Modifying Brushite Cement Degradation Using Calcium Alginate Beads

2007 ◽  
Vol 361-363 ◽  
pp. 311-314 ◽  
Author(s):  
Liam M. Grover ◽  
Sarika Patel ◽  
Y. Hu ◽  
Uwe Gbureck ◽  
J.E. Barralet
Keyword(s):  
Calcium Alginate ◽  
Alginate Beads ◽  
The Body ◽  
Cement Matrix ◽  
Calcium Alginate Beads ◽  
Long Term Stability ◽  
The Matrix ◽  
Implant Degradation

The hydrolysis of brushite in calcium phosphate cements to form hydroxyapatite is known to result in the long term stability of the material in the body. It has previously been established that this hydrolysis reaction can be influenced by implant volume, media refreshment rate and media composition. In this study, the effect of macroporosity on the rate of degradation of the material is investigated. Macroporosity was incorporated into the material using calcium alginate beads mixed into the cement paste. The inclusion of the calcium alginate beads did not influence the degree of conversion of the material and allowed the incorporation of porosity at up to maximum of 57%. The macroporosity weakened the cement matrix (from 46.5 to 3.2 MPa). When aged the brushite in the macroporous cement dissolved completely from the matrix resulting in a weight loss of 60wt% in a period of 28 days. This suggests that the controlled incorporation of calcium alginate beads into brushite cements in vivo can be used to control implant degradation rate.

Calcium alginate beads as a slow-release system for delivering angiogenic molecules In Vivo and In Vitro

1992 ◽  
Vol 152 (2) ◽  
pp. 422-429 ◽  
Author(s):  
Elizabeth C. Downs ◽  
Nancy E. Robertson ◽  
Terry L. Riss ◽  
Marian L. Plunkett
Keyword(s):  
Calcium Alginate ◽  
Slow Release ◽  
Alginate Beads ◽  
Calcium Alginate Beads ◽  
Release System ◽  
Slow Release System

THE ROLE OF POLYETHYLENIMINE IN ENHANCING PERFORMANCE OF GLUTAMATE BIOSENSORS

2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia
Keyword(s):  
First Generation ◽  
Good Reproducibility ◽  
Complex Matrices ◽  
Long Term Stability ◽  
In Vitro Characterization ◽  
Glutamate Oxidase

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors

scholarly journals Biocompatibility of Bacterial Magnetosomes as MRI Contrast Agent: A Long-Term In Vivo Follow-Up Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1235
Author(s):  
Xiaohui Nan ◽  
Wenjia Lai ◽  
Dan Li ◽  
Jiesheng Tian ◽  
Zhiyuan Hu ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Magnetic Domain ◽  
Bilayer Membrane ◽  
The Body ◽  
Mri Contrast Agent ◽  
Mri Imaging ◽  
Mri Contrast

Derived from magnetotactic bacteria (MTB), magnetosomes consist of magnetite crystals enclosed within a lipid bilayer membrane and are known to possess advantages over artificially synthesized nanoparticles because of the narrow size distribution, uniform morphology, high purity and crystallinity, single magnetic domain, good biocompatibility, and easy surface modification. These unique properties have increasingly attracted researchers to apply bacterial magnetosomes (BMs) in the fields of biology and medicine as MRI imaging contrast agents. Due to the concern of biosafety, a long-term follow-up of the distribution and clearance of BMs after entering the body is necessary. In this study, we tracked changes of BMs in major organs of mice up to 135 days after intravenous injection using a combination of several techniques. We not only confirmed the liver as the well-known targeted organs of BMs, but also found that BMs accumulated in the spleen. Besides, two major elimination paths, as well as the approximate length of time for BMs to be cleared from the mice, were revealed. Together, the results not only confirm that BMs have high biocompatibility, but also provide a long-term in-vivo assessment which may further help to forward the clinical applications of BMs as an MRI contrast agent.

scholarly journals The Enzymatic Decolorization of Textile Dyes by the Immobilized Polyphenol Oxidase from Quince Leaves

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Gulnur Arabaci ◽  
Ayse Usluoglu
Keyword(s):  
Polyphenol Oxidase ◽  
Calcium Alginate ◽  
Enzyme Stability ◽  
Industrial Effluent ◽  
Alginate Beads ◽  
Textile Dyes ◽  
Kinetic Properties ◽  
Synthetic Dyes ◽  
Cydonia Oblonga ◽  
Calcium Alginate Beads

Water pollution due to release of industrial wastewater has already become a serious problem in almost every industry using dyes to color its products. In this work, polyphenol oxidase enzyme from quince (Cydonia Oblonga) leaves immobilized on calcium alginate beads was used for the successful and effective decolorization of textile industrial effluent. Polyphenol oxidase (PPO) enzyme was extracted from quince (Cydonia Oblonga) leaves and immobilized on calcium alginate beads. The kinetic properties of free and immobilized PPO were determined. Quince leaf PPO enzyme stability was increased after immobilization. The immobilized and free enzymes were employed for the decolorization of textile dyes. The dye solutions were prepared in the concentration of 100 mg/L in distilled water and incubated with free and immobilized quince (Cydonia Oblonga) leaf PPO for one hour. The percent decolorization was calculated by taking untreated dye solution. Immobilized PPO was significantly more effective in decolorizing the dyes as compared to free enzyme. Our results showed that the immobilized quince leaf PPO enzyme could be efficiently used for the removal of synthetic dyes from industrial effluents.

scholarly journals Improving the Stability of Astaxanthin by Microencapsulation in Calcium Alginate Beads

PLoS ONE ◽  
2016 ◽  
Vol 11 (4) ◽  
pp. e0153685 ◽  
Author(s):  
Shen-Fu Lin ◽  
Ying-Chen Chen ◽  
Ray-Neng Chen ◽  
Ling-Chun Chen ◽  
Hsiu-O Ho ◽  
...  
Keyword(s):  
Calcium Alginate ◽  
Alginate Beads ◽  
Calcium Alginate Beads ◽  
The Stability

Calcium alginate beads motion in a foaming three-phase bubble column

2017 ◽  
Vol 324 ◽  
pp. 358-369 ◽  
Author(s):  
Gabriel Salierno ◽  
Mauricio Maestri ◽  
Stella Piovano ◽  
Miryan Cassanello ◽  
María Angélica Cardona ◽  
...  
Keyword(s):  
Calcium Alginate ◽  
Bubble Column ◽  
Alginate Beads ◽  
Calcium Alginate Beads ◽  
Three Phase
Sign in / Sign up

Export Citation Format

Share Document