Browsing by Author "Ajeesh, M"

Now showing 1 - 3 of 3
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    Nano iron oxide hydroxyapatite composite ceramics with enhanced radiopacit
    (Journal of Materials Science: Materials in Medicine., 2010) Ajeesh, M; Francis, BF; John, A; Varma, PRH
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    Nano iron oxide-hydroxyapatite composite ceramics with enhanced radiopacity
    (JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, 2010) Ajeesh, M; Francis, BF; Annie, J; Varma, PRH
    Hydroxyapatite has been widely used for a variety of bone filling and augmentation applications. But the poorly resolved X-ray image of certain hydroxyapatite (HA) based implants such as porous blocks and self setting HA cements is a radiological problem to surgeons for monitoring of the implant and early diagnosis complications. In the present work the practical difficulty related to the reduced X-ray opacity was overcome by exploiting the contrast enhancement property of iron oxide nano particles. Sintered nano iron oxide-HA composite ceramics were prepared from powders produced through a co-precipitation route. The phase purity and bioactivity of the composites were analyzed as a function of percentage iron oxide in the composite. The X-ray attenuation of dense and porous composites was compared with pure HA using a C-arm X-ray imaging system and micro computed tomography. In all the prepared composites, HA retains its phase identity and high X-ray opacity as obtained for a composition containing 40 wt% iron oxide. The increased cell viability and cell adhesion nature depicted by the prepared composite offers considerable interest for the material in bone tissue engineering applications.
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    Synthesis and Characterization of Iron Oxide Embedded Hydroxyapatite Bioceramics
    (JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 2012) Ansar, EB; Ajeesh, M; Yokogawa, Y; Wunderlich, W; Varma, H
    A homogeneous dispersion of nano iron oxide (IO) crystallites inside the hydroxyapatite (HA) particles was achieved by a co-precipitation method. This highly stable colloidal dispersion of magnetic nano composite (HAIO) was made without the use of any surfactants. The in situ generated dispersion of the composite powders showed submicron HA particles with 5 nm iron oxide inside. The phase analysis results showed the presence of hydroxyapatite (HA) and iron oxide with no tertiary phase. The enhancement of relative peak intensities with increased percentage of iron oxide phase in X-ray diffraction analysis suggests the formation of iron oxide together with HA without affecting the phase purity of the latter, which is important when the biological behavior of HA is concerned. This also confirms the quantitative nature of the precipitated nanocomposites. The High Resolution Transmission Electron Microscope (HRTEM) of the composite shows elongated crystal flakes or platelike surfaces of HA crystallites having particle sizes in the range 70-100 nm. HRTEM with XRD analysis matches HAIO only with iron oxide particles of Magnetite (Fe3O4) and HA phases. The FTIR data confirm that the introduction of iron oxide did not produce any considerable change in the chemical structure of HA.