nephrectomy in the Overweight Patient: an Overview

The diagnosis and treatment of kidney cancer continues to evolve with advances in imaging and surgical approaches. The use of nephron sparing surgery (NSS) has become the operation of choice for treating small renal masses. Yet, technical difficulty and a variety of approaches have left debate for best method in the overweight population. This review summarizes the current knowledge in the open, laparoscopic, and robotic approaches to identify key risk factors, general assessments, complication rates, and the influence of body habitus for each approach.

Transcriptome Analysis of Ullrich Congenital Muscular Dystrophy Fibroblasts Reveals a Disease Extracellular Matrix Signature and Key Molecular Regulators

Background

Collagen VI related myopathies encompass a range of phenotypes with involvement of skeletal muscle, skin and other connective tissues. They represent a severe and relatively common form of congenital disease for which there is no treatment. Collagen VI in skeletal muscle and skin is produced by fibroblasts.

Aims & Methods

In order to gain insight into the consequences of collagen VI mutations and identify key disease pathways we performed global gene expression analysis of dermal fibroblasts from patients with Ullrich Congenital Muscular Dystrophy with and without vitamin C treatment. The expression data were integrated using a range of systems biology tools. Results were validated by real-time PCR, western blotting and functional assays.

Findings

We found significant changes in the expression levels of almost 600 genes between collagen VI deficient and control fibroblasts. Highly regulated genes included extracellular matrix components and surface receptors, including integrins, indicating a shift in the interaction between the cell and its environment. This was accompanied by a significant increase in fibroblasts adhesion to laminin. The observed changes in gene expression profiling may be under the control of two miRNAs, miR-30c and miR-181a, which we found elevated in tissue and serum from patients and which could represent novel biomarkers for muscular dystrophy. Finally, the response to vitamin C of collagen VI mutated fibroblasts significantly differed from healthy fibroblasts. Vitamin C treatment was able to revert the expression of some key genes to levels found in control cells raising the possibility of a beneficial effect of vitamin C as a modulator of some of the pathological aspects of collagen VI related diseases.

Establishment of an Animal Model of Bisphosphonate-Related Osteonecrosis of the Jaws in Spontaneously Diabetic Torii Rats

Background

We evaluated the side effects of bisphosphonate (BP) on tooth extraction socket healing in spontaneously diabetic Torii (SDT) rats, an established model of non-obese type 2 diabetes mellitus, to develop an animal model of BP-related osteonecrosis of the jaws (BRONJ).

Materials and Methods

Male Sprague-Dawley (SD) rats and SDT rats were randomly assigned to the zoledronic acid (ZOL)-treated groups (SD/ZOL or SDT/ZOL) or to the control groups (SD/control or SDT/control). Rats in the SD/ZOL or SDT/ZOL groups received an intravenous bolus injection of ZOL (35 μg/kg) every 2 weeks. Each group consisted of 6 rats each. Twenty-one weeks after ZOL treatment began, the left maxillary molars were extracted. The rats were euthanized at 2, 4, or 8 weeks after tooth extraction, and the total maxillae were harvested for histological and histochemical studies.

Results

In the oral cavity, bone exposure persisted at the tooth extraction site in all rats of the SDT/ZOL group until 8 weeks after tooth extraction. In contrast, there was no bone exposure in SD/control or SDT/control groups, and only 1 of 6 rats in the SD/ZOL group showed bone exposure. Histologically, necrotic bone areas with empty lacunae, microbial colonies, and less invasion by inflammatory cells were observed. The number of tartrate-resistant acid phosphatase-positive osteoclasts was lower in the SDT/ZOL group than in the SD/control group. The mineral apposition rate was significantly lower in the SDT/ZOL group compared with the SD/control group.

Conclusions

This study demonstrated the development of BRONJ-like lesions in rats and suggested that low bone turnover with less inflammatory cell infiltration plays an important role in the development of BRONJ.

Wound Care: Multicenter Feasibility Study

OBJECTIVES

The aims of this study were to determine a sound recruitment strategy for multisite wound studies to address the rising prevalence and incidence of chronic wounds and to identify appropriate adult patient populations with wounds of interest and establish partnerships with their clinicians and clinical services as a model for a multisite wound care feasibility study.

DESIGN

A pilot multisite recruitment feasibility study.

SETTING

Three wound clinics located in a large, Midwestern metropolitan area.

PARTICIPANTS AND INTERVENTION

A convenience sample of 3 staff and 3 patients with lower-extremity wounds from each clinic was interviewed. Medical records of all patients with lower-extremity wounds seen during 1 week at each clinic were reviewed. Outcome measures included characteristics of patients being treated at the 3 wound care clinics (patient demographics and wound characteristics) and wound treatments used. Barriers and opportunities that could be addressed in recruitment and other research strategies were identified.

MAIN RESULTS

Barriers and facilitators for future research were identified and varied within and between clinics. Patients reported they were willing to participate in future research, although fewer were willing if the study was blinded. Patients received a variety of treatments within and across clinics. Medical record reviews provided further information about wound clinic patients, wound characteristics, and barriers and facilitators for future study.

CONCLUSIONS

Characteristics of wound clinic patients and their wounds were found to vary by site, suggesting tailored recruitment methods by site within multisite wound care studies may be most productive. This study suggests successful recruitment strategies for future wound care intervention research.

Insight into Reepithelialization: How Do Mesenchymal Stem Cells Perform?

Wound reepithelialization is a cooperative multifactorial process dominated by keratinocyte migration, proliferation, and differentiation that restores the intact epidermal barrier to prevent infection and excessive moisture loss. However, in wounds that exhibit impaired wound healing, such as chronic nonhealing wounds or hypertrophic scars, the reepithelialization process has failed. Thus, it is necessary to explore a suitable way to mitigate these abnormalities to promote reepithelialization and achieve wound healing. Mesenchymal stem cells (MSCs) have the capacity for self-renewal as well as potential multipotency. These cells play important roles in many biological processes, including anti-inflammation, cell migration, proliferation, and differentiation, and signal pathway activation or inhibition. The mechanism of the involvement of MSCs in reepithelialization is still not fully understood. An abundance of evidence has shown that MSCs participate in reepithelialization by inhibiting excessive inflammatory responses, secreting important factors, differentiating into multiple skin cell types, and recruiting other host cells. This review describes the evidence for the roles that MSCs appear to play in the reepithelialization process.

Wound Complications after Laparotomy for Endometrial Cancer

This study was conducted to determine the incidence of wound complications after laparotomy for endometrial cancer and significant predictors of risks. Medical records of patients with endometrial cancer undergoing laparotomy for surgical staging at Srinagarind Hospital, Khon Kaen University between January 2007 and December 2013 were reviewed. Intravenous antibiotic prophylaxis was routinely given 30 minutes before surgery. The primary endpoint was wound complications (including seroma, hematoma, separation, or infection) requiring additional medical and/or surgical management within 4 weeks of laparotomy. During the study period, 357 patients with complete medical records were reviewed. The mean age was 56.9 years. Wound complications were observed in 28 patients (7.84%, 95% CI, 5.27% to 11.14%). Body mass index (BMI) ≥ 30 kg/m2, diabetes mellitus (DM), and prior abdominal surgery were observed as significant independent factors predicting an increased risk of wound complications with adjusted odds ratios (95% CIs) of 2.96 (1.23-7.16), 2.43 (1.06-5.54), and 3.05 (1.03-8.98), respectively. In conclusion, the incidence of wound complications after laparotomy for endometrial cancer was 7.8%. Significant independent predictors of risk included BMI, DM and prior abdominal surgery.

Wound dressings - a review

Wound healing is a dynamic and complex process which requires suitable environment to promote healing process. With the advancement in technology, more than 3000 products have been developed to treat different types of wounds by targeting various aspects of healing process. The present review traces the history of dressings from its earliest inception to the current status and also discusses the advantage and limitations of the dressing materials.

Physical Therapy in Wound Care: A Cost-Effectiveness Analysis

Management of chronic wounds remains unsatisfactory in terms of treatment cost and time required for complete wound closure (CWC).This study aimed to calculate the healing rates, estimated cost, and time required for CWC in wounds; compare estimated wound care costs between healing and nonhealing wounds; and compare cost effectiveness between venous leg ulcer (VLU) and non-VLU.This was a retrospective cohort study performed at a physical therapy (PT) wound care clinic. Deidentified patient data in the electronic medical database from September 10, 2012 to January 23, 2015 were extracted.Among 159 included patients with wounds, 119 (74.84%) patients were healed with CWC. The included patients were treated for 109.70 ± 95.70 days, 29.71 ± 25.66 visits, and at the costs per treatment episode of $1629.65 ± 1378.82 per reimbursement rate and $2711.42 ± 2356.81 per breakeven rate. For patients with CWC (healing group), the treatment duration was 98.01 ± 76.12 days with the time for CWC as 72.45 ± 64.21 days; the cost per treatment episode was $1327.24 ± 1143.53 for reimbursement rate and $2492.58 ± 2106.88 for breakeven cost. For patients with nonhealing wounds, treatment duration was found to be longer with costs significantly higher (P < 0.01 for all). In the healing group, no differences were found between VLU and non-VLU in treatment duration (95.46 days vs. 100.88 days, P = 0.698), time for CWC (68.06 days vs. 77.38 days, P = 0.431), and cost ($2756.78 vs. 2397.84 for breakeven rate, P = 0.640) with the exception of wound dressing costs ($329.19 vs. 146.47, P = 0.001).Healing rates may be affected with patient exclusions. Costs at physicians' offices were not included.Incorporation of PT in wound care appeared to be cost effective. PT may thus be a good referral option for patients with wounds. However, the results should be interpreted cautiously and further studies are warranted.

Comparison of hemostatic dressings for superficial wounds using a new spectrophotometric coagulation assay

Background

Due to demographical changes the number of elderly patients depending on oral anticoagulation is expected to rise. Prolonged bleeding times in case of traumatic injuries represent the drawback of these medications, not only in major trauma, but also in superficial wounds. Therefore, dressings capable of accelerating coagulation onset and shortening bleeding times are desirable for these patients.

Methods

The hemostatic potential and physical properties of different types of superficial wound dressings (standard wound pad, two alginates, chitosan, collagen (Lyostypt^®), oxidized cellulose, and QuikClot^®) were assessed in vitro. For this purpose the clotting times of blood under the influence of the named hemostatics from healthy volunteers were compared with Marcumar^® or ASS^® treated patients. For that, a newly developed coagulation assay based on spectrophotometric extinction measurements of thrombin activity was used.

Results

The fastest coagulation onset was observed for oxidized cellulose (Ø 2.47 min), Lantor alginate-l (Ø 2.50 min) and QuikClot^® (Ø 3.01 min). Chitosan (Ø 5.32 min) and the collagen Lyostypt^® (Ø 7.59 min) induced clotting comparatively late. Regarding physical parameters, QuikClot^® showed the lowest absorption capacity and speed while chitosan and both alginates achieved the highest. While oxidized cellulose displayed the best clotting times, unfortunately it also revealed low absorption capacity.

Conclusions

All tested specimens seem to induce clotting independently from the administered type of oral anticoagulant, providing the possibility to neglect the disadvantage in clotting times arising from anticoagulation on a local basis. QuikClot^®, oxidized cellulose and unexpectedly alginate-l were superior to chitosan and Lyostypt^®. Due to its additional well-known positive effect on wound healing alginate-l should be considered for further investigations.

Postoperative Hemodynamic Index Measurement With Miniaturized Dynamic Light Scattering Predicts Colorectal Anastomotic Healing

INTRODUCTION

Perioperative bowel perfusion (local hemodynamic index [LHI]) was measured with a miniaturized dynamic light scattering (mDLS) device, aiming to determine whether anastomotic perfusion correlates with the anastomotic healing process and whether LHI measurement assists in the detection of anastomotic leakage (AL) in colorectal surgery.

METHODS

A partial colectomy was performed in 21 male Wistar rats. Colonic and anastomotic LHIs were recorded during operation. On postoperative day (POD) 3, the rats were examined for AL manifestations. Anastomotic LHI was recorded before determining the anastomotic bursting pressure (ABP). The postoperative LHI measurements were repeated in 15 other rats with experimental colitis. Clinical manifestations and anastomotic LHI were also determined on POD3. Diagnostic value of LHI measurement was analyzed with the combined data from both experiments.

RESULTS

Intraoperative LHI measurement showed no correlation with the ABP on POD3. Postoperative anastomotic LHI on POD3 was significantly correlated with ABP in the normal rats (R(2) = 0.52; P < .001) and in the rats with colitis (R(2) = 0.63; P = .0012). Anastomotic LHI on POD3 had high accuracy for identifying ABP <50 mm Hg (Area under the curve = 0.86; standard error = 0.065; P < .001). A cutoff point of 1236 yielded a sensitivity of 100% and a specificity of 65%. On POD3, rats with LHIs <1236 had significantly higher dehiscence rates (40% vs 0%), more weight loss, higher abscess severity, and lower ABPs (P < .05); worse anastomotic inflammation and collagen deposition were also found in the histological examination.

CONCLUSION

Our data suggest that postoperative evaluation of anastomotic microcirculation with the mDLS device assists in the detection of AL in colorectal surgery.

Engineering macrophages to control the inflammatory response and angiogenesis

Macrophage (MΦ) dysregulation is increasingly becoming recognized as a risk factor for a number of inflammatory complications including atherosclerosis, cancer, and the host response elicited by biomedical devices. It is still unclear what roles the pro-inflammatory (M1) MΦ and pro-healing (M2) MΦ phenotypes play during the healing process. However, it has been shown that a local overabundance of M1 MΦs can potentially lead to a chronically inflamed state of the tissue; while a local over-exuberant M2 MΦ response can lead to tissue fibrosis and even promote tumorigenesis. These notions strengthen the argument that the tight temporal regulation of this phenotype balance is necessary to promote inflammatory resolution that leads to tissue homeostasis. In this study, we have engineered pro-inflammatory MΦs, MΦ-cTLR4 cells, which can be activated to a M1-like MΦ phenotype with a small molecule, the chemical inducer of dimerization (CID) drug. The MΦ-cTLR4 cells when activated with the CID drug, express increased levels of TNFα, IL-6, and iNOS. Activated MΦ-cTLR4 cells stay stimulated for at least 48h; once the CID drug is withdrawn, the MΦ-cTLR4 cells return to baseline state within 18h. Further, in vitro CID-activated MΦ-cTLR4 cells induce upregulation of VCAM-1 and ICAM-1 on endothelial cells (EC) in a TNFα-dependent manner. With the ability to specifically modulate the MФ-cTLR4 cells with the presence or absence of a small molecule, we now have the tool necessary to observe a primarily M1 MФ response during inflammation. By isolating this phase of the wound healing response, it may be possible to determine conditions for ideal healing.

Downregulation of miRNAs during Delayed Wound Healing in Diabetes: Role of Dicer

Delayed wound healing is a major complication associated with diabetes and is a result of a complex interplay among diverse deregulated cellular parameters. Although several genes and pathways have been identified to be mediating impaired wound closure, the role of microRNAs (miRNAs) in these events is not very well understood. Here, we identify an altered miRNA signature in the prolonged inflammatory phase in a wound during diabetes, with increased infiltration of inflammatory cells in the basal layer of the epidermis. Nineteen miRNAs were downregulated in diabetic rat wounds (as compared with normal rat wound, d 7 postwounding) together with inhibited levels of the central miRNA biosynthesis enzyme, Dicer, suggesting that in wounds of diabetic rats, the decreased levels of Dicer are presumably responsible for miRNA downregulation. Compared with unwounded skin, Dicer levels were significantly upregulated 12 d postwounding in normal rats, and this result was notably absent in diabetic rats that showed impaired wound closure. In a wound-healing specific quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) array, 10 genes were significantly altered in the diabetic rat wound and included growth factors and collagens. Network analyses demonstrated significant interactions and correlations between the miRNA predicted targets (regulators) and the 10 wound-healing specific genes, suggesting altered miRNAs might fine-tune the levels of these genes that determine wound closure. Dicer inhibition prevented HaCaT cell migration and affected wound closure. Altered levels of Dicer and miRNAs are critical during delayed wound closure and offer promising targets to address the issue of impaired wound healing.

Pulsed low-intensity ultrasound increases proliferation and extracelluar matrix production by human dermal fibroblasts in three-dimensional culture

This study evaluated the effect of pulsed low-intensity ultrasound on cell proliferation, collagen production and glycosaminoglycan deposition by human dermal fibroblasts encapsulated in alginate. Hoechst 33258 assay for cell number, hydroxyproline assay for collagen content, dimethylmethylene blue assay for glycosaminoglycan content and scanning electron microscopy were performed on the encapsulated cells treated with pulsed low-intensity ultrasound and a control group that remained untreated. Pulsed low-intensity ultrasound showed a significant effect on cell proliferation and collagen deposition but no consistent pattern for glycosaminoglycan content. Alcian blue staining showed that glycosaminoglycans were deposited around the cells in both treated and control groups. These results suggest that pulsed low-intensity ultrasound alone shows a positive effect on cell proliferation and collagen deposition even without growth factor supplements.

Wound Healing Effects of Rose Placenta in a Mouse Model of Full-Thickness Wounds

Background

Rosa damascena, a type of herb, has been used for wound healing in Eastern folk medicine. The goal of this study was to evaluate the effectiveness of rose placenta from R. damascena in a full-thickness wound model in mice.

Methods

Sixty six-week-old C57BL/6N mice were used. Full-thickness wounds were made with an 8-mm diameter punch. Two wounds were made on each side of the back, and wounds were assigned randomly to the control and experimental groups. Rose placenta (250 µg) was injected in the experimental group, and normal saline was injected in the control group. Wound sizes were measured with digital photography, and specimens were harvested. Immunohistochemical staining was performed to assess the expression of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1), and CD31. Vessel density was measured. Quantitative analysis using an enzyme-linked immunosorbent assay (ELISA) for EGF was performed. All evaluations were performed on postoperative days 0, 2, 4, 7, and 10. Statistical analyses were performed using the paired t-test.

Results

On days 4, 7, and 10, the wounds treated with rose placenta were significantly smaller. On day 2, VEGF and EGF expression increased in the experimental group. On days 7 and 10, TGF-β1 expression decreased in the experimental group. On day 10, vessel density increased in the experimental group. The increase in EGF on day 2 was confirmed with ELISA.

Conclusions

Rose placenta was found to be associated with improved wound healing in a mouse full-thickness wound model via increased EGF release. Rose placenta may potentially be a novel drug candidate for enhancing wound healing.

Effect of nanostructured thin film on minimally invasive surgery devices applications: characterization, cell cytotoxicity evaluation and an animal study in rat

BACKGROUND

Minimally invasive surgery is performed using an endoscope and other instruments including the electrosurgical units. However, concerns including surgical smoke, tissue sticking and thermal injury are remaining in electrosurgery.

AIMS

Accordingly, a newly developed electrosurgical electrode coating with hydrogenated Cu-incorporated diamond-like carbon (DLC-Cu) film is purposed to improve the instrument performance.

METHODS

The morphologies of DLC-Cu surfaces were characterized using transmission electron microscopy, scanning electron microscopy and atomic force microscopy. In this study, lesions were made on the liver lobes of adult rats, using a monopolar electrosurgical unit equipped with untreated stainless steel electrodes or treated-electrodes. Animals were killed for evaluations at 0, 3, 7 and 28 days postoperatively.

RESULTS

Treated-electrodes generate less sticking tissues and adhesive blood cells. Thermography revealed that the surgical temperature in liver tissue from the treated-electrode was significantly lower than the untreated-electrode. Total injury area of livers treated with treated-electrodes was significantly smaller than the untreated-electrodes treatment. Moreover, treated-electrodes caused a relatively smaller area of lateral thermal injury, a smaller area of fibrotic tissue and a faster process of remodeling than the untreated-electrodes. Western blot analysis showed that rats treated with treated-electrode expressed lower levels of NF-κB, caspase-3 and MMP-9 than untreated-electrode. Immunofluorescence staining for caspase-3 revealed that the untreated-electrode caused more serious injury.

CONCLUSIONS

This study reveals that the plating of electrodes with hydrogenated Cu-incorporated diamond-like carbon film is an efficient method for improving the performance of electrosurgical units, and should benefit wound remodeling. However, more tests must be carried out to confirm these promising findings in human patients.

Transdermal Wound Oxygen Therapy on Pressure Ulcer Healing: A Single-Blind Multi-Center Randomized Controlled Trial

Background:

Although healthcare quality has considerably improved in many countries, pressure ulcer is still a major health challenge worldwide.

Objectives:

The current study aimed to evaluate the effects of TWOT on the healing of pressure ulcers.

Patients and Methods:

This study was a randomized controlled trial, and the convenient sample including 100 patients hospitalized in two university-affiliated medical-surgical intensive care units and one neurology unit located in Qazvin, Iran were studied. Patients with stage II-IV pressure ulcer on the sacral or ischial areas were randomly assigned to either the control or the experimental groups. The experimental group received a 12-day transdermal wound oxygen therapy. Wound status was assessed seven times before the intervention, as well as two, four, six, eight, ten, and twelve days after the intervention.

Results:

After 12 days of wound oxygen therapy, the number of patients with complete wound healing in the experimental group was significantly greater than that of the control group. Moreover, the total mean of wound area in the experimental group was significantly lower than that of the control group.

Conclusions:

Transdermal wound oxygen therapy can effectively promote wound healing in patients with pressure ulcers.

Highly effective detection of inflamed cells using a modified bradykinin ligand labeled with FITC fluorescence

Detection of inflammation in live cells is important because long-lasting inflammation is considered to be a primary cause of several diseases. However, few reports have been published on imaging analysis of inflammation in live cells. In this study, we developed an effective imaging system for detection of inflamed cells using a bradykinin ligand (BK) or a modified BK (mBK), which has specific affinity with the cellular B1R receptor. Synthetic BK or mBK labeled with FITC at the N-terminus was employed for discriminating between inflamed and normal cells; this method was found to be effective for detection of inflammation in live cells. In addition, using the mBK-based cell imaging system, we successfully performed flow-based analysis of live cell inflammation on a micro-chip channel, composed of a Starna flow cell and PDMS (Polydimethylsiloxane) walls. The BK-based cell imaging methods designed here would be a useful platform for development of a high-throughput live cell analysis system for investigating the factors underlying inflammation or for screening of anti-inflammation candidate drugs.

Fast and sensitive HPLC method for the determination of neopterin, kynurenine and tryptophan in amniotic fluid, malignant effusions and wound exudates

Aim: A new HPLC method for the determination of neopterin, kynurenine and tryptophan using a second-generation monolith stationary phase and high-throughput sample preparation procedure based on microplates was developed and fully validated. Materials & methods: As the stationary phase a monolithic C18 Chromolith high-resolution column with dimensions of 4.6 × 100 mm connected to a monolithic 4.6 × 10-mm security guard was used. Separation was achieved using 15 mM phosphate buffer (KH2PO4 +K2HPO4·3H2O at pH 3) and acetonitrile in gradient mode. Results: Target analytes were determined in 5.5 minutes in amniotic fluid, effusions and wound exudates with a limit of quantification (LOQ) of 1.25 nM for neopterin, 2.5 µM for tryptophan and 0.25 µM for kynurenine. Discussion: The method was applied to real clinical sample measurements, and it will be used to monitor neopterin, kynurenine and tryptophan levels in biological fluids to assess the patient response to therapy and clinical status.

Stress-related changes to immune cells in the skin prior to wounding may impair subsequent healing

Higher psychological stress is associated with slower dermal wound healing, but the immunological mechanisms behind this effect are only partially understood. This paper aims to investigate whether immune cells present in the skin prior to wounding can affect subsequent healing in high-stress and low-stress participants. Two studies are presented in which skin biopsies were analysed using immunohistochemistry for numbers of macrophages and Langerhans cells, and immune cell activation (Study 2 only). Immune cells were related to perceived stress levels and subsequent healing. Study 1 included 19 healthy older adults and showed that higher stress was associated with significantly fewer macrophages in the skin. Study 2 included 22 younger adults and showed that higher stress was associated with significantly lower activation of immune cells in the skin. Furthermore, lower activation of immune cells (as measured by human leukocyte antigen (HLA expression)) and fewer Langerhans cells were associated with slower healing. Together these studies show the first preliminary evidence that the number and activation of immune cells in the skin prior to wounding are affected by stress and can impact healing. Larger studies are needed to confirm these effects.

Scar-free cutaneous wound healing in the leopard gecko, Eublepharis macularius

Cutaneous wounds heal with two possible outcomes: scarification or near-perfect integumentary restoration. Whereas scar formation has been intensively investigated, less is known about the tissue-level events characterising wounds that spontaneously heal scar-free, particularly in non-foetal amniotes. Here, a spatiotemporal investigation of scar-free cutaneous wound healing following full-thickness excisional biopsies to the tail and body of leopard geckos (Eublepharis macularius) is provided. All injuries healed without scarring. Cutaneous repair involves the development of a cell-rich aggregate within the wound bed, similar to scarring wounds. Unlike scar formation, scar-free healing involves a more rapid closure of the wound epithelium, and a delay in blood vessel development and collagen deposition within the wound bed. It was found that, while granulation tissue of scarring wounds is hypervascular, scar-free wound healing conspicuously does not involve a period of exuberant blood vessel formation. In addition, during scar-free wound healing the newly formed blood vessels are typically perivascular cell-supported. Immunohistochemistry revealed widespread expression of both the pro-angiogenic factor vascular endothelial growth factor A and the anti-angiogenic factor thrombospondin-1 within the healing wound. It was found that scar-free wound healing is an intrinsic property of leopard gecko integument, and involves a modulation of the cutaneous scar repair program. This proportional revascularisation is an important factor in scar-free wound healing.

Copper/zinc bimetal nanoparticles-dispersed carbon nanofibers: A novel potential antibiotic material

Copper (Cu) and zinc (Zn) nanoparticles (NPs) were asymmetrically distributed in carbon nanofibers (CNFs) grown on an activated carbon fiber (ACF) substrate by chemical vapor deposition (CVD). The CVD conditions were chosen such that the Cu NPs moved along with the CNFs during tip-growth, while the Zn NPs remained adhered at the ACF. The bimetal-ACF/CNF composite material was characterized by the metal NP release profiles, in-vitro hemolytic and antibacterial activities, and bacterial cellular disruption and adhesion assay. The synergetic effects of the bimetal NPs distributed in the ACFs/CNFs resulted from the relatively slower release of the Cu NPs located at the tip of the CNFs and faster release of the Zn NPs dispersed in the ACF. The Cu/Zn-grown ACFs/CNFs inhibited the growth of the Gram negative Escherichia coli, Gram positive Staphylococcus aureus, and Methicillin resistance Staphylococcus aureus bacterial strains, with superior efficiency (instant and prolonged inhibition) than the Cu or Zn single metal-grown ACFs/CNFs. The prepared bimetal-carbon composite material in this study has potential to be used in different biomedical applications such as wound healing and antibiotic wound dressing.

Antibacterial activity and therapeutic efficacy of Fl-P(R)P(R)P(L)-5, a cationic amphiphilic polyproline helix, in a mouse model of staphylococcal skin infection

The antibacterial activities and therapeutic efficacy of the cationic, unnatural proline-rich peptide Fl-P(R)P(R)P(L)-5 were evaluated against multidrug-resistant Staphylococcus aureus in a mouse model of skin infection. Fl-P(R)P(R)P(L)-5 showed potent activity against all clinical isolates of S. aureus tested, including methicillin- and vancomycin-resistant S. aureus (MRSA and VRSA, respectively). Fl-P(R)P(R)P(L)-5 was also superior in clearing established in vitro biofilms of S. aureus and Staphylococcus epidermidis, compared with the established antimicrobials mupirocin and vancomycin. Additionally, topical treatment of an MRSA-infected wound with Fl-P(R)P(R)P(L)-5 enhanced wound closure and significantly reduced bacterial load. Finally, 0.5% Fl-P(R)P(R)P(L)-5 significantly reduced the levels of the inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) in wounds induced by MRSA skin infection. In conclusion, the results of this study suggest the potential application of Fl-P(R)P(R)P(L)-5 in the treatment of staphylococcal skin infections.

The influence of platelet-derived products on angiogenesis and tissue repair: a concise update

Platelet degranulation allows the release of a large amount of soluble mediators, is an essential step for wound healing initiation, and stimulates clotting, and angiogenesis. The latter process is one of the most critical biological events observed during tissue repair, increasing the growth of blood vessels in the maturing wound. Angiogenesis requires the action of a variety of growth factors that act in an appropriate physiological ratio to assure functional blood vessel restoration. Platelets release main regulators of angiogenesis: Vascular Endothelial Growth Factors (VEGFs), basic fibroblast growth factor (FGF-2), and Platelet derived growth factors (PDGFs), among others. In order to stimulate tissue repair, platelet derived fractions have been used as an autologous source of growth factors and biomolecules, namely Platelet Rich Plasma (PRP), Platelet Poor Plasma (PPP), and Platelet Rich Fibrin (PRF). The continuous release of these growth factors has been proposed to promote angiogenesis both in vitro and in vivo. Considering the existence of clinical trials currently evaluating the efficacy of autologous PRP, the present review analyses fundamental questions regarding the putative role of platelet derived fractions as regulators of angiogenesis and evaluates the possible clinical implications of these formulations.

Nutrition and anabolic pharmacotherapies in the care of burn patients

Thermal injury is a devastating injury that results in a number of pathological alterations in almost every system in the body. Hypermetabolism, muscle wasting, depressed immunity, and impaired wound healing are all clinical features of burns. Failure to address each of these specific pathological alterations can lead to increased mortality. Nutrition supplementation has been recommended as a therapeutic tool to help attenuate the hypermetabolism and devastating catabolism evident following burn. Despite the wide consensus on the need of nutrition supplementation in burn patients, controversy exists with regard to the type and amount of nutrition recommended. Nutrition alone is also not enough in these patients to halt and reverse some of the damage done by the catabolic pathways activated following severe burn injury. This has led to the use of anabolic pharmacologic agents in conjunction with nutrition to help improve patient outcome following burn injury. In this review, we examine the relevant literature on nutrition after burn injury and its contribution to the attenuation of the postburn hypermetabolic response, impaired wound healing, and suppressed immunological responses. We also review the commonly used anabolic agents clinically in the care of burn patients. Finally, we provide nutrition and pharmacological recommendations gained from prospective trials, retrospective analyses, and expert opinions based on our practice at the Ross Tilley Burn Center in Toronto, Canada.

Electrochemical scaffold generates localized, low concentration of hydrogen peroxide that inhibits bacterial pathogens and biofilms

We hypothesized that low concentrations of H2O2 could be generated through the electrochemical conversion of oxygen by applying an electric potential to a conductive scaffold and produce a low, but constant, concentration of H2O2 that would be sufficient to destroy biofilms. To test our hypothesis we used a multidrug-resistant Acinetobacter baumannii strain, because this species is often implicated in difficult-to-treat biofilm infections. We used conductive carbon fabric as the scaffold material ("e-scaffold"). In vitro experiments demonstrated the production of a maximum constant concentration of ~25 μM H2O2 near the e-scaffold surface. An e-scaffold was overlaid onto an existing A. baumannii biofilm, and within 24 h there was a ~4-log reduction in viable bacteria with an ~80% decrease in biofilm surface coverage. A similar procedure was used to overlay an e-scaffold onto an existing A. baumannii biofilm that was grown on a porcine explant. After 24 h, there was a ~3-log reduction in viable bacteria from the infected porcine explants with no observable damage to the underlying mammalian tissue based on a viability assay and histology. This research establishes a novel foundation for an alternative antibiotic-free wound dressing to eliminate biofilms.

Visible Light-Triggered On-Demand Drug Release from Hybrid Hydrogels and its Application in Transdermal Patches

On-demand release from stimuli-responsive hydrogels has received great attention due to an increasing clinical need. Here, we have prepared spherical hydrogel beads showing visible light-induced volume change at body temper-ature. By spray injection of the monomer solution using the alginate templ-ating method, hybrid beads of several hundred micrometers, consisting of temperature-responsive poly(N-isopropylacrylamide-co-vinyl-2-pyrrolidinone) hydrogel and magnetite nanoparticles (MNP), are produced. MNP dispersed in the hydrogel matrix absorbed visible light and generated heat, increasing the temperature of the matrix and resulting in shrinkage of the beads proportional to light intensity. It is demonstrated that light-induced volume change of dexamethasone-loaded hybrid beads result in on-demand and localized release of the drug by exposure to moderate visible light. As a potential application of the light-sensitive hybrid hydrogel beads, a transdermal patch is developed that incorporates drug-loaded hydrogel beads in multiple drug reservoirs, achieving enhanced release of a model drug when exposed to visible light. This platform should be applicable to on-demand, sequential, and long-term release of drugs via light exposure.

Improved burn wound healing by the antimicrobial peptide LLKKK18 released from conjugates with dextrin embedded in a carbopol gel

Antimicrobial peptides (AMPs) are good candidates to treat burn wounds, a major cause of morbidity, impaired life quality and resources consumption in developed countries. We took advantage of a commercially available hydrogel, Carbopol®, a vehicle for topical administration that maintains a moist environment within the wound site. We hypothesized that the incorporation of LLKKK18 conjugated to dextrin would improve the healing process in rat burns. Whereas the hydrogel improves healing, LLKKK18 released from the dextrin conjugates further accelerated wound closure, and simultaneously improving the quality of healing. Indeed, the release of LLKKK18 reduced oxidative stress and inflammation (low neutrophil and macrophage infiltration and pro-inflammatory cytokines levels). Importantly, it induced a faster resolution of the inflammatory stage through early M2 macrophage recruitment. In addition, LLKKK18 stimulated angiogenesis (increased VEGF and microvessel development in vivo). Moreover, collagen staining evaluated by Masson's Trichrome was visually much more intense after treatment with LLKKK18, suggesting higher collagen deposition. Overall, we generated an effective, safe and inexpensive formulation that maintains a moist environment in the wound, easy to apply and remove, and with potential to prevent infection due to the presence of an antimicrobial peptide. These findings propel us to further study this LLKKK18-containing formulation, setting the foundations towards a potential therapeutic approach for burn wound treatment.

STATEMENT OF SIGNIFICANCE

This work presents a newly developed formulation that holds great potential as a therapeutic approach for burn treatment. It is based on the sustained delivery of an antimicrobial peptide - LLKKK18 - from conjugates with dextrin, after degradation of dextrin backbone upon exposure to wound α-amylases. Conjugates were further embedded in Carbopol®, a commercially available hydrogel, suitable for topical administration and that provides a moist environment to the wound. Overall, we obtained an efficient, safe and non-expensive formulation that improves burn wound healing, maintains a moist environment within the wound, is easy to apply-and-remove, and has potential to prevent infection due to the presence of an antimicrobial peptide. Importantly, this is the first time the wound healing ability of LLKKK18 is demonstrated and that its main mechanisms of action are identified.

Comparative Studies on Phenolic Composition, Antioxidant, Wound Healing and Cytotoxic Activities of Selected Achillea L. Species Growing in Turkey

Turkey is one of the most important centers of diversity for the genus Achillea L. in the world. Keeping in mind the immense medicinal importance of phenols, in this study, three species growing in Turkey, A. coarctata Poir. (AC), A. kotschyi Boiss. subsp. kotschyi (AK) and A. lycaonica Boiss. & Heldr. (AL) were evaluated for their phenolic compositions, total phenolic contents (TPC), antioxidant properties, wound healing potencies on NIH-3T3 fibroblasts and cytotoxic effects on MCF-7 human breast cancer cells. Comprehensive LC-MS/MS analysis revealed that AK was distinctively rich in chlorogenic acid, hyperoside, apigenin, hesperidin, rutin, kaempferol and luteolin (2890.6, 987.3, 797.0, 422.5, 188.1, 159.4 and 121.2 µg analyte/g extract, respectively). The findings exhibited a strong correlation between TPC and both free radical scavenging activity and total antioxidant capacity (TAC). Among studied species, the highest TPC (148.00 mg GAE/g extract) and TAC (2.080 UAE), the strongest radical scavenging (EC₅₀ = 32.63 μg/mL), the most prominent wound healing and most abundant cytotoxic activities were observed with AK. The results suggested that AK is a valuable source of flavonoids and chlorogenic acid with important antioxidant, wound healing and cytotoxic activities. These findings warrant further studies to assess the potential of AK as a bioactive source that could be exploited in pharmaceutical, cosmetics and food industries.

Nano-porous nitrocellulose liquid bandage modulates cell and cytokine response and accelerates cutaneous wound healing in a mouse model

Nitrocellulose liquid bandage (L-Bandage) is extensively used in hard-to-cover cuts and wounds management, owing to its flexibility, softness, transparency, and conformability. However, evidence supporting their mechanisms of action as wound dressing is scanty. This study introduces a novel nano-porous L-Bandage, and provides results from a mouse full-thickness wound model investigating its mechanism of action on wound healing. Different characteristics, such as porosity, mechanical properties and water vapor transmission rate (WVTR) were determined. The L-Bandage formed film had a porous network structure with mean diameter of 18 nm that could effectively prevent the bacterial invasion, and favorable properties of tensile strength, elongation, and WVTR. The L-Bandage treated wound exhibited accelerated healing, with reduced inflammations, enhanced wound re-epithelialization, contraction, granulation tissue formation, and rapid angiogenesis. Our data suggested that L-Bandage could serve as a promising wound dressing, because of its desirable properties for wound healing.

Identifying Mechanisms of Homeostatic Signaling in Fibroblast Differentiation

Fibroblasts play an important role in the wound-healing process by generating extracellular matrix (ECM) and undergoing differentiation into myofibroblasts, but these cells can also be involved in pathologic remodeling of tissue. Nascent ECM provides a substrate for re-epithelialization to occur, restoring damaged tissue to a functional state. Dysregulation of this process can result in fibrosis--stiffening and scarring of the tissue. Current treatments cannot halt or reverse this process. The molecular mechanisms underlying fibrotic dysregulation are poorly understood, providing an untapped pool of potential therapeutic targets. Transforming growth factor-β (TGF-β) and adhesion signaling are involved in inducing fibroblast differentiation into α-smooth muscle actin (αSMA) expressing myofibroblasts, while prostaglandin E₂ (PGE₂) has been shown to antagonize TGF-β signaling; however, the temporal and mechanistic details of this relationship have not yet been fully characterized. We measured αSMA, a marker of fibroblast to myofibroblast differentiation, as a function of: TGF-β1 receptor-ligand complex internalization, PGE₂ binding, and adhesion signaling and developed a mathematical model capturing the molecular mechanisms of fibroblast differentiation. Using our model, we predict the following: Periodic dosing with PGE₂ temporarily renders fibroblasts incapable of differentiation and refractory to additional TGF-β1 stimulation; conversely, periodic dosing with TGF-β1 in the presence of PGE₂ induces a reduced signal response that can be further inhibited by the addition of more PGE₂. Controlled fibroblast differentiation is necessary for effective wound healing; however, excessive accumulation of αSMA-expressing myofibroblasts can result in fibrosis. Homeostasis of αSMA in our model requires a balance of positive and negative regulatory signals. Sensitivity analysis predicts that PGE₂ availability, TGF-β1 availability, and the rate of TGF-β1 receptor recycling each highly influence the rates of αSMA production. With this model, we are able to demonstrate that regulation of both TGF-β1 and PGE₂ signaling levels is essential for preventing fibroblast dysregulation.

SDF-1 liposomes promote sustained cell proliferation in mouse diabetic wounds

Chronic skin wounds are a common complication of diabetes. When standard wound care fails to heal such wounds, a promising approach consists of using decellularized matrices and other porous scaffold materials to promote the restoration of skin. Proper revascularization is critical for the efficacy of such materials in regenerative medicine. Stromal cell-derived factor-1 (SDF-1) is a chemokine known to play a key role for angiogenesis in ischemic tissues. Herein we developed nanosized SDF-1 liposomes, which were then incorporated into decellularized dermis scaffolds used for skin wound healing applications. SDF-1 peptide associated with liposomes with an efficiency of 80%, and liposomes were easily dispersed throughout the acellular dermis. Acellular dermis spiked with SDF-1 liposomes exhibited more persistent cell proliferation in the dermis, especially in CD31(+) areas, compared to acellular dermis spiked with free SDF-1, which resulted in increased improved wound closure at day 21, and increased granulation tissue thickness at day 28. SDF-1 liposomes may increase the performance of a variety of decellularized matrices used in tissue engineering.

Fabrication and Characterization of a Conformal Skin-like Electronic System for Quantitative, Cutaneous Wound Management

Recent advances in the development of electronic technologies and biomedical devices offer opportunities for non-invasive, quantitative assessment of cutaneous wound healing on the skin. Existing methods, however, still rely on visual inspections through various microscopic tools and devices that normally include high-cost, sophisticated systems and require well trained personnel for operation and data analysis. Here, we describe methods and protocols to fabricate a conformal, skin-like electronics system that enables conformal lamination to the skin surface near the wound tissues, which provides recording of high fidelity electrical signals such as skin temperature and thermal conductivity. The methods of device fabrication provide details of step-by-step preparation of the microelectronic system that is completely enclosed with elastomeric silicone materials to offer electrical isolation. The experimental study presents multifunctional, biocompatible, waterproof, reusable, and flexible/stretchable characteristics of the device for clinical applications. Protocols of clinical testing provide an overview and sequential process of cleaning, testing setup, system operation, and data acquisition with the skin-like electronics, gently mounted on hypersensitive, cutaneous wound and contralateral tissues on patients.

Bioactive bilayered dressing for compromised epidermal tissue regeneration with sequential activity of complementary agents

The article deals with the design, preparation, and evaluation of a new bilayered dressing for application in the healing of compromised wounds. The system is based on the sequential release of two complementary bioactive components to enhance the activation of the regeneration of dermal tissue. The internal layer is a highly hydrophilic and biodegradable film of gelatin and hyaluronic acid (HG), crosslinked with the natural compound genipin, which reacts with the amine groups of gelatin. This film is loaded with the proangiogenic, anti-inflammatory, and antibacterial peptide, proadrenomedullin N-terminal 20 peptide (PAMP), that is released slowly in the wound site. The external layer, more stable and less hydrophilic, is constituted by a biodegradable polyurethane derived from poly(caprolactone) and pluronic L61. This layer is loaded with resorbable nanoparticles of bemiparin (a fractionated low molecular weight heparin), which promotes the activation of growth factors, FGF and VEGF, and provides a good biomechanical stability and controlled permeability of the bilayered dressing. Experiments carried out in mice demonstrate the excellent angiogenic effect of the HG film in the dermal tissue. Application of the bilayered dressing in the wound healing rabbit ear model shows an improved cicatrization of the wound in both ischemic and non-ischemic defects, favoring epithelialization and reducing noticeably the contraction and the inflammation.

Electrospun bioactive mats enriched with Ca-polyphosphate/retinol nanospheres as potential wound dressing

BACKGROUND

While electrospun materials have been frequently used in tissue engineering no wound dressings exist that significantly improved wound healing effectively.

METHODS

We succeeded to fabricate three-dimensional (3D) electrospun poly(D,l-lactide) (PLA) fiber mats into which nanospheres, formed from amorphous calcium polyphosphate (polyP) nanoparticles (NP) and encapsulated retinol ("retinol/aCa-polyP-NS" nanospheres [NS]), had been incorporated.

RESULTS

Experiments with MC3T3-E1 cells revealed that co-incubation of the cells with Ca-polyP together with retinol (or incubation with retinol/aCa-polyP-NS) resulted in a significant synergistic effect on cell growth compared with particle-free polyP complexed with Ca2+ or amorphous Ca-polyP NPs and retinol alone. Incubation of the cells in the presence of the retinol/aCa-polyP NSs also caused a significant increase of the expression levels of the genes encoding for the fatty acid binding protein 4 (FABP4), as well as of the genes encoding for leptin and the leptin receptor. In contrast, the single components, soluble Na-polyP, complexed to Ca2+, or retinol-free aCa-polyP NPs, and retinol, had no significant effect on the expression of these genes.

CONCLUSIONS

These results indicate that the PLA fibers, supplemented with aCa-polyP-NP or retinol/aCa-polyP-NS, elicit morphogenetic activity, suggesting that these fiber mats, along with the antibacterial effect of polyP, have a beneficial potential as wound dressings combining antimicrobial and regenerative (wound healing) properties.

GENERAL SIGNIFICANCE

The PLA-based fiber mats, containing retinol and polyP nanoparticles, provide promising bioactive meshes that are urgently needed as dressings for chronic wounds.

Effects of delayed delivery of dexamethasone-21-phosphate via subcutaneous microdialysis implants on macrophage activation in rats

Macrophage activation is of interest in the biomaterials field since macrophages with an M(Dex) characteristic phenotype, i.e., CD68(+)CD163(+), are believed to result in improved integration of the biomaterial as well as improved tissue remodeling and increased biomaterial longevity. To facilitate delivery of a macrophage modulator, dexamethasone-21-phosphate (Dex), microdialysis probes were subcutaneously implanted in male Sprague-Dawley rats. Dex localized delivery was delayed to the third day post implantation as a means to alter macrophage activation state at an implant site. To better elucidate the molecular mechanisms associated with M(Dex) macrophage activation, CCL2 was quantified in dialysates, gene expression ratios were determined from excised tissue surrounding the implant, histological analyses, and immunohistochemical analyses (CD68, CD163) were performed. Delayed Dex infusion resulted in the up-regulation of IL-6 at the transcript level in the tissue in contact with the microdialysis probe and decreased CCL2 concentrations collected in dialysates. Histological analyses showed increased cellular density as compared to controls in response to delayed Dex infusion. Dex delayed infusion resulted in an increased percentage of CD68(+)CD163(+), M(Dex), macrophages in the tissue surrounding the microdialysis probe as compared to probes that served as controls.

Treatment of Hyaluronic Acid Filler-Induced Impending Necrosis With Hyaluronidase: Consensus Recommendations

Injection-induced necrosis is a rare but dreaded consequence of soft tissue augmentation with filler agents. It usually occurs as a result of injection of filler directly into an artery, but can also result from compression or injury. We provide recommendations on the use of hyaluronidase when vascular compromise is suspected. Consensus recommendations were developed by thorough discussion and debate amongst the authors at a roundtable meeting on Wednesday June 18, 2014 in Las Vegas, NV as well as significant ongoing written and verbal communications amongst the authors in the months prior to journal submission. All authors are experienced tertiary care providers. A prompt diagnosis and immediate treatment with high doses of hyaluronidase (at least 200 U) are critically important. It is not felt necessary to do a skin test in cases of impending necrosis. Some experts recommend dilution with saline to increase dispersion or lidocaine to aid vasodilation. Additional hyaluronidase should be injected if improvement is not seen within 60 minutes. A warm compress also aids vasodilation, and massage has been shown to help. Some experts advocate the use of nitroglycerin paste, although this area is controversial. Introducing an oral aspirin regimen should help prevent further clot formation due to vascular compromise. In our experience, patients who are diagnosed promptly and treated within 24 hours will usually have the best outcomes.

Topical Hypericum perforatum Improves Tissue Regeneration in Full-Thickness Excisional Wounds in Diabetic Rat Model

Delayed wound healing process is one of the most important concerns in diabetes. Healing of wounds has four phases, namely, hemostasis, inflammation, proliferation, and remodeling. For a successful repair, all four factors must occur properly. Hence, we aimed to evaluate the healing effects of Hypericum perforatum (HP) on full-thickness diabetic skin wounds by using stereological methods. Forty-eight female diabetic rats were randomly divided into four groups (n = 12): gel base treated group, HP 5% gel treated group, HP 10% gel treated group, and the control group which received no treatment. A circular 1 cm² full-thickness wound was created on the animal's neck and wound area was measured every three days. After sacrificing the animals, skin samples were fixed and prepared for stereological evaluations. Based on the results, HP treated group showed faster wound closure rate in comparison with control and vehicle groups (P < 0.05). In addition, numerical density of fibroblasts, volume density of collagen bundles, and mean diameter and volume densities of the vessels in HP group were significantly higher than control and vehicle groups. The results of this study showed that HP has the ability to improve tissue regeneration by enhancing fibroblast proliferation, collagen bundle synthesis, and revascularization.

Advanced Therapeutic Dressings for Effective Wound Healing--A Review

Advanced therapeutic dressings that take active part in wound healing to achieve rapid and complete healing of chronic wounds is of current research interest. There is a desire for novel strategies to achieve expeditious wound healing because of the enormous financial burden worldwide. This paper reviews the current state of wound healing and wound management products, with emphasis on the demand for more advanced forms of wound therapy and some of the current challenges and driving forces behind this demand. The paper reviews information mainly from peer-reviewed literature and other publicly available sources such as the US FDA. A major focus is the treatment of chronic wounds including amputations, diabetic and leg ulcers, pressure sores, and surgical and traumatic wounds (e.g., accidents and burns) where patient immunity is low and the risk of infections and complications are high. The main dressings include medicated moist dressings, tissue-engineered substitutes, biomaterials-based biological dressings, biological and naturally derived dressings, medicated sutures, and various combinations of the above classes. Finally, the review briefly discusses possible prospects of advanced wound healing including some of the emerging physical approaches such as hyperbaric oxygen, negative pressure wound therapy and laser wound healing, in routine clinical care.

Nanomaterials for wound healing: scope and advancement

Innovative methods for treating impaired and hard-to-heal wounds are needed. Novel strategies are needed for faster healing by reducing infection, moisturizing the wound, stimulating the healing mechanisms, speeding up the wound closure and reducing scar formation. In the past few years, nanotechnology has been constantly revolutionizing the treatment and management of wound care, by offering novel solutions which include but are not limited to: state-of-the-art materials, so called 'smart' biomaterials and theranostic nanoparticles. Nanotechnology-based therapy has recently announced itself as a possible next-generation therapy that is able to advance wound healing to cure chronic wounds. In this communication, the recent progress in advanced therapy for cutaneous wound healing during last 5 years using a nanotechnology-based approach is summarized.

Prevalence and microbiological characteristics of clinically infected foot-ulcers in patients with rheumatoid arthritis: a retrospective exploratory study

BACKGROUND

The prevalence of foot ulcers in patients with rheumatoid arthritis (RA) has been reported at almost 10 %. These foot ulcers often occur at multiple sites and are reoccurring, with the potential risk of infection increased due to RA diagnosis and disease modifying medications. The objective of this study was to estimate the prevalence of clinical infection in foot-ulcers of patients with RA; describe the microbiological characteristics and investigate risk factors.

METHODS

Retrospective clinical data was collected for all patients attending a rheumatology foot ulcer clinic between 1st May 2012 and 1st May 2013: wound swab data was collected from those with clinical infection.

RESULTS

Twenty-eight patients with RA and foot-ulcers were identified; eight of these patients had clinical infection and wound swabs taken (29 %). Of these eight patients there were equal men and women, with median age 74 years, and average disease duration 22 years. Cardiovascular disease/peripheral-vascular disease (CVD/PVD) were reported in six patients, diabetes in two patients. Six patients were treated with disease-modifying anti-rheumatic drugs (DMARDs); three were on biologic medications and two on steroids. Five wound swabs cultured skin flora, one staphylococcus aureus, one had no growth after culture; and one was rejected due to labelling error.

CONCLUSION

Almost a third of people with RA and foot ulcers attending clinic over one year had clinical infection, however microbiological analysis failed to isolate pathogens in six of seven wound swabs. This may be due to inaccurate diagnosis of ulcer infection or to issues with sampling, collection, transport, analysis or reporting. There was insufficient data to relate risk of clinical infection with risk factors. Further research is required to identify the most appropriate techniques for infection diagnosis, wound sampling and processing.

TRIAL REGISTRATION

Ethical approval was obtained from University of Leeds, Faculty of Medicine and Health (Reference number: SHREC/RP/349).