In vitro and in vivo study on the osseointegration of magnesium and strontium ion with two different proportions of mineralized collagen and its mechanism

2021 ◽  
pp. 088532822110169
Author(s):  
Yi Sun ◽  
Hai Liu ◽  
Xiao-Yu Sun ◽  
Wen Xia ◽  
Chao Deng
Keyword(s):  
Signaling Pathway ◽  
Laser Scanning ◽  
Critical Role ◽  
Laser Scanning Microscopy ◽  
Female Rats ◽  
Confocal Laser ◽  
Complete Medium ◽  
Strontium Ion ◽  
Impregnation Solution ◽  
Mineralized Collagen

To explore the optimal combination of Mg2+, Sr2+ and mineralized collagen (nHAC) with two different proportions of hydroxyapatite (HA) and collagen (COL) on differentiation of MC3T3-E1 and the underlying mechanism, as well as achieve bone osseointegration. MC3T3-E1 cells were cultured in a complete medium with Mg2+ at the concentration of 0, 4, 8, 12, 16, 20 mmol/L, Sr2+ at the concentration of 0, 3, 6, 12 mmol/L, and the impregnation solution of 3:7 and 5:5nHAC. The differentiation of MC3T3-E1 was measured by expression of osteogenic genes and proteins including Runx-2, BMP-2 and OCN and determined the activation of PI3K/AKT/GSK3β/β-catenin signaling pathway in 12 mmol/LMg 2 ++3 mmol/LSr 2 ++3:7nHAC group. Osteoporosis was induced in 18 female rats by means of ovariectomy, the implants were immersed in 60 mmol/LMg 2 ++15 mmol/LSr 2 ++3:7nHAC impregnation solution and implanted into the mesial alveolar fossa for immediate implantation. The osseointegration of the implants was observed by Confocal laser scanning microscopy (CLSM) and histology at 4 and 8 weeks. The groups cultured with 12 mmol/LMg 2 +, 3 mmol/LSr 2 + and 3:7nHAC impregnation solution showed the osteogenic genes and proteins were significantly higher respectively (P < 0.05), as well as p-Akt, p-GSK3β and β-catenin proteins (P < 0.05). CLSM and histology showed that the implant surface was surrounded by thick lamellar bone plate, and the trabecular bone were dense and continuous in the impregnation solution. These results found that magnesium and strontium ion-loaded mineralized collagen play an critical role in up-regulating the cells activity through PI3K/AKT/GSK3β/β-catenin signaling pathway and could be promote the formation of osseointegration.

scholarly journals Design of new acid-activated cell-penetrating peptides for tumor drug delivery

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3429 ◽  
Author(s):  
Jia Yao ◽  
Yinyun Ma ◽  
Wei Zhang ◽  
Li Li ◽  
Yun Zhang ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Targeted Delivery ◽  
Laser Scanning ◽  
Critical Role ◽  
Cell Penetrating Peptides ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ph Response ◽  
Cell Penetrating ◽  
Ph Dependent

TH(AGYLLGHINLHHLAHL(Aib)HHIL-NH2), a histidine-rich, cell-penetrating peptide with acid-activated pH response, designed and synthesized by our group, can effectively target tumor tissues with an acidic extracellular environment. Since the protonating effect of histidine plays a critical role in the acid-activated, cell-penetrating ability of TH, we designed a series of new histidine substituents by introducing electron donating groups (Ethyl, Isopropyl, Butyl) to the C-2 position of histidine. This resulted in an enhanced pH-response and improved the application of TH in tumor-targeted delivery systems. The substituents were further utilized to form the corresponding TH analogs (Ethyl-TH, Isopropyl-TH and Butyl-TH), making them easier to protonate for positive charge in acidic tumor microenvironments. The pH-dependent cellular uptake efficiencies of new TH analogs were further evaluated using flow cytometry and confocal laser scanning microscopy, demonstrating that ethyl-TH and butyl-TH had an optimal pH-response in an acidic environment. Importantly, the new TH analogs exhibited relatively lower toxicity than TH. In addition, these new TH analogs were linked to the antitumor drug camptothecin (CPT), while butyl-TH modified conjugate presented a remarkably stronger pH-dependent cytotoxicity to cancer cells than TH and the other conjugates. In short, our work opens a new avenue for the development of improved acid-activated, cell-penetrating peptides as efficient anticancer drug delivery vectors.

miR-21 Inhibits Cell Proliferation and Apoptosis Through Regulating the Phosphatase and Tensin Homolog/Phosphoinositide 3-Kinase/Akt Signaling Pathway in Cervical Cancer Cells

2020 ◽  
Vol 10 (2) ◽  
pp. 276-280
Author(s):  
Zhijia Zhan ◽  
Xiaoyan Xu ◽  
Zining Li ◽  
Xiujuan Chen ◽  
Qian Li ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Cancer Cells ◽  
Signaling Pathway ◽  
Cell Apoptosis ◽  
Laser Scanning ◽  
Annexin V ◽  
Akt Signaling ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Cervical Cancer Cells

A variety of miRNAs regulate cellular physiology and tumor cells. miR-21 regulates tumorigenesis though the modulating cell apoptosis, migration and invasiveness via activating PTEN/PI3K signaling pathway. This study aimed to assess miR-21’s effect on cervical cancer cells and the underlying mechanisms. HeLa were cultured in DMEM medium. Western blotting was to measure bcl-2, bax, p-Akt, PTEN protein level. Annexin V-FITC was measured to analyze the samples by using confocal laser scanning microscopy. Our result showed that miR-21 significantly induced the cell apoptosis of HeLa via decreasing the protein expression of bcl-2. miR-21 markedly inhibited PI3K/Akt signaling, increased PTEN level, induced cancer cell apoptosis and retarded the tumor angiogenesis and proliferation. miR-21 could regulate the proliferation of HeLa via upregulation of PTEN and downregulation of PI3K/Akt pathway, which provides a novel therapeutic insight for the therapy of cervical cancer.

scholarly journals Experimental Assessment of the Performance of Two Marine Coatings to Curb Biofilm Formation of Microfoulers

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 893 ◽  
Author(s):  
Sara I. Faria ◽  
Rita Teixeira-Santos ◽  
Luciana C. Gomes ◽  
Elisabete R. Silva ◽  
João Morais ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
Critical Role ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Marine Biofouling ◽  
Marine Coatings ◽  
Antifouling Coatings ◽  
Wet Weight ◽  
Biofilm Structure

Biofilms formed on submerged marine surfaces play a critical role in the fouling process, causing increased fuel consumption, corrosion, and high maintenance costs. Thus, marine biofouling is a major issue and motivates the development of antifouling coatings. In this study, the performance of two commercial marine coatings, a foul-release silicone-based paint (SilRef) and an epoxy resin (EpoRef), was evaluated regarding their abilities to prevent biofilm formation by Cyanobium sp. and Pseudoalteromonas tunicata (common microfoulers). Biofilms were developed under defined hydrodynamic conditions to simulate marine settings, and the number of biofilm cells, wet weight, and thickness were monitored for 7 weeks. The biofilm structure was analyzed by confocal laser scanning microscopy (CLSM) at the end-point. Results demonstrated that EpoRef surfaces were effective in inhibiting biofilm formation at initial stages (until day 28), while SilRef surfaces showed high efficacy in decreasing biofilm formation during maturation (from day 35 onwards). Wet weight and thickness analysis, as well as CLSM data, indicate that SilRef surfaces were less prone to biofilm formation than EpoRef surfaces. Furthermore, the efficacy of SilRef surfaces may be dependent on the fouling microorganism, while the performance of EpoRef was strongly influenced by a combined effect of surface and microorganism.

3-D imaging of cells using a confocal laser scanning microscope and digital image processing

1988 ◽  
Vol 46 ◽  
pp. 96-97
Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Scanning Microscope ◽  
Laser Scanning Microscope ◽  
Biochemical Processes ◽  
Adjacent Structures

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.

Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

1990 ◽  
Vol 48 (3) ◽  
pp. 168-169
Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich
Keyword(s):  
Acridine Orange ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ulcer Disease ◽  
Gastroduodenal Disease ◽  
H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

Use of confocal laser scanning microscopy and a computer model to understand ink cavitation and filamentation

TAPPI Journal ◽  
2010 ◽  
Vol 9 (10) ◽  
pp. 7-15
Author(s):  
HANNA KOIVULA ◽  
DOUGLAS BOUSFIELD ◽  
MARTTI TOIVAKKA
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Print Quality ◽  
Length Scale ◽  
Offset Printing ◽  
Significant Difference ◽  
Printing Speed

In the offset printing process, ink film splitting has an important impact on formation of ink filaments. The filament size and its distribution influence the leveling of ink and hence affect ink setting and the print quality. However, ink filaments are difficult to image due to their short lifetime and fine length scale. Due to this difficulty, limited work has been reported on the parameters that influence filament size and methods to characterize it. We imaged ink filament remains and quantified some of their characteristics by changing printing speed, ink amount, and fountain solution type. Printed samples were prepared using a laboratory printability tester with varying ink levels and operating settings. Rhodamine B dye was incorporated into fountain solutions to aid in the detection of the filaments. The prints were then imaged with a confocal laser scanning microscope (CLSM) and images were further analyzed for their surface topography. Modeling of the pressure pulses in the printing nip was included to better understand the mechanism of filament formation and the origin of filament length scale. Printing speed and ink amount changed the size distribution of the observed filament remains. There was no significant difference between fountain solutions with or without isopropyl alcohol on the observed patterns of the filament remains.

ACTIVATED SLUDGE FLOC CHARACTERIZATION BY CONFOCAL LASER SCANNING MICROSCOPY

2012 ◽  
Vol 11 (3) ◽  
pp. 669-674 ◽  
Author(s):  
Szabolcs Szilveszter ◽  
Botond Raduly ◽  
Szilard Bucs ◽  
Beata Abraham ◽  
Szabolcs Lanyi ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser

Cuticular structures in the copulatory apparatus of Planorbis planorbis (Linnaeus, 1758) (Gastropoda: Pulmonata: Planorbidae)

2009 ◽  
Vol 18 (1) ◽  
pp. 11-16
Author(s):  
E.V. Soldatenko ◽  
A.A. Petrov
Keyword(s):  
Light Microscopy ◽  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Taxonomic Status ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Copulatory Apparatus ◽  
The Family ◽  
Cuticular Structures

The morphology of the copulatory apparatus and associated cuticular structures in Planorbis planorbis was studied by light microscopy, SEM, TEM and confocal laser scanning microscopy. The significance of these cuticular structures for the taxonomic status of the species and for the systematics of the family Planorbidae in general is discussed.

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