Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Department of Bio-Sciences

In situ synthesis of biphasic calcium phosphate doped with magnesium fluoride using microwave irradiation was carried out. The powders were analyzed using X-ray diffractometer and monochromatic radiation. Stability of the powders was examined by infrared spectra. The use of the compound in osteoporotic applications was discussed.

School of Bio Sciences and Technology

Vellore Campus

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Journal of Materials Science Letters

Preparation of biphasic calcium phosphate doped with magnesium fluoride for osteoporotic applications

Hydroxyapatite (HA) and fluoroapatite (FHA) have been widely investigated as bone substitute and replacement materials. We report here the preparation of hydroxy/fluoroapatite solid solution using wet chemical precipitation method via brushite hydrolysis. Various amounts of sodium fluoride (1-5 mol%) were added during the preparation of hydroxyapatite to form hydroxy/fluoroapatite solid solution. The various experimental techniques like XRD, DTA, TGA, FT-IR and Vicker's hardness measurements were used to characterize the synthesized powders. Thermal analysis of the samples shows only the decomposition reaction of residues formed and the corresponding weight loss due to these reactions. The XRD data of all the samples calcined at 900°C shows well defined peaks of hydroxyapatite and fluoroapatite. The merging of (211) and (112) peak of apatite lattice in the FHA pattern indicates the formation of hydroxy/fluoroapatite solid solution. The decrease in the a-axis of HA lattice parameter indicates the substitution of F- ion in the OH- site of HA lattice. The FT-IR spectroscopic studies of the samples confirms the substitution of the F- ion in the OH- site of the HA lattice. The Vicker's hardness measurement shows that the hardness value of hydroxy/fluoroapatite solid solution is greater than the hydroxyapatite.

Journal of Materials Science

Synthesis and characterisation of hydroxy/fluoroapatite solid solution

Hydroxyapatite (HA) has been widely used in the field of orthopaedics and dentistry. Due to HA's lack of mechanical properties, composites containing hydroxyapatite and zirconia have been suggested for the purpose of increasing strength and fracture toughness. This paper reports the preparation of fluorine-doped hydroxyapatite from Indian coast corals and zirconia composites using coralline hydroxyapatite and coralline fluoroapatite. The fluoroapatite and composites were prepared by two methods: (i) low temperature (LT) or hydrothermal method and (ii) high temperature (HT) or solid state reaction method. These materials were characterized by X-ray diffraction (XRD) analysis, Fourier-transform infrared spectroscopy (FT-IR) and thermal analysis. Decrease in the a-axis of HA lattice was observed in the fluoroapatite, suggesting partial fluorination of hydroxyapatite resulting in hydroxy/fluoroapatite solid solution. The analysis of the composites shows the formation of β-tricalcium phosphate due to the decomposition of hydroxyapatite. © 2001 Elsevier Science B.V. All rights reserved.

Materials Letters

Preparation of hydroxyapatite/fluoroapatite-zirconia composites using Indian corals for biomedical applications

Adjuvant induced arthritis (AIA) is accompanied by marked changes in the levels of lysosomal enzymes, glycoproteins and metabolic turnover of collagen. The role of a pentacyclic triterpene and eicosapentaenoic acid (EPA) derivative - Lupeol-EPA (50 mg/kg body weight - orally) was tested in vivo in rats. The increased activities of lysosomal enzymes and glycoproteins associated with decreased collagen in arthritic animals were significantly altered to nearly that of controls. Indomethacin (3 mg/kg body weight) was used as a reference compound. The therapeutic usefulness of Lupeol-EPA derivative in inflammatory conditions is attractive and deserves further work in this direction. © 2001 Harcourt Publishers Ltd.

Prostaglandins Leukotrienes and Essential Fatty Acids

A novel derivative pentacyclic triterpene and ω3 fatty acid [Lupeol-EPA] in relation to lysosomal enzymes glycoproteins and collagen in adjuvant induced arthritis in rats

Microwave synthesis of ceramics offers the advantage of efficient transformation of energy and heating throughout the volume efficiently in shorter period leading to fine crystallites. Hydroxyapatite (HA) and tricalcium phosphate (TCP) are widely used in the field of medicine and dentistry. Recently, biphasic calcium phosphate (BCP) ceramics has been paid attention as an ideal bone substitute due to its controlled degradability. In this paper, we report the in situ formation of BCP ceramic consisting of a mixture of HA and β-TCP in various ratios synthesized under microwave irradiation. The BCP powders were characterized by various techniques like DTA, TGA, XRD and FTIR. The thermal stability of the BCP powders was determined using differential thermal analyser and thermogravimetric analyser. The X-ray diffraction pattern of BCP powders shows the in situ formation of β-TCP in BCP powder. The amount of β-TCP phase increases as the Ca/P ratio decreases from 1.67 to 1.52. The Fourier transformed infrared spectroscopy analysis also confirmed the BCP formation. The in vitro solubility study of BCP powders in phosphate buffer of pH 7.2 showed the resorbable nature of the BCP ceramics. The present study demonstrates the feasibility of in situ formation of BCP ceramics using a domestic microwave oven. © 2001 Elsevier Science B.V. All rights reserved.

Materials Chemistry and Physics

In-situ synthesis of biphasic calcium phosphate ceramics using microwave irradiation

The effect of Withania somnifera Linn. Dunal (Solanaceae) on adjuvant arthritic rats was studied and compared with that of indomethacin. The anti- inflammatory activity of Withania somnifera was assessed by measuring paw swelling and lysosomal enzyme activity in control and experimental rats. Increased paw diameter and lysosomal enzyme activity in the arthritic animals were significantly suppressed to near normal levels in rats treated with 1000 mg kg-1 Withania somnifera root powder and 3 mg kg-1 indomethacin. These results indicate that Withania somnifera has promising anti-arthritic activity as a result of its stabilizing action on lysosomal enzyme activity.

Pharmacy and Pharmacology Communications

Effect of Withania somnifera on lysosomal acid hydrolases in adjuvant- induced arthritis in rats

The combined effect of titanium dioxide and silver oxide on the in situ formation of biphasic calcium phosphate ceramics was investigated. Titania (5-20mol%) was mixed with pure hydroxyapatite (HA) or HA containing Ag2O (10-20mol%) and was heated to 900°C for 12h. The sintered samples were found to contain tricalcium phosphate (β-TCP) and other phases along with HA depending upon the amount as well as the type of the additives used as evidenced by X-ray powder diffraction (XRD) and fourier transform infrared (FT-IR) spectroscopic studies. Enhanced TCP formation with reduced impurity phases was observed with TiO2-Ag2O addition. In vitro solubility study in phosphate buffer at physiological conditions shows the resorbable nature of these materials. A functionally graded material (FGM) structure was formed by spreading TiO2-Ag2O mixture on the surface of the HA green compact and heating at 900°C. The FGM shows gradient structure of TCP and HA from the surface to the interior of the pellet in addition to titania and silver phases. Copyright (C) 2000 Elsevier Science Ltd. The combined effect of titanium dioxide and silver oxide on the in situ formation of biphasic calcium phosphate ceramics was investigated. Titania (5-20 mol%) was mixed with pure hydroxyapatite (HA) or HA containing Ag2O (10-20 mol%) and was heated to 900 °C for 12 h. The sintered samples were found to contain tricalcium phosphate (β-TCP) and other phases along with HA depending upon the amount as well as the type of the additives used as evidenced by X-ray powder diffraction (XRD) and fourier transform infrared (FT-IR) spectroscopic studies. Enhanced TCP formation with reduced impurity phases was observed with TiO2-Ag2O addition. In vitro solubility study in phosphate buffer at physiological conditions shows the resorbable nature of these materials. A functionally graded material (FGM) structure was formed by spreading TiO2-Ag2O mixture on the surface of the HA green compact and heating at 900 °C. The FGM shows gradient structure of TCP and HA from the surface to the interior of the pellet in addition to titania and silver phases.

Biomaterials

Effect of TiO2-Ag2O additives on the formation of calcium phosphate based functionally graded bioceramics

Carbonated hydroxyapatites (CHA) were synthesized by the substitution of calcium carbonate for calcium hydroxide during the reaction with diammonium phosphate under microwave irradiation. The X-ray powder diffraction analysis indicates the decrease of a-axis up to 20mol% of carbonate substitution confirming the formation of the B-type CHA. Further increase of carbonate content shows the presence of tricalcium phosphate (TCP) in addition to CHA. Reaction of substituted magnesium carbonate instead of calcium carbonate in the above process results in the formation of biphasic calcium phosphate (BCP) ceramics consisting of both CHA and TCP phases. Fourier transform infrared spectroscopic study also confirmed the carbonate substitution in HA and BCP formation. The in vitro solubility study in phosphate buffer of pH 7.2 at 37°C showed the resorbable nature of the BCP samples. The present study thus indicates the feasibility of in situ formation of BCP ceramics using microwave irradiation. (C) 2000 Elsevier Science Ltd. Carbonated hydroxyapatites (CHA) were synthesized by the substitution of calcium carbonate for calcium hydroxide during the reaction with diammonium phosphate under microwave irradiation. The X-ray powder diffraction analysis indicates the decrease of a-axis up to 20 mol% of carbonate substitution confirming the formation of the B-type CHA. Further increase of carbonate content shows the presence of tricalcium phosphate (TCP) in addition to CHA. Reaction of substituted magnesium carbonate instead of calcium carbonate in the above process results in the formation of biphasic calcium phosphate (BCP) ceramics consisting of both CHA and TCP phases. Fourier transform infrared spectroscopic study also confirmed the carbonate substitution in HA and BCP formation. The in vitro solubility study in phosphate buffer of pH 7.2 at 37°C showed the resorbable nature of the BCP samples. The present study thus indicates the feasibility of in situ formation of BCP ceramics using microwave irradiation.

Synthesis of carbonated calcium phosphate ceramics using microwave irradiation

The partial conversion of coralline hydroxyapatite (HA) into tricalcium phosphate (TCP) catalyzed by the thermal decomposition of silver oxide was investigated. The thermal analysis of HA powder mixed with 5 mol % Ag2O indicated the decomposition of silver oxide to be around 550°C in the presence of HA. Subsequently a functional gradient structure was formed by spreading silver oxide on one surface of the HA compact of diameter 10 mm and then firing at 700 °C in air. The X-ray powder diffraction analysis confirmed the formation of α-TCP induced by the Ag2O decomposition. The content of α-TCP of the sintered pellet was found to decrease with the increasing depth from the surface of the pellet. In vitro solubility study in phosphate buffer of pH 7.2 showed the stability of the biphasic material as in between HA and TCP. (C) 2000 Kluwer Academic Publishers. The partial conversion of coralline hydroxyapatite (HA) into tricalcium phosphate (TCP) catalyzed by the thermal decomposition of silver oxide was investigated. The thermal analysis of HA powder mixed with 5 mol % Ag2O indicated the decomposition of silver oxide to be around 550 °C in the presence of HA. Subsequently a functional gradient structure was formed by spreading silver oxide on one surface of the HA compact of diameter 10 mm and then firing at 700 °C in air. The X-ray powder diffraction analysis confirmed the formation of α-TCP induced by the Ag2O decomposition. The content of α-TCP of the sintered pellet was found to decrease with the increasing depth from the surface of the pellet. In vitro solubility study in phosphate buffer of pH 7.2 showed the stability of the biphasic material as in between HA and TCP.

Journal of Materials Science: Materials in Medicine

Synthesis and characterization of functional gradient materials using Indian corals

Protein-protein interactions (PPIs) are critical, and so are the databases and tools (resources) concerning PPIs. But in absence of systematic comparisons, biologists/bioinformaticians may be forced to make a subjective selection among such protein interaction databases and tools. In fact, a comprehensive list of such bioinformatics resources has not been reported so far. For the first time, we compiled 375 PPI resources, short-listed and performed preliminary comparison of 125 important ones (both lists available publicly at startbioinfo.com), and then systematically compared human PPIs from 16 carefully-selected databases. General features have been first compared in detail. The coverage of ‘experimentally verified’ vs. all PPIs, as well as those significant in case of disease-associated and other types of genes among the chosen databases has been compared quantitatively. This has been done in two ways: outputs manually obtained using web-interfaces, and all interactions downloaded from the databases. For the first approach, PPIs obtained in response to gene queries using the web interfaces were compared. As a query set, 108 genes associated with different tissues (specific to kidney, testis, and uterus, and ubiquitous) or diseases (breast cancer, lung cancer, Alzheimer’s, cystic fibrosis, diabetes, and cardiomyopathy) were chosen. PPI-coverage for well-studied genes was also compared with that of less-studied ones. For the second approach, the back-end-data from the databases was downloaded and compared. Based on the results, we recommend the use of STRING and UniHI for retrieving the majority of ‘experimentally verified’ protein interactions, and hPRINT and STRING for obtaining maximum number of ‘total’ (experimentally verified as well as predicted) PPIs. The analysis of experimentally verified PPIs found exclusively in each database revealed that STRING contributed about 71% of exclusive hits. Overall, hPRINT, STRING and IID together retrieved ~94% of ‘total’ protein interactions available in the databases. The coverage of certain databases was skewed for some gene-types. The results also indicate that the database usage frequency may not correlate with their advantages, thereby justifying the need for more frequent studies of this nature.