New antioxidant therapy for hard-to-heal neuroischaemic diabetic foot ulcers with deep exposure.

OBJECTIVE: To evaluate the clinical efficacy of a new antioxidant therapy for the treatment of complex neuroischaemic diabetic foot ulcers (DFUs). METHOD: A prospective case series study has been conducted in patients with complex neuroischaemic DFUs after transmetatarsal amputation. DFUs were locally treated with an antioxidant dressing twice a week for the first two weeks, and then once a week until the end of the study or complete wound closure. Patients were followed-up for eight weeks and assessed weekly to analyse wound outcome. Primary outcomes were the wound closure ratio and percentage of granulation tissue; secondary outcomes were parameters related to wound management, namely, presence of non-viable tissue in the wound bed, levels of maceration and exudates, presence of erythema and pain. RESULTS: A total of 20 patients were included with a mean baseline wound area of 20.4cm2. At 8 weeks, the mean reduction in wound area was 88.1% (p<0.0001) and complete closure was observed in 33% of cases. In addition, there was a mean increase of 94.7% in granulation tissue in the wound bed (p<0.0001). Furthermore, the therapy was associated with a significant percentage reduction in wounds with non-viable tissue, good exudate management, and the maintenance of low levels of maceration, erythema and pain. CONCLUSION: The new antioxidant therapy was associated with good clinical outcomes in large hard-to-heal neuroischaemic DFUs, with significant wound area reduction and granulation tissue formation. The therapy was also found to be safe and perform well from a practical perspective.

The Epidemiological Profile of Multiple Casualty Incidents in Northern Spain: 2014-2020.

OBJECTIVE: To describe the epidemiological profile of multiple casualty incidents (MCI) and contribute to the better understanding of their impacts in Northern Spain. METHOD: Retrospective, population-based observational study of MCI between 2014 and 2020 in 5 autonomous communities (Aragón, Castilla y León, Galicia, the Basque Country and Principado de Asturias) that participated in the MCI Database of Northern Spain. Inclusion criteria was any incident with 4 or more patients needing ambulance mobilization. A total of 54 variables were collected. This study presents the most relevant results. RESULTS: There were 253 MCI. Of these, 79.8% were road traffic accidents, 12.3% fires or explosions, 2.0% poisonings and 5.9% defined as others. Monthly average was 2.9 (SD = 0.35; EEM = 15.90), average of victims by MCI was 6.8 (CI95% 6.16 - 7.60). There were significantly (P < 0.05) more victims in 3 types of MCI (fires, poisonings, and others). We saw 37.7% of MCI involved 4 victims, 18.8% 5 victims, and 37.9% more than 5. Mean response time was 30.8 minutes (95% CI 28.6 - 33.1), longer in maritime incidents. A total of 67% (95% CI 64.5 - 69.5) of victims were mild. CONCLUSIONS: Road traffic accidents are the most frequent MCI and minor injuries predominate. More than 50% of the MCI have 5 or fewer patients. Fires had significantly more mild patients and significantly more resources deployed. Maritime incidents had a significantly longer response time.

A Digital Tool for Measuring Healing of Chronic Wounds Treated with an Antioxidant Dressing: A Case Series.

(1) Abstract: Wound monitoring is an essential aspect in the evaluation of wound healing. This can be carried out with the multidimensional tool HELCOS, which develops a quantitative analysis and graphic representation of wound healing evolution via imaging. It compares the area and tissues present in the wound bed. This instrument is used for chronic wounds in which the healing process is altered. This article describes the potential use of this tool to improve the monitoring and follow-up of wounds and presents a case series of various chronic wounds with diverse etiology treated with an antioxidant dressing. (2) Methods: A secondary analysis of data from a case series of wounds treated with an antioxidant dressing and monitored with the HELCOS tool. (3) Results: The HELCOS tool is useful for measuring changes in the wound area and identifying wound bed tissues. In the six cases described in this article, the tool was able to monitor the healing of the wounds treated with the antioxidant dressing. (4) Conclusions: the monitoring of wound healing with this multidimensional HELCOS tool offers new possibilities to facilitate treatment decisions by healthcare professionals.

Neddylation tunes peripheral blood mononuclear cells immune response in COVID-19 patients.

The COVID-19 pandemic caused by SARS-CoV-2 has reached 5.5 million deaths worldwide, generating a huge impact globally. This highly contagious viral infection produces a severe acute respiratory syndrome that includes cough, mucus, fever and pneumonia. Likewise, many hospitalized patients develop severe pneumonia associated with acute respiratory distress syndrome (ARDS), along an exacerbated and uncontrolled systemic inflammation that in some cases induces a fatal cytokine storm. Although vaccines clearly have had a beneficial effect, there is still a high percentage of unprotected patients that develop the pathology, due to an ineffective immune response. Therefore, a thorough understanding of the modulatory mechanisms that regulate the response to SARS-CoV-2 is crucial to find effective therapeutic alternatives. Previous studies describe the relevance of Neddylation in the activation of the immune system and its implications in viral infection. In this context, the present study postulates Neddylation, a reversible ubiquitin-like post-translational modification of proteins that control their stability, localization and activity, as a key regulator in the immune response against SARS-CoV-2. For the first time, we describe an increase in global neddylation levels in COVID-19 in the serum of patients, which is particularly associated with the early response to infection. In addition, the results showed that overactivation of neddylation controls activation, proliferation, and response of peripheral blood mononuclear cells (PBMCs) isolated from COVID-19 patients. Inhibition of neddylation, and the subsequent avoidance of activated PBMCs, reduces cytokine production, mainly IL-6 and MCP-1 and induce proteome modulation, being a critical mechanism and a potential approach to immunomodulate COVID-19 patients.

SCA® Slows the Decline of Functional Parameters Associated with Senescence in Skin Cells.

The identification of compounds and natural ingredients that can counteract tissue stress and dysfunction induced by aging in skin cells is warranted. Here, we investigated the activity of the secretion from the snail Cryptomphalus aspersa (SCA®), an active compound with well-established beneficial effects on skin integrity and aging. To determinate its senescence-regulation mechanisms, we used a model where damage was induced by hydrogen peroxide (H2O2). The results showed that SCA® positively modulated factors involved in cell senescence such as ß-galactosidase and cell morphology, secretory efficiency markers (SIRT1/6 and carboxymethyl-lysine), and metabolic and redox homeostasis (mTOR and ROS). This study demonstrated a novel compound that is activity-modulating, reduces cell senescence, and increases longevity to maintain skin homeostasis and functionality.

The Role of Antioxidants on Wound Healing: A Review of the Current Evidence.

(1) Background: Reactive oxygen species (ROS) play a crucial role in the preparation of the normal wound healing response. Therefore, a correct balance between low or high levels of ROS is essential. Antioxidant dressings that regulate this balance are a target for new therapies. The purpose of this review is to identify the compounds with antioxidant properties that have been tested for wound healing and to summarize the available evidence on their effects. (2) Methods: A literature search was conducted and included any study that evaluated the effects or mechanisms of antioxidants in the healing process (in vitro, animal models or human studies). (3) Results: Seven compounds with antioxidant activity were identified (Curcumin, N-acetyl cysteine, Chitosan, Gallic Acid, Edaravone, Crocin, Safranal and Quercetin) and 46 studies reporting the effects on the healing process of these antioxidants compounds were included. (4) Conclusions: this review offers a map of the research on some of the antioxidant compounds with potential for use as wound therapies and basic research on redox balance and oxidative stress in the healing process. Curcumin, NAC, quercetin and chitosan are the antioxidant compounds that shown some initial evidence of efficacy, but more research in human is needed.

Bioresorbable and Mechanically Optimized Nerve Guidance Conduit Based on a Naturally Derived Medium Chain Length Polyhydroxyalkanoate and Poly(ε-Caprolactone) Blend.

Severe peripheral nerve injuries represent a large clinical problem with relevant challenges such as the development of successful synthetic scaffolds as substitutes to autologous nerve grafting. Numerous studies have reported the use of polyesters and type I collagen-based nerve guidance conduits (NGCs) to promote nerve regeneration through critical nerve defects while providing protection from external factors. However, none of the commercially available hollow bioresorbable NGCs have demonstrated superior clinical outcomes to an autologous nerve graft. Hence, new materials and NGC geometries have been explored in the literature to mimic the native nerve properties and architecture. Here, we report a novel blend of a natural medium chain length polyhydroxyalkanoate (MCL-PHA) with a synthetic aliphatic polyester, poly(ε-caprolactone) (PCL), suitable for extrusion-based high-throughput manufacturing. The blend was designed to combine the excellent ability of PHAs to support the growth and proliferation of mammalian cells with the good processability of PCL. The material exhibited excellent neuroregenerative properties and a good bioresorption rate, while the extruded porous tubes exhibited similar mechanical properties to the rat sciatic nerve. The NGCs were implanted to treat a 10 mm long sciatic nerve defect in rats, where significant differences were found between thin and thick wall thickness implants, and both electrophysiological and histological data, as well as the number of recovered animals, provided superior outcomes than the well-referenced synthetic Neurolac NGC.

Hydrogen Peroxide-Preconditioned Human Adipose-Derived Stem Cells Enhance the Recovery of Oligodendrocyte-Like Cells after Oxidative Stress-Induced Damage.

Oxidative stress associated with neuroinflammation is a key process involved in the pathophysiology of neurodegenerative diseases, and therefore, has been proposed as a crucial target for new therapies. Recently, the therapeutic potential of human adipose-derived stem cells (hASCs) has been investigated as a novel strategy for neuroprotection. These cells can be preconditioned by exposing them to mild stress in order to improve their response to oxidative stress. In this study, we evaluate the therapeutic potential of hASCs preconditioned with low doses of H2O2 (called HC016 cells) to overcome the deleterious effect of oxidative stress in an in vitro model of oligodendrocyte-like cells (HOGd), through two strategies: i, the culture of oxidized HOGd with HC016 cell-conditioned medium (CM), and ii, the indirect co-culture of oxidized HOGd with HC016 cells, which had or had not been exposed to oxidative stress. The results demonstrated that both strategies had reparative effects, oxidized HC016 cell co-culture being the one associated with the greatest recovery of the damaged HOGd, increasing their viability, reducing their intracellular reactive oxygen species levels and promoting their antioxidant capacity. Taken together, these findings support the view that HC016 cells, given their reparative capacity, might be considered an important breakthrough in cell-based therapies.

H2O2-preconditioned human adipose-derived stem cells (HC016) increase their resistance to oxidative stress by overexpressing Nrf2 and bioenergetic adaptation.

BACKGROUND: Mesenchymal stem cells, including those derived from human adipose tissue (hASCs), are currently being widely investigated for cell therapy. However, when transplanted at the site of injury, the survival and engraftment rates of hASCs are low, mainly due to the harsh microenvironment they encounter, characterized by inflammation and oxidative stress. To overcome these therapeutic limitations, cell preconditioning with low-concentration of hydrogen peroxide (H2O2) has been proposed as a plausible strategy to increase their survival and adaptation to oxidative stress. Nonetheless, the underlying mechanisms of this approach are not yet fully understood. In this study, we analyzed molecular and bioenergetic changes that take place in H2O2 preconditioned hASCs. METHODS: Long-term exposure to a low concentration of H2O2 was applied to obtain preconditioned hASCs (named HC016), and then, their response to oxidative stress was analyzed. The effect of preconditioning on the expression of Nrf2 and its downstream antioxidant enzymes (HO-1, SOD-1, GPx-1, and CAT), and of NF-κB and its related inflammatory proteins (COX-2 and IL-1ß), were examined by Western blot. Finally, the Seahorse XF96 Flux analysis system was used to evaluate the mitochondrial respiration and glycolytic function, along with the total ATP production. RESULTS: We found that under oxidative conditions, HC016 cells increased the survival by (i) decreasing intracellular ROS levels through the overexpression of the transcription factor Nrf2 and its related antioxidant enzymes HO-1, SOD-1, GPx-1, and CAT; (ii) reducing the secretion of pro-inflammatory molecules COX-2 and IL-1ß through the attenuation of the expression of NF-κB; and (iii) increasing the total ATP production rate through the adaption of their metabolism to meet the energetic demand required to survive. CONCLUSIONS: H2O2 preconditioning enhances hASC survival under oxidative stress conditions by stimulating their antioxidant response and bioenergetic adaptation. Therefore, this preconditioning strategy might be considered an excellent tool for strengthening the resistance of hASCs to harmful oxidative stress.

Antioxidant dressing therapy versus standard wound care in chronic wounds (the REOX study): study protocol for a randomized controlled trial.

BACKGROUND: A wound that does not heal in the orderly stages of the healing process or does not heal within 3 months is considered a chronic wound. Wound healing is impaired when the wound remains in the inflammatory stage for too long. A range of factors can delay the healing process: imbalance between proteases and protease inhibitors in the wound bed; bacterial colonization and the presence of biofilm; and oxidative stress. Recently, wound management has improved significantly. A new antioxidant dressing has been developed, which combines an absorbent matrix obtained from locust bean gum galactomannan and a hydration solution with curcumin and N-acetylcysteine. This dressing combines the advantages of moist healing in exudate management and free radical neutralization, achieving wound reactivation. The primary aim of this study is to compare the effect of the antioxidant dressing on chronic wound healing against the use of a standard wound dressing in patients with hard-to-heal wounds. METHODS: We will conduct a multicentre, single-blind, randomized controlled trial with parallel groups. Participants will be selected from three primary public health care centres located in Andalucía (southern Spain). Patients will be randomized into an intervention group (antioxidant dressing) or a control group (standard wound dressing). Assessments will be carried out at weeks 2, 4, 6 and 8. Follow-up will be for a period of 8 weeks or until complete healing if this occurs earlier. DISCUSSION: The findings from this study should provide scientific evidence on the efficacy of the antioxidant dressing as an alternative for the treatment of chronic wounds. This study fills some of the gaps in the existing knowledge about patients with hard-to-heal wounds. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03934671. Registered on 2 May 2019.

UV-Casting on Methacrylated PCL for the Production of a Peripheral Nerve Implant Containing an Array of Porous Aligned Microchannels.

Peripheral nerves are basic communication structures guiding motor and sensory information from the central nervous system to receptor units. Severed peripheral nerve injuries represent a large clinical problem with relevant challenges to successful synthetic nerve repair scaffolds as substitutes to autologous nerve grafting. Numerous studies reported the use of hollow tubes made of synthetic polymers sutured between severed nerve stumps to promote nerve regeneration while providing protection for external factors, such as scar tissue formation and inflammation. Few approaches have described the potential use of a lumen structure comprised of microchannels or microfibers to provide axon growth avoiding misdirection and fostering proper healing. Here, we report the use of a 3D porous microchannel-based structure made of a photocurable methacrylated polycaprolactone, whose mechanical properties are comparable to native nerves. The neuro-regenerative properties of the polymer were assessed in vitro, prior to the implantation of the 3D porous structure, in a 6-mm rat sciatic nerve gap injury. The manufactured implants were biocompatible and able to be resorbed by the host's body at a suitable rate, allowing the complete healing of the nerve. The innovative design of the highly porous structure with the axon guiding microchannels, along with the observation of myelinated axons and Schwann cells in the in vivo tests, led to a significant progress towards the standardized use of synthetic 3D multichannel-based structures in peripheral nerve surgery.

Natural Histogel-Based Bio-Scaffolds for Sustaining Angiogenesis in Beige Adipose Tissue.

In the treatment of obesity and its related disorders, one of the measures adopted is weight reduction by controlling nutrition and increasing physical activity. A valid alternative to restore the physiological function of the human body could be the increase of energy consumption by inducing the browning of adipose tissue. To this purpose, we tested the ability of Histogel, a natural mixture of glycosaminoglycans isolated from animal Wharton jelly, to sustain the differentiation of adipose derived mesenchymal cells (ADSCs) into brown-like cells expressing UCP-1. Differentiated cells show a higher energy metabolism compared to undifferentiated mesenchymal cells. Furthermore, Histogel acts as a pro-angiogenic matrix, induces endothelial cell proliferation and sprouting in a three-dimensional gel in vitro, and stimulates neovascularization when applied in vivo on top of the chicken embryo chorioallantoic membrane or injected subcutaneously in mice. In addition to the pro-angiogenic activity of Histogel, also the ADSC derived beige cells contribute to activating endothelial cells. These data led us to propose Histogel as a promising scaffold for the modulation of the thermogenic behavior of adipose tissue. Indeed, Histogel simultaneously supports the acquisition of brown tissue markers and activates the vasculature process necessary for the correct function of the thermogenic tissue. Thus, Histogel represents a valid candidate for the development of bioscaffolds to increase the amount of brown adipose tissue in patients with metabolic disorders.

Sustained Human Hair Follicle Growth Ex Vivo in a Glycosaminoglycan Hydrogel Matrix.

Glycosaminoglycans (GAGs) and associated proteoglycans have important functions in homeostatic maintenance and regenerative processes (e.g., wound repair) of the skin. However, little is known about the role of these molecules in the regulation of the hair follicle cycle. Here we report that growing human hair follicles ex vivo in a defined GAG hydrogel mimicking the dermal matrix strongly promotes sustained cell survival and maintenance of a highly proliferative phenotype in the hair bulb and suprabulbar regions. This significant effect is associated with the activation of WNT/ß-catenin signaling targets (CCDN1, AXIN2) and with the expression of stem cell markers (CK15, CD34) and growth factors implicated in the telogen/anagen transition (TGFß2, FGF10). As a whole, these results point to the dermal GAG matrix as an important component in the regulation of the human hair follicle growth cycle, and to GAG-based hydrogels as potentially relevant modulators of this process both in vitro and in vivo.

Cryopreserved H2 O2 -preconditioned human adipose-derived stem cells exhibit fast post-thaw recovery and enhanced bioactivity against oxidative stress.

Human adipose-derived stem cells (ASCs), despite being one of the most attractive cell populations for tissue engineering and regenerative medicine, currently have certain limitations that reduce their therapeutic efficacy. One of the most serious problems is the poor engraftment of cryopreserved ASCs at injured tissue, attributed to the diminished biological activity of ASCs immediately post-thaw and their poor survival under harsh conditions of oxidative stress. Seeking to address these issues, we have developed a hormetic strategy to preadapt human ASCs to oxidative stress based on a new hydrogen peroxide preconditioning procedure, resulting in cells we call HC016. These cells rapidly recover their biological activity and functionality after cryopreservation while maintaining their mesenchymal stem cell status. Compared with non-preconditioned ASCs, HC016 cells showed (a) faster in vitro adhesion capacity and cell cycle progression immediately post-thaw, (b) enhanced cell survival under oxidative stress in a serum-free environment, and (c) heightened chemotaxis towards damage signals of oxidized glial cells. In addition, compared with ASC-conditioned medium, HC016-conditioned medium showed a greater cytoprotective and pro-recovery effect on oxidized fibroblasts under serum-free conditions. Consistent with these results, in HC016 cells exposed to oxidative stress, we observed markedly higher expression of insulin-like growth factor-1 (a key factor in cell survival and migration) and of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 and pyruvate dehydrogenase kinase isozyme 1 (essential enzymes to upregulate glycolysis and downregulate oxidative phosphorylation) along with lower basal mitochondrial activity. Taking into account all the aforementioned advantages, HC016 cells might be considered an important breakthrough in ASC-based cell therapies.

Evaluation of the Safety and Efficacy of the Therapeutic Potential of Adipose-Derived Stem Cells Injected in the Cerebral Ischemic Penumbra.

INTRODUCTION: Stroke represents an attractive target for cell therapy. Although different types of cells have been employed in animal models with variable results, the human adipose-derived stem cells (hASCs) have demonstrated favorable characteristics in the treatment of diseases with inflammatory substrate, but experience in their intracerebral administration is lacking. The purpose of this study is to evaluate the effect and safety of the intracerebral application of hASCs in a stroke model. METHODS: A first group of Athymic Nude mice after stroke received a stereotactic injection of hASCs at a concentration of 4 × 104/µL at the penumbra area, a second group without stroke received the same cell concentration, and a third group had only stroke and no cells. After 7, 15, and 30 days, the animals underwent fluorodeoxyglucose-positron emission tomography and magnetic resonance imaging; subsequently, they were sacrificed for histological evaluation (HuNu, GFAP, IBA-1, Ki67, DCX) of the penumbra area and ipsilateral subventricular zone (iSVZ). RESULTS: The in vitro studies found no alterations in the molecular karyotype, clonogenic capacity, and expression of 62 kDa transcription factor and telomerase. Animals implanted with cells showed no adverse events. The implanted cells showed no evidence of proliferation or differentiation. However, there was an increase of capillaries, less astrocytes and microglia, and increased bromodeoxyuridine and doublecortin-positive cells in the iSVZ and in the vicinity of ischemic injury. CONCLUSIONS: These results suggest that hASCs in the implanted dose modulate inflammation, promote endogenous neurogenesis, and do not proliferate or migrate in the brain. These data confirm the safety of cell therapy with hASCs.

Low-Temperature Cross-Linking of PEDOT:PSS Films Using Divinylsulfone.

Recent interest in bioelectronics has prompted the exploration of properties of conducting polymer films at the interface with biological milieus. Poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS) from a commercially available source has been used as a model system for these studies. Different cross-linking schemes have been used to stabilize films of this material against delamination and redispersion, but the cost is a decrease in the electrical conductivity and/or additional heat treatment. Here we introduce divinylsulfone (DVS) as a new cross-linker for PEDOT:PSS. Thanks to the higher reactiveness of the vinyl groups of DVS, the cross-linking can be performed at room temperature. In addition, DVS does not reduce electronic conductivity of PEDOT:PSS but rather increases it by acting as a secondary dopant. Cell culture studies show that PEDOT:PSS:DVS films are cytocompatible and support neuroregeneration. As an example, we showed that this material improved the transconductance value and stability of an organic electrochemical transistor (OECT) device. These results open the way for the utilization of DVS as an effective cross-linker for PEDOT:PSS in bioelectronics applications.

In vitro characterization of a nanostructured fibrin agarose bio-artificial nerve substitute.

Neural tissue engineering is focused on the design of novel biocompatible substitutes to repair peripheral nerve injuries. In this paper we describe a nanostructured fibrin-agarose bioartificial nerve substitute (NFABNS), based on nanostructured fibrin-agarose hydrogels (FAHs) with human adipose-derived mesenchymal stem cells (HADMSCs). These NFABNSs were mechanically characterized and HADMSCs behaviour was evaluated using histological and ultrastructural techniques. Mechanical characterization showed that the NFABNSs were resistant, flexible and elastic, with a high deformation capability. Histological analyses carried out in vitro during 16 days revealed that the number of HADMSCs decreased over time, with a significant increase after 16 days. HADMSCs formed cell clusters and degraded the surrounding scaffold during this time; additionally, HADMSCs showed active cell proliferation and cytoskeletal remodelling, with a progressive synthesis of extracellular matrix molecules. Finally, this study demonstrated that it is possible to generate biologically active and mechanically stable tissue-like substitutes with specific dimensions, based on the use of HADMSCs, FAHs and a nanostructure technique. However, in vivo analyses are needed to demonstrate their potential usefulness in peripheral nerve repair. Copyright © 2015 John Wiley & Sons, Ltd.

Poly(3,4-ethylenedioxythiophene):GlycosAminoGlycan Aqueous Dispersions: Toward Electrically Conductive Bioactive Materials for Neural Interfaces.

UNLABELLED: There is an actual need of advanced materials for the emerging field of bioelectronics. One commonly used material is the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) ( PEDOT: PSS) due to its general use in organic electronics. However, depending on the application in bioelectronics, PEDOT: PSS is not fully biocompatible due to the high acidity of the residual sulfonate protons of PSS. In this paper, the synthesis and biocompatibility properties of new poly(3,4-ethylenedioxythiophene):GlycosAminoGlycan ( PEDOT: GAG) aqueous dispersions and its resulting films are shown. Thus, negatively charged GAGs as an alternative to PSS are presented. Three different commercially available GAGs, hyaluronic acid, heparin, and chondroitin sulfate are used. Indeed, PEDOT: GAGs dispersions are prepared through an oxidative chemical polymerization in water. Biocompatibility assays of the PEDOT: GAGs coatings are performed using SH-SY5Y and CCF-STTG1 cell lines and with ATP and Ca(2+) . Results show full biocompatibility and a pronounced anti-inflammatory effect. This last characteristic becomes crucial if implanted in the body. These materials can be used for in vivo applications, as transistor or electrode for electrical recording and for all the possible situations when there is contact between electronic circuits and living tissues.

Deciphering the Lipid Architecture of the Rat Sciatic Nerve Using Imaging Mass Spectrometry.

Knowledge on the normal structure and molecular composition of the peripheral nerves is essential to understand their pathophysiology and to select the regeneration strategies after injury. However, the precise lipid composition of the normal peripheral nerve is still poorly known. Here, we present the first study of distribution of individual lipids in the mature sciatic nerve of rats by imaging mass spectrometry. Both positive and negative ion modes were used to detect, identify and in situ map 166 molecular species of mainly glycerophospholipids, sphingomyelins, sulfatides, and diacyl and triacylglycerols. In parallel, lipid extracts were analyzed by LC-MS/MS to verify and complement the identification of lipids directly from the whole tissue. Three anatomical regions were clearly identified by its differential lipid composition: the nerve fibers, the connective tissue and the adipose tissue that surrounds the nerve. Unexpectedly, very little variety of phosphatidylcholine (PC) species was found, being by far PC 34:1 the most abundant species. Also, a rich composition on sulfatides was detected in fibers, probably due to the important role they play in the myelin cover around axons, as well as an abundance of storage lipids in the adipose and connective tissues. The database of lipids here presented for each region and for the whole sciatic nerve is a first step toward understanding the variety of the peripheral nerves' lipidome and its changes associated with different diseases and mechanical injuries.

Development and preclinical evaluation of a new galactomannan-based dressing with antioxidant properties for wound healing.

We describe a novel wound dressing (HR006) with two components: a lyophilized matrix of the galactomannan from locust bean gum (LBG) and an antioxidant hydration solution (AHsol) containing curcumin and N-acetyl-L-cysteine (NAC). Physico-structural analyses of the LBG matrix revealed homogeneous interconnected pores with high absorbing capacity showing excellent properties for moist wound care (MWC). In an in vitro oxidative stress fibroblast injury model, the AHsol showed relevant protective effects reducing intracellular reactive oxygen species (ROS) production, rescuing cell viability, and regulating expression of inflammation-related genes (COX-2, TNF-α, IL-1α, IL-1ß). The new dressing showed good biocompatibility profile as demonstrated by cytotoxicity, hemocompatibility, and skin irritation tests. Moreover, in an in vivo skin wound model in pigs, this dressing enhanced the production of healthy and organized granulation tissue and re-epithelization. In summary, HR006 exhibits significant antioxidant activity, good biocompatibility, and excellent repair capabilities improving tissue remodeling and the healing of wounds.