WITHDRAWN: Preparation and characterization of PMMA-based bone cements containing magnetic nanoparticles for application in therapeutic hyperthermia of bone metastasis

ABSTRACT Polymethylmetacrylte (PMMA) is used in the fields of dentistry and biomedicine as a constituent of bone cements. Hydroxyapatite (HAp) is a bioceramic produced naturally in the bones. PMMA and HAp are fundamental constituents in the preparation of bone cements. Bisphosphonates have also been used as radiopharmaceutical in dental implants and nuclear medicine, or as palliative systemic treatment for pain reduction in bone metastasis. Vertebroplasty and kyphoplasty are bone cement-based techniques used in orthopedics, being minimally invasive procedures with low risks of infections, applied in osteoporosis and high-impact fractures. Recently, Núcleo de Radiações Ionizantes da Universidade Federal de Minas Gerais proposed a synthetic composite of M-HAp with a metallic nuclide M. After irradiation, M-HAp was added to PMMA, compounding a radioactive bone cement that can recover bone body stabilization, pasting microfractures and recomposing the anatomy and functionality of the affected parts by the compression of bone metastases, with possible pain reduction through quick radiation-induced decompression. Computational dosimetric models, and the synthesis and characterization of bioceramics that incorporate Re-188, Ho-166, or Sm-153 have demonstrated the benefits of these biometrics as promising alternative therapies, mainly from their ability to maintain the ionization in the bone structure, thereby sparing the spinal cord. This article presents a review on this topic. Level of Evidence V, Expert Opinion.

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Synthesis and Characterization of Novel Magnetic Nanoparticles Supported Imidazole Ion as an Efficient Catalytic System for the Three-Component Reaction of Arylaldehydes, Malononitrile and α-hydroxy or α-Amino Active Methylene Compounds

Letters in Organic Chemistry ◽

10.2174/1570178614666170329152804 ◽

2017 ◽

Vol 14 (5) ◽

Cited By ~ 6

Author(s):

Mahboobeh Zahedifar ◽

Pourya Mohammadi ◽

Hassan Sheibani

Keyword(s):

Magnetic Nanoparticles ◽

Catalytic System ◽

Synthesis And Characterization ◽

Three Component Reaction ◽

Active Methylene Compounds ◽

Active Methylene

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Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters

Water ◽

10.3390/w13131757 ◽

2021 ◽

Vol 13 (13) ◽

pp. 1757

Author(s):

Yesica Vicente-Martínez ◽

Manuel Caravaca ◽

Antonio Soto-Meca ◽

Miguel Ángel Martín-Pereira ◽

María del Carmen García-Onsurbe

Keyword(s):

Magnetic Nanoparticles ◽

Nitrate Content ◽

Adsorption Efficiency ◽

Experimental Conditions ◽

Dependent Behavior ◽

Before And After ◽

Naoh Solution ◽

High Concentrations ◽

Interference Studies

This paper presents a novel procedure for the treatment of contaminated water with high concentrations of nitrates, which are considered as one of the main causes of the eutrophication phenomena. For this purpose, magnetic nanoparticles functionalized with silver (Fe3O4@AgNPs) were synthesized and used as an adsorbent of nitrates. Experimental conditions, including the pH, adsorbent and adsorbate dose, temperature and contact time, were analyzed to obtain the highest adsorption efficiency for different concentration of nitrates in water. A maximum removal efficiency of 100% was reached for 2, 5, 10 and 50 mg/L of nitrate at pH = 5, room temperature, and 50, 100, 250 and 500 µL of Fe3O4@AgNPs, respectively. The characterization of the adsorbent, before and after adsorption, was performed by energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller analysis and Fourier-transform infrared spectroscopy. Nitrates can be desorbed, and the adsorbent can be reused using 500 µL of NaOH solution 0.01 M, remaining unchanged for the first three cycles, and exhibiting 90% adsorption efficiency after three regenerations. A deep study on equilibrium isotherms reveals a pH-dependent behavior, characterized by Langmuir and Freundlich models at pH = 5 and pH = 1, respectively. Thermodynamic studies were consistent with physicochemical adsorption for all experiments but showed a change from endothermic to exothermic behavior as the temperature increases. Interference studies of other ions commonly present in water were carried out, enabling this procedure as very selective for nitrate ions. In addition, the method was applied to real samples of seawater, showing its ability to eliminate the total nitrate content in eutrophized waters.

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