Browsing by Author "Kalkura, SN"

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    Enhancement of wettability and antibiotic loading/release of hydroxyapatite thin film modified by 100 MeV Ag7+ ion irradiation
    (MATERIALS CHEMISTRY AND PHYSICS, 2012) Elayaraja, K; Rajesh, P; Joshy, MIA; Chandra, VS; Suganthi, RV; Kennedy, J; Kulriya, PK; Sulania, I; Asokan, K; Kanjilal, D; Avasthi, DK; Varma, HK; Kalkura, SN
    The effect of swift heavy 100 MeV Ag7+ ions irradiation was studied on hydroxyapatite (HAp) thin film prepared by pulsed laser deposition technique (PLD). The GIXRD analysis confirmed the absence of any phase in the HAp phase due to irradiation. In addition, there was a considerable decrease in crystallinity and crystallite size on irradiation. There was no significant variation in the stoichiometry of the irradiated films. Irradiation seemed to decrease the optical band gap energy of HAp thin films. The surface roughness, wettability and bioactivity were improved on irradiation of the samples. Amount of amoxicillin loading/release increased (10%) in ion beam irradiated (1 x 10(12) ions cm(-2)) sample. Irradiated sample showed fast rate of amoxicillin (AMX) release than the pristine. Bactericidal effect was found to increase on irradiation. Surface modified and antibiotics incorporated HAP coated titanium implants may be used to prevent post-surgical infections and to promote bone-bonding of orthopedic devices. (C) 2012 Elsevier B.V. All rights reserved.
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    Polymeric precursor route for the preparation of calcium phosphate compounds
    (CERAMICS INTERNATIONAL, 1998) Varma, HK; Kalkura, SN; Sivakumar, R
    A polymeric combustion synthesis is described for the preparation of calcium phosphate compounds. The polymeric gel containing calcium and phosphate ions were synthesised by concentrating a solution of calcium nitrate and ethyl phosphate. When the above gel was introduced to a furnace kept at 500 degrees C, a self combustion reaction was observed, leaving behind a calcium phosphate precursor powder. The above powder on heat treatment at 1000 degrees C resulted in beta-TCP, HAP or a mixture of the two phases depending on the Ca/P ratio in the gel. Dependence of Ca/P ratio on the composition of the calcium phosphate phase was studied by XRD. The morphological features of the precursor as well as the heat treated compounds were studied by SEM. The method offers an easy route for the preparation of beta-TCP or HAP in the powder or in the porous form. (C) 1998 Elsevier Science Limited and Techna S.r.l. All rights reserved.
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    Self-assembled right handed helical ribbons of the bone mineral hydroxyapatite
    (JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, 2009) Suganthi, RV; Girija, EK; Kalkura, SN; Varma, HK; Rajaram, A
    A self-assembled right handed helical ribbon of bone mineral, hydroxyapatite (HAp) was crystallized in sodium meta silicate gel matrix at 27A degrees C and the physiological pH (7.4). At temperatures 37 and 47A degrees C, helical structures were followed by many Liesegang rings. The samples were characterized by FT-IR, XRD, SEM, ICP-OES and TG-DTA techniques. The helical ribbon consisted of platy Ca-deficient apatite crystals of size 2.8 mu m. Liesegang ring had a continuous network of fibers with interconnected pores. The samples exhibited bioactivity when soaked in SBF.