Orthophosphate and Alkaline Phosphatase Induced the Formation of Apatite with Different Multilayered Structures and Mineralization Balance

Nanoscale ◽  
2022 ◽  
Author(s):  
Tianming Du ◽  
Yumiao Niu ◽  
Zhenzhen Jia ◽  
Youjun Liu ◽  
Aike Qiao ◽  
...  

Mineralized collagen is a natural organic-inorganic composite. The combination of organic collagen and inorganic apatite to form different nanostructures is the key to produce bone- substitutes with biomechanical properties that...

Bone ◽  
2016 ◽  
Vol 89 ◽  
pp. 66
Author(s):  
L.R. Brun ◽  
C. Retamozo ◽  
M. Terjes ◽  
J.L. Millán ◽  
A. Rigalli

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1069
Author(s):  
Janine Waletzko-Hellwig ◽  
Michael Saemann ◽  
Marko Schulze ◽  
Bernhard Frerich ◽  
Rainer Bader ◽  
...  

One main disadvantage of commercially available allogenic bone substitute materials is the altered mechanical behavior due to applied material processing, including sterilization methods like thermal processing or gamma irradiation. The use of high hydrostatic pressure (HHP) might be a gentle alternative to avoid mechanical alteration. Therefore, we compressed ground trabecular human bone to granules and, afterwards, treated them with 250 and 300 MPa for 20 and 30 min respectively. We characterized the formed bone granule cylinders (BGC) with respect to their biomechanical properties by evaluating stiffness and stress at 15% strain. Furthermore, the stiffness and yield strength of HHP-treated and native human trabecular bone cylinders (TBC) as control were evaluated. The mechanical properties of native vs. HHP-treated TBCs as well as HHP-treated vs. untreated BGCs did not differ, independent of the applied HHP magnitude and duration. Our study suggests HHP treatment as a suitable alternative to current processing techniques for allogenic bone substitutes since no negative effects on mechanical properties occurred.


2020 ◽  
Vol 10 (2) ◽  
pp. 139-150
Author(s):  
Yuan-Xin Shen ◽  
Xi-Rao Sun ◽  
Cheng-Yue Wang ◽  
Jing-Xin Yang ◽  
Jia-Xin Bao

In this study, we composited mineralized collagen and magnesium-calcium alloy by freeze-drying, followed by dip-coating PMMA bone cement to enhance the composite of mineralized collagen and magnesium-calcium alloy. In vitro degradation test was performed to observe the pH and weight loss of the material. The contact angle test was used to detect the hydrophilicity of the material. Subsequently, MC3T3-E1 were used to assess cell biocompatibility In vitro by cell adhesion, cytotoxicity, alkaline phosphatase, alizarin red staining, and cytoskeleton. The results showed that the pH changes of the PMMA/NHAC/Mg–Ca was slower than that of the Mg–Ca , and the weight loss rate at 7 d and 14 d were lower than that of the Mg–Ca (P < 0.05) in degradation test. Wettability experiment showed that PMMA/NHAC/Mg–Ca was a hydrophilic material and Mg–Ca was a hydrophobic material (P < 0.05). In vitro cell experiments, the PMMA/NHAC/Mg–Ca had more cell adhesion than Mg–Ca and more synapses were connected to others. In the cytotoxicity experiment, the cell proliferation lever of PMMA/NHAC/Mg–Ca was higher than that of Mg–Ca at each time point (P < 0.05). In the 7 d alkaline phosphatase experiment, the PMMA/NHAC/Mg–Ca showed higher ALP activity than the Mg–Ca (P < 0.05), and in the alizarin red experiment at 14 d and 28 d, there were more obvious calcified nodules and mineralized area. After 1 day of culture in the PMMA/NHAC/Mg–Ca extract, the cells showed a clearer and more complete cytoskeletal structure and better cell morphology. In conclusion, PMMA/NHAC/Mg–Ca orthopedic implants had a better hydrophilicity, cytotoxicity and osteogenic ability, besides with a slower rate of degradation, and could be implanted in animals for further research, which were expected to be used for the repair of clinical bone defects.


Author(s):  
Xiaorong Zhu ◽  
Richard McVeigh ◽  
Bijan K. Ghosh

A mutant of Bacillus licheniformis 749/C, NM 105 exhibits some notable properties, e.g., arrest of alkaline phosphatase secretion and overexpression and hypersecretion of RS protein. Although RS is known to be widely distributed in many microbes, it is rarely found, with a few exceptions, in laboratory cultures of microorganisms. RS protein is a structural protein and has the unusual properties to form aggregate. This characteristic may have been responsible for the self assembly of RS into regular tetragonal structures. Another uncommon characteristic of RS is that enhanced synthesis and secretion which occurs when the cells cease to grow. Assembled RS protein with a tetragonal structure is not seen inside cells at any stage of cell growth including cells in the stationary phase of growth. Gel electrophoresis of the culture supernatant shows a very large amount of RS protein in the stationary culture of the B. licheniformis. It seems, Therefore, that the RS protein is cotranslationally secreted and self assembled on the envelope surface.


Author(s):  
C. Jennermann ◽  
S. A. Kliewer ◽  
D. C. Morris

Peroxisome proliferator-activated receptor gamma (PPARg) is a member of the nuclear hormone receptor superfamily and has been shown in vitro to regulate genes involved in lipid metabolism and adipocyte differentiation. By Northern analysis, we and other researchers have shown that expression of this receptor predominates in adipose tissue in adult mice, and appears first in whole-embryo mRNA at 13.5 days postconception. In situ hybridization was used to find out in which developing tissues PPARg is specifically expressed.Digoxigenin-labeled riboprobes were generated using the Genius™ 4 RNA Labeling Kit from Boehringer Mannheim. Full length PPAR gamma, obtained by PCR from mouse liver cDNA, was inserted into pBluescript SK and used as template for the transcription reaction. Probes of average size 200 base pairs were made by partial alkaline hydrolysis of the full length transcripts. The in situ hybridization assays were performed as described previously with some modifications. Frozen sections (10 μm thick) of day 18 mouse embryos were cut, fixed with 4% paraformaldehyde and acetylated with 0.25% acetic anhydride in 1.0M triethanolamine buffer. The sections were incubated for 2 hours at room temperature in pre-hybridization buffer, and were then hybridized with a probe concentration of 200μg per ml at 70° C, overnight in a humidified chamber. Following stringent washes in SSC buffers, the immunological detection steps were performed at room temperature. The alkaline phosphatase labeled, anti-digoxigenin antibody and detection buffers were purchased from Boehringer Mannheim. The sections were treated with a blocking buffer for one hour and incubated with antibody solution at a 1:5000 dilution for 2 hours, both at room temperature. Colored precipitate was formed by exposure to the alkaline phosphatase substrate nitrobluetetrazoliumchloride/ bromo-chloroindlylphosphate.


Author(s):  
S.K. Aggarwal

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.


1962 ◽  
Vol 42 (4) ◽  
pp. 431-438 ◽  
Author(s):  
Stanton G. Polin ◽  
Mitchell A. Spellberg ◽  
Lloyd Teitelman ◽  
Makoto Okumura

2019 ◽  
Vol 25 ◽  
pp. 67
Author(s):  
Jinetsy Rivera-Ortiz ◽  
Milliette Alvarado-Santiago ◽  
Margarita Ramirez-Vick ◽  
Naomi Collazo-Gutierrez ◽  
Loida Gonzalez-Rodriguez

Sign in / Sign up

Export Citation Format

Share Document