Dendritic Polyglycerol Amine: An Enhanced Substrate to Support Long-Term Neural Cell Culture

Long-term stable cell culture is a critical tool to better understand cell function. Most adherent cell culture models require a polymer substrate coating of poly-lysine or poly-ornithine for the cells to adhere and survive. However, polypeptide-based substrates are degraded by proteolysis and it remains a challenge to maintain healthy cell cultures for extended periods of time. Here, we report the development of an enhanced cell culture substrate based on a coating of dendritic polyglycerol amine (dPGA), a non-protein macromolecular biomimetic of poly-lysine, to promote the adhesion and survival of neurons in cell culture. We show that this new polymer coating provides enhanced survival, differentiation and long-term stability for cultures of primary neurons or neurons derived from human induced pluripotent stem cells (hiPSCs). Atomic force microscopy analysis provides evidence that greater nanoscale roughness contributes to the enhanced capacity of dPGA-coated surfaces to support cells in culture. We conclude that dPGA is a cytocompatible, functionally superior, easy to use, low cost and highly stable alternative to poly-cationic polymer cell culture substrate coatings such as poly-lysine and poly-ornithine. Summary statement Here, we describe a novel dendritic polyglycerol amine-based substrate coating, demonstrating superior performance compared to current polymer coatings for long-term culture of primary neurons and neurons derived from induced pluripotent stem cells.

Propagating acoustic waves on a culture substrate regulate the directional collective cell migration

Collective cell migration plays a critical role in physiological and pathological processes such as development, wound healing, and metastasis. Numerous studies have demonstrated how various types of chemical, mechanical, and electrical cues dictate the collective migratory behaviors of cells. Although an acoustic cue can be advantageous because of its noninvasiveness and biocompatibility, cell migration in response to acoustic stimulation remains poorly understood. In this study, we developed a device that is able to apply surface acoustic waves to a cell culture substrate and investigated the effect of propagating acoustic waves on collective cell migration. The migration distance estimated at various wave intensities revealed that unidirectional cell migration was enhanced at a critical wave intensity and that it was suppressed as the intensity was further increased. The increased migration might be attributable to cell orientation alignment along the direction of the propagating wave, as characterized by nucleus shape. Thicker actin bundles indicative of a high traction force were observed in cells subjected to propagating acoustic waves at the critical intensity. Our device and technique can be useful for regulating cellular functions associated with cell migration.

Features of forming plants hybrids of tomato indeterminant type in spring greenhouses in southern Russia

Совершенствование технологий выращивания томата в весенних теплицах сопровождается изменением сортимента культуры. Все большее распространение получают гибриды индетерминантного типа. Основной целью исследований было изучение различных способов формировки растений гибридов томата с индетерминантным типом роста в весенних теплицах. Исследования проводили в 2018-2020 годах в Селекционно-семеноводческом центре «Ростовский» компании «Поиск», расположенном в Ростовской области. Материалом исследований служили гибриды томата с индетерминантным типом роста собственной селекции F1Армада, F1 Пегас, F1 Огневский и F1 Розовый фрегат. Опыты проводили в необогреваемых весенних теплицах ангарного типа с поликарбонатным светопрозрачным покрытием в грунтовой культуре. Почвогрунт – чернозем обыкновенный. Содержание основных элементов питания – высокое, рН почвенного раствора 7,0-7,2. Схема посадки растений 70×30 см, по 10 растений каждого варианта в четырехкратной повторности. Рассаду выращивали в разводочной теплице с пикировкой в пластиковые контейнеры. Возраст рассады перед высадкой – 55 дней. Рассаду высаживали в последней декаде апреля. Использовали общепринятые приемы ухода за растениями. Для полива и подкормок применяли капельную систему с фертигацией. Урожай убирали в несколько приемов по мере созревания плодов. Исследования показали, что формировка растений влияет на высоту растений и их облиственность. С увеличением количества оставленных побегов высота растений снижается, а площадь листовой поверхности увеличивается. Увеличение количества оставленных побегов приводит к возрастанию общего количества кистей на растении, но количество плодов, сформировавшихся в кисти, снижается, как и средняя масса плода на растении. Наиболее высокая продуктивность растений и их урожайность с единицы площади достигается при формировке в два стебля. И это характерно для всех гибридов вне зависимости от индивидуальных особенностей роста и развития. Improving the technology of growing tomatoes in spring greenhouses is accompanied by a change in the variety of crop. Hybrids of the indeterminant type are becoming more common. The main purpose of the research was to study different ways of forming plants of tomato hybrids with an indeterminant type of growth in spring greenhouses. The research was carried out in 2018-2020 at the Breeding Center in the Rostov region. The material for the research was tomato hybrids with an indeterminant type of growth of its own breeding F1 Armada, F1Pegas, F1 Ognevskiy and F1 Rozovy Fregat. Experiments were conducted in unheated spring greenhouses of hangar type with polycarbonate translucent coating in the soil culture. Substrate is ordinary black earth. The contents of the main elements of food - high, pH soil solution 7.0-7.2. Plant planting scheme 70×30 cm, 10 plants of each variant in four-fold. A fertigation drip system was used for watering and feeding. Harvest was carried out in several receptions as the fruit matured. Studies have shown that the formation of plants affects the height of plants and their obliging. As the number of shoots left, the height of the plants decreases and the area of the leaf surface increases. The increase in the number of abandoned shoots leads to an increase in the total number of brushes on the plant, but the number of fruits formed in the brush, decreases, as well as the average mass of the fruit on the plant. The highest productivity of plants and their yield from a unit of area is achieved when formed in 2 stems. And this is typical for all hybrids, regardless of individual features of growth and development.

Induction of Anisotropic Orientation and Enhancement of Gene Functional Expression of Human Pluripotent Stem Cell-Derived Cardiomyocytes Cultured on Nanofabricated Substrates Consisting of Micron Planar Lines and Nano Dot Structures.

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs) are expected to have applications in the fields of regenerative medicine and drug discovery. However, the immaturity of hiPS-CMs is an issue to be considered, and in order to replicate in vivo responsivity, there have been several attempts to induce maturation in hiPS-CMs, including methods to induce differentiation of hiPS-CMs by changing culture medium and culture substrate. In particular, anisotropic culture, in which the cultured cells are aligned in one direction, induces the cellular morphology resembling that of in vivo cardiomyocytes and is expected to be a useful method for maturation of hiPS-CMs. We tried forming a nanostructure on the surface of the cell culture substrate using our original nanofabrication technology, with the aim of aligning cardiomyocytes and inducing maturation. Our newly developed nanostructure for anisotropic culture (line/dot structure) comprises a region of cone-shaped nanopillars with pitch distance of several hundred nm and a planar region, alternating in a striped pattern with intervals of several tens of µm, arranged on the surface of the cell culture substrate. The hiPS-CMs cultured using the line/dot structure showed anisotropic orientation, and increased mRNA expression was observed in myocardial structural protein genes, genes relating to ion channels, and the gene for Cx43. These results suggest that the line/dot nanostructure is effective for anisotropic culture and cell maturation of hiPS-CMs.