Characterization of the Calcium Phosphate Porous Ceramic Obtained by Foam Consolidation Using Albumin

2007 ◽  
Vol 361-363 ◽  
pp. 971-974 ◽  
Author(s):  
Christiane Ribeiro ◽  
José Carlos Bressiani ◽  
Ana Helena A. Bressiani
Keyword(s):  
Calcium Phosphate ◽  
Porous Ceramic ◽  
Mercury Porosimetry ◽  
Porous Ceramics ◽  
Tissue Growth ◽  
Porous Microstructure ◽  
Interconnected Pores

In many in-vivo and in vitro studies, the behavior of calcium phosphate ceramics like β - tricalcium phosphate in biological environments has been reported to be predictive and positive. In terms of bone tissue growth, this ceramic can be more attractive presenting a porous microstructure. To obtain biomaterial quality ceramics, in this investigation β- TCP porous ceramics were prepared by a special consolidation method with albumin as a foam generating agent. This technique enables preparation a variety of formats with complex geometries. To obtain porous samples using albumin, heat had to be introduced into the system during the consolidation stage. After consolidation, the samples were sintered at 1250oC for 30 minutes and characterized using X-ray diffractometry, scanning electron microscopy and mercury porosimetry. The foams that were obtained by this method exhibited spherical and interconnected pores, characteristics desirable in biomedical implants.

In vitro and in vivo characterization of novel calcium phosphate and magnesium (CaP-Mg) bilayer coated titanium for implantation

2019 ◽  
Vol 374 ◽  
pp. 784-796 ◽  
Author(s):  
Lanyue Chen ◽  
Xudong Yan ◽  
Lili Tan ◽  
Bowen Zheng ◽  
Fenik Kaml Muhammed ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
In Vivo Characterization

Distribution of Seeded Mesenchymal Stem Cells on Hydroxyapatite Porous Ceramics

2007 ◽  
Vol 330-332 ◽  
pp. 1141-1144 ◽  
Author(s):  
Mika Tadokoro ◽  
Noriko Kotobuki ◽  
Akira Oshima ◽  
Hajime Ohgushi
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
In Vitro Culture ◽  
Porous Ceramic ◽  
Porous Ceramics ◽  
Human Mscs ◽  
Ceramic Scaffold ◽  
Before And After

This study focused on in vivo osteogenic capability of bone marrow mesenchymal stem cells (MSCs) seeded on ceramic scaffold. Human MSCs from a single donor were seeded on hydroxyapatite porous ceramic (HAP) and were induced to the osteogenic lineage during in vitro culture condition, then the MSCs/HAP composites were implanted subcutaneously into immunodeficient rats. The cellular activities of the composites were assayed in order to evaluate the distribution and differentiation capability of seeded MSCs before and after implantation. These results showed that the new bone, after implantation, was derived from the donor MSCs, which adhered to the surface of the ceramics pore areas during in vitro culture. Therefore, the engrafted donor cells proliferated and showed continuous osteogenic differentiation within the recipients. Consequently, our study demonstrates the usefulness of MSCs/HAP composites for clinical applications.

In Vitro Characterization of Calcium Phosphate Biomaterial Loaded with Linezolid for Osseous Bone Defect Implantation

2010 ◽  
Vol 26 (7) ◽  
pp. 811-828 ◽  
Author(s):  
Hélène Gautier ◽  
Adrien Plumecocq ◽  
Gilles Amador ◽  
Pierre Weiss ◽  
Christian Merle ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Mercury Porosimetry ◽  
In Vitro Release ◽  
Release Time ◽  
Wet Granulation ◽  
Gram Positive Bacteria ◽  
In Vitro Characterization ◽  
Vitro Release

Osteomyelitis is a severe bone infection frequently caused by Staphylococcus aureus, which shows significant resistance to methicillin. One therapeutic treatment would be to insert a bone substitute loaded to an antibiotic, which would enable the bone to be filled while the illness is being treated. Linezolid is an oxazolidinone antibiotic with a large spectrum of action. It is effective against most Gram-positive bacteria and displays a specific mode of action. The aim of this work was to study the association of linezolid with a calcium phosphate-deficient apatite matrix. Granules containing 10% and 50% linezolid were prepared by wet granulation and characterized. Porosity analyses performed by mercury porosimetry and scanning electron microscopy revealed that grain porosity with 50% linezolid was higher than that of the grains containing 10% linezolid. NMR analyses showed no change in structure of linezolid when linked to calcium-deficient apatite. These results were confirmed by studying the antibacterial activity of linezolid, which remained proportional to the quantity of loaded linezolid, proving that the antibiotic released was active. The in vitro release time varied from 9 days for granules containing 10% linezolid to 26 days for granules containing 50% linezolid.

In Vitro and in Vivo Characterization of a Foam-Like Polyurethane Bone Adhesive for Promoting Bone Tissue Growth

2019 ◽  
Vol 5 (10) ◽  
pp. 5489-5497 ◽  
Author(s):  
Kun Lei ◽  
Qi Zhu ◽  
Xinling Wang ◽  
Haijun Xiao ◽  
Zhen Zheng
Keyword(s):  
Bone Tissue ◽  
Tissue Growth ◽  
In Vivo Characterization

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

In vitro and in vivo characterization of graphene oxide coated porcine bone granules

Carbon ◽  
2016 ◽  
Vol 103 ◽  
pp. 291-298 ◽  
Author(s):  
Valeria Ettorre ◽  
Patrizia De Marco ◽  
Susi Zara ◽  
Vittoria Perrotti ◽  
Antonio Scarano ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
In Vivo Characterization

scholarly journals Functional identification of ygiP as a positive regulator of the ttdA-ttdB-ygjE operon

Microbiology ◽  
2006 ◽  
Vol 152 (7) ◽  
pp. 2129-2135 ◽  
Author(s):  
Taku Oshima ◽  
Francis Biville
Keyword(s):  
Functional Characterization ◽  
Anaerobic Growth ◽  
Functional Identification ◽  
New Members ◽  
E Coli ◽  
Inner Membrane Protein ◽  
Tartrate Dehydratase

Functional characterization of unknown genes is currently a major task in biology. The search for gene function involves a combination of various in silico, in vitro and in vivo approaches. Available knowledge from the study of more than 21 LysR-type regulators in Escherichia coli has facilitated the classification of new members of the family. From sequence similarities and its location on the E. coli chromosome, it is suggested that ygiP encodes a lysR regulator controlling the expression of a neighbouring operon; this operon encodes the two subunits of tartrate dehydratase (TtdA, TtdB) and YgiE, an integral inner-membrane protein possibly involved in tartrate uptake. Expression of tartrate dehydratase, which converts tartrate to oxaloacetate, is required for anaerobic growth on glycerol as carbon source in the presence of tartrate. Here, it has been demonstrated that disruption of ygiP, ttdA or ygjE abolishes tartrate-dependent anaerobic growth on glycerol. It has also been shown that tartrate-dependent induction of the ttdA-ttdB-ygjE operon requires a functional YgiP.

scholarly journals Functional Characterization of the mazEF Toxin-Antitoxin System in the Pathogenic Bacterium Agrobacterium tumefaciens

2021 ◽  
Vol 9 (5) ◽  
pp. 1107
Author(s):  
Wonho Choi ◽  
Yoshihiro Yamaguchi ◽  
Ji-Young Park ◽  
Sang-Hyun Park ◽  
Hyeok-Won Lee ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Physiological Function ◽  
Functional Characterization ◽  
Site Directed Mutagenesis ◽  
In Vitro Assays ◽  
Cell Growth Inhibition ◽  
The Right

Agrobacterium tumefaciens is a pathogen of various plants which transfers its own DNA (T-DNA) to the host plants. It is used for producing genetically modified plants with this ability. To control T-DNA transfer to the right place, toxin-antitoxin (TA) systems of A. tumefaciens were used to control the target site of transfer without any unintentional targeting. Here, we describe a toxin-antitoxin system, Atu0939 (mazE-at) and Atu0940 (mazF-at), in the chromosome of Agrobacterium tumefaciens. The toxin in the TA system has 33.3% identity and 45.5% similarity with MazF in Escherichia coli. The expression of MazF-at caused cell growth inhibition, while cells with MazF-at co-expressed with MazE-at grew normally. In vivo and in vitro assays revealed that MazF-at inhibited protein synthesis by decreasing the cellular mRNA stability. Moreover, the catalytic residue of MazF-at was determined to be the 24th glutamic acid using site-directed mutagenesis. From the results, we concluded that MazF-at is a type II toxin-antitoxin system and a ribosome-independent endoribonuclease. Here, we characterized a TA system in A. tumefaciens whose understanding might help to find its physiological function and to develop further applications.

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