The Cytotoxic Effects of Betulin-Conjugated Gold Nanoparticles as Stable Formulations in Normal and Melanoma Cells

Gold nanoparticles are currently investigated as theranostics tools in cancer therapy due to their proper biocompatibility and increased efficacy related to the ease to customize the surface properties and to conjugate other molecules. Betulin, [lup-20(29)-ene-3β, 28-diol], is a pentacyclic triterpene that has raised scientific interest due to its antiproliferative effect on several cancer types. Herein we described the synthesis of surface modified betulin-conjugated gold nanoparticles using a slightly modified Turkevich method. Transmission electron microscopy (TEM) imaging, dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used for the characterization of obtained gold nanoparticles. Cytotoxic activity and apoptosis assessment were carried out using the MTT and Annexin V/PI apoptosis assays. The results showed that betulin coated gold nanoparticles presented a dose-dependent cytotoxic effect and induced apoptosis in all tested cell lines

Towards effective COVID\u201119 vaccines: Updates, perspectives and challenges (Review)

In the current context of the pandemic triggered by SARS-COV-2, the immunization of the population through vaccination is recognized as a public health priority. In the case of SARS\u2011COV\u20112, the genetic sequencing was done quickly, in one month. Since then, worldwide research has focused on obtaining a vaccine. This has a major economic impact because new technological platforms and advanced genetic engineering procedures are required to obtain a COVID\u201119 vaccine. The most difficult scientific challenge for this future vaccine obtained in the laboratory is the proof of clinical safety and efficacy. The biggest challenge of manufacturing is the construction and validation of production platforms capable of making the vaccine on a large scale

Large Scale Structures a Gradient Lines: the case of the Trkal Flow

A specific asymptotic expansion at large Reynolds numbers (R)for the long wavelength perturbation of a non stationary anisotropic helical solution of the force less Navier-Stokes equations (Trkal solutions) is effectively constructed of the Beltrami type terms through multi scaling analysis. The asymptotic procedure is proved to be valid for one specific value of the scaling parameter,namely for the square root of the Reynolds number (R).As a result large scale structures arise as gradient lines of the energy determined by the initial conditions for two anisotropic Beltrami flows of the same helicity.The same intitial conditions determine the boundaries of the vortex-velocity tubes, containing both streamlines and vortex linesComment: 27 pages, 2 figure

Опыт лечения обширной диабетической флегмоны стопы на фоне лимфедемы пораженной конечности

The article presents the experience of treating a patient with diabetic foot syndrome complicated by the development of osteomyelitis of the first metatarsophalangeal joint and cuboid bone, putrid phlegmon of the left foot. The disease proceeded against the background of a pronounced systemic reaction of the body to the presence of purulent infection focus in a polymorbid patient (IHD: postinfarction cardiosclerosis, chronic heart failure of grade 2 (FC1), chronic lymphovenous insufficiency). The complex treatment of the patient included surgical debridement of the purulent left foot focus with a hydrosurgical scalpel, disarticulation of the first toe, NPWT in the postoperative period, pathogenetic and symptomatic treatment, which were aimed at the early transition of the wound to the reparative stage. The second phase of the wound healing process was reached by the 18th day of treatment, which made it possible to perform skin grafting. On the 29th day of treatment, the patient was discharged in satisfactory condition with good cosmetic and functional results.В статье представлен опыт лечения больного синдромом диабетической стопы, осложненным развитием остеомиелита I плюснефалангового сустава и кубовидной кости, а также гнилостной флегмоны. Заболевание протекало на фоне выраженной системной реакции организма на наличие очага гнойной инфекции у полиморбидного пациента (ИБС: постинфарктный кардиосклероз, хроническая сердечная недостаточность 2 ст. (ФК1), хроническая лимфовенозная недостаточность). Комплексное лечение включало хирургическую обработку гнойного очага левой стопы гидрохирургическим скальпелем, экзартикуляцию I пальца, терапию раны отрицательным давлением, патогенетическую и симптоматическую терапию, которые были направлены на достижение скорейшего перехода раны в репаративную стадию. Вторая фаза течения раневого процесса была достигнута к 18-м сут лечения, что позволило выполнить аутодермопластику раны расщепленным кожным трансплантатом. На 29-е сут больной в удовлетворительном состоянии выписан с хорошим косметическим и функциональным результатом

Размер и форма частиц полипиррола в водных растворах поли-( N-винилпирролидона)

Based on the IR spectroscopy data and on the analysis of rheological characteristics of polypyrrole aqueous suspension stabilized with poly-(N-vinylpyrrolidone) we conjecture that a physical lattice composed with poly-(N-vinylpyrrolidone) is formed, where the lattice points are the polypyrrole chain aggregates interlaced with poly-(N-vinylpyrrolidone) chains. It was shown that there is a hydrogen bond between the constitutional repeating units of poly-(N-vinylpyrrolidone) and polypyrrole. It was determined that the size of the particles of the disperse phase decreases with the increase of poly-(N-vinylpyrrolidone) molecular weight. It was also determined that the size of particles increases with the increase of the mass fraction of polypyrrole aqueous suspension. It was shown that the disperse phase particles are rod-like, and the increase of molecular weight of poly-(N-vinylpyrrolidone) in an aqueous solution results in additional lengthwise stretching of particles. It was also shown that the viscosity of the stabilized poly-(N-vinylpyrrolidone) aqueous suspension follows the Einstein law.На основании данных ИК-спектроскопии и анализа реологических характеристик водной суспензии полипиррола, стабилизированной поли-( N -винилпирролидоном), выдвинуто предположение об образовании физической сетки, формируемой цепями поли-( N -винилпирролидона), узлами которой являются агрегаты цепей полипиррола, переплетенные с цепями поли-( N -винилпирролидона). Установлено уменьшение размера частиц дисперсной фазы при увеличении молекулярной массы поли-( N -винилпирролидона)

Кинетика и механизм окисления 2,4,6-триметиланилина

The kinetics of oxidation of 2,4,6-trimethylaniline hydrochloride with ammonia peroxydisulfate in an aqueous solution was studied by the potentiometric method. It was shown that the reaction proceeds as the second order process. The rate constants of one-electron transfer from 2,4,6-trimethylaniline molecule to peroxydisulfate ion were determined and are 1.46, 2.3, and 3.17 l/(mol.sec) at 30, 35 and 40° С , respectively. The activation energy of one-electron transfer from 2,4,6-trimethylaniline molecule to peroxydisulfate ion is 61 kJ/mol, the entropy of activation is –63 J/(mol К ), and the enthalpy of activation is 58.5kJ/mol. It was determined that 2,4,6-trimethylaniline is not prone to oxidative polymerization. This indicates that cation-radicals of aromatic amines which act as active centers of aniline oxidative polymerization are formed. The fact that there is no autoacceleration during oxidation of 2,4,6-trimethylaniline hydrochloride indicates that the oxidative polymerization of aniline is an autocatalytical process.Потенциометрическим методом исследована кинетика окисления 2,4,6-триметиланилина под действием пероксидисульфата аммония в водном растворе. Показано, что скорость реакции подчиняется уравнению второго порядка. Определены константы скорости и энергия активации окисления 2,4,6-триметиланилина, а также предложен механизм реакции

КИНЕТИКА И МЕХАНИЗМ ОКИСЛИТЕЛЬНОЙ ПОЛИМЕРИЗАЦИИ 2-МЕТИЛАНИЛИНА

The kinetics of oxidative polymerization of 2-methylaniline in hydrochloric acid aqueous solution in the presence of ammonium peroxydisulfate as the oxidant was studied. The presence of autocatalysis was demonstrated, and the reaction mechanism was suggested. On the basis of the mechanism a kinetic model of oxidative polymerization of 2-methylaniline was built. The model is in satisfactory agreement with the experimental results.И сследована кинетика окислительной полимеризации 2-метиланилина в солянокислом водном растворе в присутствии пероксидисульфата аммония в качестве окислителя. Показано наличие автокатализа, предложен механизм реакции. На основании механизма построена кинетическая модель окислительной полимеризации 2-метиланилина, находящаяся в удовлетворительном соот-ветствии с результатами эксперимента

Исследование элюционных характеристик противотуберкулезных препаратов, смешанных с костным цементом

The objective: to assess the elution characteristics of anti-tuberculosis drugs (isoniazid, cycloserine, rifampicin, amikacin, kanamycin, ethambutol) placed into bone cement samples and put in a liquid medium to determine the possibility of using such systems as a drug reservoir.Subjects and methods. For in vitro studies, pure substances of the drugs were used. The spectrophotometry was used to study the elution kinetics of the drugs. Absorption spectra of the drugs in the visible and ultraviolet regions were analyzed to reveal the absorption maxima, and the resistance of the chemical structure of the drugs to heating was assessed. Further, the changes of drug release from hardened bone cement samples under static conditions were studied.Results. It has been found that studied drugs demonstrated satisfactory parameters of thermal stability and elution which makes it possible to use them in a mixture with bone cement.Цель исследования: оценка элюционных характеристик противотуберкулезных препаратов (изониазид, циклосерин, рифампицин, амикацин, канамицин, этамбутол), загруженных в образцы костного цемента и помещенных в жидкую среду для определения возможности использования подобных систем в качестве депо препарата.Материалы и методы. Для исследования in vitro использовались химически чистые субстанции препаратов. Для изучения кинетики элюции препаратов применялся спектрофотометрический метод. Проведен анализ спектров поглощения препаратов в видимой и ультрафиолетовой области для выявления максимумов поглощения, и оценена устойчивость химической структуры препаратов к нагреванию. Далее изучена динамика выделения препаратов из образцов отвержденного костного цемента в статических условиях.Результаты. Получены удовлетворительные показатели термостабильности и элюции изучаемых препаратов, что позволяет использовать их в смеси с костным цементом