Chronic Leg Ulcers: Are Tissue Engineering and Biomaterials Science the Solution?

Chronic leg ulcers (CLUs) are full thickness wounds that usually occur between the ankle and knee, fail to heal after 3 months of standard treatment, or are not entirely healed at 12 months. CLUs present a considerable burden on patients, subjecting them to severe pain and distress, while healthcare systems suffer immense costs and loss of resources. The poor healing outcome of the standard treatment of CLUs generates an urgent clinical need to find effective solutions for these wounds. Tissue Engineering and Biomaterials Science offer exciting prospects for the treatment of CLUs, using a broad range of skin substitutes or scaffolds, and dressings. In this review, we summarize and discuss the various types of scaffolds used clinically in the treatment of CLUs. Their structure and therapeutic effects are described, and for each scaffold type representative examples are discussed, supported by clinical trials. Silver dressings are also reviewed due to their reported benefits in the healing of leg ulcers, as well as recent studies on new dermal scaffolds, reporting on clinical results where available. We conclude by arguing there is a further need for tissue-engineered products specifically designed and bioengineered to treat these wounds and we propose a series of properties that a biomaterial for CLUs should possess, with the intention of focusing efforts on finding an effective treatment

Carbohidrate Distribution In The Small Intestine of Sumba Ongole Cattle (Bos indicus)

The small intestine has cells that function to secrete mucus that protects the intestine from pathogenic agents and mechanical damage. One of the components of mucus is carbohydrates. This study aims to knowing the distribution of acidic and neutral carbohydrates in the small intestine of sumba ongole (Bos indicus) cattle. Six samples of the small intestine were collected from East Sumba Slaughter House. The tissue was fixed in formalin 10 %, continued with processed histologically and AB-PAS staining. The results showed that acidic and neutral carbohydrates were distributed in the tunica of the duodenum, jejunum, and ileum with varying intensity. The strong intensity was seen in goblet cells, Lieberkuhn crypts, and Brunner's glands. The different distribution of carbohydrates in the small intestine is related to the mucus secretion of each cell and that function

SUSY QCD impact on top-pair production associated with a Z0Z^0-boson at a photon-photon collider

The top-pair production in association with a $Z^0$-boson at a photon-photon collider is an important process in probing the coupling between top-quarks and vector boson and discovering the signature of possible new physics. We describe the impact of the complete supersymmetric QCD(SQCD) next-to-leading order(NLO) radiative corrections on this process at a polarized or unpolarized photon collider, and make a comparison between the effects of the SQCD and the standard model(SM) QCD. We investigate the dependence of the lowest-order(LO) and QCD NLO corrected cross sections in both the SM and minimal supersymmetric standard model(MSSM) on colliding energy $\sqrt{s}$ in different polarized photon collision modes. The LO, SM NLO and SQCD NLO corrected distributions of the invariant mass of $t\bar t$-pair and the transverse momenta of final $Z^0$-boson are presented. Our numerical results show that the pure SQCD effects in \ggttz process can be more significant in the $+ +$ polarized photon collision mode than in other collision modes, and the relative SQCD radiative correction in unpolarized photon collision mode varies from 32.09% to $-1.89$ when $\sqrt{s}$ goes up from $500 GeV$ to $1.5 TeV$.Comment: 22 pages and 13 figure

Cell morphology as a design parameter in the bioengineering of cell-biomaterial surface interactions

Control of cell–surface interaction is necessary for biomaterial applications such as cell sheets, intelligent cell culture surfaces, or functional coatings. In this paper, we propose the emergent property of cell morphology as a design parameter in the bioengineering of cell–biomaterial surface interactions. Cell morphology measured through various parameters can indicate ideal candidates for these various applications thus reducing the time taken for the screening and development process. The hypothesis of this study is that there is an optimal cell morphology range for enhanced cell proliferation and migration on the surface of biomaterials. To test the hypothesis, primary porcine dermal fibroblasts (PDF, 3 biological replicates) were cultured on ten different surfaces comprising components of the natural extracellular matrix of tissues. Results suggested an optimal morphology with a cell aspect ratio (CAR) between 0.2 and 0.4 for both increased cell proliferation and migration. If the CAR was below 0.2 (very elongated cell), cell proliferation was increased whilst migration was reduced. A CAR of 0.4+ (rounded cell) favoured cell migration over proliferation. The screening process, when it comes to biomaterials is a long, repetitive, arduous but necessary event. This study highlights the beneficial use of testing the cell morphology on prospective prototypes, eliminating those that do not support an optimal cell shape. We believe that the research presented in this paper is important as we can help address this screening inefficiency through the use of the emergent property of cell morphology. Future work involves automating CAR quantification for high throughput screening of prototypes

Experimental evaluation of a new approach for a two-stage hydrothermal biomass liquefaction process

A new approach for biomass liquefaction was developed and evaluated in a joint research project. Focus of the project, called FEBio@H2O, lies on a two-step hydrothermal conversion. Within step 1, the input biomass is converted employing a hydrothermal degradation without added catalyst or by homogeneous catalysis. Within step 2, the hydrogen accepting products of step 1, e.g., levulinic acid (LA) are upgraded by a heterogeneously catalyzed hydrogenation with hydrogen donor substances, e.g., formic acid (FA). As a result, components with an even lower oxygen content in comparison to step 1 products are formed; as an example, γ-valerolactone (GVL) can be named. Therefore, the products are more stable and contained less oxygen as requested for a possible application as liquid fuel. As a hydrothermal process, FEBio@H2O is especially suitable for highly water-containing feedstock. The evaluation involves hydrothermal conversion tests with model substances, degradation of real biomasses, transfer hydrogenation or hydrogenation with hydrogen donor of model substances and real products of step 1, catalyst selection and further development, investigation of the influence of reactor design, the experimental test of the whole process chain, and process assessment

Three dimensional porous scaffolds derived from collagen, elastin and fibrin proteins orchestrate adipose tissue regeneration

Current gold standard to treat soft tissue injuries caused by trauma and pathological condition are autografts and off the shelf fillers, but they have inherent weaknesses like donor site morbidity, immuno-compatibility and graft failure. To overcome these limitations, tissue-engineered polymers are seeded with stem cells to improve the potential to restore tissue function. However, their interaction with native tissue is poorly understood so far. To study these interactions and improve outcomes, we have fabricated scaffolds from natural polymers (collagen, fibrin and elastin) by custom-designed processes and their material properties such as surface morphology, swelling, wettability and chemical cross-linking ability were characterised. By using 3D scaffolds, we comprehensive assessed survival, proliferation and phenotype of adipose-derived stem cells in vitro. In vivo, scaffolds were seeded with adipose-derived stem cells and implanted in a rodent model, with X-ray microtomography, histology and immunohistochemistry as read-outs. Collagen-based materials showed higher cell adhesion and proliferation in vitro as well as higher adipogenic properties in vivo. In contrast, fibrin demonstrated poor cellular and adipogenesis properties but higher angiogenesis. Elastin formed the most porous scaffold, with cells displaying a non-aggregated morphology in vitro while in vivo elastin was the most degraded scaffold. These findings of how polymers present in the natural polymers mimicking ECM and seeded with stem cells affect adipogenesis in vitro and in vivo can open avenues to design 3D grafts for soft tissue repair

The importance of myo-inositol and D-chiro-inositol to support fertility and reproduction

This review details the physiologic roles of two insulin sensitizers, myo-inositol (MI) and D-chiro-inositol (DCI). In the human ovary, MI is a second messenger of follicle stimulating hormone (FSH) and DCI is an aromatase inhibitor. These activities allow a treatment for polycystic ovary syndrome (PCOS) to be defined based on the combined administration of MI and DCI, where the best MI:DCI ratio is 40:1. In addition, MI plays a pivotal role in the physiology of reproduction, and has beneficial effects on the development of oocytes, spermatozoa, and embryos. By contrast, DCI has little effect on spermatozoa, but high concentrations in the ovary can negatively affect the quality of oocytes and the blastocyst. Overall, the evidence in the literature supports the beneficial effects of MI in both female and male reproduction, warranting clinical use of MI in assisted reproductive treatment (ART).Cette revue détaille les rôles physiologiques de deux sensibilisateurs à l'insuline, le myo-inositol (MI) et le D-chiro-inositol (DCI). Dans l'ovaire humain, le MI est un second messager de l'hormone folliculostimulante (FSH) et le DCI est un inhibiteur de l'aromatase. Ces activités permettent de définir un traitement du syndrome des ovaires polykystiques (SOPK) basé sur l'administration combinée de MI et de DCI, où le meilleur rapport MI:DCI est de 40:1. En outre, le MI joue un rôle essentiel dans la physiologie de la reproduction et a des effets bénéfiques sur le développement des ovocytes, des spermatozoïdes et des embryons. En revanche, le DCI a peu d'effet sur les spermatozoïdes, mais des concentrations élevées dans l'ovaire peuvent avoir un effet négatif sur la qualité des ovocytes et du blastocyste. Dans l'ensemble, les données de la littérature confirment les effets bénéfiques du MI dans la reproduction féminine et masculine, ce qui justifie l'utilisation clinique du MI dans l'assistance médicale à la procréation

Uganda's experience in Ebola virus disease outbreak preparedness, 2018-2019.

BACKGROUND: Since the declaration of the 10th Ebola Virus Disease (EVD) outbreak in DRC on 1st Aug 2018, several neighboring countries have been developing and implementing preparedness efforts to prevent EVD cross-border transmission to enable timely detection, investigation, and response in the event of a confirmed EVD outbreak in the country. We describe Uganda's experience in EVD preparedness. RESULTS: On 4 August 2018, the Uganda Ministry of Health (MoH) activated the Public Health Emergency Operations Centre (PHEOC) and the National Task Force (NTF) for public health emergencies to plan, guide, and coordinate EVD preparedness in the country. The NTF selected an Incident Management Team (IMT), constituting a National Rapid Response Team (NRRT) that supported activation of the District Task Forces (DTFs) and District Rapid Response Teams (DRRTs) that jointly assessed levels of preparedness in 30 designated high-risk districts representing category 1 (20 districts) and category 2 (10 districts). The MoH, with technical guidance from the World Health Organisation (WHO), led EVD preparedness activities and worked together with other ministries and partner organisations to enhance community-based surveillance systems, develop and disseminate risk communication messages, engage communities, reinforce EVD screening and infection prevention measures at Points of Entry (PoEs) and in high-risk health facilities, construct and equip EVD isolation and treatment units, and establish coordination and procurement mechanisms. CONCLUSION: As of 31 May 2019, there was no confirmed case of EVD as Uganda has continued to make significant and verifiable progress in EVD preparedness. There is a need to sustain these efforts, not only in EVD preparedness but also across the entire spectrum of a multi-hazard framework. These efforts strengthen country capacity and compel the country to avail resources for preparedness and management of incidents at the source while effectively cutting costs of using a "fire-fighting" approach during public health emergencies