Role of calcium phosphate and bioactive glass coating on in vivo bone healing of new Mg–Zn–Ca implant

AbstractPresent investigation focuses on development and detailed characterization of a new Mg alloy sample (BM) with and without coating of hydroxyapatite (BMH) and bioactive glass (BMG) by air plasma spray method. After detailed mechano-physico-chemical characterization of powders and coated samples, electrochemical corrosion and SBF immersion tests were carried out. Detailed in vitro characterizations for cell viability were undertaken using MG-63 cell line followed by in vivo tests in rabbit model for studying bone healing up to 60 days. Starting current density increases from BM to BMH to BMG indicating highest resistance towards corrosion in case of BMG samples, however BMH also showed highest icorr value suggesting slowest rate of corrosion than BM and BMG samples. Dissolution of calcium ion in case of BMH and BMG control formation of apatite phases on surface. Ca2+ ions of coatings and from SBF solution underwent reduction reaction simultaneously with conversion of Mg to MgCl2 releasing OH− in the solution, which increases pH. Viability and propagation of human osteoblast-like cells was verified using confocal microscopy observations and from expression of bone specific genes. Alkaline phosphatase assay and ARS staining indicate cell proliferation and production of neo-osseous tissue matrix. In vivo, based on histology of heart, kidney and liver, and immune response of IL-2, IL-6 and TNFα, all the materials show no adverse effects in body system. The bone creation was observed to be more for BMH. Although both BMH and BMG show rays of possibilities in early new bone formation and tough bone–implant bonding at interface as compared to bare Mg alloy, however, BMG showed better well-sprayed coating covering on substrate and resistance against corrosion prior implanting in vivo. Also, better apatite formation on this sample makes it more favourable implant.

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In Vivo Characterization of Atherosclerotic Plaque Depositions by Raman-Probe Spectroscopy and in Vitro Coherent Anti-Stokes Raman Scattering Microscopic Imaging on a Rabbit Model

Analytical Chemistry ◽

10.1021/ac301522d ◽

2012 ◽

Vol 84 (18) ◽

pp. 7845-7851 ◽

Cited By ~ 52

Author(s):

Christian Matthäus ◽

Sebastian Dochow ◽

Gero Bergner ◽

Annika Lattermann ◽

Bernd F. M. Romeike ◽

...

Keyword(s):

Atherosclerotic Plaque ◽

Rabbit Model ◽

Microscopic Imaging ◽

Probe Spectroscopy ◽

In Vivo Characterization ◽

Anti Stokes ◽

Raman Probe

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Apatite Growth on Bioactive Glass in Artificial Saliva

MRS Proceedings ◽

10.1557/proc-662-ll2.5 ◽

2000 ◽

Vol 662 ◽

Author(s):

Sarah E. Efflandt ◽

Robert F. Cook ◽

Lorraine F. Francis

Keyword(s):

Bioactive Glass ◽

Artificial Saliva ◽

Apatite Formation ◽

X Ray Diffraction ◽

X Ray ◽

Time Period ◽

Surface Morphologies ◽

Surface Changes

AbstractBioactive glass disks from the MgO-CaO-P2O5-SiO2 system were placed in artificial saliva for time periods varying from 1 to 42 days. Surfaces were then analyzed using scanning electron microscopy (SEM) and x-ray diffraction to investigate surface morphologies and crystallinity. SEM examination exhibited dramatic surface changes as early as 2 d. X-ray results showed crystallinity in the form of apatite at 10 d, which became more developed though 42 d. The bioactive glass in water and non-bioactive glass in artificial saliva were used as controls; both exhibited no evidence of apatite formation on their surfaces through the 42 d time period. This study shows that bioactive glass reacts in artificial saliva to form apatite and that the apatite layer becomes better crystallized over an extended time period. These results give a better understanding of the surface changes and mineralization that occur over time and can be used to interpret results from in vitro and in vivo studies done on bioactive glass in the oral environment.

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Characterization of Haemophilus ducreyi cdtA, cdtB, and cdtC Mutants in In Vitro and In Vivo Systems

Infection and Immunity ◽

10.1128/iai.69.9.5626-5634.2001 ◽

2001 ◽

Vol 69 (9) ◽

pp. 5626-5634 ◽

Cited By ~ 34

Author(s):

David A. Lewis ◽

Marla K. Stevens ◽

Jo L. Latimer ◽

Christine K. Ward ◽

Kaiping Deng ◽

...

Keyword(s):

Hela Cells ◽

Culture Supernatant ◽

Cell Envelope ◽

Rabbit Model ◽

Haemophilus Ducreyi ◽

Supernatant Fluid ◽

E Coli

ABSTRACT Haemophilus ducreyi expresses a soluble cytolethal distending toxin (CDT) that is encoded by the cdtABC gene cluster and can be detected in culture supernatant fluid by its ability to kill HeLa cells. The cdtA, cdtB, and cdtCgenes of H. ducreyi were cloned independently into plasmid vectors, and their encoded proteins expressed singly or in various combinations in an Escherichia coli background. All three gene products had to be expressed in order for E. coli-derived culture supernatant fluids to demonstrate cytotoxicity for HeLa cells. Isogenic H. ducreyi cdtA and cdtB mutants were constructed and used in combination with the wild-type parent strain and a previously describedH. ducreyi cdtC mutant (M. K. Stevens, J. L. Latimer, S. R. Lumbley, C. K. Ward, L. D. Cope, T. Lagergard, and E. J. Hansen, Infect. Immun. 67:3900–3908, 1999) to determine the relative contributions of the CdtA, CdtB, and CdtC proteins to CDT activity. Expression of CdtA, CdtB, and CdtC appeared necessary for H. ducreyi-derived culture supernatant fluid to exhibit cytotoxicity for HeLa cells. Whole-cell sonicates and periplasmic extracts from the cdtB and cdtC mutants had no effect on HeLa cells, whereas these same fractions from a cdtA mutant had a very modest cytotoxic effect on these same human cells. CdtA appeared to be primarily associated with the H. ducreyi cell envelope, whereas both CdtB and CdtC were present primarily in the soluble fraction from sonicated cells. Both the cdtAmutant and the cdtB mutant were found to be fully virulent in the temperature-dependent rabbit model for experimental chancroid.

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In vivo and in vitro characterization of immediate release dosage forms containing n-acetylcysteine using the dynamic open flow-through test apparatus

10.26226/morressier.57d6b2b7d462b8028d88dd29 ◽

2016 ◽

Author(s):

Maximilian Sager

Keyword(s):

Immediate Release ◽

Dosage Forms ◽

Test Apparatus ◽

Open Flow ◽

In Vitro Characterization ◽

Flow Through

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

10.26434/chemrxiv.7725002.v1 ◽

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.

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Faculty Opinions recommendation of In vitro and in vivo characterization of a novel semaphorin 3A inhibitor, SM-216289 or xanthofulvin.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1014793.196553 ◽

2003 ◽

Author(s):

Genevieve Rougon

Keyword(s):

Semaphorin 3A ◽

In Vivo Characterization

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

Carbon ◽

10.1016/j.carbon.2016.03.010 ◽

2016 ◽

Vol 103 ◽

pp. 291-298 ◽

Cited By ~ 27

Author(s):

Valeria Ettorre ◽

Patrizia De Marco ◽

Susi Zara ◽

Vittoria Perrotti ◽

Antonio Scarano ◽

...

Keyword(s):

Graphene Oxide ◽

In Vivo Characterization

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

Microbiology ◽

10.1099/mic.0.28753-0 ◽

2006 ◽

Vol 152 (7) ◽

pp. 2129-2135 ◽

Cited By ~ 17

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.

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

Microorganisms ◽

10.3390/microorganisms9051107 ◽

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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