Characterisation of factors contributing to the performance of nonwoven fibrous matrices as substrates for adenovirus vectored vaccine stabilisation

Adenovirus vectors offer a platform technology for vaccine development. The value of the platform has been proven during the COVID-19 pandemic. Although good stability at 2–8 °C is an advantage of the platform, non-cold-chain distribution would have substantial advantages, in particular in low-income countries. We have previously reported a novel, potentially less expensive thermostabilisation approach using a combination of simple sugars and glass micro-fibrous matrix, achieving excellent recovery of adenovirus-vectored vaccines after storage at temperatures as high as 45 °C. This matrix is, however, prone to fragmentation and so not suitable for clinical translation. Here, we report an investigation of alternative fibrous matrices which might be suitable for clinical use. A number of commercially-available matrices permitted good protein recovery, quality of sugar glass and moisture content of the dried product but did not achieve the thermostabilisation performance of the original glass fibre matrix. We therefore further investigated physical and chemical characteristics of the glass fibre matrix and its components, finding that the polyvinyl alcohol present in the glass fibre matrix assists vaccine stability. This finding enabled us to identify a potentially biocompatible matrix with encouraging performance. We discuss remaining challenges for transfer of the technology into clinical use, including reliability of process performance.

Micro-RNA as a predictor of cardiovascular diseases

Сердечно-сосудистые заболевания, особенно ишемическая болезнь сердца (ИБС), являются наиболее распространенными заболеваниями во всем мире. Более 50% смертности приходится на данную патологию. В последние десятилетия существует тенденция к «омоложению» сердечно-сосудистых заболеваний – прежде всего гипертонической болезни и ИБС, что вызывает особую тревогу. Общепризнано, что основным этиологическим моментом развития ИБС является атеросклероз. ИБС включает в себя целый ряд клинических диагнозов (стенокардия, инфаркт миокарда и т. д.) и связана с атеросклерозом, распространенным дегенеративным заболеванием, при котором липиды и фиброзный матрикс откладываются в артериальной стенке с формированием атероматозной бляшки. Разрыв нестабильных бляшек в коронарных артериях приводит к высвобождению тромбогенного содержимого в просвет сосуда, приводя к тромбозу коронарных артерий, окклюзии и последующему инфаркту миокарда – критическому состоянию с высокой смертностью [5]. Несмотря на большое количество известных факторов риска, влияющих на развитие данного заболевания, существуют данные, подтвержденные крупными исследованиями, о наличии генетической предрасположенности к нему. Cardiovascular diseases, especially coronary heart disease (CHD), are the most common diseases worldwide. More than 50% of mortality occurs in this pathology. In recent decades, there is a tendency to «rejuvenate» cardiovascular diseases – primarily hypertension and СHD, which is of particular concern [6, 8]. It is generally recognized that atherosclerosis is the main etiological moment in the development of coronary heart disease. CHD includes a number of clinical diagnoses (angina pectoris, myocardial infarction, etc.) and is associated with atherosclerosis, a common degenerative disease in which lipids and the fibrous matrix are deposited in the arterial wall with the formation of an atheromatous plaque. Rupture of unstable plaques in the coronary arteries leads to the release of thrombogenic contents into the lumen of the vessel, leading to coronary artery thrombosis, occlusion and subsequent myocardial infarction, critical state with high mortality [5]. Despite the large number of known risk factors affecting the development of this disease, there is evidence, confirmed by large studies, about the presence of a genetic predisposition to this disease.

MODELLING FLAX FIBRE STRETCHING AND TEARING PROCESS UNDER SINGLE AXIS LOAD

The article examines existing works considering the process of tearing of flax fibre, specifically fibrous matrix and linkages within it. In particular authors point out the necessity of taking into account the destruction of individual fibres during deformation and tearing process. The end result of this analysis is a multipart mechanical model allowing for various effects that may take place during the said process. This model is implemented in software and used to model the behaviour of several strands of fibre of varying quality. The results match the observed behaviour of actual samples with similar properties, which allows using the model presented to estimate the effect various properties of flax fibre have on its tensile strength.

Fast and accurate computation of interactions between linear fiber segments

PurposeFiber networks represent a vast class of materials, which can be modeled by representing its microstructure using one-dimensional fiber embedded in three-dimensional space. Investigating the statics, dynamics and thermodynamics of such structures from computational first principles requires the efficient estimation of cohesive-repulsive energies and forces between interacting fiber segments. This study offers a fast, efficient and effective computational methodology to estimate such interactions which can be coupled with Hamiltonian mechanics to simulate the behavior of fibrous systems.Design/methodology/approachThis method preserves the uniformly continuous distribution of particles on the line segments and utilizes adaptive numerical integration of relevant distance-distribution functions to estimate the effective interaction energy and forces.FindingsThis method is found to be cheaper to compute and more accurate than the corresponding discrete scheme. This scheme is also versatile in the sense that any pair-wise interaction model can be used.Research limitations/implicationsThe scheme depends on the availability of a suitable pair-interaction potential, such as a Lennard-Jones potential or Morse potential. Additionally, it can only be used for systems which are purely fibrous in nature. For example, fiber composites with a non-fibrous matrix are not addressed.Practical implicationsPaper, woven and hair can be represented as purely fibrous at some relevant length scales and are thus excellent candidate systems for this scheme.Originality/valueThis paper presents a novel method which allows rapid and accurate implementation of an otherwise computationally expensive process.

Diversity and Evolution of Mineralized Skeletal Tissues in Chondrichthyans

The diversity of skeletal tissues in extant vertebrates includes mineralized and unmineralized structures made of bone, cartilage, or tissues of intermediate nature. This variability, together with the diverse nature of skeletal tissues in fossil species question the origin of skeletonization in early vertebrates. In particular, the study of skeletal tissues in cartilaginous fishes is currently mostly restrained to tessellated cartilage, a derived form of mineralized cartilage that evolved at the origin of this group. In this work, we describe the architectural and histological diversity of neural arch mineralization in cartilaginous fishes. The observed variations in the architecture include tessellated cartilage, with or without more massive sites of mineralization, and continuously mineralized neural arches devoid of tesserae. The histology of these various architectures always includes globular mineralization that takes place in the cartilaginous matrix. In many instances, the mineralized structures also include a fibrous component that seems to emerge from the perichondrium and they may display intermediate features, ranging from partly cartilaginous to mostly fibrous matrix, similar to fibrocartilage. Among these perichondrial mineralized tissues is also found, in few species, a lamellar arrangement of the mineralized extracellular matrix. The evolution of the mineralized tissues in cartilaginous fishes is discussed in light of current knowledge of their phylogenetic relationships.

The air permeability of composite fiber material

The air permeability of composite materials obtained by impregnating a non-woven needle-punched cloth with latex was investigated. The permeability of composite materials with different rubber content was estimated by the coefficient of air permeability at a pressure drop of 49 and 100 Pa. The dependence of the air permeability coefficient on the degree of impregnation of the fabric showed that at 15 – 20 % of the rubber content, the maximum air permeability coefficient is observed, and when the degree of impregnation increases, the air permeability coefficient decreases. The process of forming a porous structure of composite materials and its influence on air transport is considered. The increase of the coefficient of permeability is explained by the fixation of the fibers of the surface layer with limited mobility under the action of air flow, and a reduction in the coefficient of air permeability by reducing pore space and an increase in fiber matrix composite materials in the process of sushi-Ki-impregnated material. The air permeability of composite materials is determined by the ratio between the processes of increasing the volume of the fibrous matrix and reducing porosity when filling the space between the portages with rubber particles. A model is proposed for calculating the coefficient of breathability of composite materials of known density.

Stretch-responsive adhesive microcapsules for strain-regulated antibiotic release from fabric wound dressings

Mussel-inspired adhesive mechano-activatable microcapsules have strong adhesion to a 3D fibrous matrix under aqueous conditions and are capable of delivering therapeutic cargos in response to uniaxial stretching.