Browsing by Author "Palangadan, R"

Now showing 1 - 4 of 4
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    Hydroxyapatite scaffolds constituting highly oriented crystals derived from synthetic precursors by hydrothermal reactions
    (CERAMICS INTERNATIONAL, 2016) Mohan, N; Palangadan, R; Varma, H
    A series of hydroxyapatite scaffolds having oriented crystal morphologies were fabricated through hydrothermal exchange reactions of tri calcium phosphate porous precursors in different solutions by the regulation of reaction parameters. The newly developed scaffolds have unique crystal morphologies and a preferred orientation with hybrid micro and nano dimensional structures such as fibres, rods, tubes and flowers. These crystals of apatite grow in the a(b)-plane of the hydroxyapatite lattice with orientation along the c-axis. The developed scaffolds were subjected to in vitro bioactivity evaluation in simulated body fluid (SBF). Physicochemical characterisation of the materials were performed by scanning electron microscopy, X-ray diffraction and fourier transform infra-red spectroscopy. This study shows the transformation of a lower calcium phosphate material to a fast resorbing hydroxyapatite scaffold with a preferred orientation along the c-axis and a higher aspect ratio of crystals which is intended for use in the field of dentistry and orthopaedics as a scaffold for tissue regeneration. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
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    Preparation of hydroxyapatite porous scaffolds from a coral like synthetic inorganic precusrsor for use as a bone graft substitute and a drug delivery vehicle
    (Materials Science and Engineering C, 2018-11) Nimi, N; Palangadan, R; Fernandez, FB; Varma, H
    A novel surfactant free hydrothermal method was developed for the preparation of large hydroxyapatite scaffolds. Synthetic calcium carbonate (calcite) was used as the starting material which when mixed with an inorganic setting solution containing phosphoric acid and sodium hydroxide forms the porous precursor body with pore size 20-700 μm. The porous precursor body was then hydrothermally converted to hydroxyapatite scaffolds when treated in basic phosphate solution of pH 10.5 at 150 °C and 15 bar pressure maintaining the structural stability and integrity. X-ray diffraction and the Fourier transform infrared spectroscopy confirmed that the developed material consist of single phase crystalline hydroxyapatite. Surface morphology and microstructures were studied using scanning electron microscopy and porosity was evaluated by micro CT analysis. The cell material interactions evaluated by cell viability assays and live cell staining methods confirmed the cell compatibility. The drug release study at physiological pH implied that the developed materials could be promising in sustained long-term release. The results emerged have shown that the hydrothermal conversion of inorganic coral-like precursor is effective to produce porous bioactive hydroxyapatite scaffolds for bone regeneration as well as drug delivery vehicles for the treatment of infectious bone diseases such as osteomyelitis.
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    Pulsed laser deposition and in vitro characteristics of triphasic - HASi composition on titanium
    (JOURNAL OF BIOMATERIALS APPLICATIONS, 2014) Palangadan, R; Sukumaran, A; Fernandez, FB; John, A; Varma, H
    Pulsed laser deposition was used to deposit bioactive triphasic glass-ceramic composition (HASi) over titanium substrate using dense HASi target. Bioactive glass compositions are considered the most useful synthetic materials for immediate bone attachment because of its bioresorption, osteoconduction and osteointegration characteristics under invivo conditions. The disadvantage of its brittleness associated with bioactive glass-ceramics has prompted its coating over metallic implants for the combination of duo mechanical and bioactive properties. The hard HASi target was able to undergo laser ablation under ambient gas pressure without bulk erosion of the target. Laser deposition was found to be efficient in depositing triphasic composition for immediate bone integration. The target and deposits were analyzed for the phase, composition and microstructural characteristics by means of X-ray diffraction, Fourier transform infrared spectroscopy, energy-dispersive X-ray analysis and scanning electron microscopy. Simultaneously, the adherent nature and mechanical behaviour of deposits were confirmed by scratch test and micro-indentation methods. Further, the invitro dissolution and bioactivity were assessed by soaking in simulated body fluid followed by elemental analysis using inductively coupled plasma spectroscopy. The deposits were found to be cell-friendly, which was indicated by the phenomenology of stem cells under invitro conditions.
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    Pulsed laser deposition and in vitro characteristics of triphasic ? HASi composition on titanium
    (Journal of Biomaterials Applications., 2014-02) Palangadan, R; Sukumaran, A; Fernandez, FB; John, A; Varma, H