Biomedical Devices and Instrumentation Commons^™

Design And Evaluation Of 3d Printed Features To Improve Stability Of Plasma-Cell Pack Interface In Bacteria Separating Hollow Spinning Disk, Colin G. Bledsoe, Ryan L. Wood, Daneil S. Mcclellan, Dr. William G. Pitt

Biomedical Engineering Western Regional Conference

PDF submission of abstract.

A Novel Tantalum-Containing Bioglass. Part Ii. Development Of A Bioadhesive For Sternal Fixation And Repair, Adel Mf Alhalawani, Cina Mehrvar, Wendy Stone, Stephen D. Waldman, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

With over a million median sternotomy surgeries performed worldwide every year, sternal wound complications have posed a serious risk to the affected patients. A rigid therapeutic sternal fixation device has therefore become a necessity. In this work, the incorporation of up to 0.5 mol% of tantalum pentoxide (Ta₂O₅), in exchange for zinc oxide (ZnO), into the SiO₂-ZnO-CaO-SrO-P₂O₅ glass system is presented. The effect of Ta incorporation on the physical, chemical and biological properties of the glass polyalkenoate cements (GPCs) prepared from them have been presented in this manuscript. The data obtained …

Characterization Of Polyurethane For Use As Substrate In Nanofiber Sensor For Biomedical Applications, Megan Theaker

Williams Honors College, Honors Research Projects

The purpose of this project is to begin to determine properties of polymer nanocomposites that make a suitable substrate for nanofiber sensors. In this work, sensitivity of a sodium ion selective sensor constructed with polyurethane was used as a benchmark for comparison with sensors constructed with nylon-6. The sensors were characterized using contact angle and chronoamperometry. Using an ANOVA analysis, the results showed that the multi-walled carbon nanotube type was a significant factor on sensor response both with and without additional functionalization of the polymer by calixarene. The weight percentage of polyurethane in the electrospinning solution was also statistically significant …

Surface Enabled Lab-On-A-Chip (Loc) Device For Protein Detection And Separation, Zhichao Wang

Dissertations, Master's Theses and Master's Reports

Sensitive and selective chemical/biological detection/analysis for proteins is essential for applications such as disease diagnosis, species phenotype identification, product quality control, and sample examination. Lab-on-a-chip (LOC) device provides advantages of fast analysis, reduced amount of sample requirements, and low cost, to magnificently facilitate protein detection research. Isoelectric focusing (IEF) is a strong and reliable electrophoretic technique capable of discerning proteins from complex mixtures based on the isoelectric point (pI) differences. It has experienced plenty of fruitful developments during previous decades which has given it the capability of performing with highly robust and reproducible analysis. This progress has made IEF devices …

Materials And Techniques Used In Cranioplasty Fixation: A Review, Basel A. Khader, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Cranioplasty is the surgical repair of a deficiency or deformity of the skull. The purpose of cranioplasty is to provide protection for the brain following cranial surgery, and to offer relief to psychological disadvantages while increasing social performance. There are several materials that had been used for cranioplasty, but an ideal product has yet to be developed, hence the ongoing research into biologic and non-biologic alternatives to the existing materials. This article critiques the products currently used for cranioplasty in order to facilitate the development of new materials, which can improve patient outcomes.

Hydrothermal Synthesis And Characterisation Of Bioactive Glass-Ceramic Nanorods, Ehsan Zeimaran, Sara Pourshahrestani, Seyed Farid Seyed Shirazi, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this study fabrication of rod-like bioactive glass-ceramics (BGCs) using hydrothermal treatment based on a sol-gel precursor is reported for the first time. BGCs with composition 58 wt% SiO₂, 33 wt% CaO and 9 wt% P₂O₅ were synthesized in different thermal conditions (200 and 220 °C) and characterised with regard to morphology, chemical composition and crystallinity. The bioactivity of the materials was assessed by immersion in simulated body fluid for up to 7 days. The results revealed that as the reaction temperature increased from 200 to 220 °C, the diameter of rods was reduced from …

Raman Spectroscopic Analysis Of Fingernail Clippings Can Help Differentiate Between Postmenopausal Women Who Have And Have Not Suffered A Fracture, James R. Beattie, Niamh M. Cummins, Clare Caraher, Olive M. O'Driscoll, Aruna T. Bansal, Richard Eastell, Stuart H. Ralston, Michael D. Stone, Gill Pearson, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Raman spectroscopy was applied to nail clippings from 633 postmenopausal British and Irish women, from six clinical sites, of whom 42% had experienced a fragility fracture. The objective was to build a prediction algorithm for fracture using data from four sites (known as the calibration set) and test its performance using data from the other two sites (known as the validation set). Results from the validation set showed that a novel algorithm, combining spectroscopy data with clinical data, provided area under the curve (AUC) of 74% compared to an AUC of 60% from a reduced QFracture score (a clinically accepted …

The Role Of Poly(Acrylic Acid) In Conventional Glass Polyalkenoate Cements, Adel M.F. Alhalawani, Declan J. Curran, Daniel Boyd, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) have been used in dentistry for over 40 years. These novel bioactive materials are the result of a reaction between a finely ground glass (base) and a polymer (acid), usually poly (acrylic acid) (PAA), in the presence of water. This article reviews the types of PAA used as reagents (including how they vary by molar mass, molecular weight, concentration, polydispersity and content) and the way that they control the properties of the conventional GPCs (CGPCs) formulated from them. The article also considers the effect of PAA on the clinical performance of CGPCs, including biocompatibility, rheological and …

Characterization Of Silica-Based And Borate-Based, Titanium-Containing Bioactive Glasses For Coating Metallic Implants, Omar Rodriguez, Declan J. Curran, Marcello Papini, Lana M. Placek, Anthony W. Wren, Emil H. Schemitsch, Paul Zalzal, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioactive glasses have found applications in diverse fields, including orthopedics and dentistry, where they have been utilized for the fixation of bone and teeth and as scaffolds for drug delivery. The present work outlines the characterization of two novel titanium-containing glass series, one silica-based and one borate-based. For the silica-based series, titanium is added at the expense of silicon dioxide whereas for the borate-based series, it is added at the expense of boron oxide as confirmed by Energy Dispersive Spectroscopy. Amorphous structures are obtained for silica-based glass at 15 mol% TiO₂ and for borate-based glasses at 0 mol% and …

Gallium-Containing Mesoporous Bioactive Glass With Potent Hemostatic Activity And Antibacterial Efficacy, Sara Pourshahrestani, Ehsan Zeimaran, Nahrizul Adib Kadri, Nicola Gargiulo, Shani Samuel, Sangeetha Vasudevaraj Naveen, Tunku Kamarul, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Haemorrhage remains the leading cause of potentially survivable death in both military and civilian populations. Although a large variety of hemostatic agents have been developed, many of them have an inadequate capacity to induce hemostasis and are not effective in killing bacteria. In recent years, mesoporous bioactive glasses (MBGs) were found to be effective in inducing hemostasis. However, the materials may not be considered as ideal hemostats since they do not offer antimicrobial activity. The gallium ion (Ga⁺³) not only exhibits antibacterial properties but also accelerates the blood coagulation cascade. The aim of this study was to develop …

Relating Ion Release And Ph To In Vitro Cell Viability For Gallium-Inclusive Bioactive Glasses, Timothy J. Keenan, L. M. Placek, T. L. Mcginnity, Mark R. Towler, M. M. Hall, A. W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

A bioactive glass (BG) in which Ga was substituted for Zn was formulated to investigate whether the ionic form of Ga can elicit effects similar to gallium nitrate. The ion release and pH of BG extracts were evaluated, as well as the in vitro cytocompatibility of extracts in contact with mouse fibroblasts and human osteoblasts. After incubation times of 1 year, the glass (TGa-1) containing the smaller Ga-addition (8 mol%) released the most sodium (Na) (1420 mg/L), silicon (Si) (221 mg/L), and Ga (1295 mg/L), while the glass (TGa-2) containing the larger Ga-addition (16 mol%), exhibited release levels between TGa-1, …

Antibacterial Properties Of Poly (Octanediol Citrate)/Gallium-Containing Bioglass Composite Scaffolds, Ehsan Zeimaran, Sara Pourshahrestani, Ivan Djordjevic, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Anthony W. Wren, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioactive glasses may function as antimicrobial delivery systems through the incorporation and subsequent release of therapeutic ions. The aim of this study was to evaluate the antimicrobial properties of a series of composite scaffolds composed of poly (octanediol citrate) with increased loads of a bioactive glass that releases zinc (Zn²⁺) and gallium (Ga³⁺) ions in a controlled manner. The antibacterial activity of these scaffolds was investigated against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The ability of the scaffolds to release ions and the subsequent ingress of these ions into hard tissue was evaluated …

Inorganic Hemostats: The State-Of-The-Art And Recent Advances, Sara Pourshahrestani, Ehsan Zeimaran, Ivan Djordjevic, Nahrizul Adib Kadri, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Hemorrhage is the most common cause of death both in hospitals and on the battlefield. The need for an effective hemostatic agent remains, since all injuries are not amenable to tourniquet use. There are many topical hemostatic agents and dressings available to control severe bleeding. This article reviews the most commonly used inorganic hemostats, subcategorized as zeolite and clay-based hemostats. Their hemostatic functions as well as their structural properties that are believed to induce hemostasis are discussed. The most important findings from in vitro and in vivo experiments are also covered.

The Role Of Biological Fluid And Dynamic Flow In The Behavior And Cellular Interactions Of Gold Nanoparticles, Emily K. Breitner, Saber M. Hussain, Kristen K. Comfort

Chemical and Materials Engineering Faculty Publications

Background: Due to their distinctive physicochemical properties, nanoparticles (NPs) have proven to be extremely advantageous for product and application development, but are also capable of inducing detrimental outcomes in biological systems. Standard in vitro methodologies are currently the primary means for evaluating NP safety, as vast quantities of particles exist that require appraisal. However, cell-based models are plagued by the fact that they are not representative of complex physiological systems. The need for a more accurate exposure model is highlighted by the fact that NP behavior and subsequent bioresponses are highly dependent upon their surroundings. Therefore, standard in vitro models …

Raman Spectroscopy Applied To The Noninvasive Detection Of Monosodium Urate Crystal Deposits, Declan J. Curran, Laurence Rubin, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

An off-the-shelf Raman Spectrometer (RS) was used to noninvasively determine the presence of monosodium urate (MSU) crystals on the metatarsophalangeal joint (MTPJ) of a single gout sufferer. The spectrum sourced from the clinically diagnosed gout sufferer was compared to that sourced from an age-matched healthy subject scanned using the same protocol. Minimal signal processing was conducted on both spectra. Peaks characteristic of MSU crystals were evident on the spectrum sourced from the gout sufferer and not on the spectrum from the healthy control.

Silver Nanoparticle Coated Bioactive Glasses - Composites With Dex/Cmc Hydrogels: Characterization, Solubility, And In Vitro Biological Studies, Anthony W. Wren, Pegah Hassanzadeh, Lana M. Placek, Timothy J. Keenan, Aisling Coughlan, Lydia R. Boutelle, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Silver (Ag) coated bioactive glass particles (Ag-BG) were formulated and compared to uncoated controls (BG) in relation to glass characterization, solubility and microbiology. X-ray diffraction (XRD) confirmed a crystalline AgNP surface coating while ion release studies determined low Ag release (/L). Cell culture studies presented increased cell viability (127 and 102%) with lower liquid extract (50 and 100 ml/ml) concentrations. Antibacterial testing of Ag-BG in E. coli, S. epidermidis and S. aureus significantly reduced bacterial cell viability by 60-90%. Composites of Ag-BG/CMC-Dex Hydrogels were formulated and characterized. Agar diffusion testing was conducted where Ag-BG/hydrogel composites produced the largest inhibition zones …

Bioactive Glass Reinforced Elastomer Composites For Skeletal Regeneration: A Review, Ehsan Zeimaran, Sara Pourshahrestani, Ivan Djordjevic, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Biodegradable elastomers have clinical applicability due to their biocompatibility, tunable degradation and elasticity. The addition of bioactive glasses to these elastomers can impart mechanical properties sufficient for hard tissue replacement. Hence, a composite with a biodegradable polymer matrix and a bio glass filler can offer a method of augmenting existing tissue. This article reviews the applications of such composites for skeletal augmentation.

Effects Of Strontium Substitution On Bioactivity Of Hydroxyapatite, Chokchai Yatongchai, Lana M. Placek, Mark R. Towler, Anthony W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

Effect of strontium (Sr) substitution on bioactivity of hydroxyapatite (HA) was investigated. The substitution of Sr²⁺ for Ca²⁺ in the HA lattice increases biodegradability of Sr-substituted HA (Sr-HA) and accelerates the formation of apatite crystals on the Sr-HA surface. Moreover, the dissolution products from HA and Sr-HA samples are not cyto-toxic.

Fabrication And Characterization Of Poly(Octanediol Citrate)/Gallium-Containing Bioglass Microcomposite Scaffolds, Ehsan Zeimaran, Sara Pourshahrestani, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Hussin A. Rothan, Rohana Yusof, Mark R. Towler, Ivan Djordjevic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bone can be affected by osteosarcomae requiring surgical excision of the tumor as part of the treatment regime. Complete removal of cancerous cells is difficult and conventionally requires the removal of a margin of safety around the tumor to offer improved patient prognosis. This work considers a novel series of composite scaffolds based on poly (octanediol citrate) (POC) impregnated with gallium-based bioglass microparticles for possible incorporation into bone following tumor removal. The objective of this research was to fabricate and characterize these scaffolds and subsequently report on their mechanical and biological properties. The porous micro composite scaffolds with various concentrations …

A Glass Polyalkenoate Cement Carrier For Bone Morphogenetic Proteins, Adel M.F. Alhalawani, Omar Rodriguez, Declan J. Curran, Russell Co, Sean Kieran, Saad Arshad, Timothy J. Keenan, Anthony W. Wren, Gazelle Crasto, Sean A.F. Peel, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This work considers a glass polyalkenoate cement (GPC)-based carrier for the effective delivery of bone morphogenetic proteins (BMPs) at an implantation site. A 0.12 CaO–0.04 SrO–0.36 ZnO–0.48 SiO₂ based glass and poly(acrylic acid) (PAA, Mw 213,000) were employed for the fabrication of the GPC. The media used for the water source in the GPC reaction was altered to produce a series of GPCs. The GPC liquid media was either 100 % distilled water with additions of albumin at 0, 2, 5 and 8 wt% of the glass content, 100 % formulation buffer (IFB), and 100 % BMP (150 µg …

Investigating The Solubility And Cytocompatibility Of Cao-Na2o-Sio2/Tio2 Bioactive Glasses, Anthony W. Wren, Aisling Coughlan, Courtney M. Smith, Sarah P. Hudson, Fathima R. Laffir, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study aims to investigate the solubility of a series of titanium (TiO₂)-containing bioactive glasses and their subsequent effect on cell viability. Five glasses were synthesized in the composition range SiO₂-Na₂O-CaO with 5 mol % of increments TiO₂ substituted for SiO₂. Glass solubility was investigated with respect to (1) exposed surface area, (2) particle size, (3) incubation time, and (4) compositional effects. Ion release profiles showed that sodium (Na⁺) presented high release rates after 1 day and were unchanged between 7 and 14 days. Calcium (Ca²⁺) release …

Effect Of Nitrogen On Properties Of Na2o-Cao-Sro-Zno-Sio2 Glasses, Ahmed Bachar, Cyrille Mercier, Arnaud Tricoteaux, Jean Christophe Hornez, Anne Leriche, Claudine Follet, Bertrand Revel, Stuart Hampshire, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glasses in the Na₂O-CaO-SrO-ZnO-SiO₂ system have previously been investigated for suitability as a reagent in Al-free glass polyalkenoate cements (GPCs). These materials have many properties that offer potential in orthopedics. However, their applicability has been limited, to date, because of their poor strength. This study was undertaken with the aim of increasing the mechanical properties of a series of these Zn-based GPC glasses by doping with nitrogen to give overall compositions of: 10Na₂O-10CaO-20SrO-20ZnO-(40-3x)SiO₂-xSi₃N₄ (x is the no. of moles of Si₃N₄). The density, glass-transition temperature, hardness, …

Processing And Mechanical Testing Of Strontium-Substituted Hydroxyapatite/Glass Composites, Chokchai Yatongchai, Mark R. Towler, Anthony W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

Sr-HA/Glass composites were produced. Phase composition of composites was evaluated. Their physical and mechanical properties were determined. Sintered composites mainly consisted of Sr-HA/β-TCP, or β-TCP/Ca₂ZnSi₂O₇. The composites had porosity up to 4 times those of undoped Sr-HA. Compared to undoped Sr-HA, the Sr-HA/Glass composites had lower biaxial flexural strength and hardness. The Weibull modulus for the composites ranged from 2.77 to 18.74.

Wear Resistant And Biocompatible Coatings For Medical Devices And Method Of Fabrication, Mary Gilliam, Susan Farhat, Ali Zand

Chemical Engineering Patents

Abstract: A method of forming a biocompatible or biologically inert article for use in an application in which the article will make contact with at least one tissue, organ, or fluid within a human or animal body is provided. The method generally comprises providing an article having an external sur face; selecting chemical precursors; using a means to direct one or more chemical precursors towards or to apply such chemical precursors to the ex ternal surface; activating the chemical precursors by exposing said precursors to atmospheric pressure plasma; and grafting and/or cross-linking the chem ical precursors to form a solid …

Investigating The Effect Of Sio2-Tio2-Cao-Na 2o-Zno Bioactive Glass Doped Hydroxyapatite: Characterisation And Structural Evaluation, Chokchai Yatongchai, Anthony W. Wren, Declan J. Curran, Stuart Hampshire, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effects of increasing bioactive glass additions,

SiO₂-TiO₂-CaO-Na₂O-ZnO up to 25 wt% in increments of 5 wt%, on the physical and mechanical properties of hydroxyapatite (HA) sintered at 900, 1000, 1100 and 1200°C for 2 h was investigated. Increasing both the glass content and the temperature resulted in increased HA decomposition. This resulted in the formation of a number of bioactive phases. However the presence of the liquidus glass phase did not result in increased densification levels. At 1000 and 1100°C the additions of 5 wt% glass resulted in a decrease in density which …

Degradable Borate Glass Polyalkenoate Cements, L. Shen, A. Coughlan, Mark R. Towler, M. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) containing aluminum-free borate glasses having the general composition Ag₂O-Na₂O-CaO-SrO-ZnO- TiO₂-B₂O₃ were evaluated in this work. An initial screening study of sixteen compositions was used to identify regions of glass formation and cement compositions with promising rheological properties. The results of the screening study were used to develop four model borate glass compositions for further study. A second round of rheological experiments was used to identify a preferred GPC formulation for each model glass composition. The model borate glasses containing higher levels of TiO₂ (7.5 mol %) …

Characteristics Of Glass Ionomer Cements Composed Of Glass Powders In Cao-Sro-Zno-Sio2 System Prepared By Two Different Synthetic Routes, Ill Yong Kim, Chikara Ohtsuki, Aisling Coughlan, Lana Placek, Anthony W. Wren, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass ionomer cements (GICs) are composed of an acid degradable glass, polyacrylic acid and water. Sol-gel processing to prepare the glass phase has certain advantages, such as the ability to employ lower synthesis temperatures than melt quenching and glasses that are reported to have higher purity. A previous study reported the effects of glass synthesis route on GIC fabrication. However, in that study, the sol-gel derived glass exhibited a reduced concentration of cations. This study investigates increasing the cation content of a sol-gel derived glass, 12CaO·4SrO·36ZnO·48SiO₂ (molar ratio) by heating before aging to reduce dissolution of cations. This glass …

Relating Ph And Ion Release From Ga2o3-Na 2o-Cao-Zno-Sio2 Bioactive Glasses, T. J. Keenan, A. W. Wren, A. Coughlan, Mark R. Towler, M. M. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

Three glasses were designed for this study, including one Ga-free glass (Control), and two Ga-containing glasses (TGa-1, TGa-2). In the Ga-containing glasses, Ga₂O₃ is included at the expense of ZnO. This study focuses on the relation between pH and ion concentration present in solution in which these bioactive glasses have been submerged for periods of 1, 7, and 14 days. © 2013 IEEE.

Gallium Containing Glass Polyalkenoate Bone Cements: Ion Release And E. Coli Inhibition, L. Placek, A. W. Wren, A. Coughlan, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Glass Polyalkenoate Cement (GPC) series (LCon., LGa-1 and LGa-2) containing gallium (Ga) and a 50 wt% addition of E11 polyacrylic acid (PAA), previously developed, was evaluated for ion release, specifically Si, Ca, Zn and Ga, and E. coli inhibition. The maximum inhibition was observed in the t = 0 samples and was 0.35 mm for LCon. and 0.65 mm for LGa-1 and LGa-2. © 2013 IEEE.

Biocompatibility Of Cao-Na2o-Sio2/Tio2 Glass Ceramic Scaffolds For Orthopaedic Applications, A. W. Wren, A. Coughlan, K. E. Smale, S. T. Misture, B. P. Mahon, O. M. Clarkin, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This work aims to determine the effect of substituting TiO₂ for SiO₂ in a 0.62SiO₂-Na₂O-0.24CaO based glass-ceramic scaffold. High temperature X-ray Diffraction (HT-XRD) was used to determine the sintering temperature (700oC). Both optical microscopy and x-ray micotomography was used to determine the average pore size (540-680ìm) of each scaffold. Cytocompatibility of each scaffold was conducted using murine mesenchymal stem cells. © 2013 IEEE.