Materials Science and Engineering Commons^™

The Angiogenic Potential Of Ph-Neutral Borophosphate Bioactive Glasses, Bradley A. Bromet, Nathaniel P. Blackwell, Nada Abokefa, Parker Freudenberger, Rebekah L. Blatt, Richard K. Brow, Julie A. Semon

Materials Science and Engineering Faculty Research & Creative Works

Borate bioactive glasses have gained attention in recent years due to their therapeutic and regenerative effects in vivo. However, borate bioactive glasses release alkaline ions, increasing the local pH and creating a toxic environment for cell culture studies. A partial compositional substitution of phosphate for borate can create a pH-neutral glass that does not significantly affect the local pH while still releasing therapeutic ions. In the present study, a series of Na-Ca-borophosphate bioactive glasses with different borate-to-phosphate ratios was evaluated in vitro and in vivo for cytotoxicity and angiogenic effects. Compared to more basic borate glasses, the pH-neutral glasses supported …

Bbt Acoustic Alternative Top Bracing Cadd Data Set-Norev-2022jun28, Bill Hemphill

STEM Guitar Project’s BBT Acoustic Kit

This electronic document file set consists of an overview presentation (PDF-formatted) file and companion video (MP4) and CADD files (DWG & DXF) for laser cutting the ETSU-developed alternate top bracing designs and marking templates for the STEM Guitar Project’s BBT (OM-sized) standard acoustic guitar kit. The three (3) alternative BBT top bracing designs in this release are
(a) a one-piece base for the standard kit's (Martin-style) bracing,
(b) 277 Ladder-style bracing, and
(c) an X-braced fan-style bracing similar to traditional European or so-called 'classical' acoustic guitars.

The CADD data set for each of the three (3) top bracing designs includes …

Bbt Side Mold Assy, Bill Hemphill

STEM Guitar Project’s BBT Acoustic Kit

This electronic document file set covers the design and fabrication information of the ETSU Guitar Building Project’s BBT (OM-sized) Side Mold Assy for use with the STEM Guitar Project’s standard acoustic guitar kit. The extended 'as built' data set contains an overview file and companion video, the 'parent' CADD drawing, CADD data for laser etching and cutting a drill &/or layout template, CADD drawings in AutoCAD .DWG and .DXF R12 formats of the centerline tool paths for creating the mold assembly pieces on an AXYZ CNC router, and support documentation for CAM applications including router bit specifications, feeds, speed, multi-pass …

Open Source Vacuum Oven Design For Low-Temperature Drying: Performance Evaluation For Recycled Pet And Biomass, Benjamin R. Hubbard, Lindsay I. Putman, Stephen Techtmann, Joshua M. Pearce

Michigan Tech Publications

Vacuum drying can dehydrate materials further than dry heat methods, while protecting sensitive materials from thermal degradation. Many industries have shifted to vacuum drying as cost-or time-saving measures. Small-scale vacuum drying, however, has been limited by the high costs of specialty scientific tools. To make vacuum drying more accessible, this study provides design and performance information for a small-scale open source vacuum oven, which can be fabricated from off-the-shelf and 3-D printed components. The oven is tested for drying speed and effectiveness on both waste plastic polyethylene terephthalate (PET) and a consortium of bacteria developed for bioprocessing of terephthalate wastes …

Bioprinting With Human Stem Cell-Laden Alginate-Gelatin Bioink And Bioactive Glass For Tissue Engineering, Krishna C. R. Kolan, Julie A. Semon, Bradley Bromet, D. E. Day, Ming-Chuan Leu

Biological Sciences Faculty Research & Creative Works

Three-dimensional (3D) bioprinting technologies have shown great potential in the fabrication of 3D models for different human tissues. Stem cells are an attractive cell source in tissue engineering as they can be directed by material and environmental cues to differentiate into multiple cell types for tissue repair and regeneration. In this study, we investigate the viability of human adipose-derived mesenchymal stem cells (ASCs) in alginate-gelatin (Alg-Gel) hydrogel bioprinted with or without bioactive glass. Highly angiogenic borate bioactive glass (13-93B3) in 50 wt% is added to polycaprolactone (PCL) to fabricate scaffolds using a solvent-based extrusion 3D bioprinting technique. The fabricated scaffolds …

The Effects Of Organic And Inorganic Nanoparticles On Bacterial Deactivation, Lauren Cooper

Mahurin Honors College Capstone Experience/Thesis Projects

Antibacterial resistance is one of the greatest problems in modern medicine, as healthcare professionals are experiencing more and more difficulty in providing effective care. As such, alternative methods of treatment are needed in order to overcome this issue. One recently proposed method of alternative treatment is photodynamic therapy. Photodynamic therapy is a light-based method of treatment that utilizes (1) a photosensitizing agent, (2) light, (3) produced oxygen species. When the photosensitizing agent is injected into an infected region of interest and then irradiated with a certain wavelength of light, the agent is photoactivated and begins to produce harmful forms of …

Geometric Effects Of Open Hollow Hydroxyapatite Microspheres Influence Bone Repair And Regeneration In Sprague Dawley Rats, Youqu Shen, M. N. Rahaman, Yongxian Liu, Yue-Wern Huang

Materials Science and Engineering Faculty Research & Creative Works

Effective regeneration of bone defects caused by trauma or chronic diseases is a significant clinical challenge. Bone deficiency is overcome using treatments that rely on bone regeneration and augmentation. While various treatments have been investigated with encouraging results, complete and predictable bone reconstruction is often difficult [1]. Synthetic bone grafts have advantages such as consistent quality, safety, and good tissue tolerance. They usually function as inert or osteoconductive implants. Encouraging results from synthetic grafts have been reported. For instance, hollow hydroxyapatite (HA) microspheres showed the ability to facilitate bone repair in rats with non-healing calvarial defects [2,3]. However, new bone …

Near-Field Electrospinning Of A Polymer/Bioactive Glass Composite To Fabricate 3d Biomimetic Structures, Krishna C. R. Kolan, Jie Li, Sonya Roberts, Julie A. Semon, Jonghyun Park, D. E. Day, Ming-Chuan Leu

Biological Sciences Faculty Research & Creative Works

Bioactive glasses have recently gained attention in tissue engineering and three-dimensional (3D) bioprinting because of their ability to enhance angiogenesis. Some challenges for developing biological tissues with bioactive glasses include incorporation of glass particles and achieving a 3D architecture mimicking natural tissues. In this study, we investigate the fabrication of scaffolds with a polymer/bioactive glass composite using near-field electrospinning (NFES). An overall controlled 3D scaffold with pores, containing random fibers, is created and aimed to provide superior cell proliferation. Highly angiogenic borate bioactive glass (13-93B3) in 20 wt.% is added to polycaprolactone (PCL) to fabricate scaffolds using the NFES technique. …

Solvent Based 3d Printing Of Biopolymer/Bioactive Glass Composite And Hydrogel For Tissue Engineering Applications, Krishna Kolan, Yong Liu, Jakeb Baldridge, Caroline Murphy, Julie A. Semon, D. E. Day, Ming-Chuan Leu

Biological Sciences Faculty Research & Creative Works

Three-dimensional (3D) bioprinting is an emerging technology in which scaffolding materials and cell-laden hydrogels may be deposited in a pre-determined fashion to create 3D porous constructs. A major challenge in 3D bioprinting is the slow degradation of melt deposited biopolymer. In this paper, we describe a new method for printing poly-caprolactone (PCL)/bioactive borate glass composite as a scaffolding material and Pluronic F127 hydrogel as a cell suspension medium. Bioactive borate glass was added to a mixture of PCL and organic solvent to make an extrudable paste using one syringe while hydrogel was extruded and deposited in between the PCL/borate glass …

Scaffold For Tissue Regeneration In Mammals, D. E. Day, Steven B. Jung, Roger F. Brown

Materials Science and Engineering Faculty Research & Creative Works

A three-dimensional scaffold with interconnected pores for repair of tissue comprising a scaffold body for structural support of the tissue scaffold, where the scaffold body comprises scaffold body components bonded to each other and made from component materials comprising about 40 to about 90 wt % B₂O₃, and two or more other oxides, wherein the scaffold body has a porosity between about 15 and about 90 vol %.

3d Bioprinting Of Stem Cells And Polymer/Bioactive Glass Composite Scaffolds For Bone Tissue Engineering, Caroline Murphy, Krishna Kolan, Wenbin Li, Julie A. Semon, D. E. Day, Ming-Chuan Leu

Biological Sciences Faculty Research & Creative Works

A major limitation of using synthetic scaffolds in tissue engineering applications is insufficient angiogenesis in scaffold interior. Bioactive borate glasses have been shown to promote angiogenesis. There is a need to investigate the biofabrication of polymer composites by incorporating borate glass to increase the angiogenic capacity of the fabri-cated scaffolds. In this study, we investigated the bioprinting of human adipose stem cells (ASCs) with a polycaprolac-tone (PCL)/bioactive borate glass composite. Borate glass at the concentration of 10 to 50 weight %, was added to a mixture of PCL and organic solvent to make an extrudable paste. ASCs suspended in Matrigel …

Broad-Spectrum Antibacterial Characteristics Of Four Novel Borate-Based Bioactive Glasses, Megan Ottomeyer, Ali Mohammadkah, D. E. Day, David J. Westenberg

Materials Science and Engineering Faculty Research & Creative Works

Bioactive glasses have been developed for medical applications in the body for bone and tissue repair and regeneration. We have developed a borate-containing bioactive glass (13-93B3, referred to as B3), which is undergoing clinical trials to assess its wound-healing properties. To complement the healing properties of B3, metal ion dopants have been added to enhance its antimicrobial properties. Bioactive glasses doped with silver, gallium or iodine ions were found to have broad spectrum antimicrobial effects on clinically relevant bacteria including MRSA. While the B3 glass alone was sufficient to produce antibacterial effects on select bacteria, adding dopants enhanced the broad-spectrum …

3d Printing Of A Polymer Bioactive Glass Composite For Bone Repair, Caroline Murphy, Krishna C. R. Kolan, M. Long, Ming-Chuan Leu, Julie A. Semon, D. E. Day

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A major limitation of synthetic bone repair is insufficient vascularization of the interior region of the scaffold. In this study, we investigated the 3D printing of adipose derived mesenchymal stem cells (AD-MSCs) with polycaprolactone (PCL)/bioactive glass composite in a single process. This offered a three-dimensional environment for complex and dynamic interactions that govern the cell’s behavior in vivo. Borate based bioactive (13-93B3) glass of different concentrations (10 to 50 weight %) was added to a mixture of PCL and organic solvent to make an extrudable paste. AD-MSCs suspended in Matrigel was extruded as droplets using a second syringe. Scaffolds measuring …

Patterns Around Us Presentation, Benny Davidovitch

Patterns Around Us

No abstract provided.

Angiogenic Effect Of Bioactive Borate Glass Microfibers And Beads In The Hairless Mouse, Richard J. Watters, Roger F. Brown, D. E. Day

Biological Sciences Faculty Research & Creative Works

The purpose of this project was to investigate the angiogenic mechanism of bioactive borate glass for soft tissue repair in a 'hairless' SKH1 mouse model. Subcutaneous microvascular responses to bioactive glass microfibers (45S5, 13-93B3, and 13-93B3Cu) and bioactive glass beads (13-93, 13-93B3, and 13-93B3Cu) were assessed via: noninvasive imaging of skin microvasculature; histomorphometry of microvascular densities; and quantitative PCR measurements of mRNA expression of VEGF and FGF-2 cytokines. Live imaging via dorsal skin windows showed the formation at two weeks of a halo-like structure infused with microvessels surrounding implanted borate-based 13-93B3 and 13-93B3Cu glass beads, a response not observed with …

Ultrasonic Wave Propagation Assessment Of Native Cartilage Explants And Hydrogel Scaffolds For Tissue Engineering, Sean S. Kohles, Shelley S. Mason, Anya P. Adams, Robert J. Berg, Jessica Blank, Fay Gibson, Johnathan Righetti, Lesha S. Washington, Asit K. Saha

Mechanical and Materials Engineering Faculty Publications and Presentations

Non-destructive techniques characterising the mechanical properties of cells, tissues, and biomaterials provide baseline metrics for tissue engineering design. Ultrasonic wave propagation and attenuation has previously demonstrated the dynamics of extracellular matrix synthesis in chondrocyte-seeded hydrogel constructs. In this paper, we describe an ultrasonic method to analyse two of the construct elements used to engineer articular cartilage in real-time, native cartilage explants and an agarose biomaterial. Results indicated a similarity in wave propagation velocity ranges for both longitudinal (1500-1745 m/s) and transverse (350-950 m/s) waveforms. Future work will apply an acoustoelastic analysis to distinguish between the fluid and solid properties including …

Structures Of Human Thymidylate Synthase R163k With Dump, Fdump And Glutathione Show Asymmetric Ligand Binding, Lydia M. Gibson, Lesa R. Celeste, Leslie L. Lovelace, Lukasz Lebioda

Faculty Publications

Thymidylate synthase (TS) is a well validated target in cancer chemotherapy. Here, a new crystal form of the R163K variant of human TS (hTS) with five subunits per asymmetric part of the unit cell, all with loop 181-197 in the active conformation, is reported. This form allows binding studies by soaking crystals in artificial mother liquors containing ligands that bind in the active site. Using this approach, crystal structures of hTS complexes with FdUMP and dUMP were obtained, indicating that this form should facilitate high-throughput analysis of hTS complexes with drug candidates. Crystal soaking experiments using oxidized glutathione revealed that …

Growth Of Mc3t3-El Pre-Osteoblasts On Borate Containing Glasses & Growth Of Osteoblastic Cells On 13-93 Glass Scaffolds, Agatha Dwilewicz

Opportunities for Undergraduate Research Experience Program (OURE)

Three borate-based glasses, compositions designated 1B, 2B, and 3B, with B₂0₃ levels of 15, 31, and 46 mole percent (Table 1), respectively, were tested for their effects on the growth of MC3T3-El mouse pre-osteoblastic cells under physiological fluid conditions. Silicate type 45S5 glass was used as a control for comparison. Independently, the biocompatibility of recently developed silicate-based porous 13-93 bioactive glass scaffolds was tested; Saos-2 human osteosarcoma cell line was used. Tests performed for the two studies included: contact assays of cell growth at the glass interface, chemical analysis of borate released into the culture medium, quantitative …

Process Development For The Formation Of Post-Bonding Biorecognition Layers In Microfluidic Biosensors, Martin G. Perez, Phaninder R. Kanikella, James N. Reck, Chang-Soo Kim, Matthew O'Keefe

Electrical and Computer Engineering Faculty Research & Creative Works

Formation of the biorecognition layers within microfluidic sensor channels must be done after the completion of the channel structure since these layers cannot withstand the wafer bonding temperature. We propose a new post-bonding immobilization process to prepare the enzyme layers within microfluidic channels of electrochemical biosensors. An array of Pt vertical electrodes is electroplated using a SU-8 mold. The cured SU-8 is then removed by plasma etching to expose the Pt electrode and to define the fluidic channel cavity simultaneously. An array of enzyme posts is formed on the Pt surface by either electropolymerizing or photopolymerizing enzyme precursor solutions injected …

Structure Of Human Thymidylate Synthase Under Low-Salt Conditions, Leslie L. Lovelace, Wladek Minor, Lukasz Lebioda

Faculty Publications

Human thymidylate synthase, a target in cancer chemotherapy, was crystallized from PEG 3350 with 30 mM ammonium sulfate (AS) in the crystallization medium. The crystals are isomorphous with the high-salt crystals (~2.0 M AS) and the structure has been solved and refined (R = 22.6%, Rfree = 24.3%) at 1.8 Å resolution. The high- and low-AS-concentration structures are quite similar, with loop 181-197 is in the inactive conformation. Also, residues 95-106 and 129-135 (eukaryotic inserts region) show high mobility as assessed by poor electron density and high values of crystallographic temperature factors (residues 1-25 and 108-129 are disordered in both …