MS&T'11 Poster Session: Biomaterial Technology
Program Organizers: Chris Wood, TMS
Tuesday 11:00 AM
October 18, 2011
Room: Exhibit Hall C
Location: Greater Columbus Convention Center
001 A Novel Protocol for Synthesis of Pd/TiO2/SiO2 Nanocomposite Following Sol-Gel Process: Arvind Prakash1; Prem Pandey1; 1Institute of Technology, Banaras Hindu University
The present study is focussed on the synthesis of nanocomposite of Palladium/Titanium oxide/Silicon oxide (Pd/TiO2/SiO2) following sol-gel process.The product generated from the interaction of titanium isopropoxide with an aqueous solution of nitric acid are mixed with Pd.The latter was previously reduced via a hydrophobic alkoxysilane namely 3-Glycidoxypropyltrimethoxysilane followed by condensation and gelation steps. The so formed mixture was subjected to ultrasonication at 20 kHz followed by calcination to obtain Pd/TiO2/SiO2 nanocomposite. The calcination performed at two different temperatures viz. 6000C and 9000C resulted in dramatic structural change from amorphous to crystalline nature which is attributed to the phase transformation process taking place due to high temperature treatment. Moreover, the results obtained from structural characterizations confirmed the nanoscale morphology of the resulting material. The excellent compatibility of well-known electrocatalyst Pd with the composite matrix further suggested the significance of above material for electroanalytical applications.
002 A Quantitative Method to Assess Free Iron Removal after Passivation: Sophie Yang1; Lakshmi Sharma1; Bernice Aboud1; 1DePuy Orthopaedics, Inc
Removal of exogenous iron or iron contaminants from machined or polished surfaces of metallic medical devices is done by chemical dissolution in an acid solution, for the purpose of forming a protective passive film. Test methods used to determine if the ‘free iron’ has been removed are subjective, as it is unknown how much, or if any Fe is even present prior to testing. A quantitative method was required in order to equally compare the effectiveness of the trending citric acid passivation vs. nitric acid passivation. A novel method was developed by agitating polished disks (Ti6Al4V, CoCrMo) with 1mm steel shot in a Turbula shaker for a set time. Energy Dispersive Spectroscopy mapping and X-ray Photoelectron Spectroscopy were used to quantify Fe in each uniquely identified disk before and after passivation. A 2-Level DOE determined which time, temperature and concentration of citric acid and nitric acid passivation was more effective.
003 Biocompatibility of TiO2 nanotubes on titanium via anodic oxidation and heat treatment: Il Song Park1; Yu Kyoung Kim1; Ki Hyun Yu2; Hyeoung Ho Park3; Sung Mo Yang1; Tae Sung Bae1; Min Ho Lee1; 1Chonbuk National University; 2Jeonbuk Technopark; 3BS. COREM Co., Ltd
Anodic oxidation process was performed in 20V and 30㎃/㎠ for one hour to form homogenous nanotubes in 1NH4F-20H2O-Glycerol wt% and heat treatment at 500℃ Subsequently, cell proliferation, MTT, and ALP analysis were executed to assess the biocompatibility from each treatment. Two types of nanotubes with large and small diameter, respectively, were formed on the surface of TiO2 oxide layer formed in the early stage of anodic oxidation process. Cell bioactivity in the heat treated samples showed more than 7- fold increase, which induces crystal phase after nano surface treatment. Heat treatment process after anodic oxidation process, which induces phase transformation of nanotube structure with amorphous phase into anatase or rutile crystal phase, is likely to be more useful for the implantation of implants rather than using non-treated implants. Acknowledge: Research & Commercialization for Green-Components with High Specific Hardness Materials Project (2010-H-004-00020000-2010)funded by the Ministry of Knowledge Economy (MKE) of Korea
004 Calcination Study of Synthesized Nano Hydroxyapatite Using Cationic and Non Ionic Surfactants: Tahira Siddique1; Shahid Amin2; Mohammad Mujahid3; Syed Shah4; 1QAU; 2Pinstech; 3NUST; 4Hazara University
The present study enlightens the phase behavior, particle size and morphology of synthesized hydroxyapatite;HA ceramic powders by varying calcination temperatures. Calcination temperature range from 550ºC to 1000ºC has been considered for phase analysis. HA ceramic powders are synthesized using cationic surfactant; Cetyltrimethyl Ammonium Bromide; CTAB and two non ionic surfactants such as Sorbitane trioleate; Span 85 and Polyoxyethylene sorbitanmonolaurate; Tween20. 0.2 M concentration of each surfactant has been used separately to ensure the formation of required micellar templates. HA powders are prepared through chemical precipitation route along with 1.67 ratio of Ca and P precursors. The charge and molecular structures of surfactants are also scrutinized for the change in the phase, morphology and particle size. XRD shows high purity HA ceramic powders with minute impurity of DCPA and β-TCP while FTIR confirms the structural composition of HA at particular temperatures. Disparity in the crystallite size by means of temperature is found in the range of 14 nm to 30 nm for Span 85 and 17 nm to 24 nm for Tween 20 whereas for CTAB it is 35 nm to 65 nm. The morphology of the particles is characterized by SEM.
005 Calcium Phosphates for Drug Carrier: Adsorption and Release Kinetics of Drugs and Growth Factors: Solaiman Tarafder1; Amit Bandyopadhyay1; Susmita Bose1; 1Washington State University
Lovastatin (LOV) is a cholesterol lowering drug. 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibition by lovastatin stops inhibition of osteoblast activity, and promoting osteoclast activity. Glutamic acid (GA), an amino acid, in addition to being a neuro-transmitter can also regulate bone cell activities by glutamate signaling. Objective of this research is to understand the chemistry of adsorption and release kinetics of LOV and GA in β-tricalcium phosphate (β-TCP) based ceramics. The sigmoidal adsorption isotherm of LOV shows a cooperative effect, indicating interaction between neighboring adsorbed molecules. DSC thermogram shows an endothermic peak at 184 °C due to adsorbed lovastatin on TCP. No release detection of lovastatin or low release of GA could be due to complex formation of with Ca2+. GA is a metal chelating agent which makes it capable for strong chemical interactions with metallic ions. Interaction and release behavior of growth factors with calcium phosphates have also been investigated.
006 Corrosion Susceptibility of Magnesium Based Biodegradable Alloys in Simulated Physiological Solutions: Puneet Gill1; Norman Munroe1; Amit Datye2; 1Florida International University; 2University of Tennessee Knoxville
Metallic materials continue to play an essential role as biomaterials to assist with the repair/replacement of various diseased or damaged parts of the anatomy. Currently approved and commonly used metallic biomaterials have been found to have adverse effects leading in some cases to mechanical failure and rejection of the implant. Moreover, the physical or chemical nature of the degradation products of some implants may initiate adverse foreign body reaction in the tissue. Some metallic implants remain as permanent fixtures, whereas others such as plates, screws and pins used to secure serious fractures are removed by a second surgical procedure after the tissue has healed sufficiently. However, repeat surgical procedures increase the cost of health care and the possibility of patient morbidity. In this investigation, magnesium based biomaterials are studied for its degradation rate, mechanical and biocompatibility properties.
007 Direct Cytotoxicity Evaluation of 63s Bioactive Glass Nanoparticles Using Yeast Model and Human Chondrocyte Cells by Microcalorimetry: Ali Doostmohammadi1; Ahmad Monshi1; Mohammad Hossein Fathi1; 1Isfahan University of Technology
The cytotoxicity evaluation of 63S bioactive glass nanoparticles with yeast and human chondrocyte cells was carried out using isothermal micro-nano calorimetry (IMNC), which is a new method for studying cell/biomaterial interactions. Bioglass nanoparticles were made via sol-gel method. Elemental analysis was carried out by XRF. Amorphous structure of the glass was detected by XRD analysis. Finally, the cytotoxicity of bioactive glass nanoparticles with yeast and cultured human chondrocyte cells was evaluated using IMNC. The results confirmed the viability and proliferation of human chondrocyte cells in contact with 63S bioglass nanoparticles. Also the results indicated that yeast model which is much easier to handle, can be considered as a good proxy and can provide a rapid primary estimate of the ranges to be used in assays involving human cells. All of these results confirmed that IMNC is a convenient method which caters to measuring the cell-biomaterial interactions alongside the current methods.
008 Effect of Crystallinity on Dissolution Properties of Plasma Sprayed Hydroxyapatite Coatings: Mangal Roy1; Amit Bandyopadhyay1; Susmita Bose1; 1Washington State University
Plasma sprayed hydroxyapatite (HA) coatings are widely used in load bearing orthopaedic implants. The physical and mechanical stability of these coatings are dependent on the dissolution properties in physiological conditions. In this presentation we will discuss about the effect of crystallinity on the stability of induction plasma sprayed nano HA coatings. A 30 kW plasma spray system, equipped with supersonic nozzle, was used to prepare HA coating with different crystallinity. Dissolution experiments were performed at pH 5.5 and pH 7.4 buffered media for 32 days at 36.5± 0.5 °C with shaking at 150 rpm. The dissolution media was analyzed for Ca2+ concentration. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and adhesive bond strength test were used to study the structural, phase and mechanical property changes due to dissolution. Coatings with different crystallinity, in general, gained weight at pH 7.4 and lost weight at pH 5.5.
009 Effect of Different Type of Kenaf Fiber Composite on the Mechanical Properties: Mohamad Nor Berhan1; ZURAIDAH SALLEH1; NOR FAZLI ADULL MANAN1; YAKUB MD TAIB1; DAVID ISAAC2; 1UNIVERSITI TEKNOLOGI MARA; 2SWANSEA UNIVERSITY
The interest in using natural fibers in composites has increased in recent years due their lightweight, combustible, non-toxic, non-abrasive, low cost and biodegradable properties. In this study, three difference types of kenaf fiber are use in fiber-reinforced composites. The kenaf powder, short kenaf fiber and kenaf textile are use in of different weight percentage are prepared by cool press hand lay-up technique are investigated. A series of tensile tests were also performed to evaluate the effect of their modulus and ultimate tensile stress (UTS). Morphological and structural changes of the fibers were investigated using scanning electron microscopy (SEM). It has been found that very interesting result were the tensile strength are increase by increasing weight percentage in short kenaf fiber and textile kenaf composite, but powder kenaf composite it happen the outer ways. From this study, kenaf textile composite shown the outstanding compared with others test result.
010 Effect of the Sintering Temperature on Microstructural Properties of a Bioceramic Bone Scaffold: Juan Vivanco1; Aldo Araneda2; Heidi Ploeg1; 1The University of Wisconsin, Madison; 2Universidad Tecnica Federico Santa Maria
Bioactive calcium phosphate (CP) scaffolds have emerged as synthetic alternatives to bone graft, acting to target fracture healing and bone disease such as osteoporosis. Previous research has shown that these bioceramic materials due to their osteoinductive and biocompatible properties can potentially induce bone formation from the surrounding native tissue. Sintering temperature of CP scaffolds has been shown to influence the microstructure and properties; however, a comprehensive study to determine the influence of sintering temperature on CP scaffolds has yet to be performed. Thus, the objective of this work was to determine the microstructural properties of an injection molded CP scaffold based on the crystallographic phases and grain arrangement for different sintering temperatures. The CP scaffolds were fabricated using tricalcium phosphate and sintered at three target temperatures. The microstructural properties were characterized by different techniques such as: X-ray diffraction, scanning electron microscopy with associated energy dispersive X-ray spectroscopy, and microhardness.
011 Effects of Bioabsorbable Mg Alloys on Endothelialization: Puneet Gill1; Norman Munroe1; Ebony Daniels1; 1Florida International University
Approximately 37 % of Americans have some type of heart disease as a result of obesity, hypertension, tobacco usage and elevated cholesterol levels. The number is projected to rise to 41 % (116 million people) by 2030. The demand for new and improved materials has lead to the development of bioabsorbable materials, which degrade in the body leaving non-deleterious products. Alloys were designed so that the concentration of the dissolved ions once implanted, would not substantially exceed the concentration of dissolved metal ions normally found in human blood. The biocompatibility of the alloys was assessed by conducting corrosion tests and observing the growth of endothelial cells on their surfaces by electrochemical impedance spectroscopy (EIS). The cytotoxicity of the leached metal ions after corrosion was studied on cell viability by SRB assays. Furthermore, the effect of dissolved metal ions on clotting time of human plasma was studied.
012 Electrochemical Synthesis of Polyaniline over Prussian Blue Encapsulated Ormosil Electrodes and Its Application in the Electrochemical Oxidation of Cysteine: Dheeraj Chauhan1; Prem Pandey1; 1Institute of Technology, Banaras Hindu University
Organically modified silicates (ormosils) are hybrid organic–inorganic materials formed through the hydrolysis and condensation of organically modified alkoxysilanes. The ormosil matrix was manipulated by incorporating a well known electron transfer mediator Prussian blue (PB) and is utilized as a template for the electropolymerization of aniline. The presence of electroactive polyaniline (PAni) within the nanostructured network of ormosil is confirmed using structural and electrochemical characterizations. Role of PB on the electropolymerization was also investigated and it was observed that the presence of PB significantly improves the kinetics of the synthesis of PAni in the ormosil matrix. Above protocol lead to the synthesis of PAni/PB composite that was further utilized for electrochemical determination of cysteine, a naturally occurring amino acid bearing a thiol group. The sensing was performed using cyclic voltammetric and amperometric studies at the surface of a PAni/PB/carbon paste electrode that was oxidized from PB to Berlin green state.
013 Gelatin Stabilized Gold Nanoparticles Supported Titania Nanotubes: A Novel Platform for Medical Implants: Yukyoung Kim1; Madhav Prasad Neupane1; Myong Hun Kang1; Ji Hyun Kong1; Il Song Park1; Hyeoung Ho Park2; Min Ho Lee1; 1Institute of Oral Bioscience and BK 21 Program; 2BS. COREM Co., Ltd.
Nanotubular TiO2 has been recognized as a promising biomaterial with proven biocompatibility, thermal stability and corrosion resistance. This work improves implant functions by modulating the properties of TiO2 nanotubular surfaces by the impregnation of gelatin stabilized gold nanoparticles(AuNPs-gelatin) which facilitates the attachment, adhesion and proliferation of osteoblast cells. The growth of cells demonstrated that the adhesion and propagation of the osteoblast cells is significantly improved by the topography of TN-AuNPs-gelatin with the filopodia of the growing cells actually going into the nanotube pores, producing an interlocked cell structure. The cytotoxicity of TN-AuNPs-gelatin surface decreases as compared to polished Ti and bare TN surfaces, which is most likely caused by the pronounced hydrophilicity and biocompatibility of the loaded material and possibly the pathways for fluid present between the nanotubes. Acknowledge: Research & Commercialization for Green-Components with High Specific Hardness Materials Project (2010-H-004-00020000-2010)funded by the Ministry of Knowledge Economy (MKE) of Korea
014 Heat Treatment Effect on Different Type of Kenaf Fiber Composite: Zuraidah Salleh1; MOHAMAD NOR BERHAN1; YAKUB MD TAIB1; DAVID ISAAC2; NOR FAZLI ADULL MANAN1; 1UNIVERSITI TEKNOLOGI MARA; 2SWANSEA UNIVERSITY
Kenaf, Hibiscus cannabinus L., is biodegradable and environmentally friendly crops. The most rapidly expanding application for kenaf fibres at present is as reinforcement in composites. The interest in using natural fibers in composites has increased in recent years due their combustible, non-toxic lightweight, non-abrasive, low cost and biodegradable properties. In this study, differences of heat treatment kenaf fiber were use in fiber-reinforced composites. The kenaf powder, short kenaf fiber and kenaf textile are use in different of heat treatment are prepared by cool press hand lay-up technique are investigated. A series of tensile tests were also performed to evaluate the effect of their modulus and UTS. Morphological and structural changes of the fibers were investigated using SEM. From the result it has been found that the tensile strength is increase almost 15% percentage by increasing temperature and time in heat treatment process and the textile kenaf composite have highest UTS.
015 Highly Sensitive Determination of Ascorbic Acid over Polyaniline Synthesized Electrochemically within Nanostructured Network of Sol-Gel Matrix: Vandana Singh1; Richa Singh1; Prem Pandey1; 1Institute of Technology, Banaras Hindu University
Nano-structured network of organically modified sol-gel glass (ORMOSIL) matrix along with different redox mediators was used as a template for electropolymerization of aniline. Three categories of redox mediators, potassium ferricyanide (inorganic), tetracyanoquinodimethane (TCNQ) (organic), and ferrocene (Fc) (organometallic) were encapsulated within ormosil film. The film was cast at the surface of indium tin oxide electrodes and used as a template for electropolymerization of aniline. Polyaniline (PAni) with excellent electrochemical behavior was grown within these modified electrodes. The resulting polymers were studied using structural and spectroelectrochemical characterizations. On the basis of electroactive behavior and polymerization process, PAni synthesized through TCNQ is chosen for electrode modification to study the eletrocatalytic oxidation of ascorbic acid. The material exhibits excellent electrocatalytic activity with a great negative shift in the anodic overpotential. Significant increase in the anodic peak current and sensitivity for the oxidation of ascorbic acid was also observed over modified electrodes.
016 Impact Strength and Post Impact Tensile Strength of Kenaf Powder/PP (with and without MAPP) with Different Powder Percentage and Sizes: NOR AMALINA NORDIN1; YAKUB MD TAIB1; ZURAIDAH SALLEH1; MOHAMAD NOR BERHAN1; NOR FAZLI ADULL MANAN1; MOHD HAFEEZ MOHD AINI1; 1UNIVERSITI TEKNOLOGI MARA
Kenaf powder has potential to use as reinforcing fillers in producing natural fiber composite. This kind of natural fiber has low densities, high specific properties and also high volume of filling when producing the composite. The reason is their nature non-abrasive permits the use of kenaf as reinforcing filler. This study is focus on fabricating Kenaf Powder/PP with using Maleated Polypropylene (MAPP) and act as coupling agent to improve the bonding for kenaf powder and PP. By applying the different kenaf powder percentages and powder sizes, this paper will investigate the mechanical properties of Kenaf/PP composites in two different types of testing (izod impact strength test and post impact tensile strength test). Result obtained for izod impact and tensile test of KPC with kenaf powder size of 250 micron and 20% weight ratio without MAPP gave the highest value of the tensile strength and this KPC composite formulation.
017 In Vivo Evaluation of the Spark Plasma Sintered Al2O3-ZrO2-CeO2 Composites: Gultekin Goller1; Ipek Akin1; Simona Cavalu2; Viorica Simon3; 1Istanbul Technical University; 2University of Oradea; 3Babes-Bolyai University
In this study, Al2O3, and Al2O3/3Y-TZP composites with 3 and 5wt% CeO2 were prepared by spark plasma sintering at 1350˚C and 1400˚C for 300 s under40 MPa, respectively. Adult rats from the Wisthar-Furth lineage were used for in vivo evaluations. They were kept in a proper environment under natural lighting and temperature. A 0.75cm x 1.5cm bone defect was created on the body of each mandible in animals using a low RPM Sorensen 7.5 spherical burr. The defects were filled with granular Al2O3-based composites containing 3Y-TZP and CeO2, and blood plasma harvested from each animal prior to surgery. A collagen film was placed on the top of the filled defect in order to improve the biocompatibility of the implanted material. The histopathological tests of the surrounding tissue and specimens containing the junction between the implanted material and natural bone were characterized by using a scanning electron microscope.
018 Nanofiber-Based Sensors for Oxygen Determination: Ruipeng Xue1; Alex Roth1; Mariano Viapiano1; Dave Farson1; Andre Palmer1; John Lannutti1; 1The Ohio State University
We merge oxygen-sensing photonic engineering with a biologically relevant aligned fiber scaffold creating a device having the capability to detect and report oxygen gradients in the vicinity of model tumors. Tumor cell migration is known to be sensitive to local gradients in oxygen concentration. Understanding how the biophysical properties of migration and sensitivity to chemotherapeutics are related to the surrounding oxygen contents is key to the development of anti-migratory drugs. Electrospinning was employed to fabricate oxygen permeable, biocompatible polycaprolactone (PCL) scaffolds containing an oxygen-sensitive ruthenium dye capable of providing quantitative sensing of localized oxygen concentrations. Fluorescence microscopy is used to excite the fibers and measure the intensity of the emitted light. Results showed that the intensity decrease is proportional to the dissolved oxygen concentration likely due to dynamic quenching. Oxygen concentration could then be determined based on the calibration curve involving a series of solutions having known oxygen concentrations.
019 Post Impact Tensile on Kenaf Powder Fiberglass Laminate: Nor Fazli Adull Manan1; ZURAIDAH SALLEH1; YAKUB MD TAIB1; MOHAMAD NOR BERHAN1; FADHLUL WAFI KEYA NORDIN1; 1UNIVERSITI TEKNOLOGI MARA
Kenaf powder have a lot of advantageous of its characteristic and value such as low density, high specific strength and modulus, relative non-abrasiveness, ease of powder surface modification, and wide availability. In this research the post-impact tensile of kenaf fiberglass laminate and polyester as the matrix-resin are investigated. The specimens were prepared with hand lay-up. Then, they were cut into parallel-sided according to the testing standard from EN ISO 527-5:1997. The low-velocity impact testing done subjected with impact energies ranging from 1J to 5J by using a Falling Weight Impact (FW2 356/53). Impact test is to determine the toughness of the sample 25% of weight age for kenaf powder composite. Tensile test were carried out by using Instron 3382. The result has shown that fiberglass laminated is increase the strength kenaf composite. After the impact and tensile test, the condition of fiberglass is still holding the kenaf composite from break.
020 Post-Impact Fatigue of Short Kenaf Fibre Metal Laminates: YAKUB MD TAIB1; ZURAIDAH SALLEH1; SYARIFAH YUNUS1; MOHD HAFEEZ MOHD AINI1; NOR FAZLI ADULL MANAN1; 1UNIVERSITI TEKNOLOGI MARA
The present study aims to characterise damage due to low velocity impact on short kenaf fibre reinforced polymer (SKFRP). To attain this goal, a number of post-impact tests, unidirectional tensile tests and tension-tension fatigue tests have been carried out. Tensile test were carried out by using Servo Hydraulic with 20%, 25%, 30% and 35% wt kenaf. The result revealed that the specimen containing 25% wt kenaf exhibit better UTS and will be used and investigate further for low velocity impact test and fatigue test. To enhance the mechanical properties of the SKFRP, the composites materials were then laminated with aluminium plate (FML). The low velocity impact test were done with impact energies ranging from 1 to 20 Joules by using drop weight impact test machine. Tension fatigue tests with the stress ratio of 0.1 and frequency 10 Hz were implemented. Finally, specimens were then observed by using Stereo Zoom Microscope.
021 Radiation Interactions in Biologically Important Materials: Pravina Pawar1; Govind Bichile1; 1Dept of Physics
Biomaterials is a term used to indicate materials that constitute parts of medical implants, extracorporeal devices, and disposables that have been utilized in medicine, surgery, dentistry, and veterinary medicine as well as in every aspect of patient health care. Biomaterials are materials used in close or direct contact with the body to augment or replace faulty materials. Biomaterials must be compatible with the body so that the body does not reject them. However, in some cases, biomaterials like organ transplants do cause rejection, which can be addressed through anti-rejection medications. Biomaterials do not have to be living or once living materials however. They can be of synthetic origin as well. The paper gives the results of theoretical calculations of parameters like effective atomic number (Zeff) and electron density (Ne) which characterize the γ-ray interaction for different biocompatible materials.
022 Sintering and Bioactivities of Hydroxyapatite: Monica Sawicki1; Kyle Crosby1; Ling Li1; Leon Shaw1; Yong Wang1; 1University of Connecticut
Hydroxyapatite (HA) is the main inorganic mineral of bone. The use of HA in orthopedic implants supports bone ingrowth and osseointegration due to its bioactivity. The typical sintering temperature for dense HA bodies is 1100°C or higher. In this study, sintering of HA at temperatures lower than 1100°C is enabled by HA nano-rods synthesized from a wet precipitation process. To investigate the effect of grain sizes on the bioactivity, various sintering temperatures have been employed to create HA bodies with grain sizes ranging from ~100 nm to tens of micrometers. The relationships between the sintering temperature, grain size, and final density are established. The bioactivities of the HA bodies in terms of cell attachment and proliferation are investigated with the aid of ROS17/2.8 cells and MTT assay, while cell morphologies are studied using scanning electron microscopy. The mechanism of the effect of grain sizes on the bioactivity will be discussed.
023 SiO2 and SrO Doped β-TCP: Influence of Dopants on Mechanical and Biological Properties: Gary Fielding1; Johanna Feuerstein1; Amit Bandyopadhyay1; Susmita Bose1; 1Washington State University
The aim of this study was to understand the influence of silica (SiO2) and strontium oxide (SrO) dopants on the bioresorbable properties of β-tricalcium phosphate (TCP) ceramics. TCP powder was doped with 0.5 wt% SiO2 and 1 wt% SrO, pressed into compacts by uniaxial pressing and sintered for 2 h at 1250˚ C. In vitro mineralization and strength degradation studies were performed in simulated body fluid (SBF) for 12 weeks. Scanning electron microscopy (SEM) and attenuated total reflection infrared scectroscopy (ATR-IR) was used to examine surface apatite formation. Doped samples showed increased affinity for apatite formation and their strength remained stable over the 12 week period when compared to pure TCP samples. Atomic absorption spectroscopy (AAS) was used to determine calcium ion concentration in simulated body fluid (SBF) solution. The presentation will discuss processing and characterization of doped TCP for bone tissue engineering.
024 Sr/Mg Doped 3D Interconnected Porous β-Tricalcium Phosphate Ceramic Scaffolds for Bone Tissue Engineering: In Vivo Evaluation in Rat and Rabbit Model: Solaiman Tarafder1; William Dernell1; Neal Davies1; Amit Bandyopadhyay1; Susmita Bose1; 1Washington State University
Scaffolds with 3D interconnected pores provide pathways for micronutrients, and increased surface area allows improved mechanical interlocking. Dopant plays a vital role in controlling the degradation kinetics, mechanical strength, and biological properties of β-tricalcium phosphate (β-TCP). Objective of the present study is to investigate the effect of Sr/Mg and 3D interconnected porosity in β-TCP on mechanical strength, and in vivo osteogenesis in distal femur of rat and rabbit. In vitro study revealed an increase in cell density with a decrease in pore size, while in vivo study showed pore size greater than 200 µm is suitable for bone tissue ingrowth. Sr/Mg doped porous scaffolds showed a significant increase in osteocalcin and type I collagen after 16 week period in rat. Histological and histochemical analysis of implants from rat and rabbit femur revealed the presence of both Sr/Mg and 3D interconnected porosity induced excellent ingrowth of osteoid like new bone formation.
025 Structural Analysis and Characterization of Zn-Substituted Nano Hydroxyapatite: Uma Batra1; Seema Kapoor2; 1PEC Univ. of Technology; 2University Institute of Chemical Engineering &Technology, Panjab University
Zinc substituted nano hydroxyapatite (n-ZnHA) has been synthesized by sol-gel technique. Calcium nitrate tetrahydrate, Zinc nitrate and potassium dihydrogen phosphate were used as precursors under water based solution. Triethanolamine (TEA) was used as a capping agent. The synthesized nanopowder was calcined by conventional means at three different temperatures 800 C, 1000 C and 1200 C for 3hrs. The n-ZnHA powders were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and thermal gravimetric analyser (TGA) techniques. The results showed that Zn substitution has exhibited an evident inhibitory role on synthesis of HA through a reduction in crystallite size and a decrease in thermal stability. Bioactivity behaviour of n-ZnHA was assessed through in-vitro study in simulated body fluid (SBF) and n-ZnHA is found to be more bioactive as compared to nano hydroxyapatite synthesized without Zn substitution.
026 Synthesis and UV-Enhanced Cytotoxicity of Pure and Ni-Doped ZnS@ZnSe Quantum Dots: Melissa Cruz1; Sonia Bailon1; 1University of Puerto Rico at Mayagüez
Photodynamic therapy (PDT) in presence of semiconductor quantum dots (QDs) is a promising technique for cancer treatment that involves the use of photosensitizers to generate cytotoxic species, and kill cancer cells. The present work is focused on the synthesis and evaluation of the cytotoxicity of water-soluble pure and Ni-doped ZnSe@ZnS QDs in human-pancreatic carcinoma cells (PANC-1). QDs were fully characterized on a structural, morphological and optical viewpoint. The viability of PANC-1 decreased from 85.6±12.1% to 46.7±0.9% when contacted with 0 ppm and 300 ppm of pure QDs, respectively. The cytotoxicity of QDs was enhanced under UV-irradiation as a function of the exposure time. The viability of PANC-1 in presence of 50ppm of pure QDs decreased from 97.6 ± 4.1% (0-minutes of irradiation) down to 35.9 ± 4.4% (60-minutes of irradiation). Our results evidenced the feasibility of using selected QDs as a platform to generate cytotoxic species.
027 Synthesis of Prussian Blue/Palladium Nanocomposite and Its Application in the Electrocatalytic Determination of Hydrogen Peroxide: Ashish Pandey1; Dheeraj Chauhan1; Prem Pandey1; 1Institute of Technology, Banaras Hindu University
The present work is focussed on the fabrication of an efficient hydrogen peroxide (H2O2) sensor prepared from Prussian blue/Palladium (PB/Pd) nanocomposite. PB was synthesized following facile chemical method by the addition of an aqueous solution of ferrous sulphate to an equimolar solution of potassium ferricyanide. Palladium chloride was reduced by 3-Glycidoxypropyltrimethoxysilane following high temperature treatment. The electrochemical behavior of PB was tremendously enhanced by the incorporation of palladium metal resulting in the formation of PB/Pd nanocomposite. Thus obtained nanocomposite was utilized to modify the carbon paste electrode (CPE), leading to the development of an electrochemical sensor for H2O2. The results of cyclic voltammery and amperometric measurements are reported in this communication. The sensitivity for H2O2 determination was found out to be 22.89 AmM-1cm-2 with a limit of detection of 500 nM. The results on the effect of pH suggested that lowering of pH lead to improved kinetics of H2O2 reduction.
028 The Deposition of Chitosan-Vancomycin-Gelatin-Calcium Phosphate Composite on Post Bio-Ceramics Coated Ti6Al4V: Ming-Jia Wang1; Jung-Yi Lo1; Chi-Chum Yang1; Shiow-Kang Yen1; 1National Chung-Hsing University
In order to reduce the probability of osteomyelitis, the chitosan-vancomycin-gelatin- calcium phosphate (Chi-Van- GEL-CaP) composite is deposited on post bio-ceramics coated Ti6Al4V alloys in the study. The vancomycin drug loaded composite coated specimens are characterized by polarization tests, XRD, SEM/EDS analysis, FTIR, UV visible spectrometer, inhibition zone method and the biological evaluation by cell culture with MTT and ALP assays .The results indicate that the vancomycin drug loading is about 200 μg/cm2 in the Chi-Van-GEL-CaP composite coating and the drug releasing time is about 30 days. Besides, the inhibition zone of Staphylococcus aureus (S. A.) is 32 mm in diameter. This means that the coating effectively inhibited S.A. On the other hand, in vitro cell culture revealed no obvious side effects on the proliferation and differentiation of osteoblast on composite coated specimens.
029 Thin Film Storage Material W-DLC and Si-DLC on AISI-316 for Biomedical Applications: Fabian Lerma1; German Plazas1; Faruk Fonthal Rico1; Clara Goyes Lopez1; Carlos Rincon2; 1Advanced Materials for Micro and Nanotechnology Group - Universidad Autonoma de Occidente; 2FISICA DE BAJAS TEMPERATURAS - EDGAR HOLGUIN - Universidad del Cauca
This work has like object to improve the mechanical, tribological, biocompatibility and biofunctional properties of AISI-316, using a monolayer of diamond-like carbon (DLC) doped within W and Si. These hard coatings were studied to improve the strength and biocompatibility of the material and can be applied to the prosthesis, as the head of the femur or knee. The technique used for the growth of the coatings was by RF sputtering. The monolayer were developed using the materials: coal, titanium, silicon and tungsten. It evaluated the biocompatibility of the monolayer by means proof of cell viability, itself involve linfocitos's cultivation; getting experimental moral values good for each monolayer: W-DLC presented a yield of 51,19% over cell viability than Fe (negative control), Si-DLC presented a yield of 48,68% more cell viability in relation to the same control.
030 Tricalcium Phosphate System in Drug Delivery and Bone Graft: Joe Edgington1; Susmita Bose1; Amit Bandyopadhyay1; 1Washington State University
Recently, the lithium-doped tricalcium phosphate (Li-TCP) system has shown significant interests due to its performance toward enhanced osteoblast proliferative activity, and differentiation. The influence of Li-doping on mechanical and biological properties of TCP was investigated. Immunohistochemistry results indicated that the levels of Li-doping in β-TCP increase the level of differentiation in cells, as compared to undoped β-TCP. TCP coupled with polymer, e.g. polycaprolactone (PCL), proves to be an efficient system in protein or drug delivery. We are investigating the loading and release of agents such as bovine serum albumin (BSA), aspartic acid (ASP) and bone morphogenetic protein-2 (BMP-2) from a TCP delivery vehicle. The hypothesis is that protein or drug can be released in a controlled manner from the optimal TCP-polymer composite system. The poster will present both doped TCP and their composite system in drug delivery and bone tissue engineering.