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p 57-62 Full Text Preparation and Characterization of Microcrystalline Hydroxyapatite Using Sol Gel Method U.
Vijayalakshmi* and S. Rajeswari Hydroxyapatite ceramics have been recognized as substitute materials for bone and teeth in orthopaedic and dentistry field due to their chemical and biological similarity to human hard tissue. On implantation, the bioactive materials induce specific tissue response which results in the formation of a bonding interface between the implant and the natural bone tissue. Calcium phosphate is used as biomaterials such as synthetic bone graft, drug carrier and coating on metal prosthesis (in hip endoprosthesis and dental implants). Sol Gel technique has been developed and employed to prepare various materials because it has main advantage of easy control of chemical composition and low temperature synthesis that are very important for thin film formation. In this work, microcrystalline hydroxyapatite powder was synthesized from calcium acetate and tri ethyl phosphate in water and ethanol medium. The hydrolysis rate of tri ethyl phosphate in water and alcoholic medium was examined. The pH and gelation time of the batch containing with and without water was examined. The effect of calcinations on powder properties was studied. The XRD analysis was used to examine the phase transformation of hydroxyapatite at different temperature. At particular temperature calcium carbonate was observed and upon acid treatment the calcium carbonate peak at 29.399o was minimized and a stoichiometric hydroxyapatite was examined. The functional group change of hydroxyapatite at different temperature was observed by FT- IR spectroscopy. The morphological feature of the raw and sintered samples was examined. The synthesized powder was characterized through FT-IR, XRD and SEM analysis. p 63-69 Full Text Quality Assurance and Optimization Studies of Light Weight PU Prosthetic Foot V.V.
Karunakaran Polyurethane prosthetic foot was developed at the Vikram Sarabhai Space Centre as a substitute for the conventional Jaipur Foot. Several field trials case studies were made and this artificial aid was found to be very comfortable and acceptable to the amputee population, now under regular production by M/s. Bhagwan Mahaveer Viklang Sahayata Samiti, Jaipur. The tasks related to quality assurance and achieving standards related to these prostheses at affordable cost assume great significance especially for India and other developing countries. Generating acceptance standards and quality norms formed part of the development effort prior to regular production and use of these light weight prostheses. Careful attention is furthermore needed during various stages for maintaining quality of these artificial aids. A Flex testing machine was employed for initial qualification towards satisfactory performance while ensuring quality checks were found to be equally important during production stage and final moulding steps. p 70-73 Full Text Low Temperature Synthesis of Nanocrystalline Hydroxyapatite from Egg Shells by Combustion Method S.Sasikumar
and R.Vijayaraghavan Nanocrystalline Hydroxyapatite, which is similar in composition and crystal structure of natural bone, is found to be ideal bone graft substitute due to its controlled resorption in the body fluid upon implantation. This paper reports on a simple combustion technique for synthesizing nanocrystalline hydroxyapatite powder from Eggshell, Diammonium hydrogen phosphate and Citric acid. Fourier - Transform Infrared Spectroscopy and powder X-ray diffraction methods were employed to characterize the sample for phase formation. The particle size is calculated using XRD data, which shows an average diameter of 44 nm. Chemical analyses to determine the Ca:P atomic ratios in synthesized ceramics were performed and it is found to be 1.6. p 74-80 Full Text "Local Drug Delivery---Periocol" In Periodontics Divya
P.V, K. Nandakumar No abstract available p 81-83 Full Text Synthesis of Hydroxyapatite that Mimic Bone Minerology T.V.
Thamaraiselvi, K. Prabakaran and S. Rajeswari Biomimetic hydroxyapatite (HAP) that resemble human bone in composition and structure was synthesised using calcium nitrate dihydrate and diammonium hydrogenphosphate dissolved in synthetic body fluid (SBF). The chemical analyses of the powders were carried out by atomic absorption spectroscopy, titrimetry, gravimetry and spectrophotometry. The synthesised samples were characterised by fourier transform spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques. p 84-87 Full Text Electrochemical Evaluation of Hydroxyapatite Reinforced Phosphoric Acid Treated 316L Stainless Steel K.
Prabakaran, T.V. Thamaraiselvi and S. Rajeswari The localised corrosion resistance of 316L SS metallic implant due to H3PO4 treatment is being studied through electrochemical study involving cyclic polarisation experiment. The efficiency of hydroxyapatite(HAP) coatings on H3PO4 treated 316L SS is also been investigated through electrochemical studies. The study reveals that HAP coating on 40% H3PO4 treatment was found to be efficient in the corrosion resistance of 316L SS. p 88-92 Full Text Paclitaxel Drug Delivery from Cardiovascular Stent Devesh
Kothwala*, Ankur Raval*, Animesh Choubey1, Chhaya Engineer* and Haresh
Kotadia* The study was undertaken to assess the feasibility of sustained intracoronary delivery of paclitaxel from a polymer-coated stent. Characterization of the coating morphology and its correlation with the mechanism of drug release is critical for the development and understanding of controlled drug delivery coatings. In the present study, three successive layers of drug mixed with biodegradable polymer solutions were applied on SS 316 LVM stents using air suspension spray coating technique. In-vitro release of paclitaxel at regular intervals for 38 days from stents was analyzed using high performance liquid chromatography (HPLC). Scanning electron microscopy (SEM) was used to characterize the mechanism of drug delivery from multilayered biodegradable polymer based stent and it was observed that the drug particles were released owing to swollen polymeric matrix and bulk erosion. p 93-98 Full Text A Comparative Study of Conventional Sintering with Microwave Sintering of Hydroxyapatite Synthesized by Chemical Route Shekhar
Nath+, Bikramjit Basu+, Arvind Sinha! Hydroxyapatite is considered as one of the potential materials for the replacement and reconstruction of human bone and teeth. The biocompatibility of this material is well established. But the main problem with this material is its reliability due its very poor mechanical properties. In this perspective, the present contribution reports the sintering studies conducted on HAp powders, synthesized via solution-precipitation and spray drying route. Samples are sintered at different temperatures (950C -1200C) in microwave as well as in normal atmospheric conditions. The sintering Schedule is optimized in order to produce cracks free dense HAp. The obtained microstructure is characterized using XRD, SEM. A comparison is also made between conventional sintering and MW sintering in terms of the densification behaviour and microstructural variations. p 99-107 Full Text Characterization of Novel Bioactive Glass Coated Hydroxyapatite Granules in Correlation with in vitro and in vivo Studies Sandeep
G, H. K. Varma, T.V. Kumary, Suresh Babu S and Annie John Much attention has been directed towards the use of synthetic graft materials in bone tissue repair and development of new implant technologies has led to the design concept of novel bioactive materials. Here we compare the efficacy of a novel bioactive glass coated porous hydroxyapatite (BGHA) with low silica content with that of porous hydroxyapatite (HA) granules in enhancing bone formation. This in-house developed novel material was synthesized using sol-gel method and sintered into porous bioactive glass coated hydroxyapatite granules of 300-500 µm in size with pores of 100 µm. The phase purity, crystallinity, functional groups, microstructure and composition of the coated BGHA and uncoated HA granules were characterized using XRD, FTIR, SEM, SEMEDAX, and TEM. Atomic force microscopy (AFM) was also used to view the implanted site at higher resolution. To prove the biocompatibility of the material – (1) in vitro cytotoxicity was done using osteoblast cells (HOS Cell Lines) and (2) i n vivo study was carried out by implanting the granules in a critical size femoral-defect of New Zealand white rabbits (lapine model) and followed up over a period of 1, 2, 4, 6 and 12 weeks post-implantation, to evaluate the tissue response, osteogenesis and osteointegration process in bone bonding. These various evaluation parameters support bioactive glass coated hydroxyapatite granules to be a better potential nonloading bone substitute to replace lost, diseased or congenitally missing bone. p 108-114 Full Text Cell Interaction Studies with Novel Bioglass Coated Hydroxyapatite Porous Blocks Manitha.B.Nair,
H. K. Varma, T.V. Kumary, Suresh Babu S and Annie John Massive bone defect is a great challenge to reconstructive surgery. Surgeons circumvent these difficulties by using different biomaterials as bone substitutes that promote migration, proliferation and differentiation of bone cells. The aim of this study was to characterize and evaluate in vitro, an in-house developed bioceramic for its biocompatibility. Here, blocks of bioactive glass coated porous hydroxyapatite have been developed where the coating is presumed to increase implant union and bone formation. This porous hydroxyapatite was prepared by slurry foaming and drying method. The foam was then coated with sol-gel derived bioactive glass followed by controlled drying on sintering to form a block having a diameter of approximately 2 cm. Material was characterized by SEM, XRD, FTIR and TEM. Cytotoxicity and cell adhesion properties of the material were evaluated in association with cells. This study demonstrated that bioglass coated porous hydroxyapatite is a biocompatible material for ongoing osteogenic studies in segmental defects in the goat model in vivo. p 115-121 Full Text Polyurethane Degradation in the Biological Milieu Asha
S. Mathew*, K. Sreenivasan**, P.V. Mohanan***, T.V. Kumary*, Mira
Mohanty* Polyurethanes are used as biomaterials for a variety of applications such as pacemaker lead insulators, catheters, total artificial heart, heart valves. The popularity of polyurethane for biomedical applications stems from their excellent physical properties and good biocompatibility. Biomaterials in order to be successful as implant devices should be well accepted by the host system as well as they should not excert any adverse effect on the host. Even though polyurethanes offer good biocompatibility they are also found to degrade in in vivo situations in certain applications. Pacemaker leads with polyurethane insulators are found to be a failure due to the degradation of polyurethane component. This study indicates that the cell adhesion on implanted polyurethane is mediated by the adhesive proteins. |
