Engineering Commons^™

Micrococcal-Nuclease-Triggered On-Demand Release Of Vancomycin From Intramedullary Implant Coating Eradicates Staphylococcus Aureus Infection In Mouse Femoral Canals, Ananta Ghimire, Jordan D. Skelly, Jie Song

Orthopedics and Physical Rehabilitation Publications

Preventing orthopedic implant-associated bacterial infections remains a critical challenge. Current practices of physically blending high-dose antibiotics with bone cements is known for cytotoxicity while covalently tethering antibiotics to implant surfaces is ineffective in eradicating bacteria from the periprosthetic tissue environment due to the short-range bactericidal actions, which are limited to the implant surface. Here, we covalently functionalize poly(ethylene glycol) dimethacrylate hydrogel coatings with vancomycin via an oligonucleotide linker sensitive to Staphylococcus aureus (S. aureus) micrococcal nuclease (MN) (PEGDMA-Oligo-Vanco). This design enables the timely release of vancomycin in the presence of S. aureus to kill the bacteria both on the ...

Liver Cancer: Current And Future Trends Using Biomaterials, Sue Anne Chew, Stefania Moscato, Sachin George, Bahareh Azimi, Serena Danti

Health and Biomedical Sciences Faculty Publications and Presentations

Hepatocellular carcinoma (HCC) is the fifth most common type of cancer diagnosed and the second leading cause of death worldwide. Despite advancement in current treatments for HCC, the prognosis for this cancer is still unfavorable. This comprehensive review article focuses on all the current technology that applies biomaterials to treat and study liver cancer, thus showing the versatility of biomaterials to be used as smart tools in this complex pathologic scenario. Specifically, after introducing the liver anatomy and pathology by focusing on the available treatments for HCC, this review summarizes the current biomaterial-based approaches for systemic delivery and implantable tools ...

Selection Of An Efficient Aav Vector For Robust Cns Transgene Expression, Killian S. Hanlon, Miguel Sena-Esteves, Eloise Hudry, Casey A. Maguire

Open Access Publications by UMMS Authors

Adeno-associated virus (AAV) capsid libraries have generated improved transgene delivery vectors. We designed an AAV library construct, iTransduce, that combines a peptide library on the AAV9 capsid with a Cre cassette to enable sensitive detection of transgene expression. After only two selection rounds of the library delivered intravenously in transgenic mice carrying a Cre-inducible fluorescent protein, we flow sorted fluorescent cells from brain, and DNA sequencing revealed two dominant capsids. One of the capsids, termed AAV-F, mediated transgene expression in the brain cortex more than 65-fold (astrocytes) and 171-fold (neurons) higher than the parental AAV9. High transduction efficiency was sex-independent ...

Cdse Quantum Dots Synthesis Laboratory Course For High School Students, Danlin Zuo, Gyuseok Kim, David Jones

Protocols and Reports

Cadmium selenide quantum dot is a fascinating subject for leading high school students to the quantum world. An 8-hour laboratory course for up to 12 high school students is proposed. The 8-hour course consist of two 4-hours sections. This laboratory course includes the quantum dot syntheses, absorption and emission characterization, and data analysis. The proposes process runs at relatively lower temperature which means safe and easy, and shows apparent experimental results.

How Degrees Of Freedom Affects Sense Of Agency, Akima Connelly, Jungsu Pak, Tian Lan, Uri Maoz

Student Scholar Symposium Abstracts and Posters

Can the rubber-hand illusion be extended to a moving robotic arm in different degrees of freedom (DOF), inducing sense of ownership & agency over the arm? We hypothesize that DOF closer to what humans possess will result in a stronger sense of ownership and agency.

A Multi-Scale Approach To Study Biochemical And Biophysical Aspects Of Resveratrol On Diesel Exhaust Particle-Human Primary Lung Cell Interaction, Wei Zhang, Qifei Li, Mingjie Tang, Han Zhang, Xiaoping Sun, Sige Zou, Judy L. Jensen, Theodore G. Liou, Anhong Zhou

Biological Engineering Faculty Publications

Diesel exhaust particles (DEPs) are major air pollutants that lead to numerous human disorders, especially pulmonary diseases, partly through the induction of oxidative stress. Resveratrol is a polyphenol that ameliorates the production of reactive oxygen species (ROS) and delays aging-related processes. Herein we studied the cytoprotective effect of resveratrol on DEP-exposed human lung cells in a factorial experimental design. This work investigates biophysical features including cellular compositions and biomechanical properties, which were measured at the single-cell level using confocal Raman microspectroscopy (RM) and atomic force microscopy (AFM), respectively. Principal component analysis (PCA), hierarchical cluster analysis (HCA) and partial least square ...

An Algorithm For Coupling Multibranch In Vitro Experiment To Numerical Physiology Simulation For A Hybrid Cardiovascular Model, Ehsan Mirzaei, Masoud Farahmand, Ethan Kung

Publications

The hybrid cardiovascular modeling approach integrates an in vitro experiment with a computational lumped‐parameter simulation, enabling direct physical testing of medical devices in the context of closed‐loop physiology. The interface between the in vitro and computational domains is essential for properly capturing the dynamic interactions of the two. To this end, we developed an iterative algorithm capable of coupling an in vitro experiment containing multiple branches to a lumped‐parameter physiology simulation. This algorithm identifies the unique flow waveform solution for each branch of the experiment using an iterative Broyden's approach. For the purpose of algorithm testing ...

Spark Plasma Sintering Of Low Modulus Titanium-Niobium-Tantalum-Zirconium (Tntz) Alloy For Biomedical Applications, Nicholas Mavros, Taban Larimian, Javier Esqivel, Rajeev Kumar Gupta, Rodrigo Contieri, Tushar Borkar

Mechanical Engineering Faculty Publications

In metallurgy, titanium has been a staple for biomedical purposes. Its slow toxicity and alloying versatility make it an attractive choice for medical applications. However, studies have shown the difference in elastic modulus between titanium alloys (116 GPa) and human bone (10–40 GPa), which contributes to long term issues with loose hardware fixation. Additionally, long term studies have shown elements such as vanadium and aluminum, which are commonly used in Ti-6Al-4V biomedical alloys, have been linked to neurodegenerative diseases like Alzheimer and Parkinson. Alternative metals known to be less toxic are being explored as replacements for alloying elements in ...

Electropermeabilization Does Not Correlate With Plasma Membrane Lipid Oxidation, Olga Michel, Andrei G. Pakhomov, Maura Casciola, Jolanta Saczko, Julita Kulbacka, Olga N. Pakhomova

Bioelectrics Publications

The permeabilized condition of the cell membrane after electroporation can last minutes but the underlying mechanisms remain elusive. Previous studies suggest that lipid peroxidation could be responsible for the lasting leaky state of the membrane. The present study aims to link oxidation within the plasma membrane of live cells to permeabilization by electric pulses. We have introduced a method for the detection of oxidation by ratiometric fluorescence measurements of BODIPY-C11 dye using total internal reflection fluorescence (TIRF) microscopy, limiting the signal to the cell membrane. CHO-K1 cells were cultured on glass coverslips coated with an electroconductive indium tin oxide (ITO ...

An Evaluation Of The Host Response To An Interspinous Process Device Based On A Series Of Spine Explants: Device For Intervertebral Assisted Motion (Diam®), Jeffrey M. Toth, Justin D. Bric

Biomedical Engineering Faculty Research and Publications

Background:

The objective of this study was to evaluate the host response to an interspinous process device [Device for Intervertebral Assisted Motion (DIAM®)] based on a series of nine spine explants with a mean post-operative explant time of 35 months.

Methods:

Explanted periprosthetic tissues were processed for histology and stained with H&E, Wright-Giemsa stain, and Oil Red O. Brightfield and polarized light microscopy were used to evaluate the host response to the device and the resultant particulate debris. The host response was graded per ASTM F981-04. Quantitative histomorphometry was used to characterize particle size, shape, and area per ASTM ...

Viscoelastic Properties Of Shock Wave Exposed Brain Tissue Subjected To Unconfined Compression Experiments, Annastacia K. Mccarty, Ling Zhang, Sarah Hansen, William J. Jackson, Sarah A. Bentil

Mechanical Engineering Publications

Traumatic brain injuries (TBI) affect millions of people each year. While research has been dedicated to determining the mechanical properties of the uninjured brain, there has been a lack of investigation on the mechanical properties of the brain after experiencing a primary blast-induced TBI. In this paper, whole porcine brains were exposed to a shock wave to simulate blast-induced TBI. First, ten (10) brains were subjected to unconfined compression experiments immediately following shock wave exposure. In addition, 22 brains exposed to a shock wave were placed in saline solution and refrigerated between 30 minutes and 6.0 hours before undergoing ...

Comparison Of Artifacts Between Paste And Collodion Method Of Electrode Application In Pediatric Eeg, Danielle Brigham, Yash Shah, Kanwaljit Singh, Ivan Pavkovic, Shefali Karkare, Sanjeev V. Kothare

Open Access Publications by UMMS Authors

Objectives: Children pose challenges to obtain quality EEG data due to excessive artifact. Collodion is used in EEG electrodes due to its water resistance and strong adhesive qualities. This study was done to evaluate differences in artifacts between the collodion and paste method.

Methods: 115 subjects (children age > 3 years) were randomized into paste and collodion groups and artifacts evaluated at baseline and every hour over 30s increments. Age, sleep state, and number of electrodes with artifact were also documented. T-test was performed to determine differences in the various parameters between the two groups.

Results: 61 subjects were in the ...

Effect Of Annealing On The Contact Resistance Of Aluminum On A P-Type Substrate, Shrey Shah, George Patrick Watson

Protocols and Reports

Aluminum contacts are widely used to form both ohmic and rectifying contacts. The process to form these contacts involves annealing, thus it is important to study the effect of annealing on the electrical properties of the contacts. Here, we present a way to measure the contact resistance of aluminum contacts formed on a p-type silicon substrate. It was found the contact resistivity decreased by an average of 18%. It was thus found that annealing at 400°C in a forming gas environment improves the electrical properties of aluminum contacts.

Synergistic Activation Of Inspiratory Muscles By An Adaptive Closed-Loop Controller, Rabeya Zinnat Adury

FIU Electronic Theses and Dissertations

During diaphragmatic pacing reverse recruitment of muscle fibers causes muscle fatigue. Current diaphragmatic pacing paradigms also do not permit sigh-like behavior. In spontaneously breathing anesthetized rats, studies were carried out to determine if synergized pacing of external intercostal muscles and the diaphragm would increase the efficiency of diaphragm stimulation and thus a) achieve the desired ventilatory breath volume profile with reduced diaphragm muscle fatigue, and/or b) be able to elicit sigh-like behavior by periodically increasing stimulation. Under combined inspiratory muscle stimulation, a fatigue index calculated for the diaphragm muscle (n=6 rats) was significantly lower (p<0.05) than in the ...

Microarray Embedding/Sectioning For Parallel Analysis Of 3d Cell Spheroids., Jonathan Gabriel, David Brennan, Jennifer H Elisseeff, Vincent Beachley

Henry M. Rowan College of Engineering Faculty Scholarship

Three-dimensional cell spheroid models can be used to predict the effect of drugs and therapeutics and to model tissue development and regeneration. The utility of these models is enhanced by high throughput 3D spheroid culture technologies allowing researchers to efficiently culture numerous spheroids under varied experimental conditions. Detailed analysis of high throughput spheroid culture is much less efficient and generally limited to narrow outputs, such as metabolic viability. We describe a microarray approach that makes traditional histological embedding/sectioning/staining feasible for large 3D cell spheroid sample sets. Detailed methodology to apply this technology is provided. Analysis of the technique ...

Enhancing Single Walled Carbon Nanotube Deposition For The Study Of Extracellular Analytes, Joseph A. Stapleton

Biological Systems Engineering--Dissertations, Theses, and Student Research

Extracellular signaling is a dynamic process responsible for coordinating large scale biological processes. As such, understanding extracellular signaling is important to our determination of normal function and pathophysiological development. High resolution spatial and temporal information are critical to completely understanding these processes. Unfortunately, current methods of detection are lacking in either spatial or temporal resolution of extracellular products, limiting researchers’ ability to understand complex biological processes. A new group of sensors based on fluorescent single walled carbon nanotubes (SWNT) have shown the potential to provide both high quality spatial and temporal resolution for the sensing of analytes. However, while SWNT ...

Factors Affecting Cardiovascular Physiology In Cardiothoracic Surgery: Implications For Lumped-Parameter Modeling, Joshua Kaufmann, Ethan Kung

Publications

Cardiothoracic surgeries are complex procedures during which the patient cardiovascular physiology is constantly changing due to various factors. Physiological changes begin with the induction of anesthesia, whose effects remain active into the postoperative period. Depending on the surgery, patients may require the use of cardiopulmonary bypass and cardioplegia, both of which affect postoperative physiology such as cardiac index and vascular resistance. Complications may arise due to adverse reactions to the surgery, causing hemodynamic instability. In response, fluid resuscitation and/or vasoactive agents with varying effects may be used in the intraoperative or postoperative periods to improve patient hemodynamics. These factors ...

Pharmacokinetics Of 99mTc-Hmpao In Isolated Perfused Rat Lungs, Anne V. Clough, Katherine Barry, Benjamin Michael Rizzo, Elizabeth R. Jacobs, Said H. Audi

Biomedical Engineering Faculty Research and Publications

Lung uptake of technetium-labeled hexamethylpropyleneamine oxime (HMPAO) increases in rat models of human acute lung injury, consistent with increases in lung tissue glutathione (GSH). Since ^99mTc-HMPAO uptake is the net result of multiple cellular and vascular processes, the objective was to develop an approach to investigate the pharmacokinetics of ^99mTc-HMPAO uptake in isolated perfused rat lungs. Lungs of anesthetized rats were excised and connected to a ventilation-perfusion system. ^99mTc-HMPAO (56 MBq) was injected into the pulmonary arterial cannula, a time sequence of images was acquired, and lung time-activity curves were constructed. Imaging was repeated with a range ...

Label-Free Microrna Optical Biosensors, Meimei Lai, Gymama Slaughter

Bioelectrics Publications

MicroRNAs (miRNAs) play crucial roles in regulating gene expression. Many studies show that miRNAs have been linked to almost all kinds of disease. In addition, miRNAs are well preserved in a variety of specimens, thereby making them ideal biomarkers for biosensing applications when compared to traditional protein biomarkers. Conventional biosensors for miRNA require fluorescent labeling, which is complicated, time-consuming, laborious, costly, and exhibits low sensitivity. The detection of miRNA remains a big challenge due to their intrinsic properties such as small sizes, low abundance, and high sequence similarity. A label-free biosensor can simplify the assay and enable the direct detection ...

Estimating Cognitive Workload In An Interactive Virtual Reality Environment Using Eeg, Christoph Tremmel, Christain Herff, Tetsuya Sato, Krzysztof Rechowicz, Yusuke Yamani, Dean J. Krusienski

Electrical & Computer Engineering Faculty Publications

With the recent surge of affordable, high-performance virtual reality (VR) headsets, there is unlimited potential for applications ranging from education, to training, to entertainment, to fitness and beyond. As these interfaces continue to evolve, passive user-state monitoring can play a key role in expanding the immersive VR experience, and tracking activity for user well-being. By recording physiological signals such as the electroencephalogram (EEG) during use of a VR device, the user's interactions in the virtual environment could be adapted in real-time based on the user's cognitive state. Current VR headsets provide a logical, convenient, and unobtrusive framework for ...

Role Of The Cortex In Visuomotor Control Of Arm Stability, Dylan B. Snyder, Scott A. Beardsley, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Whereas numerous motor control theories describe the control of arm trajectory during reach, the control of stabilization in a constant arm position (i.e., visuomotor control of arm posture) is less clear. Three potential mechanisms have been proposed for visuomotor control of arm posture: 1) increased impedance of the arm through co-contraction of antagonistic muscles, 2) corrective muscle activity via spinal/supraspinal reflex circuits, and/or 3) intermittent voluntary corrections to errors in position. We examined the cortical mechanisms of visuomotor control of arm posture and tested the hypothesis that cortical error networks contribute to arm stabilization. We collected electroencephalography ...

Post-Acquisition Processing Confounds In Brain Volumetric Quantification Of White Matter Hyperintensities, Ahmed A. Bahrani, Omar M. Al-Janabi, Erin L. Abner, Shoshana H. Bardach, Richard J. Kryscio, Donna M. Wilcock, Charles D. Smith, Gregory A. Jicha

Neurology Faculty Publications

BACKGROUND: Disparate research sites using identical or near-identical magnetic resonance imaging (MRI) acquisition techniques often produce results that demonstrate significant variability regarding volumetric quantification of white matter hyperintensities (WMH) in the aging population. The sources of such variability have not previously been fully explored.

NEW METHOD: 3D FLAIR sequences from a group of randomly selected aged subjects were analyzed to identify sources-of-variability in post-acquisition processing that can be problematic when comparing WMH volumetric data across disparate sites. The methods developed focused on standardizing post-acquisition protocol processing methods to develop a protocol with less than 0.5% inter-rater variance.

RESULTS: A ...

Multi-Site Photoplethysmography Technology For Blood Pressure Assessment: Challenges And Recommendations, Gabriel Chan, Rachel Cooper, Manish Hosanee, Kaylie Welykholowa, Panayiotis A. Kyriacou, Dingchang Zheng, John Allen, Derek Abbott, Nigel H. Lovell, Richard Fletcher, Mohamed Elgendi

Open Access Publications by UMMS Authors

Hypertension is one of the most prevalent diseases and is often called the "silent killer" because there are usually no early symptoms. Hypertension is also associated with multiple morbidities, including chronic kidney disease and cardiovascular disease. Early detection and intervention are therefore important. The current routine method for diagnosing hypertension is done using a sphygmomanometer, which can only provide intermittent blood pressure readings and can be confounded by various factors, such as white coat hypertension, time of day, exercise, or stress. Consequently, there is an increasing need for a non-invasive, cuff-less, and continuous blood pressure monitoring device. Multi-site photoplethysmography (PPG ...

Invertebrate Retinal Progenitors As Regenerative Models In A Microfluidic System, Caroline D. Pena, Stephanie Zhang, Robert Majeska, Tadmiri Venkatesh, Maribel Vazquez

Publications and Research

Regenerative retinal therapies have introduced progenitor cells to replace dysfunctional or injured neurons and regain visual function. While contemporary cell replacement therapies have delivered retinal progenitor cells (RPCs) within customized biomaterials to promote viability and enable transplantation, outcomes have been severely limited by the misdirected and/or insuffcient migration of transplanted cells. RPCs must achieve appropriate spatial and functional positioning in host retina, collectively, to restore vision, whereas movement of clustered cells differs substantially from the single cell migration studied in classical chemotaxis models. Defining how RPCs interact with each other, neighboring cell types and surrounding extracellular matrixes are critical ...

Atrial Fibrillation Detection From Wrist Photoplethysmography Signals Using Smartwatches, Syed Khairul Bashar, Dong Han, Shirin Hajeb-Mohammadalipour, Eric Y. Ding, Cody Whitcomb, David D. Mcmanus, Ki H. Chon

Open Access Publications by UMMS Authors

Detection of atrial fibrillation (AF) from a wrist watch photoplethysmogram (PPG) signal is important because the wrist watch form factor enables long term continuous monitoring of arrhythmia in an easy and non-invasive manner. We have developed a novel method not only to detect AF from a smart wrist watch PPG signal, but also to determine whether the recorded PPG signal is corrupted by motion artifacts or not. We detect motion and noise artifacts based on the accelerometer signal and variable frequency complex demodulation based time-frequency analysis of the PPG signal. After that, we use the root mean square of successive ...

Investigation Of Cavitation-Induced Damage On Pdms Films, Alex H. Wrede, Faisal Al-Masri, Reza Montazami, Nicole N. Hashemi

Mechanical Engineering Publications

Traumatic brain injuries (TBIs) are complex phenomena that create epidemic healthcare and financial concerns. Recent studies have theorized that cavitation exists during a TBI and has potential to induce significant damage to the surrounding anatomy. This study seeks to implement polydimethylsiloxane (PDMS) films as a placeholder of the brain to elucidate the damage that the surrounding brain tissue would experience from nearby cavitation. The apparatus includes an existing methodology that implements controlled cavitation. 3D confocal microscopy and interferometry techniques are used to characterize the surface damage to the PDMS films. Visual representation and roughness parameters on the nanoscale help elucidate ...

Influence Of Flow Rate, Nozzle Speed, Pitch And The Number Of Passes On The Thickness Of S1805 Photoresist In Suss Microtec As8 Spray Coater, Rohan Sanghvi, Gyuseok Kim

Tool Data

S1805 positive photoresist has been deposited on single crystalline Si wafers using a Suss MicroTec Alta Spray. The influence of flow rate, nozzle speed, pitch and number of passes on the thickness of the photoresist was studied. Results show that the thickness of S1805 is linearly proportional to the flow rate and number of passes, and inversely proportional to the nozzle speed and pitch.

Vibration Propagation On The Skin Of The Arm, Valay A. Shah, Maura Casadio, Robert A. Scheidt, Leigh A. Mrotek

Biomedical Engineering Faculty Research and Publications

Vibrotactile interfaces are an inexpensive and non-invasive way to provide performance feedback to body-machine interface users. Interfaces for the upper extremity have utilized a multi-channel approach using an array of vibration motors placed on the upper extremity. However, for successful perception of multi-channel vibrotactile feedback on the arm, we need to account for vibration propagation across the skin. If two stimuli are delivered within a small distance, mechanical propagation of vibration can lead to inaccurate perception of the distinct vibrotactile stimuli. This study sought to characterize vibration propagation across the hairy skin of the forearm. We characterized vibration propagation by ...

Novel Green Micro-Synthesis Of Graphene-Titanium Dioxide Nano- Composites With Photo-Electrochemical Properties, Nourwanda M. Serour, Ahmed S.E. Hammad, Ahmed H. El-Shazly, Dina A. El-Gayar, Shaaban A. Nosier

Chemical and Biochemical Engineering Publications

Background: Graphene-Titanium dioxide nano-composite forms a very promising material in the field of photo-electrochemical research.

Methods: In this study, a novel environment-friendly synthesis method was developed to produce well-distributed anatase nano-titanium dioxide spherical particles on the surface of graphene sheets. This novel method has great advantages over previously developed methods of producing graphenetitanium dioxide nanocomposites (GTNCs). High calcination temperature 650°C was used in the preparation of nano titanium dioxide, and chemical exfoliation for graphene synthesis and GTNC was performed by our novel method of depositing titanium dioxide nanoparticles on graphene sheets using a Y-shaped micro-reactor under a controlled pumping ...

Correction Of Pattern Size Deviations In The Fabrication Of Photomasks Made With A Laser Direct-Writer, Ningzhi Xie, George Patrick Watson

Protocols and Reports

When using Heidelberg DWL66+ laser writer to fabricate the photomask, the pattern feature dimensions may have deviations. These deviations can be caused by the lithography process and the undercut in the metal etch process. The same deviation value of 0.8µm was found to appear in all the patterns independent of the pattern original size and local pattern density. To overcome this universal deviation, a universal bias is suggested to be applied to the original patterns during the data preparation for the lithography process. In order to ensure this pre-exposure bias method can work, both the laser direct-write exposure conditions ...