Biomedical Engineering and Bioengineering Commons^™

Surface Antibody Changes Protein Corona Both In Human And Mouse Serum But Not Final Opsonization And Elimination Of Targeted Polymeric Nanoparticles, Sara Capolla, Federico Colombo, Luca De Maso, Prisca Mauro, Paolo Bertoncin, Thilo Kähne, Alexander Engler, Luis Núñez, Gustavo Larsen, Et Al.

Department of Chemical and Biomolecular Engineering: Faculty Publications

Background: Nanoparticles represent one of the most important innovations in the medical field. Among nanocarriers, polymeric nanoparticles (PNPs) attracted much attention due to their biodegradability, biocompatibility, and capacity to increase efficacy and safety of encapsulated drugs. Another important improvement in the use of nanoparticles as delivery systems is the conjugation of a targeting agent that enables the nanoparticles to accumulate in a specific tissue. Despite these advantages, the clinical translation of therapeutic approaches based on nanoparticles is prevented by their interactions with blood proteins. In fact, the so-formed protein corona (PC) drastically alters the biological identity of the particles. Adsorbed …

Protocol To Develop A Synthetic Biology Toolkit For The Non-Model Bacterium R. Palustris, Mark Kathol, Cheryl Immethun, Rajib Saha

Department of Chemical and Biomolecular Engineering: Faculty Publications

Numerous biology tools are developed to work for model organisms, which, however, do not work effectively in non-model organisms. Here, we present a protocol for developing a synthetic biology toolkit for Rhodopseudomonas palustris CGA009, a non-model bacterium with unique metabolic properties. We describe steps for introducing and characterizing biological devices in nonmodel bacteria, such as the utilization of fluorescence markers and RT-qPCR. This protocol may also be applicable for other non-model organisms. For complete details on the use and execution of this protocol, please refer to Immethun et al..¹

S8e10: How Can Nature-Inspired Engineering Improve Human Health?, Ron Lisnet, Caitlin Howell

The Maine Question

Antibiotic resistance has become a growing problem in the treatment of bacterial infections. In addition to minimizing or negating the effects of existing medicine, these antibiotic-resistant bacteria, or “superbugs,” are mutating faster than the development of new remedies.

Caitlin Howell, University of Maine associate professor of biomedical engineering, is working on new tools that take notes from nature to combat antibiotic-resistant bacteria. Similar to the way in which the human body keeps balance with its own bacterial populations, Howell’s devices use nontoxic, non-invasive surface-based technology to trap bacteria and prevent them from spreading.

In this episode of “The Maine Question” …

Mitochondrial Complex Iii Bypass Complex I To Induce Ros In Gpr17 Signaling Activation In Gbm, Sana Kari, Jeyalakshmi Kandhavelu, Akshaya Murugesan, Ramesh Thiyagarajan, Srivatsan Kidambi, Meenakshisundaram Kandhavelu

Department of Chemical and Biomolecular Engineering: Faculty Publications

Guanine nucleotide binding protein (G protein) coupled receptor 17 (GPR17) plays crucial role in Glioblastoma multiforme (GBM) cell signaling and is primarily associated with reactive oxidative species (ROS) production and cell death. However, the underlying mechanisms by which GPR17 regulates ROS level and mitochondrial electron transport chain (ETC) complexes are still unknown. Here, we investigate the novel link between the GPR17 receptor and ETC complex I and III in regulating level of intracellular ROS (ROSi) in GBM using pharmacological inhibitors and gene expression profiling. Incubation of 1321N1 GBM cells with ETC I inhibitor and GPR17 agonist decreased the ROS level, …

Protocol To Engineer Nanofilms Embedded Lipid Nanoparticles For Controlled And Targeted Drug Delivery (Nectar), Rashi Porwal, Stephen L. Hayward, Srivatsan Kidambi

Department of Chemical and Biomolecular Engineering: Faculty Publications

We present a protocol to engineer a substrate-mediated delivery platform comprising hyaluronic acid-coated lipid nanoparticles (HALNPs) embedded into polyelectrolyte multilayer (PEM) films. This platform allows controlled spatiotemporal release of lipid nanoparticles (LNP) by embedding them within the polyelectrolyte multilayer films matrix. HALNP conjugate with antibodies also adds the ability for targeted delivery. The use of LNP enables this platform to encapsulate both hydrophobic and hydrophilic drugs. This platform can easily be reproduced and utilized for various biomedical drug delivery applications. For complete details on the use and execution of this protocol, please refer to Hayward et al. (2015, 2016a, 2016b), …

Computational Discovery Of Active And Selective Metal- Nitrogen-Graphene Catalysts For Electrooxidation Of Water To H2O2, Payal Chaudhary, Iman Evazzade, Rodion Belosludov,, Vitaly Alexandrov

Department of Chemical and Biomolecular Engineering: Faculty Publications

A direct electrosynthesis of H₂O₂ from either O₂ or H₂O is an attractive strategy to replace the energy-intensive industrial anthraquinone process. Two-electron water oxidation reaction (2e-WOR) offers several advantages over the oxygen reduction reaction such as better mass transfer due to the absence of gasphase reactants. However, 2e-WOR is a more challenging and less studied process with only a handful of metal oxides exhibiting reasonable activity/selectivity properties. Herein, we employ density-functional-theory calculations to screen a variety of metal-nitrogen-graphene structures for 2e-WOR. As a consequence of scaling between the adsorption energies of reaction intermediates, we …

An Older Diabetes-Induced Mice Model For Studying Skin Wound Healing, Carlos Poblete Jara, Guilherme Nogueira, Joseane Morari, Thaís Paulino Do Prado, Renan De Medeiros Bezerra, Lício A. Velloso, William Velander, Eliana Pereira De Araújo

Department of Chemical and Biomolecular Engineering: Faculty Publications

Advances in wound treatment depend on the availability of animal models that reflect key aspects of human wound healing physiology. To this date, the accepted mouse models do not reflect defects in the healing process for chronic wounds that are associated with type two diabetic skin ulcers. The long term, systemic physiologic stress that occurs in middle aged or older Type 2 diabetes patients is difficult to simulate in preclinical animal model. We have strived to incorporate the essential elements of this stress in a manageable mouse model: long term metabolic stress from obesity to include the effects of middle …

Advancing Ionomer Design To Boost Interfacial And Thin-Film Proton Conductivity Via Styrene-Calix[4]Arene-Based Ionomers, Shyambo Chatterjee, Oghenetega Allen Obewhere, Ehsan Zamani, Rajesh Keloth, Seefat Farzin, Martha D. Morton, Anandakumar Sarella, Shudipto Konika Dishari

Department of Chemical and Biomolecular Engineering: Faculty Publications

Sub-micrometer-thick ion-conducting polymer (ionomer) layers often suffer from poor ionic conductivity at the substrate/catalyst interface. The weak proton conductivity makes the electrochemical reaction at the cathode of proton-exchange-membrane fuel cells sluggish. To address this, here we report on a class of polystyrene-based ionomers having sub-nanometer-sized, sulfonated macrocyclic calix[4]arene-based pendants (PS-calix). In films with thickness comparable to that of ionomer-based binder layers, the conductivity of PS-calix film (∼41 mS/cm) is ∼13 times higher than that of the current state-of-the-art ionomer, Nafion. We observe a similar improvement in proton conductivity when PS-calix interfaces with Pt nanoparticles, demonstrating the potential of PS-calix in …

Coupling Atr-Ftir Spectroscopy With Multivariate Analysis For Polymers Manufacturing And Control Of Polymers’ Molecular Weight, Tung Nguyen, Ahmad Arabi Shamsabadi, Mona Bavarian

Department of Chemical and Biomolecular Engineering: Faculty Publications

Acrylate-based polymers are commonly used in the chemical industry. Consistent manufacturing of these polymers with the help of Process Analytical Technology (PAT) is very desirable. The capability of monitoring polymers’ molecular weight in real-time reduces operation time and eliminates the frequent samplings needed for quality control. Herein, molecular weight (M_w) of glycidyl methacrylate-co-methyl methacrylate (GMA-co- MMA) copolymer was monitored in real-time using mid-infrared ATR-FTIR spectroscopy. The Principal Component Analysis (PCA) and Partial Least Square (PLS) models were then utilized to examine, improve the latent space, and select high-quality spectra. We show that acquiring highly correlated spectra enhances the …

Coupling Nitrate Capture With Ammonia Production Through Bifunctional Redox-Electrodes, Kwiyong Kim, Alexandra Zagalskaya, Jing Lian Ng, Jaeyoung Hong, Vitaly Alexandrov, Tuan Anh Pham, Xiao Su

Department of Chemical and Biomolecular Engineering: Faculty Publications

Nitrate is a ubiquitous aqueous pollutant from agricultural and industrial activities. At the same time, conversion of nitrate to ammonia provides an attractive solution for the coupled environmental and energy challenge underlying the nitrogen cycle, by valorizing a pollutant to a carbon-free energy carrier and essential chemical feedstock. Mass transport limitations are a key obstacle to the efficient conversion of nitrate to ammonia from water streams, due to the dilute concentration of nitrate. Here, we develop bifunctional electrodes that couple a nitrate-selective redox-electrosorbent (polyaniline) with an electrocatalyst (cobalt oxide) for nitrate to ammonium conversion. We demonstrate the synergistic reactive separation …

Increased Liver Stiffness Promotes Hepatitis B Progression By Impairing Innate Immunity In Ccl4-Induced Fibrotic Hbv+ Transgenic Mice, Grace Bybee, Youra Moeun, Weimin Wang, Kusum K. Kharbanda, Larisa Y. Poluektova, Srivatsan Kidambi, Natalia A. Osna, Murali Ganesan

Department of Chemical and Biomolecular Engineering: Faculty Publications

Background: Hepatitis B virus (HBV) infection develops as an acute or chronic liver disease, which progresses from steatosis, hepatitis, and fibrosis to end-stage liver diseases such as cirrhosis and hepatocellular carcinoma (HCC). An increased stromal stiffness accompanies fibrosis in chronic liver diseases and is considered a strong predictor for disease progression. The goal of this study was to establish the mechanisms by which enhanced liver stiffness regulates HBV infectivity in the fibrotic liver tissue. Methods: For in vitro studies, HBV-transfected HepG2.2.15 cells were cultured on polydimethylsiloxane gels coated by polyelectrolyte multilayer films of 2 kPa (soft) or 24 kPa (stiff) …

Mesenchymal Stromal Cells And Alpha-1 Antitrypsin Have A Strong Synergy In Modulating Inflammation And Its Resolution, Li Han, Xinran Wu, Ou Wang, Xiao Luan, William Velander, Michael Aynardi, E. Scott Halstead, Anthony S. Bonavia, Rong Jin, Guohong Li, Yulong Li, Yong Wang, Cheng Dong, Yuguo Lei

Department of Chemical and Biomolecular Engineering: Faculty Publications

Rationale: Trauma, surgery, and infection can cause severe inflammation. Both dysregulated inflammation intensity and duration can lead to significant tissue injuries, organ dysfunction, mortality, and morbidity. Anti-inflammatory drugs such as steroids and immunosuppressants can dampen inflammation intensity, but they derail inflammation resolution, compromise normal immunity, and have significant adverse effects. The natural inflammation regulator mesenchymal stromal cells (MSCs) have high therapeutic potential because of their unique capabilities to mitigate inflammation intensity, enhance normal immunity, and accelerate inflammation resolution and tissue healing. Furthermore, clinical studies have shown that MSCs are safe and effective. However, they are not potent enough, alone, to …

In Vitro Models For The Study Of Liver Biology And Diseases: Advances And Limitations, Savneet Kaur, Srivatsan Kidambi, Martí Ortega-Ribera, Le Thi Thanh Thuy, Natalia Nieto, Victoria C. Cogger, Wei-Fen Xie, Frank Tacke, Jordi Gracia-Sancho

Department of Chemical and Biomolecular Engineering: Faculty Publications

In vitro models of liver (patho)physiology, new technologies, and experimental approaches are progressing rapidly. Based on cell lines, induced pluripotent stem cells or primary cells derived from mouse or human liver as well as whole tissue (slices), such in vitro single- and multicellular models, including complex microfluidic organ-on-a-chip systems, provide tools to functionally understand mechanisms of liver health and disease. The International Society of Hepatic Sinusoidal Research (ISHSR) commissioned this working group to review the currently available in vitro liver models and describe the advantages and disadvantages of each in the context of evaluating their use for the study of …

Ab Initio Insight Into The Electrolysis Of Water On Basal And Edge (Fullerene C20) Surfaces Of 4 Å Single-Walled Carbon Nanotubes, Zhen Jiang, Nadia N. Intan, Qiong Yang

Department of Chemical and Biomolecular Engineering: Faculty Publications

The extreme surface reactivity of 4 Å single-walled carbon nanotubes (SWCNTs) makes for a very promising catalytic material, however, controlling it experimentally has been found to be challenging. Here, we employ ab initio calculations to investigate the extent of surface reactivity and functionalization of 4 Å SWCNTs. We study the kinetics of water dissociation and adsorption on the surface of 4 Å SWCNTs with three different configurations: armchair (3,3), chiral (4,2) and zigzag (5,0). We reveal that out of three different configurations of 4 Å SWCNTs, the surface of tube (5,0) is the most reactive due to its small HOMO–LUMO …

Correlating The Macrostructural Variations Of An Ion Gel With Its Carbon Dioxide Sorption Capacity, Tung Nguyen,, Mona Bavarian, Siamak Nejati

Department of Chemical and Biomolecular Engineering: Faculty Publications

We report on a direct correlation between the macroscale structural variations and the gas sorption capacities of an ion gel. Here, we chose 1-ethyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide ([Emim][TF₂N]) and poly(vinylidene fluoride)-co-hexafluoropropylene (PVDF-HFP) as the ionic liquid and host polymer, respectively. The CO₂ sorption in the thin films of the IL-polymer was measured using the gravimetric method. The results of our experiment showed that the trend in CO₂ uptake of these mixtures was nonlinearly correlated with the content of IL. Here, we highlight that the variations in the molecular structure of the polymers were the main reason behind …

Electrophilic Aldehyde 4-Hydroxy-2-Nonenal Mediated Signaling And Mitochondrial Dysfunction, Sudha Sharma, Papori Sharma, Tara Bailey, Susmita Bhattarai, Utsab Subedi, Chloe Miller, Hosne Ara, Srivatsan Kidambi, Hong Sun, Manikandan Panchatcharam, Sumitra Miriyala

Department of Chemical and Biomolecular Engineering: Faculty Publications

Reactive oxygen species (ROS), a by-product of aerobic life, are highly reactive molecules with unpaired electrons. The excess of ROS leads to oxidative stress, instigating the peroxidation of polyunsaturated fatty acids (PUFA) in the lipid membrane through a free radical chain reaction and the formation of the most bioactive aldehyde, known as 4-hydroxynonenal (4-HNE). 4-HNE functions as a signaling molecule and toxic product and acts mainly by forming covalent adducts with nucleophilic functional groups in proteins, nucleic acids, and lipids. The mitochondria have been implicated as a site for 4-HNE generation and adduction. Several studies clarified how 4-HNE affects the …

Fabricating 3-Dimensional Human Brown Adipose Microtissues For Transplantation Studies, Ou Wang, Li Han, Haishuang Lin, Mingmei Tian, Shuyang Zhang, Bin Duan, Soonkyu Chung, Chi Zhang, Xiaojun Lian, Yong Wang, Yuguo Lei

Department of Chemical and Biomolecular Engineering: Faculty Publications

Transplanting cell cultured brown adipocytes (BAs) represents a promising approach to prevent and treat obesity (OB) and its associated metabolic disorders, including type 2 diabetes mellitus (T2DM). However, transplanted BAs have a very low survival rate in vivo. The enzymatic dissociation during the harvest of fully differentiated BAs also loses significant cells. There is a critical need for novel methods that can avoid cell death during cell preparation, transplantation, and in vivo. Here, we reported that preparing BAs as injectable microtissues could overcome the problem. We found that 3D culture promoted BA differentiation and UCP-1 expression, and the optimal initial …

Nonordered Dendritic Mesoporous Silica Nanoparticles As Promising Platforms For Advanced Methods Of Diagnosis And Therapies, S. Malekmohammadi, Riaz Ur Rehman Mohammed, H. Samadian, A. Zarebkohan, A. García-Fernández, G.R. Kokil, F. Sharifi, J. Esmaeili, M. Bhia, M. Razavi, M. Bodaghi, T. Kumeria, R. Martínez-Máñez

Department of Chemical and Biomolecular Engineering: Faculty Publications

Dendritic mesoporous silica nanoparticles (DMSNs) are a new generation of porous materials that have gained great attention compared to other mesoporous silicas due to attractive properties, including straightforward synthesis methods, modular surface chemistry, high surface area, tunable pore size, chemical inertness, particle size distribution, excellent biocompatibility, biodegradability, and high pore volume compared with conventional mesoporous materials. The last years have witnessed a blooming growth of the extensive utilization of DMSNs as an efficient platform in a broad spectrum of biomedical and industrial applications, such as catalysis, energy harvesting, biosensing, drug/gene delivery, imaging, theranostics, and tissue engineering. DMSNs are considered great …

Porcine Liver Injury Model To Assess Tantalum-Containing Bioactive Glass Powders For Hemostasis, Malvika Nagrath, Danielle Bince, Corwyn Rowsell, Deanna Polintan, Joao Rezende-Neto, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study evaluates compositions of tantalum-containing mesoporous bioactive glass (Ta-MBG) powders using a porcine fatal liver injury model. The powders based on (80-x)SiO₂-15CaO-5P₂O₅-xTa₂O₅ compositions with x = 0 (0Ta/Ta-free), 1 (1Ta), and 5 (5Ta) mol% were made using a sol–gel process. A class IV hemorrhage condition was simulated on the animals; hemodynamic data and biochemical analysis confirmed the life-threatening condition. Ta-MBGs were able to stop the bleeding within 10 min of their application while the bleeds in the absence of any intervention or in the presence of a commercial agent, AristaTM …

Review Of Biomechanical Studies And Finite Element Modeling Of Sternal Closure Using Bio-Active Adhesives, Amatulraheem Al-Abassi, Marcello Papini, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The most common complication of median sternotomy surgery is sternum re-separation after sternal fixation, which leads to high rates of morbidity and mortality. The adhered sternal fixation technique comprises the wiring fixation technique and the use of bio-adhesives. Adhered sternal fixation techniques have not been extensively studied using finite element analysis, so mechanical testing studies and finite element analysis of sternal fixation will be presented in this review to find the optimum techniques for simulating sternal fixation with adhesives. The optimal wiring technique should enhance bone stability and limit sternal displacement. Bio-adhesives have been proposed to support sternal fixation, as …

Protocol To Engineer Nanofilms Embedded Lipid Nanoparticles For Controlled And Targeted Drug Delivery (Nectar), Rashi Porwal, Stephen L. Hayward, Srivatsan Kidambi

Department of Chemical and Biomolecular Engineering: Faculty Publications

We present a protocol to engineer a substrate-mediated delivery platform comprising hyaluronic acid-coated lipid nanoparticles (HALNPs) embedded into polyelectrolyte multilayer (PEM) films. This platform allows controlled spatiotemporal release of lipid nanoparticles (LNP) by embedding them within the polyelectrolyte multilayer films matrix. HALNP conjugate with antibodies also adds the ability for targeted delivery. The use of LNP enables this platform to encapsulate both hydrophobic and hydrophilic drugs. This platform can easily be reproduced and utilized for various biomedical drug delivery applications. For complete details on the use and execution of this protocol, please refer to Hayward et al. (2015, 2016a, 2016b), …

Substrate Delivery Of Embedded Liposomes, Srivatsan Kidambi, Stephen L. Hayward

Department of Chemical and Biomolecular Engineering: Faculty Publications

This invention relates to compositions useful for localized and sustained release of therapeutic agents, and more particularly to functionalized liposomes embedded in a poly electrolyte multilayer. Methods of preparing the compositions, methods of treating diseases, devices, and pharmaceutical compositions comprising the compositions are also provided.

Antibody-Drug Nanoparticle Induces Synergistic Treatment Efficacies In Her2 Positive Breast Cancer Cells, Muhammad Raisul Abedin, Kaitlyne Powers, Rachel Aiardo, Dibbya Barua, Sutapa Barua

Chemical and Biochemical Engineering Faculty Research & Creative Works

Chemotherapeutic drugs suffer from non-specific binding, undesired toxicity, and poor blood circulation which contribute to poor therapeutic efficacy. In this study, antibody–drug nanoparticles (ADNs) are engineered by synthesizing pure anti-cancer drug nanorods (NRs) in the core of nanoparticles with a therapeutic monoclonal antibody, Trastuzumab on the surface of NRs for specific targeting and synergistic treatments of human epidermal growth factor receptor 2 (HER2) positive breast cancer cells. ADNs were designed by first synthesizing ~ 95 nm diameter × ~ 500 nm long paclitaxel (PTX) NRs using the nanoprecipitation method. The surface of PTXNRs was functionalized at 2′ OH nucleophilic site …

Expedited Pcr With Stirring, Hendrik Viljoen

Department of Chemical and Biomolecular Engineering: Faculty Publications

Disclosed are an apparatus and methods for rapid amplification of nucleic acids. More particularly, the present dis closure relates to an apparatus for mixing a reaction solution during amplification of nucleic acids and to methods for amplifying nucleic acids. Also disclosed are methods for lysing cells in a sample and amplifying nucleic acids.

Comparative Evaluation Of Two Glass Polyalkenoate Cements: An In Vivo Pilot Study Using A Sheep Model, Leyla Hasandoost, Daniella Marx, Paul Zalzal, Oleg Safir, Mark Hurtig, Cina Mehrvar, Stephen D. Waldman, Marcello Papini, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Poly(methyl methacrylate) (PMMA) is used to manage bone loss in revision total knee arthroplasty (rTKA). However, the application of PMMA has been associated with complications such as volumetric shrinkage, necrosis, wear debris, and loosening. Glass polyalkenoate cements (GPCs) have potential bone cementation applications. Unlike PMMA, GPC does not undergo volumetric shrinkage, adheres chemically to bone, and does not undergo an exothermic setting reaction. In this study, two different compositions of GPCs (GPCA and GPCB), based on the patented glass system SiO₂-CaO-SrO-P₂O₅-Ta₂O₅, were investigated. Working and setting times, pH, ion release, …

In Vitro Osteogenic Performance Of Two Novel Strontium And Zinc-Containing Glass Polyalkenoate Cements, Daniella Marx, Alireza Rahimnejad Yazdi, Marcello Papini, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass polyalkenoate cements (GPCs) are under investigation as potential bone adhesives, as they may provide an alternative to polymethylmethacrylate-based cements. GPCs containing strontium (Sr) and zinc (Zn) in place of aluminum (Al) are of particular interest because these ions are known stimulators of osteoprogenitor differentiation. GPCs have been manufactured from a novel bioactive glass (SiO2:0.48, ZnO:0.36, CaO:0.12, SrO:0.04) in the past, but, while such materials have been assessed for their influence on viability, their influence on osteogenic function has not been investigated until now. For this study, two GPCs were formulated from the same glass precursor evaluated in previous studies. …

A Gallium-Doped Cement For The Treatment Of Bone Cancers. The Effect Of Zno ↔ Ga2o3substitution Of An Ionomeric Glass Series On The Rheological, Mechanical, Ph And Ion-Eluting Properties Of Their Corresponding Glass Polyalkenoate Cements, Sunjeev Phull, Alireza Rahimnejad Yazdi, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The primary treatment for patients suffering from bone cancers is resection of the tumor followed by reconstruction of the damaged bone. Despite the administration of post-operative chemotherapy, tumor recurrence continues to present itself as a severe complication leading to re-operation. Attempts to incorporate chemotherapeutic drugs into bone cements elicits local toxic effects on healthy bone, which could compromise implant fixation. Alternatively, the local administration of gallium (Ga) may prove to be more effective. This report considers the development of a Ga ionomeric glass series (0.48SiO₂-0.355ZnO-0.06CaO-0.08SrO-0.02P₂O₅-0.005Ta₂O₅, with 0.01-0.05 mol% substitution for …

Heparan Sulfate Proteoglycan Glypican‑1 And Pecam‑1 Cooperate In Shear‑Induced Endothelial Nitric Oxide Production, Anne Marie W. Bartosch, Rick Mathews, Marwa M. Mahmoud, Limary M. Cancel, Zahin S. Haq, John M. Tarbell

Publications and Research

This study aimed to clarify the role of glypican-1 and PECAM-1 in shear-induced nitric oxide production in endothelial cells. Atomic force microscopy pulling was used to apply force to glypican-1 and PECAM-1 on the surface of human umbilical vein endothelial cells and nitric oxide was measured using a fluorescent reporter dye. Glypican-1 pulling for 30 min stimulated nitric oxide production while PECAM-1 pulling did not. However, PECAM-1 downstream activation was necessary for the glypican-1 force-induced response. Glypican-1 knockout mice exhibited impaired flow-induced phosphorylation of eNOS without changes to PECAM-1 expression. A cooperation mechanism for the mechanotransduction of fluid shear stress …

In Vivo Analysis Of A Proprietary Glass-Based Adhesive For Sternal Fixation And Stabilization Using Rabbit And Sheep Models, Cina Mehrvar, Emily Deignan, Mark Hurtig, Gideon Cohen, Paul Zalzal, Oleg Safir, Adel Alhalawani, Marcello Papini, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Wire cerclage remains the standard method of care for sternal fixation, following median sternotomy, despite being beset with complications. An emerging treatment option has been to augment the wires with an adhesive. A patented ionomeric glass (mole fraction: SiO₂:0.48, ZnO:0.36, CaO:0.12, SrO:0.04) has been used to formulate GPC+, a glass polyalkenoate cement (GPC), by mixing it with poly(acrylic) acid (PAA) and de-ionized water. In a human cadaver study, this material, when applied with wire cerclage, was able to significantly reduce sternal instability. However, the material has yet to be tested in pertinent animal models. Here, after a series …

Quantitative Pcr Of Small Nucleic Acids: Size Matters, Jay Min Lim, Rahul Tevatia, Ravi Saraf

Department of Chemical and Biomolecular Engineering: Faculty Publications

Quantitative dysregulation in small nucleic acids (NA), such as microRNA (miRNA), extracted from minimally invasive biopsies, such as, blood, stool, urine, nose, throat, are promising biomarker for diseases diagnosis and management. We quantify the effect of the extra step of poly(A) ligation for cDNA synthesis and small size of the NA on the limit of quantification (LOQ) of quantitative PCR (qPCR), the gold standard to measure copy number. It was discovered that for small NA, the cycle threshold, Ct that is proportional to −log[c], where [c] is the concentration of the target NA exhibits a sharp transition. The results indicate …