Effect of Carbonate Substitution on the Biomineralization of Apatite Bulk and Coating

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.807.87 ◽

2019 ◽

Vol 807 ◽

pp. 87-93

Author(s):

Qing Xia Zhu ◽

Quan Yi Nie

Keyword(s):

Grain Size ◽

Pore Size ◽

Carbonate Apatite ◽

Vitro Experiment ◽

In Vitro Experiment ◽

Carbonate Substitution ◽

Experiment Method ◽

Mineralization Processes ◽

Sbf Solution

In-vitro experiment method was used to study biomineralization properties of carbonate apatite bulk and electrophoresis coating with different carbonate contents. The mineralization processes in SBF solution were investigated by means of XRD, SEM and so on. Research results show that the apatite with poor crystallization and small grain size induced by the carbonate substitution is beneficial to the sintering of the bulk and the formation of the bone-like hydroxyl-carbonate apatite (HCA) layer on the surface after soaking in the SBF. However, the carbonate substitution greatly reduces the pore size and porosity of coating, which is not conducive to the deposition and growth of the mineralized layer, thus weakens the biomineralization properties of the coating.

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Acid-free Hydrothermal Process for Synthesis of Bioactive Glasses 70SiO2–(30-x)CaO–xZnO (x = 1, 3, 5 mol.%)

Proceedings ◽

10.3390/proceedings2020062006 ◽

2020 ◽

Vol 62 (1) ◽

pp. 6

Author(s):

Ta Anh Tuan ◽

Elena V. Guseva ◽

Le Hong Phuc ◽

Nguyen Quan Hien ◽

Nguyen Viet Long ◽

...

Keyword(s):

Inductively Coupled Plasma ◽

Hydrothermal Process ◽

Optical Emission ◽

Emission Spectrometry ◽

Bioactive Glasses ◽

Vitro Experiment ◽

In Vitro Experiment ◽

Zn Addition ◽

Sbf Solution

Bioactive glasses 70SiO2–(30-x)CaO–xZnO (x = 1, 3, 5 mol.%) were prepared by the acid-free hydrothermal method in keeping with green chemical technology. The synthetic glasses were investigated by TG-DSC, BET, XRD, and SEM–EDX methods. All synthetic glasses present mesoporous structures consisting of aggregates of nanoparticles. The bioactivity of synthetic glasses was confirmed through the formation of the hydroxyapatite phase after an in vitro experiment in simulated body fluid (SBF) solution. The effect of Zn addition is shown through the decrease in the bioactivity of synthetic glasses. Additionally, the inductively coupled plasma optical emission spectrometry (ICP-OES) analysis indicates that the Zn ions were released from the glassy networks during in vitro experiments, and they act as Zn(OH)2 suspended precipitation to inhibit the apatite deposition. The in vitro experiment in cell culture matter was performed for SaOS2 and Eahy929 cells. The results confirm the biocompatibility of synthetic glasses and the role of Zn addition in the proliferation of living cells.

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In Silico and in Vitro Evaluation of Deamidation Effects on the Stability of the Fusion Toxin DAB389IL-2

Current Proteomics ◽

10.2174/1570164616666190131150033 ◽

2019 ◽

Vol 16 (4) ◽

pp. 307-313 ◽

Cited By ~ 2

Author(s):

Nasrin Zarkar ◽

Mohammad Ali Nasiri Khalili ◽

Fathollah Ahmadpour ◽

Sirus Khodadadi ◽

Mehdi Zeinoddini

Keyword(s):

In Silico ◽

Catalytic Domain ◽

Md Simulations ◽

Special Importance ◽

Native Form ◽

Vitro Experiment ◽

In Vitro Experiment ◽

Pharmaceutical Protein ◽

The Stability

Background: DAB389IL-2 (Denileukin diftitox) as an immunotoxin is a targeted pharmaceutical protein and is the first immunotoxin approved by FDA. It is used for the treatment of various kinds of cancer such as CTCL lymphoma, melanoma, and Leukemia but among all of these, treatment of CTCL has special importance. DAB389IL-2 consists of two distinct parts; the catalytic domain of Diphtheria Toxin (DT) that genetically fused to the whole IL-2. Deamidation is the most important reaction for chemical instability of proteins occurs during manufacture and storage. Deamidation of asparagine residues occurs at a higher rate than glutamine residues. The structure of proteins, temperature and pH are the most important factors that influence the rate of deamidation. Methods: Since there is not any information about deamidation of DAB389IL-2, we studied in silico deamidation by Molecular Dynamic (MD) simulations using GROMACS software. The 3D model of fusion protein DAB389IL-2 was used as a template for deamidation. Then, the stability of deamidated and native form of the drug was calculated. Results: The results of MD simulations were showed that the deamidated form of DAB389IL-2 is more unstable than the normal form. Also, deamidation was carried by incubating DAB389IL-2, 0.3 mg/ml in ammonium hydrogen carbonate for 24 h at 37o C in order to in vitro experiment. Conclusion: The results of in vitro experiment were confirmed outcomes of in silico study. In silico and in vitro experiments were demonstrated that DAB389IL-2 is unstable in deamidated form.

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