Surface Functionalization and Patterning by Multifunctional Resorcinarenes

Plant phenolic compounds and catecholamines have been widely used to obtain substrate-independent precursor nanocoatings and adhesives. Nevertheless, there are downsides in using such phenolic compounds for surface modification such as formation of nonuniform coatings, need for multistep modification, and restricted possibilities for postfunctionalization. In this study, inspired by a strong binding ability of natural polyphenols found in plants, we used three different macrocyclic polyphenols, known as resorcin[4]­arenes, to modify the surface of different substrates by simple dip-coating into the dilute solution of these compounds. Eight hydroxyl groups on the large rim of these resorcin[4]­arenes provide multiple anchoring points to the surface, whereas the lower rim decorated with different appending groups introduces the desired chemical and physical functionalities to the substrate’s surface. Deposition of a uniform and transparent resorcinarene layer on the surface was confirmed by several surface characterization techniques. Incubation of the modified substrates in different environments indicated that the stability of the resorcinarene layer was dependent on the type of substrate and the pH value. The most stable resorcinarene layer was formed on amine-functionalized substrates. The surface was modified with alkenyl functional groups in one step using a resorcinarene compound possessing four alkenyl appending groups on its small rim. Thiol–ene photoclick chemistry was used to site-selectively postfunctionalize the surface with hydrophilic and hydrophobic micropatterns, which was confirmed by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. Thus, we demonstrate that resorcin[4]­arenes extend the scope of applications of plant polyphenol and mussel-inspired precursors to tailor-made multifunctional nanocoatings, suitable for a variety of potential applications in biotechnology, biology, and material science

High-throughput screening of multifunctional nanocoatings based on combinations of polyphenols and catecholamines

Biomimetic surface coatings based on plant polyphenols and catecholamines have been used broadly in a variety of applications. However, the lack of a rational cost-effective platform for screening these coatings and their properties limits the true potential of these functional materials to be unleashed. Here, we investigated the oxidation behavior and coating formation ability of a library consisting of 45 phenolic compounds and catecholamines. UV–vis spectroscopy demonstrated significant acceleration of oxidation and polymerization under UV irradiation. We discovered that several binary mixtures resulted in non-additive behavior (synergistic or antagonistic effect) yielding much thicker or thinner coatings than individual compounds measured by ellipsometry. To investigate the properties of coatings derived from new combinations, we used a miniaturized high-throughput strategy to screen 2,532 spots coated with single, binary, and ternary combinations of coating precursors in one run. We evaluated the use of machine learning models to learn the relation between the chemical structure of the precursors and the thickness of the nanocoatings. Formation and stability of nanocoatings were investigated in a high-throughput manner via discontinuous dewetting. 30 stable combinations (hits) were used to tune the surface wettability and to form water droplet microarray and spot size gradients of water droplets on the coated surface. No toxicity was observed against eukaryotic HeLa cells and Pseudomonas aeruginosa (strain PA30) bacteria after 24 h incubation at 37 °C. The strategy introduced here for high-throughput screening of nanocoatings derived from combinations of coating precursors enables the discovery of new functional materials for various applications in science and technology in a cost-effective miniaturized manner

ФЛУОРЕСЦЕНТНАЯ ДИАГНОСТИКА И ФОТОДИНАМИЧЕСКАЯ ТЕРАПИЯ В КОМБИНИРОВАННОМ ЛЕЧЕНИИ ХОЛАНГИОЦЕЛЛЮЛЯРНОГО РАКА

The results of the pilot study of combined treatment for non-resectable cholangiocarcinoma complicated with obstructive jaundice are represented this paper. Method included percutaneous transhepatic biliary drainage, endoscopic fluorescence diagnosis, photodynamic therapy of tumor stricture, and stenting of bile ducts. Fourteen patients who underwent the treatment in the surgery department clinic of I.M. Sechenov First Moscow State Medical University were enrolled in the study. Fluorescence diagnosis and photodynamic therapy were carried out using photosensitizers photosens (0.5 mg/kg), fotolon (1 mg/kg), and radachlorin (1 mg/kg). The average light dose for one session was 115±5 J/cm2. Fluorescence diagnosis using endoscopic video-fluorescence system for endoscopy and minimally invasive surgery allowed to obtain videoassisted fluorescence image of the tumor and to measure level of photosensitizer fluorescence in tumor in all patients. Malignant tumor was confirmed by morphological study in 12 patients, biopsy of material for morphological study failed in 2 patients with Klatskin tumor. The preliminary results of combined minimally invasive treatment were assessed as promising. The survival time in 4 patients after treatment accounted for 21, 17, 13 and 11 months, respectively. For now 5 patients are under follow-up. Follow-up periods are 13 and 19 months in 2 of them and from 4 to 6 months in 3 of them. Five patients with multiple distant metastases before the treatment died in 3±1 months after therapy. The average lifetime in the treatment group is 9.5 months up to date, however the duration is expected to belonger because 5 of 14 patients are alive.В статье представлены результаты пилотного исследования по применению комбинированного лечения нерезектабельной холанги-окарциномы, осложненной механической желтухой. Метод включал в себя чрескожное чреспеченочное желчеотведение, эндовидеофлуоресцентную диагностику, фотодинамическую терапию опухолевой стрикутры и стентирование желчных протоков. В исследование были включены 14 пациентов, находящихся на лечении в клинике факультетской хирургии имени Н.Н. Бурденко Первого Московского государственного медицинского университета им. И.М. Сеченова. Флуоресцентную диагностику и фотодинамическую терапию проводили с применением фотосенсибилизаторов фотосенс (0,5 мг/кг), фотолон (1,0 мг/кг) и радахлорин (1,0 мг/кг). Средняя доза лазерного облучения за один сеанс составила 115±5 Дж/см2. Флуоресцентная диагностика с использованием эндовидеофлуоресцентного модуля для эндоскопии и минимальноинвазивной хирургии позволила получить видеофлуоресцентное изображение опухоли и оценить уровень флуоресценции фотосенсибилизатора в опухоли у всех пациентов. Морфологически злокачественный процесс подтвержден у 12 пациентов, у 2 пациентов с опухолью Клатскина не удалось забрать материал из желчных протоков для морфологического исследования. Первоначальные результаты применения комбинированного минимальноинвазивного лечения оценены, как обнадеживающие. У 4 пациентов продолжительность жизни после лечения составила 21, 17, 13 и 11 мес. 5 пациентов находятся в настоящее время под динамическим наблюдением. Из них 2 наблюдаются со сроком 13 и 19 мес, и 3 – от 4 до 6 мес. 5 больных, которые изначально имели множественные отдаленные метастазы, умерли в течение 3±1 мес после проведенного лечения. Средняя продолжительность жизни у пролеченной группы пациентов составляет на данный момент 9,5 мес, но следует ожидать ее повышения вследствие того, что 5 из 14 больных в настоящий момент живы

МАТЕРИАЛЫ ДЛЯ ДИССКУСИОННОЙ ПЛОЩАДКИ

.Вопросы лля обсуждения:Выскажите свое мнение о состоянии образовательного менеджмента в России на сегодняшний день.Определите наиболее слабые места в процессе управления развития образованием.Определите сильные стороны политики в области образования на сегодняшний день

Formation of a polymer surface with a gradient of pore size using a microfluidic chip

Here we demonstrate the generation of polymer monolithic surfaces possessing a gradient of pore and polymer globule sizes from ∼0.1 to ∼0.5 μm defined by the composition of two polymerization mixtures injected into a microfluidic chip. To generate the gradient, we used a PDMS microfluidic chip with a cascade micromixer with a subsequent reaction chamber for the formation of a continuous gradient film. The micromixer has zigzag channels of 400 × 680 μm2 cross section and six cascades. The chip was used with a reversible bonding connection, realized by curing agent coating. After polymerization in the microfluidic chip the reversible bond was opened, resulting in a 450 μm thick polymer film possessing the pore size gradient. The gradient formation in the microfluidic reaction chamber was studied using microscopic laser-induced fluorescence (μLIF) and different model fluids. Formation of linear gradients was shown using the fluids of the same density by both diffusive mixing at flow rates of 0.001 mL/min and in a convective mixing regime at flow rates of 20 mL/min. By using different density fluids, formation of a two-dimensional wedge-like gradient controlled by the density difference and orientation of the microfluidic chip was observed. © 2013 American Chemical Society

Intraoperative Control of Hemoglobin Oxygen Saturation in the Intestinal Wall during Anastomosis Surgery

During surgery for colon cancer, monitoring of the oxygen saturation of hemoglobin in the tissues under study makes it possible to assess the degree of blood supply to the anastomosis areas of the colon. Adequate blood supply in this area is decisive in terms of the consistency of the anastomosis and can significantly reduce the risk leakage of anastomosis. In this work, we propose a new approach to assessing the hemoglobin oxygen saturation based on measuring both the diffuse reflectance and transmittance spectra of the colon wall tissues. The proposed method is based on the use of two fiber-optic tools for irradiation from both sides—the intestinal lumen and the outside of the intestinal wall. The spectra are recorded from the external side. To determine the degree of hemoglobin saturation, two algorithms, both based on the Taylor series expansion of the coefficient of light attenuation by tissues, are proposed. The results of a clinical study of the proposed approach on volunteers were obtained, allowing to draw a conclusion about the applicability of the approach in a clinical setting

Fabrication of quasi-2D shape-tailored microparticles using wettability contrast-based platforms

The ability to fabricate materials with ultrathin architectures enables the breakthrough of low-dimensional structures with high surface area that showcase distinctive properties from their bulk counterparts. They are exploited in a wide range of fields, including energy harvesting, catalysis, and biomedicine. Despite such versatility, the fine tuning of the lateral dimensions and geometry of these structures remains challenging. Prepatterned platforms gain significant attention as enabling technologies to process materials with highly controlled shapes and dimensions. Herein, different nanometer-thick particles of various lateral sizes and geometries (e.g., squares, circles, triangles, hexagons) are processed with high precision and definition, taking advantage of the wettability contrast of oleophilic-oleophobic patterned surfaces. Quasi-2D polymeric microparticles with high shape- and size-fidelity can be retrieved as freestanding objects in a single step. These structures show cell-mediated pliability, and their integration in gravity-enforced human adipose-derived stem cell spheroids leads to an enhanced metabolic activity and a modulated secretion of proangiogenic factors.publishe

FLUORESCENCE DIAGNOSIS AND PHOTODYNAMIC THERAPY IN COMBINED TREATMENT OF CHOLANGIOCARCINOMA

The results of the pilot study of combined treatment for non-resectable cholangiocarcinoma complicated with obstructive jaundice are represented this paper. Method included percutaneous transhepatic biliary drainage, endoscopic fluorescence diagnosis, photodynamic therapy of tumor stricture, and stenting of bile ducts. Fourteen patients who underwent the treatment in the surgery department clinic of I.M. Sechenov First Moscow State Medical University were enrolled in the study. Fluorescence diagnosis and photodynamic therapy were carried out using photosensitizers photosens (0.5 mg/kg), fotolon (1 mg/kg), and radachlorin (1 mg/kg). The average light dose for one session was 115±5 J/cm2. Fluorescence diagnosis using endoscopic video-fluorescence system for endoscopy and minimally invasive surgery allowed to obtain videoassisted fluorescence image of the tumor and to measure level of photosensitizer fluorescence in tumor in all patients. Malignant tumor was confirmed by morphological study in 12 patients, biopsy of material for morphological study failed in 2 patients with Klatskin tumor. The preliminary results of combined minimally invasive treatment were assessed as promising. The survival time in 4 patients after treatment accounted for 21, 17, 13 and 11 months, respectively. For now 5 patients are under follow-up. Follow-up periods are 13 and 19 months in 2 of them and from 4 to 6 months in 3 of them. Five patients with multiple distant metastases before the treatment died in 3±1 months after therapy. The average lifetime in the treatment group is 9.5 months up to date, however the duration is expected to belonger because 5 of 14 patients are alive