Collagen-based hydrogel functionalized with rhBMP-2

The study showed the cytocompatibility, matrix, and osteoinductive properties of collagen-fibronectin hydrogel impregnated with rhBMP-2. After 7 days of MSCs incubated with osteoplastic material the cell viability was 93.4 - 3.6%. Expression of osteoblast-related genes after 14 days was increased by 1.4-4.8 times. Furthermore alkaline phosphatase activity and calcium ion quantity in cell lysates were increased by 2 and 2.7 times. It was accompanied by extracellular matrix mineralization. The results indicate that rhBMP-2 fully retains its activity inside the collagen-based material. The use of rhBMP-2 at a concentration of 1 μg/ml was ineffective and unable to induce osteogenic differentiation of MSCs. An effective osteoinductive concentration of rhBMP-2 was determined as 10 μg/ml. © Published under licence by IOP Publishing Ltd

Osteogenic potential of multipotent mesenchymal stromal cells from human exfoliated deciduous teeth before and after cryopreservation

The use of multipotent mesenchymal stromal cellsfrom human exfoliated deciduous teeth (SHED) to stimulate bone regeneration requires data on the influence of cryopreservation on the osteogenic differentiation capacity of these cells. SHED were subjected to cryopreservation. Before freezing and after thawing, cell cultures were exposed osteogenic differentiation with vitamin D3 or dexametasone and assessed for expression of the osteogenic markers osteocalcin, alkaline phosphatase, BMP-2 and RunX2 using real-Time qPCR. Extracellular matrix (ECM) mineralization was evaluated by Alizarin red staining. Supplementation of osteogenic medium with vitamin D3 increased the expression of the osteogenic markers osteocalcin, alkaline phosphatase, BMP-2 and RunX2 as well as promoted an increase in the synthesis and mineralization of ECM in the cells both before and after cryopreservation. In the presence of vitamin D3 gene expression of alkaline phosphatase, BMP-2 and RunX2 after cryopreservation was higher than before freezing. Gene expression of osteocalcin, BMP2 RunX2 in osteogenic medium with vitamin D3was higher compared with dexamethasone for 14 days differentiation both before or after cryopreservation. The maintenance of SHED osteogenic differentiation potential after long-Term cryopreservation provides a basis for banking of these cellsfor further auto- or allotransplantation

Osteogenic potential of multipotent mesenchymal stromal cells from human exfoliated deciduous teeth before and after cryopreservation

The use of multipotent mesenchymal stromal cellsfrom human exfoliated deciduous teeth (SHED) to stimulate bone regeneration requires data on the influence of cryopreservation on the osteogenic differentiation capacity of these cells. SHED were subjected to cryopreservation. Before freezing and after thawing, cell cultures were exposed osteogenic differentiation with vitamin D3 or dexametasone and assessed for expression of the osteogenic markers osteocalcin, alkaline phosphatase, BMP-2 and RunX2 using real-Time qPCR. Extracellular matrix (ECM) mineralization was evaluated by Alizarin red staining. Supplementation of osteogenic medium with vitamin D3 increased the expression of the osteogenic markers osteocalcin, alkaline phosphatase, BMP-2 and RunX2 as well as promoted an increase in the synthesis and mineralization of ECM in the cells both before and after cryopreservation. In the presence of vitamin D3 gene expression of alkaline phosphatase, BMP-2 and RunX2 after cryopreservation was higher than before freezing. Gene expression of osteocalcin, BMP2 RunX2 in osteogenic medium with vitamin D3was higher compared with dexamethasone for 14 days differentiation both before or after cryopreservation. The maintenance of SHED osteogenic differentiation potential after long-Term cryopreservation provides a basis for banking of these cellsfor further auto- or allotransplantation

Comparative Analysis of the Paracrine Action of Neuronal and Glial Progenitor Cells Derived from Induced Human Pluripotent Stem Cells

We performed comparative analysis of paracrine activity of neuronal and glial progenitors derived from induced pluripotent stem cells under conditions of hypoxia modeled by addition of cobalt dichloride. Neuronal and glial progenitors produced neuroprotective and neurotrophic effects on SHSY-5Y neuroblastoma cells in co-culture during the post-hypoxic recovery and reduced the number of apoptotic and necrotic cells. Moreover, they produced a neurotrophic effect and promote the formation and growth of neurites in neuroblastoma cells. The paracrine effect of glial progenitors was more pronounced, which can be explained by more intensive expression and secretion of neurotrophic factors in these cells. © 2020, Springer Science+Business Media, LLC, part of Springer Nature

Сравнительный анализ паракринного действия нейрональных и глиальных предшественников, полученных из индуцированных плюрипотентных стволовых клеток человека

The article is focused on comparative analysis of the in vitro paracrine activity shown by the induced pluripotent stem cell-derived neuronal and glial progenitors and directed towards SHSY-5Y neuroblastoma cells during the recovery from hypoxic stress modeled by the exposure to cobalt dichloride. Co-cultivation with neuronal and glial progenitors exerted neuroprotective and neurotrophic effects on SHSY-5Y cells during the post-hypoxic recovery, reducing the number of apoptotic and necrotic cells and supporting neurite outgrowth. Moreover, the paracrine effect of glial progenitors was more pronounced compared to neuronal progenitors, which may be explained by a higher level of expression and secretion of neurotrophic factors by glial progenitors.Проведён сравнительный анализ паракринной активности нейрональных и глиальных предшественников, полученных из индуцированных плюрипотентных стволовых клеток, при моделировании гипоксии добавлением дихлорида кобальта. Сокультивирование с нейрональными и глиальными предшественниками оказывало нейропротективное действие на клетки нейробластомы SHSY-5Y, снижая количество апоптотических и некротических клеток в культуре. Кроме того, сокультивирование обеспечивало нейротрофический эффект, способствуя нейритогенезу в клетках линии SHSY-5Y. При этом паракринное влияние глиальных предшественников было более выраженным, что может объясняться более высоким уровнем экспрессии нейротрофических факторов в данных клетках

Development prospects of curable osteoplastic materials in dentistry and maxillofacial surgery

The article presents classification of the thermosetting materials for bone augmentation. The physical, mechanical, biological, and clinical properties of such materials are reviewed. There are two main types of curable osteoplastic materials: bone cements and hydrogels. Compared to hydrogels, bone cements have high strength features, but their biological properties are not ideal and must be improved. Hydrogels are biocompatible and closely mimic the extracellular matrix. They can be used as cytocompatible scaffolds for tissue engineering, as can protein- and nucleic acid–activated structures. Hydrogels may be impregnated with osteoinductors such as proteins and genetic vectors without conformational changes. However, the mechanical properties of hydrogels limit their use for load-bearing bone defects. Thus, improving the strength properties of hydrogels is one of the possible strategies to achieve the basis for an ideal osteoplastic material

Influence of the Degree of Deacetylation of Chitosan and BMP-2 Concentration on Biocompatibility and Osteogenic Properties of BMP-2/PLA Granule-Loaded Chitosan/β-Glycerophosphate Hydrogels

Compositions based on chitosan/β-glycerophosphate hydrogels with highly porous polylactide granules can be used to obtain moldable bone graft materials that have osteoinductive and osteoconductive properties. To eliminate the influence of such characteristics as chain length, degree of purification, and molecular weight on a designed material, the one-stock chitosan sample was reacetylated to degrees of deacetylation (DD%) of 19.5, 39, 49, 55, and 56. A study of the chitosan/β-glycerophosphate hydrogel with chitosan of a reduced DD% showed that a low degree of deacetylation increased the MSCs (multipotent stromal cells) viability rate in vitro and reduced the leukocyte infiltration in subcutaneous implantation to Wistar rats in vivo. The addition of 12 wt% polylactide granules resulted in optimal composite mechanical and moldable properties, and increased the modulus of elasticity of the hydrogel-based material by approximately 100 times. Excessive filling of the material with PLA (polylactide) granules (more than 20%) led to material destruction at a ~10% strain. Osteoinductive and osteoconductive properties of the chitosan hydrogel-based material with reacetylated chitosan (39 DD%) and highly porous polylactide granules impregnated with BMP-2 (bone morphogenetic protein-2) have been demonstrated in models of orthotopic and ectopic bone formation. When implanted into a critical-size calvarial defect in rats, the optimal concentration of BMP-2 was 10 μg/mL: bone tissue areas filled the entire material's thickness. Implantation of the material with 50 μg/mL BMP-2 was accompanied with excessive growth of bone tissue and material displacement beyond the defect. Significant osteoinductive and osteoconductive properties of the material with 10 μg/mL of BMP-2 were also shown in subcutaneous implantation

Comparative impact analysis of neuronal and glial progenitors conditioned medium on cerebellar neurons under glutamate exitotoxicity

One of the main causes of cell death in neurodegenerative diseases is excitotoxicity. Today the potential directions of treatment neurodegenerative diseases are including cell therapy, the purpose of which is to replace lost nerve tissue with donor cells. Transplanted cells along with replaced lost tissues have a paracrine effect, which requires careful study. The aim of this work was to study the effect of conditioned media, obtaining from neuronal and glial progenitor cells, on a primary culture of cerebellar neurons in a model of glutamate excitotoxicity. The cell viability, expression of marker genes for apoptosis and neuritogenesis, and the number of necrotic and apoptotic cells were determined in the culture of cerebellar neurons. The composition of the studied conditioned media was analyzed for the content of neurotrophins. A comparative analysis was revealed differences in the secretion of neurotrophins between the obtained cultures: the amount of brain-derived neurotrophic factor, nerve growth factor, ciliary neurotrophic factor and glial neurotrophic factor was higher in the secretion of glial progenitors. It was shown that the addition of conditioned media from neuronal cells does not significantly affect the viability of cerebellar neurons, whereas preincubation with media from glial progenitors has a neuroprotective effect by increasing the viability of cerebellar neurons, and during long-term cultivation promotes the growth of neurites by increasing the expression level of MAP2 and GAP43 genes. © 2019, Human Stem Cell Institute. All rights reserved