We have designed a novel two-component matrix (SPRPix) for the encapsulation of directly reprogrammed human neural precursor cells (drNPC). The matrix is comprised of 1) a solid anisotropic complex ...scaffold prepared by electrospinning a mixture of recombinant analogues of the spider dragline silk proteins - spidroin 1 (rS1/9) and spidroin 2 (rS2/12) - and polycaprolactone (PCL) (rSS-PCL), and 2) a "liquid matrix" based on platelet-rich plasma (PRP). The combination of PRP and spidroin promoted drNPC proliferation with the formation of neural tissue organoids and dramatically activated neurogenesis. Differentiation of drNPCs generated large numbers of βIII-tubulin and MAP2 positive neurons as well as some GFAP-positive astrocytes, which likely had a neuronal supporting function. Interestingly the SPRPix microfibrils appeared to provide strong guidance cues as the differentiating neurons oriented their processes parallel to them. Implantation of the SPRPix matrix containing human drNPC into the brain and spinal cord of two healthy Rhesus macaque monkeys showed good biocompatibility: no astroglial and microglial reaction was present around the implanted construct. Importantly, the human drNPCs survived for the 3 month study period and differentiated into MAP2 positive neurons. Tissue engineered constructs based on SPRPix exhibits important attributes that warrant further examination in spinal cord injury treatment.
Exposure of cells or biological tissues to high-power pulses of terahertz (THz) radiation leads to changes in a variety of intracellular processes. However, the role of heating effects due to strong ...absorption of THz radiation by water molecules still stays unclear. In this study, we performed numerical modelling in order to estimate the thermal impact on water of a single THz pulse as well as a series of THz pulses. A finite-element (FE) model that provides numerical solutions for the heat conduction equation is employed to compute the temperature increase. A simple expression for temperature estimation in the center of the spot of THz radiation is presented for given frequency and fluence of the THz pulse. It has been demonstrated that thermal effect is determined by either the average power of radiation or by the fluence of a single THz pulse depending on pulse repetition rate. Human dermal fibroblasts have been exposed to THz pulses (with an energy of Formula: see text and repetition rate of 100 Hz) to estimate the thermal effect. Analysis of heat shock proteins expression has demonstrated no statistically significant difference (Formula: see text) between control and experimental groups after 3 h of irradiation.
Upgrade of the monitoring system of LHCb ECAL Guz, Yu; Konoplyannikov, A.; Perret, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2018, Letnik:
912
Journal Article
Recenzirano
Odprti dostop
In order to improve the stability of the LHCb ECAL monitoring system, the light guides transporting LED light to PMTs have been replaced by radiation hard quartz fibers. The behavior of transparency ...of the selected fibers under moderate radiation doses, up to few kGy, was studied in detail. The performance of the upgraded version of the LHCb ECAL monitoring system is also discussed.
•Transparency variations of quartz fibers at moderate radiation doses studied in detail.•The ECAL monitoring system light guides replaced to radiation hard quartz ones.•Performance of the upgraded monitoring system was studied and found satisfactory.
For the first time, the data have been obtained on the effects of high-intensity terahertz (THz) radiation (with the intensity of 30 GW/cm
, electric field strength of 3.5 MV/cm) on human skin ...fibroblasts. A quantitative estimation of the number of histone Н2АХ foci of phosphorylation was performed. The number of foci per cell was studied depending on the irradiation time, as well as on the THz pulse energy. The performed studies have shown that the appearance of the foci is not related to either the oxidative stress (the cells preserve their morphology, cytoskeleton structure, and the reactive oxygen species content does not exceed the control values), or the thermal effect of THz radiation. The prolonged irradiation of fibroblasts also did not result in a decrease of their proliferative index.
Hepatitis C virus (HCV) is one of the basic culprits behind chronic liver disease, which may result in cirrhosis and hepatocarcinoma. In spite of the extensive research conducted, a vaccine against ...HCV has not been yet created. We have obtained human mesenchymal stem cells (hMSCs) and used them for expressing the HCV NS5A protein as a model vaccination platform. Sixteen hMSC lines of a different origin were transfected with the pcNS5A-GFP plasmid to obtain genetically modified MSCs (mMSCs). The highest efficiency was obtained by the transfection of dental pulp MSCs. C57BL/6 mice were immunized intravenously with mMSCs, and the immune response was compared with the response to the pcNS5A-GFP plasmid, which was injected intramuscularly. It was shown that the antigen-specific lymphocyte proliferation and the number of IFN-γ-synthesizing cells were two to three times higher after the mMSC immunization compared to the DNA immunization. In addition, mMSCs induced more CD4+ memory T cells and an increase in the CD4+/CD8+ ratio. The results suggest that the immunostimulatory effect of mMSCs is associated with the switch of MSCs to the pro-inflammatory phenotype and a decrease in the proportion of myeloid derived suppressor cells. Thus, the possibility of using human mMSCs for the creation of a vaccine against HCV has been shown for the first time.
The interaction of neural progenitor cells (NPCs) with the extracellular matrix (ECM) plays an important role in neural tissue regeneration. Understanding which motifs of the ECM proteins are crucial ...for normal NPC adhesion, proliferation, and differentiation is important in order to create more adequate tissue engineered models of neural tissue and to efficiently study the central nervous system regeneration mechanisms. We have shown earlier that anisotropic matrices prepared from a mixture of recombinant dragline silk proteins, such as spidroin 1 and spidroin 2, by electrospinning are biocompatible with NPCs and provide good proliferation and oriented growth of neurites. This study objective was to find the effects of spidroin-based electrospun materials, modified with peptide motifs of the extracellular matrix proteins (RGD, IKVAV, and VAEIDGIEL) on adhesion, proliferation, and differentiation of directly reprogrammed neural precursor cells (drNPCs). The structural and biomechanical studies have shown that spidroin-based electrospun mats (SBEM), modified with ECM peptides, are characterized by a uniaxial orientation and elastic moduli in the swollen state, comparable to those of the dura mater. It has been found for the first time that drNPCs on SBEM mostly preserve their stemness in the growth medium and even in the differentiation medium with brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor, while addition of the mentioned ECM-peptide motifs may shift the balance toward neuroglial differentiation. We have demonstrated that the RGD motif promotes formation of a lower number of neurons with longer neurites, while the IKVAV motif is characterized by formation of a greater number of NF200-positive neurons with shorter neurites. At the same time, all the studied matrices preserve up to 30% of neuroglial progenitor cells, phenotypically similar to radial glia derived from the subventricular zone. We believe that, by using this approach and modifying spidroin by various ECM-motifs or other substances, one may create an in vitro model for the neuroglial stem cell niche with the potential control of their differentiation.
Background: Amputation of the lower extremities is a necessary procedure to save a patient with critical arterial and neurotrophic disorders in the lower extremities. The amputation stump-related ...complications develop in many patients with diabetes mellitus (up to 40% of the total population).
Clinical case description: Patient Yu., 64 years old, was admitted on October 19, 21 for an outpatient treatment of purulent-necrotic wounds of the amputation stump of the right lower limb. А high amputation was performed on September 24, 2021 due to thrombosis of the femoral-tibial bypass, installed on September 08, 2021 (bypassing below the knee joint gap with a Vascutek 7 mm synthetic prosthesis on the right) and the development of critical ischemia of the right lower limb with necrosis of the distal phalanges of the right foot toes. The wound was assessed according to the Bates-Jensen scale (BJ) and examined according to the developed protocol. The wound treatment was carried out according to an individual plan using a conditioned culture medium from mesenchymal stem cells (CM-MSCs), which stimulates angiogenesis and improves remodeling and recovery in the wound area. CM-MSC application made it possible to reduce the healing time and achieve a scarless closure of the tissue defect.
Conclusion: The use of CM-MSC can be an effective method for healing a purulent-necrotic postoperative wound resulting from amputation of a limb in patients with critical ischemia of the lower extremities.
A42 Yuzhakov, V; Sevankaeva, L; Konoplyannikov, M ...
European journal of cancer supplements,
11/2015, Letnik:
13, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The mechanisms of mesenchymal stem cells (MSC) action on malignant neoplasms attract much attention nowadays. Studies relating to the MSC effect on tumors are contradictory and indicate that MSC has ...both stimulating and suppressive actions on experimental neoplasms. We have shown previously that a single MSC administration to tumor-bearing animals has an oncomodulating effect on the growth of tumors. Short-term stimulation of the growth of tumor nodes initially after the MSC injection was usually followed by subsequent deceleration of their growth. Here, we have studied the effects of allogeneic MSC on sarcoma M-1 in rats. On day 11 after the sarcoma M-1 implantation, 1.5 million MSC grown from the bone marrow cell population of Wistar rats was administered into the tail vein of outbred rats from the experimental group. On days 17 and 30 of the tumors growth, 10 rats from each group were used to study the sarcoma M-1. To analyze the MSC distribution and localization in the tumor parenchyma, on days 11 and 13, five rats in the study were intravenously infused 2 million MSC, labeled in vitro by bromodeoxyuridine (BrdU). The techniques for studying of the tumor reaction on the systemic MSC transplantation included immunostaining for PCNA, BrdU and PECAM-1, in conjunction with computerized analysis of the microscopic images. One day after transplantation, the BrdU-labeled MSC localized in the perivascular areas of angiogenesis on the periphery of tumor nodes with the diameter of more than 6 mm, containing foci of spontaneous necrosis. Sometimes, labeled cells could be seen near the vessels situated deep in the tumor parenchyma. On day 3, cells with the low-intense BrdU immunostaining were found only rarely and mostly perivascularly. These cells were visualized in the region of pericytes’ localization, and the low BrdU-immunostaining intensity of their nuclei indicated the label dilution effect. Six days after the MSC administration, some local areas of the connective tissue enlargements on the periphery of tumor nodes were observed with a distinct vascular ingrowth into the tumor parenchyma. In the same areas, the marginal region of tumor nodes contained a considerable number of neutrophils and lymphocytes. The PCNA staining revealed foci of increased proliferative activity of tumor cells in these areas, as well as intensive proliferation of fibroblasts and vascular endothelium, which indicates the increase of angiogenesis and stroma formation. After the MSC administration the content of parenchyma with PCNA-positive nuclei significantly increased, whereas the volume fraction of the necrosis regions decreased by more than 1.5 times. On day 30 of the sarcoma M-1 growth, tumors in the experimental group rats were surrounded by layers of connective tissue. The peritumoral area was infiltrated by numerous lymphocytes and macrophages. In the terminal period of the sarcoma growth, the most quantitative parameters for tumors in the experimental group did not significantly differ from the data obtained in the control group. Only the rate of tumor cell apoptosis in animals with transplanted MSC was statistically higher than that in control rats. Reviewing the literature regarding the influence of MSC on the malignant growth revealed that this problem still remains quite unclear and disputable. One of the contradictions is their ability to have opposite effects on the repopulation activity of tumor cells. The complex interactions between MSC, tumor microenvironment and neoplastic cells seem to be crucial for the outcome of the oncological process development. Further detailed studies of the mechanisms of the cellular therapy using MSC on carcinogenesis are necessary to generate new insights into this area.
Background: Transplantation of mesenchymal stem cells (MSCs) is one of the most promising directions in the treatment of idiopathic pulmonary fibrosis. In experimental small animal studies, ...intravenous and endobronchial (installation) techniques are used for the cell preparation delivery, while in humans inhalation of drugs is the simplest and most available method.
Aim: The aim of the study was to determine the optimal type of a nebulizer for viability of MSCs during nebulization, followed by a comparison of the effects of inhalation and intravenous delivery methods in a standard model of bleomycin pulmonary fibrosis in rabbits.
Methods: At the first stage, the survival of MSCs was assessed ex vivo after 10 minutes of compressor, ultrasound and mesh nebulization. Subsequently we used a nebulizer, which showed the best result in the cells, viability. At the next stage аfter bronchoscopic installation of bleomycin, 5 rabbits received intravenous transplantation of 2×106 allogeneic BMMSCs, other 5 rabbits — 2×107 MSCs inhaled via a compressor nebulizer; the control healthy and bleomycin groups included 5 animals each.
Results: The highest degree of viability of MSC was maintained after passing via the compressor nebulizer (72%), a significantly lower survival rate was observed in ultrasonic nebulization (20%) and no live cells were detected after mesh nebulization. Both groups treated with MSC had a significantly lower fibrosis index on the Ashcroft morphometric scale than the control group of bleomycin fibrosis. Collagen expression in the lung tissue was significantly higher in all the groups with bleomycin injury, but in animals which underwent MSC inhalation, it was significantly different (0.51 point) from the bleomycin group without treatment (2.1 points). The level of neutrophils in the BAL fluid was significantly lower in animals which received the intravenous MSC therapy. The levels of TNF-α and TGF-β1 in the BAL fluids tended to decrease in the treatment groups, but did not differ significantly from control.
Conclusions: The highest survival rate of MSCs is observed when using a compressor nebulizer, which apparently should be considered as the best way for delivering cells to the respiratory tract. Both inhalation and intravenous administration of MSCs cause similar effects of inhibiting the development of bleomycin-induced pulmonary fibrosis, which indicates the possibility of using both ways of cell delivery without loss of effectiveness.
To compare the effectiveness of the effect of combination therapy (local and systemic administration) with bone marrow mesenchymal stromal cells (MSC), anticlitokine therapy with infliximab (IFX), ...and antibiotic (AB)/immunosuppressive (IS) therapy on the frequency of healing of simple perianal fistulas in Crohn's disease.
In our study, the 1-st group of patients aged 19 to 58 years (Me-29) (n = 12) received MSCs culture systemically according to the scheme and locally. The 2-nd group of patients with CD (n = 10) from 20 to 68 years old (Me-36) received anticytokine therapy with infliximab (IFX) according to the scheme. The 3-d group of patients with CD (n=14) from 20 to 62 years old (Me-28) received antibiotics (AB) and immunosuppressors (IS). Efficacy was assessed by the index of perianal activity of Crohn's disease (PCDAI) and the frequency of relapses.
After 12 weeks among patients of the 1-st group, healing of simple fistulas was noted in 8/12 patients (66.6%), in the 2-nd group in 6/10 (60.0%) In the 3-d group, in 1/14 patients (7.14%). After 6 months in the 1-st group of patients, healing of simple fistulas was preserved in 8/12 (66.6%), in the 2-nd group - in 6/10 (60.0%). In the 3-d group - in 1/14 patients (7.14%). After 12 months in the 1-st group, healing of simple fistulas was preserved in 7/12 (58.3%), in the second group - in 6/10 (60.0%). In the 3-d group - in 2/14 patients (14.3%). After 24 months, among the patients of the 1-st group, fistula closure was maintained in 5/12 patients (41.6%), in the 2-nd group - in 4/10 (40.0%). In the 3-d group - in 0/14 patients (0.0%).
Combined cellular and anticytokine therapy of CD with perianal lesions significantly contributes to the more frequent and prolonged closure of simple fistulas, as compared to antibiotics/immunosuppressors, and to a decrease in the frequency of recurrence of the disease.
PDF
