Structural and crystal-chemical characteristics of the apatite deposits from human aortic walls

Thermal behavior of biological apatite is the object of several studies. Crystal size, carbonate content, phase composition, and other parameters change during annealing up to 900 °C in biological minerals with apatite structure. The way these parameters change reflects the specific properties of the initial bioapatite. This work presents data on thermal transformations of pathological bioapatite from the human cardiovascular system, namely aortic wall deposits. Some minor elements, foreign to calcium hydroxyapatite (e.g., Na and Mg), can be both incorporated in the apatite structure and localized in the surface layers of crystals, modifying functions of the mineral. A new approach was proposed to determine the predominant location of minor elements, such as Mg, Na, and K, in the mineral of pathological deposits. Mg and Na in pathological apatite can be in both structurally bound (substituting calcium in lattice) and labile (localized on the crystal surface) states, while K is not able to join the apatite structure in significant amount or be chemically bound to it. This approach, based on atomic spectrometry, can be used effectively in combination with a set of traditional techniques, such as like EDS, IRS, and XRD

Preparation and characterisation of new biomaterials based on chitosan iodide with biologically active dyes

New composite materials were obtained based on chitosan iodide and organic dyes – methylene blue and fuchsine in fucorcin (Castellani liquid) – by using a simple synthetic procedure. The materials were characterised by scanning electron microscopy, X-ray diffraction, temperature-programmed desorption mass spectrometry, infrared spectroscopy and visible and ultraviolet light spectroscopy. The dyes in the composites were distributed uniformly and did not form separate phases. These composites could form structured porous sponges and films and therefore be used in various fields of application. The materials displayed antibacterial activity against antibiotic resistant gram-positive and gram-negative bacteria

Chitosan-based biomaterials for closure of dural defects

Закриття дефектів твердої мозкової оболонки є необхідністю після нейрохірургічних операцій, щоб запобігти витоку цереброспінальної рідини і зменшити ризик післяопераційних інфекцій. Реконструкція твердої матерії з ендогенного матеріалу стає дуже поширеним явищем. Тим не менш, окістя або широка фасція може призвезти до додаткової операції, додаткові розрізи і час інтенсивного накладення швів. Таким чином, мета нашого дослідження є створення біосумісного і нетоксичного матеріалу на основі хітозану для заміщення дефекту твердої мозкової оболони. Крім того, ми оцінюємо його біологічні властивості. Наші результати підтверджують високі міцностні властивості, які трохи відрізняється від нативної оболони. Що стосується швидкості біодеградації цей матеріал може бути застосований в якості постійного матеріалу для заміщення дефекту твердої мозкової оболони.Закрытие дефектов твердой мозговой оболочки является необходимостью после нейрохирургических операций, чтобы предотвратить утечку цереброспинальной жидкости и уменьшить риск послеоперационных инфекций. Реконструкция твердой материи с эндогенного материала становится очень распространенным явлением. Тем не менее, надкостницы или широкая фасция может привезти к дополнительной операции, дополнительные разрезы и время интенсивного наложения швов. Таким образом, цель нашего исследования является создание биосовместимого и нетоксичного материала на основе хитозана для замещения дефекта твердой мозговой оболочки. Кроме того, мы оцениваем его биологические свойства. Наши результаты подтверждают высокие прочностные свойства, которые немного отличается от нативной оболочки. Что касается скорости биодеградации этот материал может быть применен в качестве постоянного материала для замещения дефекта твердой мозговой оболочки.Closure of dural defects is a necessity after neurosurgical procedures to prevent cerebrospinal fluid leakage and to reduce the risk of perioperative infections. Reconstruction of the dura matter with endogenous material becomes very common. However, harvesting of periosteum or fascia lata may require extended surgical approach, additional incisions and time intensive suturing. A wide range of biomaterials, both of natural and synthetic origin, are being investigated for potential applications in dural defect repair. Thus, the aim of our research is to create a biocompatible and nontoxic chitosan-based material to repair dural defects. Besides, we evaluate its biological properties. Our results appeared to confirm high strength properties that were slightly different from those of the native dura. Regarding to the rate of biodegradation this material can be applied as a permanent material to repair dural defects

Effect of chitosan molecular weight, percentage in solution and method of production to human blood cells

Adequate haemostasis after trauma and during surgical operation is a big challenge in modern medicine. About the 40% traumatic and more than 90% of combat deaths took place in pre-hospital settings. And about the 50% from these deaths have been reported due to massive blood loss [Ersoy G, 2007]. Sauaia A. reported 80% of civilian trauma fatalitieswithin the United States causes by uncontrollable haemorrhage [Sauaia A., 1995]. Also, haemorrhage in trauma patients is a leading cause resulting reoperation [Hirshberg A, 1993]. Topical haemostatic treatment was applied since ancient time. They used herbs, mixture of wax, grease and barley and also animal hides mixed with hot sand to stop bleeding [Hardean E. Achneck, 2010]. Advances in biotechnology have resulted in an explosivegrowth of topical haemostatic agentsin the last two decades. Chitin and chitosan hemostatic dressing are most promising due to effective blood stop and possible additional properties like antibacterial and stimulatory to regeneration. Both clinical and experimental evaluations of chitosan-based hemostatic dressing suggest their high effectiveness and safety in civil and battlefield application. But still not understanding how does molecular weight influence to haemostatic activities of chitosan-based materials. Also chitosan may be present in different concentration that can change effectiveness and time that need to stop bleeding

Effect of chitosan molecular weight, percentage in solution and method of production to human blood cells

Adequate haemostasis after trauma and during surgical operation is a big challenge in modern medicine. About the 40% traumatic and more than 90% of combat deaths took place in pre-hospital settings. And about the 50% from these deaths have been reported due to massive blood loss [Ersoy G, 2007]. Sauaia A. reported 80% of civilian trauma fatalitieswithin the United States causes by uncontrollable haemorrhage [Sauaia A., 1995]. Also, haemorrhage in trauma patients is a leading cause resulting reoperation [Hirshberg A, 1993]. Topical haemostatic treatment was applied since ancient time. They used herbs, mixture of wax, grease and barley and also animal hides mixed with hot sand to stop bleeding [Hardean E. Achneck, 2010]. Advances in biotechnology have resulted in an explosivegrowth of topical haemostatic agentsin the last two decades. Chitin and chitosan hemostatic dressing are most promising due to effective blood stop and possible additional properties like antibacterial and stimulatory to regeneration. Both clinical and experimental evaluations of chitosan-based hemostatic dressing suggest their high effectiveness and safety in civil and battlefield application. But still not understanding how does molecular weight influence to haemostatic activities of chitosan-based materials. Also chitosan may be present in different concentration that can change effectiveness and time that need to stop bleeding

ОПРЕДЕЛЕНИЕ СОСТАВА И ОЦЕНКА СОДЕРЖАНИЯ ЛЕТУЧИХ УГЛЕВОДОРОДОВ В ПОЧВЕ МЕТОДОМ ТВЕРДОФАЗНОЙ МИКРОЭКСТРАКЦИИ И ГАЗОВОЙ ХРОМАТОГРАФИИ/ МАСС-СПЕКТРОМЕТРИИ

The feasibility of using solid-phase microextraction  and gas chromatography/mass spectrometry for the identification and quantification of volatile petroleum hydrocarbons in soils and sediments was studied. Suitable diagnostic features provided identification of hydrocarbons  released to gas phase. Quantitation both the total content of volatile hydrocarbons and hydrocarbon types/individual compounds was performed using internal standards and calibration with n-alkanes. Volatile components in the sediments of the sedimentation pond in industrial plant were characterized as well as their migration and weathering.Keywords: petroleum products, volatile hydrocarbons, sediments, solid phase microextraction , gas chromatography/mass spectrometry.(Russian)DOI: http://dx.doi.org/10.15826/analitika.2013.17.1.008 E.S. Brodsky1, O.L. Butkova2, A.A. Shelepchikov1, G.A. Kalinkevich1,  Е.Ya. Mir-Kadyrova1, D.B. Phesin1, V.G. Jilnikov1 1A.N.Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences,Moscow, Russian Federation2Institute of Expert Examination of Mineral Waters, Russian FederationИзучена возможность применения метода твердофазной микроэкстракции в сочетании с ГХ/МС для характеристики летучих нефтяных углеводородов в почве и донных отложениях. Рассмотрены диагностические признаки летучих углеводородов, выделяющихся в газовую фазу и показана возможность идентификации и количественной оценки, как общего содержания летучих продуктов, так и отдельных групп углеводородов и индивидуальных соединений в почвах и донных отложениях с использованием внутренних стандартов и градуировки по н-алканам. Этим методом охарактеризованы летучие компоненты нефтепродуктов в донных отложениях пруда-отстойника на территории промышленного предприятия.Ключевые слова: нефтепродукты, почва, твердофазная микроэкстракция, парофазный анализ, хромато-масс-спектрометрия, летучие углеводороды.DOI: http://dx.doi.org/10.15826/analitika.2013.17.1.00

Formation of a Bacteriostatic Surface on ZrNb Alloy via Anodization in a Solution Containing Cu Nanoparticles

High strength, excellent corrosion resistance, high biocompatibility, osseointegration ability, and low bacteria adhesion are critical properties of metal implants. Additionally, the implant surface plays a critical role as the cell and bacteria host, and the development of a simultaneously antibacterial and biocompatible implant is still a crucial challenge. Copper nanoparticles (CuNPs) could be a promising alternative to silver in antibacterial surface engineering due to low cell toxicity. In our study, we assessed the biocompatibility and antibacterial properties of a PEO (plasma electrolytic oxidation) coating incorporated with CuNPs (Cu nanoparticles). The structural and chemical parameters of the CuNP and PEO coating were studied with TEM/SEM (Transmission Electron Microscopy/Scanning Electron Microscopy), EDX (Energy-Dispersive X-ray Dpectroscopy), and XRD (X-ray Diffraction) methods. Cell toxicity and bacteria adhesion tests were used to prove the surface safety and antibacterial properties. We can conclude that PEO on a ZrNb alloy in Ca–P solution with CuNPs formed a stable ceramic layer incorporated with Cu nanoparticles. The new surface provided better osteoblast adhesion in all time-points compared with the nontreated metal and showed medium grade antibacterial activities. PEO at 450 V provided better antibacterial properties that are recommended for further investigation

Chitosan–hydroxyapatite composite biomaterials made by a one step co-precipitation method: preparation, characterization and in vivo tests

A series of biocompatible chitosan/hydroxyapatite composites has been synthesized in an aqueous medium from chitosan solution and soluble precursor salts by a one-step coprecipitation method. The composite materials were produced in dense and porous variants. XRD and IR studies have shown that the apatite crystals in the composites have structural characteristics similar to those of crystals in biogenic apatite. A study of in vivo behaviour of the materials was carried out. Cylindrical rods made of the chitosan/ hydroxyapatite composite material were implanted into the tibial bones of rats. After 5, 10, 15 and 24 days of implantation, histological and histo-morphometric analyses of decalcified specimens were undertaken to evaluate their biocompatibility and the possibility to apply them in bone tissue engineering. The calcified specimens were examined by scanning electron microscopy combined with X-ray microanalysis to compare the elemental composition and morphological characteristics of the implant and the bone during integration. Porous specimens were osteoconducting and were replaced in vivo by newly formed bone tissue

Adhesion and proliferation of adipose derived mesenchymal stromal cells on chitosan scaffolds with different degree of deacetylation

Aim. Selection of the optimal scaffold for the creation of tissue engineering constructs is a key challenge of biotechnology. In this study we investigated the biocompatibility of human adipose derived mesenchymal stromal cells (MSCs) within the three-dimensional matrices based on the chitosan with a different degree of deacetylation. Methods. MSCs were seeded on the chitosan scaffolds by a perfusion method and cultured for 7 days. The morphology, viability, metabolic activity and distribution of the cells within the matrices were analyzed. Results. The level of MSCs adhesion to the surface of the chitosan scaffolds with low degree of deacetylation (67 %) was insignificant, the cells were round and formed aggregates. In the chitosan scaffolds with a high degree of deacetylation (82 %) the cells attached to the surface of matrices, were able to spread and proliferate. Conclusions. The chitosan scaffolds with a high degree of deacetylation and the human adipose derived MSCs can be used for the creation of bioengineered structures

Quantitative Estimation of Subsurface Parameters

Scattering of low-frequency SAR radiation from subsurface soil volume is not enough investigated until now. In this work we made an attempt to study scattering from large subsurface structures like subsoil water bed or natural layering of different soil types using VHF-band. A model with two soil layers is considered with rough boundary between them and gradient of dielectric constant. Possibility of layers moisture determination using X-Bragg model for surface scattering is investigated. Thickness of upper soil layer could be estimated using obtained values of moisture