Preparation and characterization of hydroxyapatite-coated iron oxide particles by spray-drying technique

Karina Donadel,Mauro C.M Laranjeira,Marcos D.V Felisberto

doi:10.1590/s0001-37652009000200004

Karina Donadel, Mauro C.M Laranjeira + Show 1 more

Open Access

https://doi.org/10.1590/s0001-37652009000200004

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Abstract

Magnetic particles of iron oxide have been increasingly used in medical diagnosis by magnetic resonance imaging and in cancer therapies involving targeted drug delivery and magnetic hyperthermia. In this study we report the preparation and characterization of iron oxide particles coated with bioceramic hydroxyapatite by spray-drying. The iron oxide magnetic particles (IOMP) were coated with hydroxyapatite (HAp) by spray-drying using two IOMP/HAp ratios (0.7 and 3.2). The magnetic particles were characterized by way of scanning electronic microscopy, energy dispersive X-ray, X-ray diffraction, Fourier transformed infrared spectroscopy, flame atomic absorption spectrometry,vibrating sample magnetometry and particle size distribution (laser diffraction). The surface morphology of the coated samples is different from that of the iron oxide due to formation of hydroxyapatite coating. From an EDX analysis, it was verified that the surface of the coated magnetic particles is composed only of HAp, while the interior containsiron oxide and a few layers of HAp as expected. The results showed that spray-drying technique is an efficient and relatively inexpensive method for forming spherical particles with a core/shell structure.

Highlights

Iron oxide magnetic particles (IOMP) are of great interest for some biomedical applications, including therapeutic applications such as magnetic hyperthermia treatment of cancer, magnetic resonance imaging (MRI) and release of drugs.The magnetic particles need to be pre-coated with substances that assure their stability, biodegradability, and non-physiological toxicity
The temperature of the cancerous tissue can be raised to within the range of 4246◦C by indirect heating produced by various magnetic materials, normal cells are not damaged at even higher temperatures
Since the synthesis was carried out in air and at a high drying temperature (170◦C), a partial oxidation of the magnetite to maghemite occurred as shown in reactions 1 and 2 (Balasubramaniam et al 2004, Chen et al 2005, Da Costa et al 1994): FeCl2 + 2FeCl3 + 8NH4OH (1)

Summary

Introduction

Iron oxide magnetic particles (IOMP) are of great interest for some biomedical applications, including therapeutic applications such as magnetic hyperthermia treatment of cancer, magnetic resonance imaging (MRI) and release of drugs.The magnetic particles need to be pre-coated with substances that assure their stability, biodegradability, and non-physiological toxicity. The spray-drying of an aqueous solution or suspension containing the particle to be coated is atomized into a warm chamber where the water is evaporated.

Results

Conclusion