Biomedical Engineering and Bioengineering Commons^™

Exploring The Effects Of Electrospun Fiber Surface Nanotopography On Neurite Outgrowth And Branching In Neuron Cultures, Anthony R. D'Amato, Devan L. Puhl, Alexis M. Ziemba, Christopher D.L. Johnson, Janneke Doedee, Jonathan Bao, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Three aligned, electro spun fiber scaffolds with unique surface features were created from poly-L-lactic acid (PLLA). Fibers without surface nano topography (smooth fibers), fibers with surface divots (shallow pits), and fibers with surface pits (deeper pits) were fabricated, and fiber alignment, diameter, and density were characterized using scanning electron microscopy (SEM). Whole dorsal root ganglia (DRG) were isolated from rats and placed onto uncoated fibers or fibers coated with laminin. On uncoated fibers, neurite outgrowth was restricted by fibers displaying devoted or pitted nano topography when compared to neurite outgrowth on smooth fibers. However, neurites extending from whole DRG cultured …

Raman Spectroscopy As A Predictive Tool For Monitoring Osteoporosis Therapy In A Rat Model Of Postmenopausal Osteoporosis, J. Renwick Beattie, Antonia Sophocleous, M. Clare Caraher, Olive O'Driscoll, Niamh M. Cummins, Steven E.J. Bell, Mark R. Towler, Alireza Rahimnejad Yazdi, Stuart H. Ralston, Aymen I. Idris

Chemical and Biochemical Engineering Faculty Research & Creative Works

Pharmacological therapy of osteoporosis reduces bone loss and risk of fracture in patients. Modulation of bone mineral density cannot explain all effects. Other aspects of bone quality affecting fragility and ways to monitor them need to be better understood. Keratinous tissue acts as surrogate marker for bone protein deterioration caused by oestrogen deficiency in rats. Ovariectomised rats were treated with alendronate (ALN), parathyroid hormone (PTH) or estrogen (E2). MicroCT assessed macro structural changes. Raman spectroscopy assessed biochemical changes. Micro CT confirmed that all treatments prevented ovariectomy-induced macro structural bone loss in rats. PTH induced macro structural changes unrelated to ovariectomy. …

The Effect Of Electrospun Fiber Diameter On Astrocyte-Mediated Neurite Guidance And Protection, Christopher D.L. Johnson, Jonathan M. Zuidema, Kathryn R. Kearns, Alianna B. Maguire, Gregory P. Desmond, Deanna M. Thompson, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

The topography of electro spun fiber scaffolds modifies astrocytes toward in vivo-like morphologies and behaviors. However, little is known about how electro spun fiber diameter influences astrocyte behavior. In this work, aligned fibers with two distinct nanoscale fiber diameters (808 and 386 nm) were prepared, and the astrocyte response was measured over time. Astrocytes on the large diameter fibers showed significantly increased elongation as early as 2 h after seeding and remained significantly more elongated for up to 4 days compared to those on small diameter fibers. Astrocytes extending along larger diameter fibers were better equipped to support long neurite …

Injectable, Magnetically Orienting Electrospun Fiber Conduits For Neuron Guidance, Christopher D.L. Johnson, Debmalya Ganguly, Jonathan M. Zuidema, Thomas J. Cardinal, Alexis M. Ziemba, Kathryn R. Kearns, Simon M. Mccarthy, Deanna M. Thompson, Ganpati Ramanath, Diana A. Borca-Tasciuc, Silvio Dutz, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Magnetic electro spun fibers are of interest for minimally invasive biomaterial applications that also strive to provide cell guidance. Magnetic electro spun fibers can be injected and then magnetically positioned in situ, and the aligned fiber scaffolds provide consistent topographical guidance to cells. In this study, magnetically responsive aligned poly-l-lactic acid electro spun fiber scaffolds were developed and tested for neural applications. Incorporating oleic acid-coated iron oxide nanoparticles significantly increased neurite outgrowth, reduced the fiber alignment, and increased the surface nano topography of the electro spun fibers. After verifying neuron viability on two-dimensional scaffolds, the system was tested as an …

Well-Ordered Mesoporous Silica And Bioactive Glasses: Promise For Improved Hemostasis, Sara Pourshahrestani, Nahrizul Adib Kadri, Ehsan Zeimaran, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Immediate control of uncontrolled bleeding and infection are essential for saving lives in both combat and civilian arenas. Inorganic well-ordered mesoporous silica and bioactive glasses have recently shown great promise for accelerating hemostasis and infection control. However, to date, there has been no comprehensive report assessing their specific mechanism of action in accelerating the hemostasis process and exerting an antibacterial effect. After providing a brief overview of the hemostasis process, this review presents a critical overview of the recently developed inorganic mesoporous silica and bioactive glass-based materials proposed for hemostatic clinical applications and specifically investigates their unique characteristics that render …

Spatiotemporal Modeling And Model Restructuration Approaches In Studies Of Intracellular Signalling Pathways, Md Shahinuzzaman

Doctoral Dissertations

"The main focus of the research is to understand the complex phenomena of cell transduction pathways and cell biology in a single cell. Mathematical modeling and experimental evaluation are widely used approaches for this kind of research. Firstly, A multiscale framework for protein-protein interaction has been established using Brownian dynamics algorithm. Sit specific feature, steric collision, diffusion, co-localization and complex formation with time and space has been included in this spatial modeling framework. By implementation of the time adaptive feature in this framework, the computation time reduces in an order of magnitude compared with traditional modeling framework. This multiscale Brownian …

Magnetic Composite Biomaterials For Neural Regeneration, Jessica L. Funnell, Bailey Balouch, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Nervous system damage caused by physical trauma or degenerative diseases can result in loss of sensory and motor function for patients. Biomaterial interventions have shown promise in animal studies, providing contact guidance for extending neurites or sustained release of various drugs and growth factors; however, these approaches often target only one aspect of the regeneration process. More recent studies investigate hybrid approaches, creating complex materials that can reduce inflammation or provide neuroprotection in addition to stimulating growth and regeneration. Magnetic materials have shown promise in this field, as they can be manipulated non-invasively, are easily functionalized, and can be used …

Applications Of Machine Learning In Nuclear Imaging And Radiation Detection, Shaikat Mahmood Galib

Doctoral Dissertations

"The main focus of this work is to use machine learning and data mining techniques to address some challenging problems that arise from nuclear data. Specifically, two problem areas are discussed: nuclear imaging and radiation detection. The techniques to approach these problems are primarily based on a variant of Artificial Neural Network (ANN) called Convolutional Neural Network (CNN), which is one of the most popular forms of 'deep learning' technique.

The first problem is about interpreting and analyzing 3D medical radiation images automatically. A method is developed to identify and quantify deformable image registration (DIR) errors from lung CT scans …

Superelastic And Ph-Responsive Degradable Dendrimer Cryogels Prepared By Cryo-Aza-Michael Addition Reaction, Juan Wang, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Dendrimers exhibit super atomistic features by virtue of their well-defined discrete quantized nanoscale structures. Here, we show that hyperbranched amine-terminated polyamidoamine (PAMAM) dendrimer G4.0 reacts with linear polyethylene glycol (PEG) diacrylate (575 g/mol) via the aza-Michael addition reaction at a subzero temperature (-20 °C), namely cryo-aza-Michael addition, to form a macroporous superelastic network, i.e., dendrimer cryogel. Dendrimer cryogels exhibit biologically relevant Young's modulus, high compression elasticity and super resilience at ambient temperature. Furthermore, the dendrimer cryogels exhibit excellent rebound performance and do not show significant stress relaxation under cyclic deformation over a wide temperature range (-80 to 100 °C). The …

Silica Nanoparticle-Endothelial Interaction: Uptake And Effect On Platelet Adhesion Under Flow Conditions, Jiban Saikia, Raziye Mohammadpour, Mostafa Yazdimamaghani, Hannah Northrup, Vladimir Hlady, Hamidreza Ghandehari

Chemical and Biochemical Engineering Faculty Research & Creative Works

Silica nanoparticles are extensively used in biomedical applications and consumer products. Little is known about the interaction of these NPs with the endothelium and effect on platelet adhesion under flow conditions in circulation. In this study, we investigated the effect of silica nanoparticles on the endothelium and its inflammation, and subsequent adhesion of flowing platelets in vitro. Platelet counts adhered onto the surface of endothelial cells in the presence of nanoparticles increased at both low and high concentrations of nanoparticles. Preincubation of endothelial cells with nanoparticles also increased platelet adhesion. Interestingly, platelet adhesion onto TNF-α-treated endothelial cells decreased in the …

Deformation Of A Ferrofluid Droplet In Simple Shear Flows Under Uniform Magnetic Fields, Md Rifat Hassan, Jie Zhang, Cheng Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We numerically investigate the deformation and orientation of a ferrofluid droplet in a simple shear flow under a uniform magnetic field. The numerical simulation is based on the finite element method and couples the magnetic and flow fields. A level set method is used to model the dynamic motion of the droplet interface. Systematic numerical simulations are used to assess the effects of the direction and the strength of the magnetic field. Focusing on low Reynolds number flows (Re ≲ 0.02), the numerical results indicate that at a small capillary number (Ca ≈ 0.02), the magnetic field dominates over the …

Incorporating Germanium Oxide Into The Glass Phase Of Novel Zinc/Magnesium-Based Gpcs Designed For Bone Void Filling: Evaluating Their Physical And Mechanical Properties, Basel A. Khader, Omar Rodriguez, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The structural role of Germanium (Ge), when substituting for Zinc (Zn) up to 8 mol % in the 0.48SiO₂-0.12CaO-0.36ZnO-0.04MgO glass series, was investigated with respect to both the glass chemistry and also the properties of glass polyalkenoate cements (GPCs) manufactured from them. The Network connectivity (NC) of the glass was calculated to increase from 1.83 to 2.42 with the addition of GeO₂ (0-8 mol %). Differential thermal analysis (DTA) results confirmed an increase in the glass transition temperature (T_g) of the glass series with GeO₂ content. X-ray photoelectron spectroscopy (XPS) showed an increase in …

Influence Of Silica Nanoparticle Density And Flow Conditions On Sedimentation, Cell Uptake, And Cytotoxicity, Mostafa Yazdimamaghani, Zachary B. Barber, Seyyed Pouya Hadipour Moghaddam, Hamidreza Ghandehari

Chemical and Biochemical Engineering Faculty Research & Creative Works

Careful evaluation of the toxicological response of engineered nanomaterials (ENMs) as a function of physicochemical properties can aid in the design of safe platforms for biomedical applications including drug delivery. Typically, in vitro ENM cytotoxicity assessments are performed under conventional static cell culture conditions. However, such conditions do not take into account the sedimentation rate of ENMs. Herein, we synthesized four types of similar size silica nanoparticles (SNPs) with modified surface roughness, charge, and density and characterized their cytotoxicity under static and dynamic conditions. Influence of particle density on sedimentation and diffusion velocities were studied by comparing solid dense silica …

Poly- L -Lactic Acid- Co-Poly(Pentadecalactone) Electrospun Fibers Result In Greater Neurite Outgrowth Of Chick Dorsal Root Ganglia In Vitro Compared To Poly- L -Lactic Acid Fibers, Alexis M. Ziemba, Keith P. Lane, Ignacio M. San Segundo, Anthony R. D'Amato, Andrew K. Mason, Ryan J. Sexton, Hubert Casajus, Richard A. Gross, David T. Corr, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Electro spun poly-l-lactic acid (PLLA) fiber scaffolds are used to direct axonal extension in neural engineering models. We aimed to improve the efficacy of these fibers in promoting neurite outgrowth by altering surface topography and reducing fiber elastic modulus through the incorporation of a compatibilized blend, poly-l-lactic acid-poly(pentadecalactone) (PLLA-PPDL) into the solution prior to electrospinning. PLLA+PLLA-PPDL fibers had a larger diameter, increased surface nano topography, and lower glass transition temperature than PLLA fibers but had similar mechanical properties. Increases in neurite outgrowth on PLLA+PLLA-PPDL fibers were observed, potentially due to the significantly increased diameter and surface coverage with nano topography. …

Development Of A Novel Bioactive Glass Suitable For Osteosarcoma-Related Bone Grafts, Alireza Rahimnejad Yazdi, Lawrence Torkan, Stephen D. Waldman, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this study, zinc borate-based glasses with increasing gallium content (0, 2.5, 5, 10, and 15 wt % Ga) were synthesized and their effect on the viability and proliferation of preosteoblasts and osteosarcoma cancer cells were investigated. Methyl thiazolyl tetrazolium (MTT) cell viability assays using glass degradation extracts revealed that the extracts from glasses with lower Ga contents could enhance the viability of preosteoblasts, while extracts from the glass composition with 15 wt % Ga caused statistically significant reduction of their viability. MTT cell viability assays using the extracts and osteosarcoma cells showed that only extracts from the glass composition …

The Effect Of Mg²⁺ Incorporation Into The Glass Phase Of Zinc-Based Glass Polyalkenoate Cements, Basel A. Khader, Omar Rodriguez, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The suitability of glass polyalkenoate cements (GPCs) as injectable adhesives in orthopedics have been compromised by the presence of aluminum (Al), a component in the glass phase of all commercial GPCs. There has been considerable work on the development of Al-free GPCs which can be formulated based on calcium (Ca) zinc (Zn) silicate (Si) glasses. These materials, in terms of biocompatibility and mechanical properties, have potential for orthopedics. However, many of these experimental Al-free GPCs have setting times shorter than 60 s, restricting clinical applications. Here, the authors incorporate Magnesium (Mg) into the glass phase of Al-free GPCs in an …

Injectable Glass Polyalkenoate Cements: Evaluation Of Their Rheological And Mechanical Properties With And Without The Incorporation Of Lidocaine Hydrochloride, P. Niranjan, A. Alhalawani, S. Phull, I. Beniluz, B. Krishnan, P. Zalzal, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Lidocaine hydrochloride is used as an anesthetic in many clinical applications. This short communication investigates the effect of complete substitution of lidocaine hydrochloride for deionized (DI) water on the physico-chemical properties of two novel glass polyalkenoate cements. Substituting DI water with lidocaine hydrochloride resulted in cements with shorter working times but comparable setting times and mechanical properties. Fourier transform infrared spectroscopy confirmed that the setting reaction in cements containing DI water and lidocaine hydrochloride was completed within 24 h, post cement preparation and maturation. Further, it was explained that lidocaine hydrochloride binds to poly(acrylic) acid (PAA) due to electrostatic forces …

Raman Spectroscopy Predicts The Link Between Claw Keratin And Bone Collagen Structure In A Rodent Model Of Oestrogen Deficiency, M. Clare Caraher, Antonia Sophocleous, J. Renwick Beattie, Olive O'Driscoll, Niamh M. Cummins, Orlaith Brennan, Fergal J. O'Brien, Stuart H. Ralston, Steven E.J. Bell, Mark R. Towler, Aymen I. Idris

Chemical and Biochemical Engineering Faculty Research & Creative Works

Osteoporosis is a common disease characterized by reduced bone mass and an increased risk of fragility fractures. Low bone mineral density is known to significantly increase the risk of osteoporotic fractures; however, the majority of non-traumatic fractures occur in individuals with a bone mineral density too high to be classified as osteoporotic. Therefore, there is an urgent need to investigate aspects of bone health, other than bone mass, that can predict the risk of fracture. Here, we successfully predicted association between bone collagen and nail keratin in relation to bone loss due to oestrogen deficiency using Raman spectroscopy. Raman signal …

Specific Nanoporous Geometries On Anodized Alumina Surfaces Influence Astrocyte Adhesion And Glial Fibrillary Acidic Protein Immunoreactivity Levels, D. Ganguly, C. D.L. Johnson, M. K. Gottipati, D. Rende, D. A. Borca-Tasciuc, R. J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Electrodes implanted in the brain or spinal cord trigger the activation of resident astrocytes. In their reactive state, astrocytes surrounding the electrode form a glial scar, compromising the ability of the electrode to interface with the surrounding neural tissue. One approach to reduce the inhibiting scar tissue is to incorporate nanoarchitecture on the surface of the implanted materials to modify the astrocytic response. The incorporated nanoarchitecture changes both the surface characteristics and the material properties of the implant interface. We investigated the response of rat cortical astrocytes to nanoporous anodic aluminum oxide (AAO) surfaces. Astrocytes were seeded onto nonporous aluminum …

The Impact Of Gallium Content On Degradation, Bioactivity, And Antibacterial Potency Of Zinc Borate Bioactive Glass, Alireza Rahimnejad Yazdi, Lawrence Torkan, Wendy Stone, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Zinc borate glasses with increasing gallium content (0, 2.5, 5, 10, and 15 Wt % Ga) were synthesized and their degradation, bioactivity in simulated body fluid (SBF), and antibacterial properties were investigated. ICP measurements showed that increased gallium content in the glass resulted in increased gallium ion release and decreased release of other ions. Degradability declined with the addition of gallium, indicating the formation of more symmetric BO₃ units with three bridging oxygens and asymmetric BO₃ units with two bridging oxygens in the glass network as the gallium content in the series increased. The formation of amorphous Ca-P …

A Preliminary Evaluation Of The Ability Of Keratotic Tissue To Act As A Prognostic Indicator Of Hip Fracture Risk, J. Renwick Beattie, Diane Feskanich, M. Clare Caraher, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Studies have shown that Raman spectroscopic analysis of fingernail clippings can help differentiate between post-menopausal women who have and who have not suffered a fracture. However, all studies to date have been retrospective in nature, comparing the proteins in nails sourced from women, post-fracture. The objective of this study was to investigate the potential of a prospective test for hip fracture based on spectroscopic analysis of nail tissue. Archived toenail samples from post-menopausal women aged 50 to 63 years in the Nurses' Health Study were obtained and analysed by Raman spectroscopy. Nails were matched case-controls sourced from 161 women; 82 …

Evaluation Of The Mechanical Properties, In Vitro Biodegradability And Cytocompatibility Of Natural Chitosan/Hydroxyapatite/Nano-Fe3o4 Composite, Fatemeh Heidari, Mehdi Razavi, Mohammad E. Bahrololoom, Mostafa Yazdimamaghani, Mohammadreza Tahriri, Hari Kotturi, Lobat Tayebi

Chemical and Biochemical Engineering Faculty Research & Creative Works

The main goal of this research was the preparation and evaluation of the mechanical properties, in vitro biodegradability and cytocompatibility, of natural chitosan/hydroxyapatite/nano magnetite (nano-Fe3O4) composite. Different ratios of these components were investigated, including chitosan/hydroxyapatite: 4/4 (S1), chitosan/hydroxyapatite: 4/6 (S2), and chitosan/hydroxyapatite: 6/4 (S3). Mechanical properties of fabricated composites were examined using bending and compression tests before immersion, and after 2 and 9 weeks of immersion in the Ringer's solution. Scanning electron microscope (SEM) was employed for observing the bending fracture surface and analyzing the degradation morphology. Human mesenchymal stem cells (hMSC) were also cultured on the samples in order …

Design And Development Of A Compact X-Ray Tube For Stationary Ct Architecture, Ashish Vighnahar Avachat

Doctoral Dissertations

"Multisource architectures enable sweeping one or more x-ray beams across the imaging field-of-view faster than physically moving a single x-ray source and/or a detector. Hence, these architectures are attractive for the applications in which temporal resolution plays an important role, for example, cardiac computed tomography (CT) or real-time CT. One of the recent developments in multisource architectures for CT imaging is stationary CT architecture, whereby two separate stationary arrays -- one for x-ray sources and one for detectors -- are utilized to sweep one or more x-ray beams along the gantry and acquire 360 degree projections. To have a stationary …

Synthesis Of Regioselectively Acylated Quercetin Analogues With Improved Antiplatelet Activity, Yu Duan, Na Sun, Min Xue, Xiaolan Wang, Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

The aim of the present study was to report on a complete synthetic approach, namely benzylation-hydrolysis-acylation-hydrogenation, to the synthesis of regioselectively acylated quercetin analogues using low-cost rutin as a starting material. Three quercetin analogues, quercetin-3-O-propionate (Q-pr), quercetin-3-O-butyrate (Q-bu) and quercetin-3-O-valerate (Q-va), containing 3-, 4- and 5-carbon aliphatic acyl chains, respectively, were synthesized and characterized with ¹H nuclear magnetic resonance (NMR), ¹³C NMR and mass spectrometry. Compared with quercetin, all three analogues exhibited improved lipophilicity. The lipophilicity of the analogue increased with increasing acyl chain length. Q-va exhibited the highest lipophilicity among the three analogues, but a lower water …

Titanium Addition Influences Antibacterial Activity Of Bioactive Glass Coatings On Metallic Implants, Omar Rodriguez, Wendy Stone, Emil H. Schemitsch, Paul Zalzal, Stephen Waldman, Marcello Papini, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

In an attempt to combat the possibility of bacterial infection and insufficient bone growth around metallic, surgical implants, bioactive glasses may be employed as coatings. In this work, silica-based and borate-based glass series were synthesized for this purpose and subsequently characterized in terms of antibacterial behavior, solubility and cytotoxicity. Borate-based glasses were found to exhibit significantly superior antibacterial properties and increased solubility compared to their silica-based counterparts, with BRT0 and BRT3 (borate-based glasses with 0 and 15 mol% of titanium dioxide incorporated, respectively) outperforming the remainder of the glasses, both borate and silicate based, in these respects. Atomic Absorption Spectroscopy …

Potency And Cytotoxicity Of A Novel Gallium-Containing Mesoporous Bioactive Glass/Chitosan Composite Scaffold As Hemostatic Agents, Sara Pourshahrestani, Ehsan Zeimaran, Nahrizul Adib Kadri, Nicola Gargiulo, Hassan Mahmood Jindal, Sangeetha Vasudevaraj Naveen, Shamala Devi Sekaran, Tunku Kamarul, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Chitosan-based hemostats are promising candidates for immediate hemorrhage control. However, they have some disadvantages and require further improvement to achieve the desired hemostatic efficiency. Here, a series of 1% Ga2O3-containing mesoporous bioactive glass-chitosan composite scaffolds (Ga-MBG/CHT) were constructed by the lyophilization process and the effect of various concentrations of Ga-MBG (10, 30, and 50 wt %) on the hemostatic function of the CHT scaffold was assessed as compared to that of Celox Rapid gauze (CXR), a current commercially available chitosan-coated hemostatic gauze. The prepared scaffolds exhibited >79% porosity and showed increased water uptake compared to that in CXR. The results …

The Effect Of Engineered Nanotopography Of Electrospun Microfibers On Fiber Rigidity And Macrophage Cytokine Production, Nicholas J. Schaub, Anthony R. D'Amato, Andrew Mason, David T. Corr, Erin Y. Harmon, Michelle R. Lennartz, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Currently, it is unknown how the mechanical properties of electro spun fibers, and the presentation of surface nano topography influence macrophage gene expression and protein production. By further elucidating how specific fiber properties (mechanical properties or surface properties) alter macrophage behavior, it may be possible to create electro spun fiber scaffolds capable of initiating unique cellular and tissue responses. In this study, we determined the elastic modulus and rigidity of fibers with varying topographies created by finely controlling humidity and including a non-solvent during electrospinning. In total, five fiber scaffold types were produced. Analysis of fiber physical properties demonstrated no …

Removal Of Retained Electrospinning Solvent Prolongs Drug Release From Electrospun Plla Fibers, Anthony R. D'Amato, Nicholas J. Schaub, Jesus M. Cardenas, Andrew S. Fiumara, Paul M. Troiano, Andrea Fischetti, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

A major challenge in developing drug-releasing electro spun nanofibers is obtaining long-term drug release over many weeks with no burst release of drug. Here, we present new methods capable of prolonging the diffusive release of small molecule drugs from electro spun poly-L-lactic acid (PLLA) nanofibers. The methods focus on removal of retained electrospinning solvent through fiber heating, maintaining fibers in a laboratory setting, or a combination of these methods. These post-fabrication methods altered the release characteristics of a model small molecule drug, 6-aminonicotinamide (6AN), from PLLA fibers. Specifically, untreated fibers released 6AN over 9 days, and fibers that underwent a …

Redox-Responsive Polysulfide-Based Biodegradable Organosilica Nanoparticles For Delivery Of Bioactive Agents, Seyyed Pouya Hadipour Moghaddam, Jiban Saikia, Mostafa Yazdimamaghani, Hamidreza Ghandehari

Chemical and Biochemical Engineering Faculty Research & Creative Works

Design and development of silica nanoparticles (SiO2 NPs) with a controlled degradation profile promises effective drug delivery with a predetermined carrier elimination profile. In this research, we fabricated a series of redox-responsive polysulfide-based biodegradable SiO2 NPs with low polydispersity and with variations in size (average diameters of 58 ± 7, 108 ± 11, 110 ± 9, 124 ± 9, and 332 ± 6 nm), porosity, and composition (disulfide vs tetra sulfide bonds). The degradation kinetics of the nanoparticles was analyzed in the presence of 8 mM glutathione (GSH), mimicking the intracellular reducing condition. Results indicate that porosity and core composition …

Raman Spectral Variation For Human Fingernails Of Postmenopausal Women Is Dependent On Fracture Risk And Osteoporosis Status, J. R. Beattie, M. C. Caraher, N. M. Cummins, O. M. O'Driscoll, R. Eastell, S. H. Ralston, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Patients diagnosed with osteoporosis have reported loss of fingernail resilience as the disease progresses. Keratin is the predominant protein in human nail tissue, and its structure has been postulated to be different in fingernails clipped from subjects who have sustained fragility fractures and those who have not, which may offer a window into the donor's bone health. This study was designed to qualify these differences, which may lead to the development of a novel screening tool for fracture risk. Raman spectroscopy was used to measure the fingernails of 633 postmenopausal women who presented at six fracture clinics located across the …