Biomedical Devices and Instrumentation Commons^™

An Investigation Into The Structure And Properties Of Cao-Zno-Sio 2-Tio2-Na2o Bioactive Glass/Hydroxyapatite Composite, Chokchai Yatongchai, Mark R. Towler, Anthony W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

Effect of the addition of CaO-ZnO-SiO₂-TiO₂-Na₂O glass as a reinforcing phase on properties of hydroxyapatite/glass composites was investigated. The addition of the glass caused the decomposition of HA phase to tricalcium phosphate, inhibiting densification in the HA/glass composites. However, depending on the glass concentration, some of the glass can act as a sintering aid enhancing the densification in the composites. © 2013 IEEE.

Comparison Of A Sio2-Cao-Zno-Sro Glass Polyalkenoate Cement To Commercial Dental Materials: Ion Release, Biocompatibility And Antibacterial Properties, A. W. Wren, A. Coughlan, M. M. Hall, M. J. German, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Ion Release and biocompatibility of a CaO-SrO-ZnO-SiO₂ (BT 101) based glass polyalkenoate cement (GPC) was compared against commercial GPCs, Fuji IX and Ketac Molar. The radiopacity (R) was similar for each material, 2.0-2.8. Ion release was evaluated on each material over 1, 7, 30 and 90 days. BT 101 release included Ca (23 mg/L), Sr (23 mg/L) Zn (13 mg/L), Si (203 mg/L). Fuji IX release includes Ca (0.7 mg/L), Al (3 mg/L) Si (26 mg/L), Na (60 mg/L) and P (0.5 mg/L) while Ketac Molar release includes Ca (1 mg/L), Al (0.6 mg/L) Si (23 mg/L), Na (76 …

Materials Education And Research In Art And Design: A New Role For Libraries (Survey Stats), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Program Sheet), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Program Booklet), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Education And Research In Art And Design: A New Role For Libraries (Website), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

No abstract provided.

Materials Collection Creation And Administration: A New Role For Libraries (White Paper), Mark Pompelia

Materials Education and Research in Art and Design: A New Role for Libraries

The Problem/Opportunity: To define, identify, and guide design-based materials collections in academic settings and foster community among those with existing collections and/or those considering creating and supporting one.

Contents and topics:

1. What is a materials collection?
2. Why have a materials collection?
3. Acquisition strategies
4. Organizational approaches
5. Programming possibilities
6. Symposium summary
7. Resources

Characterisation Of Ga2o3-Na2o-Cao-Zno- Sio2 Bioactive Glasses, A. W. Wren, T. Keenan, A. Coughlan, F. R. Laffir, D. Boyd, Mark R. Towler, M. M. Hall

Chemical and Biochemical Engineering Faculty Research & Creative Works

The structural role of Gallium (Ga) is investigated when substituted for Zinc (Zn) in a 0.42SiO₂-0.40-xZnO-0.10Na₂O-0.08CaO glass series, (where x = 0.08). Each starting material was amorphous, and the network connectivity (NC) was calculated assuming Ga acts as both a network modifier (1.23), and also as a network former. Assuming a network forming role for Ga the NC increased with increasing Ga concentration throughout the glass series (Control 1.23, TGa-1 2.32 and TGa-2 3.00). X-ray photoelectron spectroscopy confirmed both composition and correlated NC predictions. Raman spectroscopy was employed to investigate Q-structure and found that a shift …

Aluminium-Free Glass Polyalkenoate Cements: Ion Release And In Vitro Antibacterial Efficacy, A. W. Wren, J. P. Hansen, S. Hayakawa, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) have exhibited potential as bone cements. This study investigates the effect of substituting TiO₂ for SiO₂ in the glass phase and the subsequent effect on cement rheology, mechanical properties, ion release and antibacterial properties. Glass characterization revealed a reduction in glass transition temperature (T_g) from 685 to 669 C with the addition of 6 mol % TiO₂ (AT-2). Magic angle spinning nuclear magnetic resonance (MAS-NMR) revealed a shift from -81 ppm to -76pmm when comparing a Control glass to AT-2, indicating de-polymerization of the Si network. The incorporation of TiO_{2 …}

Comparison Of A Sio2-Cao-Zno-Sro Glass Polyalkenoate Cement To Commercial Dental Materials: Glass Structure And Physical Properties, A. W. Wren, A. Coughlan, F. R. Laffir, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) have previously been considered for orthopedic applications. A Zn-GPC (BT 101) was compared to commercial GPCs (Fuji IX and Ketac Molar) which have a setting chemistry analogous to BT 101. Handling properties (working, T_w and setting, T_s times) for BT 101 were shorter than the commercial GPCs. BT 101 also had a higher setting exotherm (S_x - 34 °C) than the commercial GPCs (29 °C). The maximum strengths for BT 101, Fuji IX, and Ketac Molar were 75, 238, and 216 MPa (compressive, σ_c), and 34, 54, and 62 MPa (biaxial …

Fabrication Of Cao-Nao-Sio2/Tio2 Scaffolds For Surgical 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

A series of titanium (Ti) based glasses were formulated (0.62 SiO₂-0.14 Na₂O-0.24 CaO, with 0.05 mol% TiO₂ substitutions for SiO₂) to develop glass/ceramic scaffolds for bone augmentation. Glasses were initially characterised using X-ray diffraction (XRD) and particle size analysis, where the starting materials were amorphous with 4.5 μm particles. Hot stage microscopy and high temperature XRD were used to determine the sintering temperature (̃700 °C) and any crystalline phases present in this region (Na₂Ca₃Si₆O₁₆, combeite and quartz). Hardness testing revealed that the Ti-free control (ScC- …

Developing Novel Prognostic Biomarkers For Multivariate Fracture Risk Prediction Algorithms, Ernest K. Poku, Mark R. Towler, Niamh M. Cummins, Jeff D. Newman

Chemical and Biochemical Engineering Faculty Research & Creative Works

Multivariate prediction algorithms such as FRAX® and QFracture Scores provide an opportunity for new prognostic biomarkers to be developed and incorporated, potentially leading to better fracture prediction. As more research is conducted into these novel biomarkers, a number of factors need to be considered for their successful development for inclusion in these algorithms. In this review, we describe two well-known multivariate prediction algorithms for osteoporosis fracture risk applicable to the UK population, FRAX and QFracture Scores, and comment on the current prognostic tools available for fracture risk; dual X-ray assessment, quantitative ultrasonography, and genomic/biochemical markers. We also highlight the factors …

Gallium Containing Glass Polyalkenoate Anti-Cancerous Bone Cements: Glass Characterization And Physical Properties, A. W. Wren, A. Coughlan, L. Placek, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

A gallium (Ga) glass series (0.48SiO₂-0.40ZnO-0.12CaO, with 0.08 mol% substitution for ZnO) was developed to formulate a Ga-containing Glass Polyalkenoate Cement (GPC) series. Network connectivity (NC) and X-ray Photoelectron Spectroscopy (XPS) was employed to investigate the role of Ga³⁺ in the glass, where it is assumed to act as a network modifier. Ga-GPC series was formulated with E9 and E11 polyacrylic acid (PAA) at 50, 55 and 60 wt% additions. E11 working times (T_w) ranged from 68 to 96 s (Lcon.) and 106 s for the Ga-GPCs (LGa-1 and LGa-2). Setting times (T_s) …

Experimental Composite Guidance Conduits For Peripheral Nerve Repair: An Evaluation Of Ion Release, X. F. Zhang, A. Coughlan, H. O'Shea, Mark R. Towler, S. Kehoe, D. Boyd

Chemical and Biochemical Engineering Faculty Research & Creative Works

Poly (lactide-co-glycolide) (PLGA) - Pluronic F127 - glass composites have demonstrated excellent potential, from the perspective of controlled mechanical properties and cytocompatibility, for peripheral nerve regeneration. In addition to controlling the mechanical properties and cytotoxicity for such composite devices, the glass component may mediate specific responses upon implantation via degradation in the physiological environment and release of constituent elements. However, research focused on quantifying the release levels of such therapeutic ions from these experimental medical devices has been limited. To redress the balance, this paper explores the ion release profiles for Si⁴⁺, Ca²⁺, Na⁺, …

The Structural Characterization Of Ga 2o 3-Na 2o-Cao-Zno-Sio 2 Bioactive Glasses, T. J. Keenan, A. W. Wren, A. Coughlan, M. M. Hall, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The characterization of bioactive glasses in which zinc (Zn) has been incrementally replaced by gallium (Ga). © 2012 IEEE.

Increasing The Quantity Of Silver In Zinc-Based Glass Polyalkenoate Cement: Is There An Improvement In Antibacterial Efficacy?, A. Coughlan, S. M. Breed, C. Ashraf, J. A. Cardinale, M. M. Hall, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bone cements should have the ability to chemically bond to both bone and surgical metals, exhibit no chemical or thermal necrosis, and have no significant shrinkage or exotherm upon setting. Taking these properties into consideration, glass polyalkenoate cements (GPCs) have potential as bone cements. GPCs are formed by the reaction between an ion-leachable glass and an aqueous solution of polyacrylic acid (PAA) [1] and have proven antibacterial and cariostatic properties [2], which are related to their ability to release beneficial amounts of ions over time [3, 4]. The GPCs can be formulated to release ions that can have a therapeutic …

Silver Coated Bioactive Glass Particles For Wound Healing Applications, P. Hassanzadeh, A. W. Wren, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Hench and colleagues discovered that bone could bond chemically to certain glass compositions in 1969 [1]. This group of glasses is known as bioactive glasses [1]. Some special compositions of bioactive glasses will bond to soft tissues as well as bone [1]. One of the important characteristics of bioactive glasses is their ability to release beneficial ions such as Ca²⁺, Na⁺, Zn²⁺, Sr²⁺, and PO 43- in the body, which promote self-healing [2]. Bioactive glasses generally contain much less glass former (e.g., SiO₂, B₂O₃ etc.) than conventional …

Gallium Containing Glass Polyalkenoate Bone Cements: Glass Characterization And Physical Properties, L. Placek, A. W. Wren, A. Coughlan, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Gallium (Ga) glasses were developed to formulate a Glass Polyalkenoate Cement (GPC) series with both E9 and E11 polyacrylic acid (PAA) at 50, 55 and 60wt% additions. Working times (T w), setting times (T s), compression (σ c), and biaxial flexural (σ f) strength testing were evaluated to determine the GPCs potential use in orthopedics. © 2012 IEEE.

Silver Coated Bioactive Glass Particles For Wound Healing Applications, A. W. Wren, A. Coughlan, P. Hassanzadeh, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioactive glass particles (0.42SiO₂-0.15CaO-0.23Na ₂O-0.20ZnO) of varying size (<90 >μm and 425-850 μm) were synthesized and coated with silver (Ag) to produce Ag coated particles (PAg). These were compared against the uncoated analogous particles (Pcon.). Surface area analysis determined that Ag coating of the glass particles resulted in increased the surface area from 2.90 to 9.12 m²/g (90 μm) and 1.09-7.71 m²/g (425-850 μm). Scanning electron microscopy determined that the Ag coating remained at the surface and there was little diffusion through the bulk. Antibacterial (Escherichia coli - 13 mm and Staphylococcus epidermidis …

Comparison Of Microwave And Conventionally Sintered Yttria-Doped Zirconia Ceramics, Colin J. Reidy, Thomas J. Fleming, Stuart Hampshire, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This paper reports on improvement of the physical and mechanical properties of Y₂O₃-ZrO₂ ceramics through compositional optimization, the use of nanograined powders and utilization of microwave sintering. ZrO₂ with 2-5 mol% Y₂O₃, prepared from nanopowders, was sintered in both conventional and microwave furnaces under exactly the same heating schedule. It was found that microwave sintering improves physical and mechanical properties of Y₂O₃-ZrO₂ ceramics compared with conventional sintering. Compositions containing 2 mol% Y₂O₃ exhibit the greatest improvement due to retention of tetragonal ZrO …

Sol-Gel Derived Silver-Incorporated Titania Thin Films On Glass: Bactericidal And Photocatalytic Activity, Betul Akkopru Akgun, Anthony W. Wren, Caner Durucan, Mark R. Towler, Nathan P. Mellott

Chemical and Biochemical Engineering Faculty Research & Creative Works

Titanium dioxide (TiO₂) and silver-containing TiO₂ (Ag-TiO₂) thin films were prepared on silica pre-coated float glass substrates by a sol-gel spin coating method. The bactericidal activity of the films was determined against Staphylococcus epidermidis under natural and ultraviolet (UV) illumination by four complementary methods; (1) the disk diffusion assay, (2) UV-induced bactericidal test, (3) qualitative Ag ion release in bacteria inoculated agar media and (4) surface topographical examination by laserscan profilometry. Photocatalytic activity of the films was measured through the degradation of stearic acid under UV, solar and visible light conditions. The chemical state and …

Clinical Risk Factors For Osteoporosis In Ireland And The Uk: A Comparison Of Frax And Qfracturescores, N. M. Cummins, E. K. Poku, Mark R. Towler, O. M. O'Driscoll, S. H. Ralston

Chemical and Biochemical Engineering Faculty Research & Creative Works

Recently two algorithms have become available to estimate the 10-year probability of fracture in patients suspected to have osteoporosis on the basis of clinical risk factors: the FRAX algorithm and QFractureScores algorithm (QFracture). The aim of this study was to compare the performance of these algorithms in a study of fracture patients and controls recruited from six centers in the United Kingdom and Ireland. A total of 246 postmenopausal women aged 50-85 years who had recently suffered a low-trauma fracture were enrolled and their characteristics were compared with 338 female controls who had never suffered a fracture. Femoral bone mineral …

The Effect Of Adding Organic Polymers To Ca-Sr-Zn-Si Glass Polyalkenoate Cement, A. Coughlan, N. M. Cummins, A. W. Wren, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

To conclude, the addition of polymers to GPCs resulted in little change to the Tw and Ts, however the compressive strength was found to decrease slightly. ASAP tests revealed that the cements may undergo some structural changes as a result of these additions. In the future perhaps the addition of organic polymers suspended in the liquid phase as part of the cement may yield improved results in this type of study. © 2011 IEEE.

Aluminium-Free Glass Polyalkenoate Spinal Cements, A. W. Wren, N. M. Cummins, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Addition of Yitanium increased the Wt & St and the sf strength of these cements compared to the control (BT 101). © 2011 IEEE.

Leaching Of Potential Hazardous Elements Of Coal Cleaning Rejects, Luis F.O. Silva, Maria Izquierdo, Xavier Querol, Robert B. Finkelman, Marcos L.S. Oliveira, Marcus Wollenschlager, Mark R. Towler, Rafael Pérez-López, Felipe Macias

Chemical and Biochemical Engineering Faculty Research & Creative Works

The geochemical characteristics of coal cleaning rejects (CCR) in Santa Catarina State, Brazil, were investigated. Around 3.5 million ton/ year of coal waste are dumped in Santa Catarina State. Coal beneficiation by froth flotation results in large amounts of CCR composed of coaly and mineral matter, the latter characterized by the occurrence of sulphide minerals and a broad array of leachable elements. The total and leachable contents of more than 60 elements were analyzed. Atmospheric exposure promotes sulphide oxidation that releases substantial sulphate loads as well as Ca²⁺, K⁺, Mg²⁺, Cl- and Al^{3+ …}

The Structural Role Of Titanium In Ca-Sr-Zn-Si/Ti Glasses For Medical Applications, A. W. Wren, F. R. Laffir, A. Kidari, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glasses for medical applications are used in particulate form or as a cement component. This work was undertaken to determine structural changes in 0.48SiO₂-0.36ZnO-0.12CaO-0.04SrO glass when the SiO₂ is substituted with 5 mol% increments of TiO2. X-ray Diffraction (XRD) was used to determine the presence of crystallinity. This occurred after additions of 20 mol% TiO₂. Differential Thermal Analysis (DTA) and Network connectivity (NC) calculations determined that by increasing the TiO₂ content, the T_g and NC reduced (T_g 670 °C to 632 °C, NC 1.83 to -1.14) suggesting that TiO₂ acts as …

The Bioactivity And Ion Release Of Titanium-Containing Glass Polyalkenoate Cements For Medical Applications, A. W. Wren, N. M. Cummins, F. R. Laffir, S. P. Hudson, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The ion release profiles and bioactivity of a series of Ti containing glass polyalkenoate cements. Characterization revealed each material to be amorphous with a T_g in the region of 650-660°C. The network connectivity decreased (1.83-1.35) with the addition of TiO₂ which was also evident with analysis by X-ray photoelectron spectroscopy. Ion release from cements were determined using atomic absorption spectroscopy for zinc (Zn^₂₊), calcium (Ca^₂₊), strontium (Sr^₂₊), Silica (Si^₄₊) and titanium (Ti4+). Ions such as Zn^₂₊ (0.1-2.0 mg/l), Ca²⁺ (2.0-8.3 mg/l,) Sr²⁺ (0.1-3.9 mg/l), and S^{i4+ …}

The Response Of Pseudomonas Aeruginosa Biofilm To The Presence Of A Glass Polyalkenoate Cement Formulated From A Silver Containing Glass, A. Coughlan, M. P. Ryan, N. M. Cummins, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

Comparison Of Antibacterial Properties Of Commercial Bone Cements And Fillers With A Zinc-Based Glass Polyalkenoate Cement, A. W. Wren, N. M. Cummins, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Postoperative infection following invasive surgical procedures is a significant cause for concern, particularly in spinal reconstructive surgery. The objective of this study is to compare the antibacterial efficacy of a novel zinc-based glass polyalkenoate cement (Zn-GPC) based on 0.04SrO-0.12CaO-0.36ZnO- 0.48SiO₂ glass, to a number of commercially available bone cements and fillers including Simplex P + Tobramycin (S_Tob), Spineplex (S_pine) and Novabone Putty (N_Put). The agar diffusion test was performed on each material against Escherichia coli, Staphlococcus epidermidis, Pseudomonas aeruginosa and Staphlococcus Aureus. S_Tob was found to produce large inhibition zones in each …

The Effect Of Ionic Dissolution Products Of Ca-Sr-Na-Zn-Si Bioactive Glass On In Vitro Cytocompatibility, S. Murphy, A. W. Wren, Mark R. Towler, D. Boyd

Chemical and Biochemical Engineering Faculty Research & Creative Works

Many commercial bone grafts cannot regenerate healthy bone in place of diseased bone. Bioactive glasses have received much attention in this regard due to the ability of their ionic dissolution products to promote cell proliferation, cell differentiation and activate gene expression. Through the incorporation of certain ions, bioactive glasses can become therapeutic for specific pathological situations. Calcium-strontium-sodium-zinc-silicate glass bone grafts have been shown to release therapeutic levels of zinc and strontium, however the in vitro compatibility of these materials is yet to be reported. In this study, the in vitro cytocompatibility of three different calcium-strontium-sodium-zinc-silicate glasses was examined as a …