The return of a forgotten polymer—Polycaprolactone in the 21st century

Asthma is a serious health problem throughout the world During the past two decades, many scientific advances have improved our understanding of asthma and ability to manage and control it effectively However, recommendations for asthma care need to be adapted to local conditions, resources and services Since it was formed in 1993, the Global Initiative for Asthma, a network of individuals, organisations and public health officials, has played a leading role in disseminating information about the care of patients with asthma based on a process of continuous review of published scientific investigations A comprehensive workshop report entitled "A Global Strategy for Asthma Management and Prevention", first published in 1995, has been widely adopted, translated and reproduced, and forms the basis for many national guidelines The 2006 report contains important new themes First, it asserts that "it is reasonable to expect that in most patients with asthma, control of the disease can and should be achieved and maintained," and recommends a change in approach to asthma management, with asthma control, rather than asthma severity, being the focus of treatment decisions The importance of the patient-care giver partnership and guided self-management, along with setting goals for treatment, are also emphasised

https://erj.ersjournals.com/content/erj/31/1/143.full.pdf

Global strategy for asthma management and prevention: GINA executive summary.

MUCKE aims to mine a large volume of images, to structure them conceptually and to use this conceptual structuring in order to improve large-scale image retrieval. The last decade witnessed important progress concerning low-level image representations. However, there are a number problems which need to be solved in order to unleash the full potential of image mining in applications. The central problem with low-level representations is the mismatch between them and the human interpretation of image content. This problem can be instantiated, for instance, by the incapability of existing descriptors to capture spatial relationships between the concepts represented or by their incapability to convey an explanation of why two images are similar in a content-based image retrieval framework. We start by assessing existing local descriptors for image classification and by proposing to use co-occurrence matrices to better capture spatial relationships in images. The main focus in MUCKE is on cleaning large scale Web image corpora and on proposing image representations which are closer to the human interpretation of images. Consequently, we introduce methods which tackle these two problems and compare results to state of the art methods. Note: some aspects of this deliverable are withheld at this time as they are pending review. Please contact the authors for a preview.

http://ieeexplore.ieee.org/iel2/4524/12820/00592460.pdf

Image Processing

Tissue engineering applications commonly encompass the use of three-dimensional (3D) scaffolds to provide a suitable microenvironment for the incorporation of cells or growth factors to regenerate ...

/pdf/three-dimensional-scaffolds-for-tissue-engineering-1huqh8s1ln.pdf

Three-dimensional scaffolds for tissue engineering applications : role of porosity and pore size

Although asthma has been considered as a single disease for years, recent studies have increasingly focused on its heterogeneity. The characterization of this heterogeneity has promoted the concept that asthma consists of multiple phenotypes or consistent groupings of characteristics. Asthma phenotypes were initially focused on combinations of clinical characteristics, but they are now evolving to link biology to phenotype, often through a statistically based process. Ongoing studies of large-scale, molecularly and genetically focused and extensively clinically characterized cohorts of asthma should enhance our ability to molecularly understand these phenotypes and lead to more targeted and personalized approaches to asthma therapy.

/pdf/asthma-phenotypes-the-evolution-from-clinical-to-molecular-1a6ydbpfb2.pdf

Asthma phenotypes: the evolution from clinical to molecular approaches

Background: Written action plans for asthma facilitate the early detection and treatment of an asthma exacerbation. Several versions of action plans have been published but the key components have not been determined. A study was undertaken to determine the impact of individual components of written action plans on asthma health outcomes. Methods: Randomised controlled trials (n = 26) that evaluated asthma action plans as part of asthma self-management education were identified. Action plans were classified as being individualised and complete if they specified when and how to increase treatment (n = 17), and as incomplete (n = 4) or non-specific (n = 5) if they did not include these instructions. Results: For individualised complete written action plans the use of 2–4 action points and the use of both inhaled (ICS) and oral (OCS) corticosteroid consistently improved asthma outcomes. Action points based on personal best peak expiratory flow (PEF) consistently improved health outcomes while those based on percentage predicted PEF did not. The efficacy of incomplete action plans was inconclusive because of insufficient data. Non-specific action plans led to improvements in knowledge and symptoms. Conclusion: Individualised written action plans based on personal best PEF, using 2–4 action points, and recommending both ICS and OCS for treatment of exacerbations consistently improve asthma health outcomes. Other variations appear less beneficial or require further study. These observations provide a guide to the types of variations possible with written action plans, and strongly support the use of individualised complete written action plans.

https://thorax.bmj.com/content/thoraxjnl/59/2/94.full.pdf

Written action plans for asthma: an evidence-based review of the key components

Engineered human skin is commonly fabricated using collagen scaffolds that often have poor mechanical properties. To improve the strength of collagen-based scaffolds, poly(caprolactone) (PCL) was blended with collagen and formed into submicron fibers using electrospinning. At concentrations < 10% PCL (M(PCL)/[M(Collagen) + M(PCL)] x 100), the PCL component was evenly distributed within the collagen matrix. Increasing the PCL component to 30% caused separation of the collagen and PCL phases forming local domains of PCL within the collagen matrix. Tensile testing indicated that 10-100% PCL concentrations significantly improved the strength and stiffness of the acellular scaffolds. Engineered skin (ES) made with blended collagen-PCL at a concentration of up to 10% PCL did not significantly alter the stratification of the cells, cell proliferation, or epidermal differentiation compared to the 100% collagen group. Ultimate tensile strength of ES fabricated with the collagen-PCL blends was not significantly greater than that of ES made with 100% collagen scaffolds (0% PCL). The 30% PCL group had the least amount of mechanical strength likely caused by poor epidermal formation and reduced cell viability. These results indicate that minimal additions of PCL can be blended with collagen to produce scaffolds suitable for tissue engineering of human skin. However, the increase in scaffold strength with higher PCL concentrations did not result in significantly stronger ES, indicating that high cell viability and proper development of the epidermis are important factors for developing ES with high strength.

Engineered human skin fabricated using electrospun collagen-PCL blends: morphogenesis and mechanical properties.

EDC cross-linking improves skin substitute strength and stability.

Influence of electrospun collagen on wound contraction of engineered skin substitutes

Porous, nowoven fibrous gelatin scaffolds were prepared using electrospinning. Electrospun scaffolds with varying fiber diameter, interfiber distance, and porosity were fabricated by altering the concentration of the electrospinning solution. Solution concentration was a significant predictor of fiber diameter, interfiber distance, and porosity with higher solution concentration correlated with larger fiber diameters and interfiber distances. The potential of electrospun gelatin as a scaffolding material for dermal and epidermal tissue regeneration was also evaluated. Interfiber distances >5.5 microm allowed deeper penetration of human dermal fibroblasts into the scaffold, whereas cells in scaffolds with more densely packed fibers were able to infiltrate only into the upper regions. Scaffolds with interfiber distances </=10 microm exhibited well-stratified dermal and epidermal layers including a continuous basal keratinocyte layer. These scaffolds were shown to form a keratinized layer like in normal skin, which acts as a barrier to infection and fluid loss. Interfiber distances between 5 and 10 microm appear to yield the most favorable skin substitute in vitro, demonstrating high cell viability, optimal cell organization, and excellent barrier formation. These results demonstrate the feasibility of electrospun gelatin as a scaffold for dermal-epidermal composite skin substitutes.

Heather M. Powell

Papers

Written action plans for asthma: an evidence-based review of the key components

Engineered human skin fabricated using electrospun collagen-PCL blends: morphogenesis and mechanical properties.

EDC cross-linking improves skin substitute strength and stability.

Influence of electrospun collagen on wound contraction of engineered skin substitutes

Fiber density of electrospun gelatin scaffolds regulates morphogenesis of dermal–epidermal skin substitutes